Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: Pyro on June 17, 2003, 02:19:35 PM
-
We have been going through the flight engine over the past couple of weeks. The changes have been piling up with one change leading to others. So far, we’re pretty pleased with the results but it does require extensive work. The changes we’ve made result in a more accurate model and we’ve also implemented better methods and tools to verify accuracy.
One of the major changes we’ve made is how we model the forces on the plane. We wanted to increase the number of force points by about an order of magnitude or even more if necessary. For example, prior to this the wing was split up in large chunks with the applicable forces applied to each chunk. In level steady flight this is fine, but it shows its limitations when you get outside of it. Now we have it split up into a lot of small pieces. This allows us to closely replicate the stall progression characteristics of the different planes. It’s also led us to some oversights in the model. An example of this is the effects on the propeller vortex on the wings. We’re modeling the forces of the vortex and its effect, but we weren’t applying it exactly where it needed to be applied, thereby creating an inaccurate force moment.
We’ve also discovered some processes that I used to check model accuracy that weren’t exact. I would calculate stall speeds to check that the model inputs were having the desired output but I did not account for tailplane forces and some other influences which would throw my calculation off some. F4UDOA was very helpful in documenting and quantifying this particular problem.
We’ve taken a pretty fresh look at the model mechanics and are going through the process of identifying inaccuracies and their causes and making appropriate changes. So this is a tremendous amount of revision along with some additions such as working slats. This does mean that every plane will be reworked. The change to a particular plane in 2.0 might be minor or major. There’s really no telling until we work through everything. We made a huge change to our drag model early on in AH that had a profound effect on the game. That was a very large error and we’re not really talking about a global change on that level. This is really just a big refinement to get things as accurate as we can and to also try and capture the nuances of the individual planes better.
Feel free to bring up any particular quirks in the flight modeling that you would like me to look into. Please present your thoughts in a cogent manner.
-
WOW!!! NEWS!!! KEEP IT ROLLING!!!! THANK YOU!!! NEWS!!!!
-
Seriously though, it sounds great. This will cause a more technologically complex flight physics engine, making it more realistic. You have just filled me with some more hype about AH2.
-
F4UDOA was very helpful in documenting and quantifying this particular problem.
OMG!!
I wish I knew what I said, I would say it again.
I luv when Pyro talks about realism, I get all salamanderly :D
-
Cool, better flight model :)
There's one thing that IMO should be upgraded: Engine model and engine sound. As it is now the pitch (of the sound) changes with manifold pressure and not with RPM (on constant speed drives), and the pitch (rpm) - manifold pressure coupling is static. Pitch should oscillate when the governor is acting etc.
Maybe a new engine model with separate sounds for engine and propeller ? :)
-
I have noticed that the torque effect on take off seems light. Even a 172 requires more rudder than most of the planes in AH. Just an observation.
-
A purely subjective note:
I don't seem to need as much rudder as I would have thought nessecary. I use rudders more in a glider than I do in these high torque prop planes.
I have absolutly no data to back this up; and I admit to using combat trim.
However turns do seem to be almost auto coordination.
-
There are articles that state if u would pull full throttle when starting p.e. a 109 would just flip around. In AH u still will have full control. I would suggest to take a look at some starting procedures and maybe (when necessary) refine the starting.
I ever thought u have to throttle up very very slightly.
-
Now if I could just find an accurately modeled force feedback joystick and rudder peds! For me, auto trim takes out much of the nose bounce but hinders dogfighting, remove the auto trim and dogfighting is non-existant for me. Skuzzy helped me with some settings but I am still unable to dogfight. Even at D300, my nose bounces everywhere but on the con.
I use more rudder in this sim than I do on my 180 Skywagon or any other tailwheel airplane I have ever flown, never ground looped one ... yet..., but I put many many sim fighters out of service in AH do to gear whipe-outs and ground-loops. The sim, IMO, feels nowhere near like the real thing.
BTW, my grandfather watched several P-51s piloted by Korean pilots, roll inverted on take-off and slam into the ground do to full power torque rolls.
-
Thank you for the news. Good info.
Realistic or not, I did enjoy trying to take off in the F4U back in AH 1.03. I would like to take off in a real F4U and P-51 to compare to AH. Robin Olds stated that the P-51 built up a very strong leg from using rudder on takeoff. Is there such a thing a force-feedback rudder pedals yet?
-
Greetings.
Thanks for some news as to whats been going on regarding development!
And now my observations...
It's been noted that all taildraggers depending on weight have a tendency to want to yaw a lot on the ground during takeoffs for reasons not related to thrust or control surfaces. trying to steer with a heavy tailend attempting to excert it's momentum in the direction opposite that which you would prefer to travel ruined more than one pilots day.
I found maintaining or re-establishing control on the ground was far too simple in some conditions. Also noted was the lack of effect of weight on the tail wheel or nosewheel changing the amount of turn force exerted on the ground.
The plane this is most noted is in the "Ensign Eliminator"- The F4U Corsair. I can tumble a spit in the air a whole lot easier than the F4U, which seems to be a lot more docile in handling high speed stalls and such.
Hopefull the new modeling will reflect this.
What Say Pyro? Will we be seeing new inertial effects as well as aerodynamic effects?
-
Originally posted by Pyro
Feel free to bring up any particular quirks in the flight modeling that you would like me to look into. Please present your thoughts in a cogent manner.
the N1k2 is a UFO
sry i had to... :D:D JK
seriously the bf110g2 has something odd happen and i dont know a ton about real flight but here goes.....
fly level @ least 200 mph on the white needle and do a hard rudder turn while climbing. around the moment of stall apply full opposite rudder and stall out the plane. im pretty sure how i accomplish this... i KNOW i can replicate it at will almost... it's all about the full rudder @ the start of the stall.
what happens is you will go into a 100mph tail first fall... you will literally be going backwards for part of the fall. all stall recovery tactics i have read dont work. the only way i have been able to get out of it is manual trim all the way nose UP and zero throttle, but this still takes about 5000k feet of freefall to recover... if you are below 5k AGL when this happens you will not get out.
just my 2¢ about it.... i may be missing something and this might be a real charertistic of this plane.
-
Thanks for the news Pyro.
Expectations have now gotten higher :D
ps) could we have just one itsy bitsy little teaser pic on the "MTF"?
-
I know the Flight Dynamics are being reworked, But I have noticed that when the tail sect (empinage) is shot off the nose pitches up. The center of pressure(lift) moves aft on the main wing the faster the plane goes, the horizontal stab create"s down force for the plane to be in balance. When the tail section is shot off the nose should pitch down not up. Same with flaps when flaps are used the AC should pitch down not up.
I was wandering how accurate the new flight models will be?
A real P-51D can not take off with full power, theres is not enough rudder to counter the torge,P Factor, Prop Slip Stream and Gyroscopic procession. Power has to craduley be increased on takeoff.
In AH aileron is used to counter torge, rudder is the only thing that counters torge. Ailerons on take off have no effect on torge no airflow at 0 airspeed. Aileron trim should be used to balance fuel or ordinance not torge, once set the plane plane should stay lvl at any airspeed.
-
One thing that I mentioned with regards to torque is that the propellor slipstream effects on the wings were being placed too far out thus creating an artificially large force moment. This effect counteracts torque to a degree, an overly large degree in AH until now. The propwash from a propellor comes off in a vortex that corkscrews back over the airplane. In a standard clockwise rotating engine, the vortex strikes the right wing with a downward component and the left wing with an upward component. This increases the effective aoa of the left wing and decreases the effective aoa of the right wing, hence more lift on the left wing and less on the right.
The slipstream continues to corkscrew back to the tailplane where it impacts the vertical stabilizer on the left side which pushes the tail to the right and the nose to the left. This is the main force causing the left yaw on your takeoff roll.
With regards to that, the main factor countering that in AH is the modeling of the tailwheel. All the planes have a steerable tailwheel and that is a change we are looking at as well.
-
This is the main force causing the left yaw on your takeoff roll.
Are you saying that this is the main cause in AH or on "Real" airplanes? I hope you are refering to AH modeling!
In a tailwheel airplane applying full power from a stand still (for example), with nose high attitude, (edited)"P" Factor is the #1 effect, not slip stream. Once the aircraft gets rolling then its basicly a combo of torque, slipstream and P Factor. As the tail comes up, then Gyroscopic Precession plays a roll among the total of four effects. (i.e.; High Angles of attack as in the "Take-Off" roll or stall attitude.
1. Reactive Force
2. Spiraling Slipstream
3. Gyroscopic Precession
4. "P" Factor
Remove the vertical stab and rudder, and the nose will still yaw left, from stand still to a foward "take-off" motion. Thats P Factor, not slip stream.
How these four factors are actually created varies greatly from one explination to the next.
-
I'm referring to both real planes and AH. The yaw is often attributed to torque, but that is not what torque does.
Here's a couple of links I found on google to explain it.
http://www.djaerotech.com/dj_askjd/dj_questions/propeffects.html
http://www.av8n.com/how/#contents
-
Originally posted by F4UDOA
OMG!!
I wish I knew what I said, I would say it again.
I luv when Pyro talks about realism, I get all salamanderly :D
Thumb up, buddy! :D
-
Btw. if you're remodeling all the planes will the 110G2 get its historical self-sealing fueltanks? The inboard tanks seem to catch fire every time they're hit.
-
re: the effect of torque
The effect of torque is an old discussion that probably arose from the semantics of the word "torque" being used to generically refer to multiple forces(which is why I referenced the first link earlier). So this discussion has come up fairly regularly over the years but I just came up with a simple and obvious example - the helicopter. Ask yourself two questions. 1- What is the purpose of the tail rotor? 2- Why is the tail rotor aligned perpendicularly to the main rotor rather than in parallel?
-
re: the effect of torque
The effect of torque is an old discussion that probably arose from the semantics of the word "torque" being used to generically refer to multiple forces(which is why I referenced the first link earlier). So this discussion has come up fairly regularly over the years but I just came up with a simple and obvious example - the helicopter. Ask yourself two questions. 1- What is the purpose of the tail rotor? 2- Why is the tail rotor aligned perpendicularly to the main rotor rather than in parallel?
-
Originally posted by Pyro
re: the effect of torque
1- What is the purpose of the tail rotor? 2- Why is the tail rotor aligned perpendicularly to the main rotor rather than in parallel?
Uhm, Pyro... :D May I introduce to you the CH-46?
(http://daniel.clanbaker.com/clients/Goodies/air%20combat%20art%202162.jpg)
-
Thanks for the news pyro.
MiniD
-
ditto. News was much appreciated!
-
Thanks for the update Pyro :)
Now about that steerable tail wheel, are you thinking of having some planes with fixed tail wheels (if any of them had um) or maybe being able to lock the tail wheel for takeoff (if this was done)?
-
Domo arigato Pyro-san.
-
Pyro if your saying that a helicopter flies the way an airplane does Im sorry there is no comparison.
Let me see if I understand what your saying, 1 you say that torge is not countered by rudder. On takeoff lets say a P-51 when you apply power the rudder is effective because of prop slip stream,ailerons have no air over them yet. elevator is effective somewhat enough to raise the tail.
On a tail dragger you have "P"factor right off the bat the from the 12 oclock trough 6 oclock position on a clock wise turning propeller the right side of the prop disk has more angle of attack on the prop then the 6 back to 12 side of the prop. Therefor more lift is created on the right side,and the nose goes left.
Prop slip stream rotates around the fuselage and hits the tail on the left side of the vertical stab pushes the tail to the right and nose to the left rudder is then right rudder is applied to counter force .
Ailerons still have no effect at this time no relative wind yet .The right wing is mounted to the fuselage at a higher angel on incidence then the left wing this counters torge , p factor and prop slip stream, not gyro procession which effects the airplane force to the right. Ailerons are not effective till about 35kts. Ailerons are used on takeoff for crosswind conditions max deflection is used at first until effective to counter crosswind.
After you get airborne pfactor is still present until level flight egual lift on prop disk when you climb pfactor plays a role again.
Torgue disapates in un accelrated flight but is still present.
Call any flight instructor at your local airport they will say the samething. Or get a book its all there.
I have been a pilot for over 30yrs, 91/2 with the US Navy jet fighter pilot, the rest as an Airline Pilot with a major carrier flying DC10s and B767s. Im both airplane and helicopter flight instructor with ATP in both. I have a master in aeronautical engineering,with over 500 hrs in a P-51D
Next lesson coming soon
Straiga
-
Oh no, not helicopter talk...hehehehehe
Guess I should have better explained myself. "Torque" is the combo of the four forces so to speek, not just "slipstream". I ment to sya "P Factor" and it has been edited.
I have a pretty good book, its called "Aerodynamics for Naval Aviatiors"...I used it in coledg...colag...calleg...col ledg....Advanced School :D Yes this redneck does have an eegucatiomon !!!!!
-
Originally posted by F4UDOA
I luv when Pyro talks about realism, I get all salamanderly :D
Hey put that thing away... you might put someones eye out!
Appreciate the news Pyro! I've been hearing the words "Vaporware" on occasion lol. Now I got some ammo.
-
Straiga,
what you say is good and true but pyro is still right.
All the forces you described are there but they create torque around a different axis.
The prop's torque is a twist force in the roll axis. All the other secondary forces you described create a twist around the yaw axis.
I'm sure you know your physics, but as Pyro said, torque is commonly used to described multiple forces. He was talking about the primary (the direct) effect on the roll and secondary effects on the same axis.
btw, in P factor you mean the force difference of the blades created by a prop disc not moving perpendicular to the air flow?
Bozon
-
Thanks for the news! Seems we will need to learn to fly again as we did after the "chess in the sky" were fixed :)
It seems fixing this problems will lead to correct modeling of la7, so it will be both faster and will turn with spit V like in reality. :D
-
Originally posted by Fariz
It seems fixing this problems will lead to correct modeling of la7, so it will be both faster and will turn with spit V like in reality. :D
:eek: OH, NOOO!!!!!
:D
Thanks Pyro for the news, I must confess, I am trying Il2FB and I like the FM and the engine management it have, and AH2 seem to point in an improvement that will goes near to it, and this have only a big difference for me:
I will never be free from AH addiction!! :)
Help!
;)
HTC and WTG!
-
Straiga,
You do realize that in trying to "school" pyro, you said the exact same thing he said:Pyro:
The propwash from a propellor comes off in a vortex that corkscrews back over the airplane. In a standard clockwise rotating engine, the vortex strikes the right wing with a downward component and the left wing with an upward component. This increases the effective aoa of the left wing and decreases the effective aoa of the right wing, hence more lift on the left wing and less on the right.
The slipstream continues to corkscrew back to the tailplane where it impacts the vertical stabilizer on the left side which pushes the tail to the right and the nose to the left. This is the main force causing the left yaw on your takeoff roll.
The helicopter requires something to offset torque between the blade and the fuselage. Basically, the blades turn one way and the fuselage wants to rotate the other. If this could be done using a rudder, there would simply be a paddle on the bottom of a helicopter. But it can't, so there isn't.
MiniD
-
Thanks for the update Pyro, we certainly appreciate anything you can tell us.
Glad to hear the planes are getting touched up as needed.
Should make this a brand new game again.
-
Curtis: Pfactor has 0 effect when a plane isn't moving simply because up and down sweaping blades don't have a difference in air speed, as when the plane is moving. Vortex/slipstream is the primary yaw force at the start of a take off roll. Next primary effect is gyro when the tail lifts. Pfactor biggest effect is at high AOA and hi speed.
What pyro was talking about with the tail wheel is all tail wheels are the same currently in AH, and the all are fixed to and turn with the rudder.
We once made one simple change to the model of a castoring tail wheel like some of the planes had. This little change made takeoffs completly different. We are currently looking into the different types of tail wheel linkages and might make a change to it.
HiTech
-
hitech, your gonna have to edimicate use old timers, I'm 36 but learned to fly taildraggers 22 years ago...yes I was 14.
I sat down and started reading the books again and concluded that what I said was right, however, upon further reading of modern up to date material, I must sit neutral for a while. I also found this........"There are quite a lot of myths surrounding P-factor. For some reason, P-factor gets blamed for the fact that typical aircraft require right rudder on initial takeoff roll. This is impossible for several reasons.
* Nearly everybody these days learns to fly in nose-wheel type aircraft, which means the propeller disk is vertical during the initial the takeoff roll. Since there is no angle between the relative wind and the propeller axis, P-factor obviously cannot occur.
* Now let's suppose, just for sake of argument, that you are flying a taildragger, in which the propeller disk is actually non-vertical during the initial takeoff roll. Common experience is that the most right rudder is required at the very beginning of the takeoff, before much forward speed has been achieved. The Flight Training Handbook says this is because P-factor is worst at low airspeeds. But wait a minute — real P-factor is proportional to airspeed. In the initial moments of the takeoff roll, there is no relative wind, so there can't possibly be any P-factor. Of course, if you are taking off into a headwind, there could be a little bit of P-factor — but does that mean if you take off with a slight tailwind there will be a negative amount of P-factor, requiring left rudder? Don't bet on it.
The real reason that you need right rudder on initial takeoff roll is because of the helical propwash, as discussed in section 8.4. P-factor exists in some circumstances, but it cannot possibly explain the behavior we observe during initial takeoff roll."
Makes since huh?
-
We are currently looking into the different types of tail wheel linkages and might make a change to it.
It will be nice to be able to lock one brake and spin around, i.e. refuel pad, preparing for formation departures etc. There is nothing like having to taxi completly off the runway to form up at a 45 deg angle on the edge of the runway.
You guys keep on, maybe we can use AH as a"currency" tool and log this flight time as "sim time" in our log books..hehehehehe
-
Straiga: Currious who your instructors are because they are just wrong.
Explain how with 0 forward speed one blade has more aoa than another. Note air flow do to low pressure in front of the prop will be perpendicular to the prop plane, not paralell with the ground.
Curtiss: "helical propwash" vortex and slipstream all refer to the same thing. So the 2nd piece of your post is what I was explaining.
HiTech
-
Originally posted by Fariz
Thanks for the news! Seems we will need to learn to fly again as we did after the "chess in the sky" were fixed :)
It seems fixing this problems will lead to correct modeling of la7, so it will be both faster and will turn with spit V like in reality. :D
La's get Slats!!!
Whooopeeee lower stall speeds (High speed and low) but when you do that wing will lose lift with no warning other than the audible click of the slat hard agin its actuator arm.
Torque effects corrected ........short stumpy plane gonna have increased yaw with throttle changes compared to others?
But will they give it the gear bounce it was infamous for?
and correct the 6 view changing half the steel brackets to a thick glass section?
and strip it of half it's AH instrumentation.
you were kidding about the speed and turn rate thing tho right;)
-
Originally posted by 2Hawks
Uhm, Pyro... :D May I introduce to you the CH-46?
(http://daniel.clanbaker.com/clients/Goodies/air%20combat%20art%202162.jpg)
Um the rotors counter rotate cancelling out the torque!
-
Straiga,
Re-read what I wrote and the links I provided. It comes across as hypocritical to suggest somebody get a book when you're obviously not bothering to read what's been provided. As to my helicopter example, it is not a comparison between the flight physics of rotary and fixed wing aircraft. It is just two simple questions to illustrate the effect of engine torque. They aren't trick questions.
-
Hey Pyro, would you please look into acceleration (overall on all planes).
In AH, as it is now, about every twin in the game has better initial acceleration than most single prop planes, this goes for both the 110, Mossie, P38 and A20. Specially when diving. Just a feeling, nothing to back it up with, maybe it was like it for real but seams odd, specially judging from what you read about the twins against single engine planes, specially the 110 which got pretty slaughtered.
Also, the 190/Ta152 accel and F4u accel seem off after reading about tests made during WW2.
Great news btw, looking very much forward to it.
-
Originally posted by icemaw
Um the rotors counter rotate cancelling out the torque!
I am aware of this, I was having a passive aggressive moment and felt the need to be a twit. :)
Look forward to that 'New' LA7 - keep the updates coming Pryo! Thank You!
-
While we are discussing correcting some of the problem areas of the Current Aces High Aircraft, there is one area that "irks" me to "no end".
That is the fact that in aircraft such as the bf 109 the current model allows Combat Trim to overcome the stick applied control forces.
On the bf 109-G10 for example with control trim "on" as the manuvers get tighter and airspeed is reduced the applications of stick movements are given less and less control authority. In the worst case you can have the stick all the way to the left and still be rolling to the right. due to the fact that the combat trim still applying the control it had set a few seconds before.
The control authority of the trim system should never overcome the pilots stick input control commands.....
:rolleyes:
This effect seems to be present on most of the AH fighters. I gave the 109-G10 as an example.:)
-
Originally posted by Wilbus
In AH, as it is now, about every twin in the game has better initial acceleration than most single prop planes, this goes for both the 110, Mossie, P38 and A20.
I don't know about the bf110 and the A-20 but I think that's how it really was with the P-38, at least that what they say in the 1943 training film "Flight Characteristics of the P-38".
Flight Characteristics of the P-38 - 1943 WW II training film (http://www.zenoswarbirdvideos.com/P38.html)
Ack-Ack
-
ummm this isn't really a flight model suggestion as it is a use case suggestion.
Would it be possible for the FE to ignore control inputs when a pilot is in black or red out due to G's or wounding? This would include hitting the autopilot button.
ummmm lessee I guess I should come up with a flight model question to keep this on topic.
How about vibration modelling due to guns firing?
Sorry, I got nothin.
ZPB
-
Will the revised flight model finally do away with the auto-retracting flaps for all planes except those that had them in real life?
Speaking as a dedicated P-38 driver in AH, auto-retracting flaps seriously hinder the P-38.
Ack-Ack
-
Originally posted by Straiga
I know the Flight Dynamics are being reworked, But I have noticed that when the tail sect (empinage) is shot off the nose pitches up. The center of pressure(lift) moves aft on the main wing the faster the plane goes, the horizontal stab create"s down force for the plane to be in balance. When the tail section is shot off the nose should pitch down not up.
Depends on CG location. For a lot of WW2 fighters, the CG is between the wing's aerodynamic center and the tail's aerodynamic center. Which means that the tail provides lift in 1-g flight, and when you remove the tail, the airplane pitches up.
-
Did you want that with or without the weather interface??
-
Originally posted by Ack-Ack
Will the revised flight model finally do away with the auto-retracting flaps for all planes except those that had them in real life?
Speaking as a dedicated P-38 driver in AH, auto-retracting flaps seriously hinder the P-38.
Ack-Ack
Would like them as option. We already have helpers like "autotakeoff" "autotrim" etc., why not to add "retract flaps" there?
-
Good to see that Pyro and Hitech obviously know what they're doing :)
Can you please check the prop of the g10? Either the prop is too heavy, too large or transmission is off, at least gyro effect feels a bit too pronounced.
When you're done with the flight physics, do you plan on checking the structural physics, too? I heard some planes break easier when the wings are heavy (e.g. fuel wing tanks or bombs on the wings).
-
One aspect of the flight model that always makes me scratch my noggin is e retention when your engine conks out. Planes like the P-51 are very hard to lose airspeed with even a slight down nose angle, despite full flaps and the drag of lowered gear.
-
Originally posted by Ack-Ack
Speaking as a dedicated P-38 driver in AH, auto-retracting flaps seriously hinder the P-38.
Ack-Ack
I agree to this statement, nothing like using a little brake and have it go away the faster I move...
If we overspead we should get the same effect as lowering the gear and going too fast.
-
Originally posted by AKWeav
One aspect of the flight model that always makes me scratch my noggin is e retention when your engine conks out. Planes like the P-51 are very hard to lose airspeed with even a slight down nose angle, despite full flaps and the drag of lowered gear.
Reduce rpm to initiate more prop drag.
-
When you take a WWII taildragger on takeoff with a lot of power
and high nose attatude, the effect of torge increase in direct proportion to engine power, airspeed, and airplane attitude.
If the power setting is high, the airspeed slow, and angle of attack high, the effect of torge is greater. During takeoffs and climbs, when the effect of torge is most pronounced, the pilot must apply sufficient right rudder pressure to counteract the left turning tendency maintain a straight takeoff path.
As soon as the tires turn on takeoff you have increasing relative wind. "P" factor increase, slip stream increase, torge is high. Yes torge is a rolling moment on the airframe, but on takeoff the left tire carries the weight of this force,which tends to pull the airplane to the left.
Ailerons can not counter the left turning tendency on takeoff.
I see what your saying about cg on WWII airplanes. The horizontal stabilizer creates lift in a downward motion on all airplanes for equalibrium. The center of pressure moves forward and aft on the main wing depending on airspeed, angle of attack.
If the cg is in a certian location and the airplane is say is above 200 kts its more than likely that when the tail is blow off, that the tail would pitch down and nose would pitch down. The center of pressure was holding up the weight of the entire airplane and would be have more force over weight. When a palne is fast center of pressure moves aft on the main wing and would pitch the nose down.
-
Tailwheels on most airplanes are free wheeling and have no control to them. P-51s and b-17s when taxi on to the runway straight, you have to lock the tail wheels into postion. This in order to have at gear retraction time to have the tail wheel clear the gear bay doors. and not jam. Plus on take most takeoffs the tail wheel is airbourne and is useless anyway.
Taxiing and airplane on the ground just requires indepentant brake application on trycycle and taildraggers. Some try gear airplanes have no steering ither except for brakes.
-
Just for the record :)
Torque = Force * arm
Power = Torque * angular velocity
All the torque that tries to rotate the plane is actually lost power, totally wasted (could be as much as 20-30% of total shaft power).
Wings and fins will naturally counteract the torque through the slipstream. A clockwise rotating propeller (seen from cockpit) will produce a clockwise rotating slipstream. This produces a torque on the plane rotating the plane counterclockwise. When the slipstrean (clockwise) hits the left wing it will cause a force in upward direction, when it hits the right wing it will cause a force in downward direction (the same goes for the horizontal stab), when it hits the vertical fin it will cause a force in clockwise (right) direction. The force on the vertical fin causes a torque in clockwise direction about the longitudinal axis and a torque trying to rotate the plane left in yaw. When applying right rudder to compensate for the yaw you actually adjust the force on the vertical fin so that it is zero (no yawing motion). This means that the vertical fin no longer contributes in conteracting the torque, thus the overall torque rotating the plane will actually be larger.
A counter-rotating propeller (one just ahead of the other rotating in opposite directions) produces no torque trying to rotate the plane, and also have better theoretical efficiency (20%) because there is no rotating slipstream (the wind blows straight bacward). A high bypass ratio turbofan used on typical airliners has stationary vanes to straighten up the slipstream, thus no torque trying to rotate the plane (the torque on the stationary vanes and the torque on the rotating vanes are equal but opposite in direction). "Torquewise" the wings and fins on a typical propeller plane is a low efficiency version of the high efficiency stationary vanes in an enclosed fan.
When flying slow with a small amount of power and suddenly hit max power several things happend. First the propeller is accelerated, this causes a tremendous amount of exess torque (unbalanced torque). Just about all of the horsepower and torque in the engine is used to accelerate the propeller (and rotate the airplane) instead of producing thrust. Then the speed governor starts reacting by increasing pitch to reduce the speed of the propeller. When doing this, more and more torque is used to produce thrust, thus the exess torque dicreases.
-
Originally posted by AKWeav
One aspect of the flight model that always makes me scratch my noggin is e retention when your engine conks out. Planes like the P-51 are very hard to lose airspeed with even a slight down nose angle, despite full flaps and the drag of lowered gear.
This is a gripe for me, as well.
culero
-
Originally posted by Tilt
Reduce rpm to initiate more prop drag.
I think that is part of the problem when your engines cut out. I heard that your props automatically get feathered when your engine cuts out in midflight.
I have noticed that when I turn off my engines in mid-flight, there's a noticable drag but when my engines cut out from damage or lack of fuel, there's hardly any noticable drag and I can glide for a long time.
Ack-Ack
-
I would be happy if they brought back the pre 1.3 flight model... Was way more fun than now.
-
One aspect of the flight model that always makes me scratch my noggin is e retention when your engine conks out. Planes like the P-51 are very hard to lose airspeed with even a slight down nose angle, despite full flaps and the drag of lowered gear.
Could be the fact that the prop is feathered. A prop doesn't only give the plane thrust, it also gives it drag. The prop is the reason no prop plane can ever go supersonic (with the prop still attatched). Once near supersonic (what you talk about as a planes "mach number") the plane won't go any faster as the prop gives more drag than thrust. Killing the prop kills the drag (some of it).
-
One aspect of the flight model that always makes me scratch my noggin is e retention when your engine conks out. Planes like the P-51 are very hard to lose airspeed with even a slight down nose angle, despite full flaps and the drag of lowered gear.
Could be the fact that the prop is feathered. A prop doesn't only give the plane thrust, it also gives it drag. The prop is the reason no prop plane can ever go supersonic (with the prop still attatched). Once near supersonic (what you talk about as a planes "mach number") the plane won't go any faster as the prop gives more drag than thrust. Killing the prop kills the drag (some of it).
-
Personally I think that the combat trim is actually too good.If used properly it is actually so effective it makes those of us who try to trim manually (as the real pilots had to) have a hard time. Especially in energy fighting.Could we have it toned down a little?
Im all for helping a newbie but its too much help imo.
As for some stuff that id like to see loked into :
P51 durability I think at the moment is way too strong vs ground fire. I have had 3 or 4 ack hits withour even losing a part in the p51d.True sometimes it goes down first hit but that seems rare.
From accounts of almost every pilot who ever speaks about it they all say the p51d was not suited to ground attack generally because it was so susceptable to even small arms fire. It should reflect this in AH.
The acceleration of 190 A5 seems to be a hell of a lot slower than a spitfireV yet flight tests of 190a3's and spitV's clearly state it had a huge advantage in acceleration, roll , dive etc.
I realise we have the 190a5 and it was heavier than the A3 but was it REALLY that much of a step down in speed?
Surely if suddenly the 190a5 was slower than the 190a3 and it made the spitV and spitIX faster the pilots would have started screaming blue murder!? anyhow Id like to see some kind of data to ease my mind on this.
I would also have to say that the 110G2 seems to have a superb acceleration for such an apparently unweildy aircraft.Certainly better than the 190a5 , even 'feels' better than the 190d9 to me! :) This might be a bug or maybe thats how they were?
One last thing could you please explain why when we apply an auto level (x) or auto climb (alt x) to some aircraft it takes a LOT longer for some than others.There is a VERY large difference.
As auto trim and auto level werent really on these aircraft why on earth is there such glaring differences? Surely as its an added feature most planes of the same size should behave exactly the same using what is after all a 'unreal' feature.I do however greatly appreciate the feature and use it often but i have noticed some aircraft take up to 2.5 times longer to settle into position than others.seems weird.
-
Bod,
I total cannot understand what you are talking about. First of all Jet turbines do have torge its measured on takeoff on the N1 and N2 gauges or torge gauge in someplanes or EPR gauge. Increase power on a turbine can torge an airplane. A single Eng Jet figher needs to on takeoff, counter torge and gyro precession.(a Rotating Mass) depending on what type of turbine is in its belly.
The N1 stage off a jet engine has as many as 13 stages of stator vanes, these are for diverting and decreasing pressure of the air before it enters the burner canisters, fuel is introduced into fine mist not touching anypart of the canisters, then the ignitors light the fuel. Then the exploding gas exits onto the N2 stage of the
of the turbine which has a shaft that turns the N1 compressure. this is an axil flow type turbine. Some N1 and N2 sections turn opposite of each other. No torge just gyro precession.
Counter rotating or not you will still have prop slip stream! Thats just the way its is.
About the vertical Stab zeroing out. ???????????????????????????
-
Pyro,
Dont get me wrong this is a class A1 combat sim you guys have here. We have started a 3rd sqd and doing great. I just would like to help in any way I can. I have a lot of experience flying airplanes and helicopters for a living with over 18,000 hrs of flying time.
I was just trying help out and I feal like the bad guy. I dont know what experince you guys have at AH at all. But I was just trying to say that I have never used Aileron in any airplane that I have flown to counter torge.
If I can help in anyway please let me know.
Thanks Pyro
-
But I was just trying to say that I have never used Aileron in any airplane that I have flown to counter torge
Straiga,
you just misread Pyro. He said:
[/I]Pyro:
An example of this is the effects on the propeller vortex on the wings. We’re modeling the forces of the vortex and its effect, but we weren’t applying it exactly where it needed to be applied, thereby creating an inaccurate force moment.
He's talking about torque in the ROLL axis where secondary prop wash on the wings wasn't modeled correctly.
There's no mention of "while taking off". Inflight you do use ailrons when increasing throttle (or insert pedal on helicopter when moving collective as he tried to example).
Bozon
-
Pyro I would also like to give you this quote from 'wings of the luftwaffe' by captain eric brown RAF test pilot.
regarding the ju87:
'Every dive bomber of WWII vintage featured some sort of synthetic aid to judging dive angle, and in the ju87 this consisted of a series of lines of incllination marked on the starboard front side screen.These marks , when aligned with the horizon gave dive angles of 30 to 90 degrees. Now a dive angle of 90 degrees is a pretty palpitating experience for it always feels as if the aircraft is over the vertical and is bunting, and all the while terra firma is rushing closer with apparently suicidal rapidity.In fact , I have rarely seen a specialist dive bomber put over 70 degrees in a dive, but the ju87 is a genuine 90 degree screamer!. For some indefinable reason the ju87 felt right standing on its nose'
This got me thinking about the way its possible to divebomb vertically in almost any aircraft in AH with little or no fear of 'bunting' or any other adverse problem apart from locking up with compression.I was wondering if we should have a much more unstable platform when we use aircraft that werent designed to bomb in this manner so easily all the time. Could a P47 loaded with 3000lbs of ordinance dive vertically with ease?
Could 190s and p51s etc ? Was it common for the pilots to do this?
It would seem according to Eric Brown it didnt happen often.Do you think maybe we need to add some unnerving effect to this sort of behaviour? locking up earlier maybe? Is there any data on compression when an aircraft carries an extra 1000 to 3500 lbs of bombs and rockets?
I get the impression in AH that diving vertically is the easiest way to bomb stuff yet according to people like eric brown the stuka was UNUSUAL in that it could go vertical to 90 degrees and yet feel right. If he flew any of the AH planes im sure he wouldnt even notice a difference between the stuka and others. Certainly not enough to make remarks like these. Maybe this area needs looking into especially with people these days using b26s and lancasters to do just this type of bombing.
thnx
-
Originally posted by culero
This is a gripe for me, as well.
culero
I think it's really wierd too. I have no idea what real planes act like with no engine but the inability to slow down (or ability to glide forever and a day) has always struck me as being ??... unusual?
-
a few tip bits ive read which are interesting to test in AH
Me262 : 'if one throttle was cut at 160mph the me262 went into a violent diving turn.Full rudder was required to counteract the swing and roll and backward stick pressure had to be applied to keep the nose up.This action had to be taken within 2 seconds or else the situation was disasterous.The rudder force involved was high'
Havent gone to test this yet but i have landed the me262 with one engine and i have to say it wasnt terribly difficult. Perhaps i stayed at high enough speed to avoid any of this swing and roll effect? ust afer reading about the me262 in this boook it did make me think we have a very easy to fly me262 compared to the one described in the book.Seeing as how it is a perk plane I began to think maybe all its bad characteristics should be modeled. It had qute a few bad vices.
heres one:
'The jumo turbojets tended toward tempremental above 13,125 ft at which altitude the fuel pumps had to be switched on to sustain combustion.and above 29,530 ft it was considered inadvisable to reduce revs below 6000 per minute as to do so was to ensure a flameout, and restarting could not be attempted above 13,125 ft!'
but also theres a small thing which seems a little off with the current AH me262:
'For landing the undercarraige could be lowered at 310 mph but it was preferable to reduce speed to 250 mph and throttle back to 5000 rpm'
-
One last thing i dont quite understand:
The mk108 or 103 cannon on the me262 , if you use the .target command to test it, when fired at 800 yards you will see your bullets land. BUT if you set it to 900 yards you cannot hit the target. Does this mean all bullets with the 30mm are removed at or over 900 yards?
There seems to be a rather large discrepancy between different guns .
Id like an explanation as to why some guns can fire over 1000 yards and some have the bullets stop a lot shorter. Surely its silly to remove the bullets as they will continue to travel and hit regardless of distances. AT least up to 1000 yards.
In 'veiw from the cockpit' by adolf galland he clearly states the effective range of the mk108 was 800 meters. Thats a lot further than 800 yards.
heres a quick list of various guns in AH and the range at which AH ceases (it seems) to calculate them:
MK 108 30mm range at wich no bullets hit .target is @850-900 yards
Browning .50 cal range at which no bullets hit .target is @1350 yards
mg151 20mm range at which no bullets hit .target is @ 1100 yards
MG131 13mm range at which no bullets hit .target is @1190-1200 yards
Hispano MK II range at which no bullets hit .target is @1200 yards
shavak 20mm range at which no bullets hit .target is @ 940 yards
Type 99 model 2 20mm range at which no bullets hit .target is @1080 yards
Now i realise this may be a quirk of the graphical display on the .target command but as it is the only way we can test guns and their effective range it should at least give us accurate data.
IF it is accurate Id just like to know why the 50 cals are effective or are ACTUALLY modeled out to 1350 yards whereas others are it seems removed at a far lesser distance? doesnt make sense to me. surely the bullets are still there for all guns, shouldnt we have all guns calculated to this range even if they have dropped a considerable distance and are not as effective. As the game is now 50 cals can reach at least 150 yards further than any other gun, and at worse some 450 yards more!!!!. Ok so the 30mm at 1350 yards is next to useless because of its velocity but it should still BE there, just cause less damage.
If this is a quirk of the .target feature then fair enough. If its not then i have to say i find this a blatent extra ability for the 50 cals in this game.They already have a laser like trajectory, do we really want them to be the only guns with bullets calculated over 1200 yards? seems damn unfair to me.
slightly peeved! :(:confused:
-
Hazed, believe all bullets have timed flying distance. Say 3 seconds flying time. Difference is thanks to higher initial velocity the 50 cal will go further than a 30mm.
-
Originally posted by Wilbus
Hazed, believe all bullets have timed flying distance. Say 3 seconds flying time. Difference is thanks to higher initial velocity the 50 cal will go further than a 30mm.
well thats a bit convenient isnt it? :( sheesh who decided that was fair? :D
now i understand why my bullets from a 30mm dont hit ground targets if fired at from over 900 yards. This is a completely unfair system, no wonder straffing Gv's etc is so difficult. Im amazed its set up this way to be honest and pretty dissapointed.
-
Originally posted by Straiga
Taxiing and airplane on the ground just requires indepentant brake application on trycycle and taildraggers.
Lavochkins did not have independant brakes they had one brake lever mounted on the JS which operated an air valve via a bowden cable.
The tail wheel was a free castor design
La 5's had a nasty bounce upon landing (worse than the spit) and the La 7 was worse still(longer gear). Pilots were taught to ignore the bounce as attempts to compensate for it usually put the AC on its nose.
On the ground Lavochkins must have been horrendous........ taxi ing could only be accomplished with the hood pulled back and even then the AC was required to snake as much as the rudder would allow
-
Hazed, actually all your tests are a bit short I believe. The "target" travels with your plane (to stay at the set range). You could say that your test is correct if fiering at a plane flying away from you at aprox. the same speed. I've been pinged by B17's .50 cals as far out as d1.8k.
However you are absulutely correct that the guns with a higher muzzle velocity has an unfair range advantage, in addition to being easier to aim (which is correct).
-
From accounts of almost every pilot who ever speaks about it they all say the p51d was not suited to ground attack generally because it was so susceptable to even small arms fire. It should reflect this in AH.
-Hazed
Because it had a radiator and its placement. Otherwise, the airframe isn't any weaker than your typical fighter.
-
Originally posted by hazed-
Personally I think that the combat trim is actually too good.If used properly it is actually so effective it makes those of us who try to trim manually (as the real pilots had to) have a hard time. Especially in energy fighting.Could we have it toned down a little?
Im all for helping a newbie but its too much help imo.
I think the effectiveness of CT depend on the plane you fly. Turn on CT in a P-38 and you'll find that CT will seriously hamper your ability to ride the edge of the envelope. Read Lephturn's article on Combat Trim because he explains why CT is effective in some planes and why it's not in others.
Ack-Ack
-
Perhaps I should have made my post a bit clearer. If I lose my engine for lack of fuel, and don't reduce rpm prior to the engine cutting out, the plane don't glide worth two dead flies. However it the engine gets shot out, it's like all of a sudden I'm in the most areodynamic machine ever built. Don't know if that is correct or not, just doesn't seem right.:confused:
-
Originally posted by Straiga
First of all Jet turbines do have torge its measured on takeoff on the N1 and N2 gauges or torge gauge in someplanes or EPR gauge. Increase power on a turbine can torge an airplane. A single Eng Jet figher needs to on takeoff, counter torge and gyro precession.(a Rotating Mass) depending on what type of turbine is in its belly.
Counter rotating or not you will still have prop slip stream! Thats just the way its is.
About the vertical Stab zeroing out. ???????????????????????????
Bod is right, sorry to say.
NASA web site on jet propulsion:
http://www.grc.nasa.gov/WWW/K-12/airplane/shortp.html
BTW, no pilot would ever confuse N1, N2, and EPR with a torque gauge. EPR is the difference in pressure between the compressor face and exhaust nozzle. The only place you'll find an EPR gauge is on jet fighters and airliners. N1 is low compressor speed, N2 is high compressor speed. Torque is not measured on jets, only on turbo-props and helos. Even then, it's measured at the transmission; something jet engines don't have. You claim to be a high-time helo pilot? A student could get this right.
-----------------------
Flakbait [Delta6]
Delta Six's Flight School (http://www.worldaccessnet.com/~delta6)
Put the P-61B in Aces High
(http://www.worldaccessnet.com/~delta6/sig/global.gif)
-
When I go fly mys Dads P-51D Mustang,When i Get a chance, Either on takeoff or airbourne I use rudder to counter torge nothing else. On takeoff If the rudder goes to the stop I get of the Power you only use 1/3 of the power to get airbourne as you steadly and slowly increase power. At altitude I still use rudder to counter torge you never want to just jam the power to it then there would be nothing nothing to counter torge anyway. Airplanes fly just as good with out Ailerons I teach students emergency procedures on control failures where the students use rudder and elevator trim to fly the plane back to the airport
-
Please implement new FM to the Ki-84!
:D
-
Oh yeah Straiga, many of the early airplanes didn't even have ailerons, just rudder and elevator. A couple of days ago I landed a 152 with both wingtips and ailerons missing, and later that same day I landed a 110 with no elevators or rudders. Amazing what you can do without when you have to.
-
Originally posted by GScholz
Hazed, actually all your tests are a bit short I believe. The "target" travels with your plane (to stay at the set range). You could say that your test is correct if fiering at a plane flying away from you at aprox. the same speed. I've been pinged by B17's .50 cals as far out as d1.8k.
However you are absulutely correct that the guns with a higher muzzle velocity has an unfair range advantage, in addition to being easier to aim (which is correct).
not if you fire a continueous burst with 7800 rounds of ammo in the guns.(10x) by testing this way the target behaves like a paper target would, if placed at the same distance from a moving gun platform. If no bullets fly through it then those bullets arent making it that far ever.This is what is happening in AH
This is often the way we fire at running aircraft anyway.If your slowly closing and you fire a shavak 20mm when your target is 1000 yards away, and your barely closing, this means no matter how many 20mm you fire, they will never reach the target. No matter how good your aim.
However a 50 caliber can start firing at them as soon as they come within 1350 yards!!!. Any way you look at it this makes the 50 cals the longest ranged weapons with the fastest bullets and the best trajectory.
The Bombers get an advantage of distance too if the 3 second rule applies to them also because after 3 seconds all bullets dissapear. If it was set so after a certain distance has been travelled by the bullets we would ALL be able to shoot right out to 14k! (or whatever the b17s manage to shoot to, I must say ive been hit further out than 14k by themtoo so for now, ill use 50cal length from my test).
As it is in AH now, if you had 30mm guns defending a b17 you would be unable to hit anything further out than 900 yards! no matter what you did they would be unhurt because your bullets would cease to exist after 3 seconds (the furthest they will travel will be a lot less than any 50cals ergo less defensive range)
surely i cant be alone in thinking this method really doesnt help any type of gun that is slower or heavier in caliber when in fact although some were very hard to aim due to their poor trajectory they had the fact that they were filled with far more explosive power to, in most cases, compensate fully for it. The 20mm did far more damage than the 50 caliber and both would be still capable of causing damage at well over 1300 yards. The 20mm would have to be aimed differently(raised) but it could still hit and probably cause more damage. Not so in AH. Because of a timer it ceased to exist.
now i know why its so easy to hit with those 50's in bombers! :)
-
Aren't LW cannon shells fuzed to explode at a certain distance/time ?
-
Originally posted by AKWeav
Perhaps I should have made my post a bit clearer. If I lose my engine for lack of fuel, and don't reduce rpm prior to the engine cutting out, the plane don't glide worth two dead flies. However it the engine gets shot out, it's like all of a sudden I'm in the most areodynamic machine ever built. Don't know if that is correct or not, just doesn't seem right.:confused:
This is something I've noticed too. If I run out of fuel... the prop generates tons of drag. If the engine is shot out... nadda.
MiniD
-
Originally posted by Mini D
This is something I've noticed too. If I run out of fuel... the prop generates tons of drag. If the engine is shot out... nadda.
MiniD
It appears that the planes go into automatic feathering when the engines shuts down due to engine damage. I've also noticed (at least in the P-38), the same thing happens even when the engine shuts down from lack of fuel. The only time I've noticed drag from a shut down engine is when I shut it down manually.
One thing that has always made me curious is why do the wheel brakes still work if you do a belly landing and why don't they work if you land dead stick?
Ack-Ack
-
Originally posted by Straiga
When I go fly mys Dads P-51D Mustang...
Out of curiosity, what is the name of your Dad's P-51?
Ack-Ack
-
Perhaps I should have made my post a bit clearer. If I lose my engine for lack of fuel, and don't reduce rpm prior to the engine cutting out, the plane don't glide worth two dead flies. However it the engine gets shot out, it's like all of a sudden I'm in the most areodynamic machine ever built. Don't know if that is correct or not, just doesn't seem right.
What Ack-Ack said, auto-feathering was implamented some time ago in AH so all planes that could feather automaticly do it when engine is shot dead.
Tourqe is AFAIK not countered by rudder on the ground. What you counter on the ground is Yaw effect created by the prop slip stream that pushes the vertical stabilizer one way or the other (depending on what way the prop is spinning). The prop stream pushes the tail plain (vertical stab) one way thus the nose wants to turn.
Tourqe is an effect created by the prop spinning and the actual plane want spin with it. If you throttle up slowly the plane will be able to counter this it self on the ground, still being stable. If you throttle up to max very quickly it will flip it over, has got nothing to do with slip stream only the fact that two bodies will want to spin together. The prop has a force working in one direction (well every direction really but let's say one) while the body must counter that force.
-
Just to clearify one more time...
Tourqe and slip stream are NOT the same things. Tourqe doesn't make a plane want to turn on the runway.
-
There has been some discussion in the past about the inability to perform proper hammerheads and tailslides due to some peculiarity in the AH flight model. I have no idea whether the claims about the flight model are correct, but I do know that I have never been able to perform a pure hammerhead or tailslide. If I kill and slam the throttle at the top of the vertical climb, I can produce sort of an ugly approximation of a hammerhead, but I don't think that this is the way it is normally done.
Anyway, I'm no expert, but if there is there is a problem with the current FM that prevents or inhibits these maneuvers, the ability to perform them properly might be a good verification of your modifications.
Thanks.
- JNOV
-
Gents,
Everytime I hear a conversation about torque and aircraft modeling I get motion sick.
In an envirement were annecedotal evindence is largely ignored for some reason the mention of torque modeling sends people into a rant about Ground loops, ensign eliminator, torque roll etc.
Let us not forget that this is all annecdotal Bullsh*t until someone proves otherwise.
Here are my reasons for this.
1. Aircraft with large engines and high HP also had the control surfaces to counteract this affect.
2. These aircraft also had trim tabs to counter these effects which worked quite well. We should have trim settings in degrees so we can use them realistically IMHO.
3. Annecdotal evidence is relative to pilot experiance. IE if your used to a T-6 then a P-51 will have much torque. If your used to a Wildcat a F4U will have much torque. It doesn't mean anything in practical FM modeling.
4. If your going to arrive at a conclusion and then change the facts to match the conclusion you will be changing the FM weekly to match what Joe Blows uncle may have said 40 years ago.
If you want to model torque I think a good starting point would be the A/C with high HP ie 109G10, La-7 and 190D9 which had very high HP and almost no relative control surface to dampen the effect. The190D9 didn't even have aileron trim IRL.
Basically stay away from revisionest history and we will be fine.
-
As i said: Power = Torque * angular velocity, No torque - no power, so obviously you want torque, you need torque or the plane will not move.
But from an aerodynamic point of view you want to use the engine to accelerate air, and you want to accelerate it straight bakcward. Any other direction, including spinning of that air is lost power (except vectoring thrust where you want to divert the thrust). A turbojet and turbofan does this with exellence, a propeller does not.
Newton said that force equal opposite force, this is the truth, and there really is no way of fooling it (although many have tried :) ). If you manage to accelerate the air straight back, you will have thrust straight forward. If for some reason you set the air into spin, you will also have an opposing force rotating the plane in opposite direction. What you want is to convert all the torque on the engine shaft into thrust, straight clean thrust with no spin because this will give maximum efficiency, maximum thrust. In a fan or propeller the torque on the shaft is a result of the drag on the blades. The drag on the blades is a direct result of the lift on the blades (thrust) - more thrust = more drag = more torque. The air see this thrust (lift) as linear acceleration straight back while it see the drag as angular acceleration (spinning).
In a fan this spinning is stopped by stationary vanes. The result of this is that the fan sets the air into spin. You need torque to do this from the shaft. The stationary vanes stop the spinning of the air which require an equal amount of torque in the opposite direction. The engine see two torques - one from the shaft and one from the stationary vanes and since they are opposite in direction and roughfly equal in size they cansel each other out. The air comes in straight and linear and leaves straight and linear, thus no net spin is put on the air and therefore no net torque is put on the plane (Newton's law). The torque on the shaft however, is large but so are the torque on the stationary vanes. (The stationary vanes can also be in front of the fan setting the air in spinning motion and any combination, it doesnt matter just as long as the air comes in straight and leaves straight).
On a propeller there really is no way of balancing the torque properly, unless you use contrarotating props which is complicated and expensive, and does not work as good in real life as in theory. On a propeller airplane you therefore allways will have an amount of unbalanced torque that will rotate the plane in roll and create swirling propeller slipstream.
Another general principle is that it is more efficient to accelerate large amounts of air a little than it is to accelerate a small amount of air alot (Thrust = mass of air * acceleration of air). This means that although a propeller is not as efficient in terms of lost torque, it can nevertheless have a better overall efficiency due to the large amount of air that is accelerated just a little.
Gyroscopic forces and other transient forces (slamming the throttle for instance) really has nothing to do with aerodynamics at all. They all produce torque in some way, but not continously. Ever done a lomcevak by the way?
About the vertical stab, just think about it, force = opposite force ALLWAYS. The slipstream hits the vertical fin and creates a force on it - you adjust the rudder to compensate. What you really are doing is to set an effective aoa on the vertical fin so that the rotating slipstream do not create any force either way. The effective aoa on the vertical fin = angle on slipstream. The only way to have the plane not to yaw is to have zero resulting torque about the yaw axis (Newton again) and there is NO other way.
Originally posted by Straiga
Bod,
I total cannot understand what you are talking about. First of all Jet turbines do have torge its measured on takeoff on the N1 and N2 gauges or torge gauge in someplanes or EPR gauge. Increase power on a turbine can torge an airplane. A single Eng Jet figher needs to on takeoff, counter torge and gyro precession.(a Rotating Mass) depending on what type of turbine is in its belly.
The N1 stage off a jet engine has as many as 13 stages of stator vanes, these are for diverting and decreasing pressure of the air before it enters the burner canisters, fuel is introduced into fine mist not touching anypart of the canisters, then the ignitors light the fuel. Then the exploding gas exits onto the N2 stage of the
of the turbine which has a shaft that turns the N1 compressure. this is an axil flow type turbine. Some N1 and N2 sections turn opposite of each other. No torge just gyro precession.
Counter rotating or not you will still have prop slip stream! Thats just the way its is.
About the vertical Stab zeroing out. ???????????????????????????
-
Originally posted by F4UDOA
If you want to model torque I think a good starting point would be the A/C with high HP ie 109G10, La-7 and 190D9 which had very high HP and almost no relative control surface to dampen the effect. The190D9 didn't even have aileron trim IRL.
This makes sense...
btw
Any 109 exerting Hp over 1800 had a greater hp/m^2 of wing area than the La7 {la7 had more wing surface area than the 109}
The la7 was slightly shorter and had slightly less wing span. Its wing deepened however at the root.........also its tail surfaces were larger but closer to the C of G.
I have not done the maths on the D9 but would expect its hp/m^2 to be lower still.
Also if by control surface you refer to elevator and rudder surface area then you will note the significant size difference between Lavochkins and other AC of similar size.
Both these plan views are to the same scale.
(http://www.btinternet.com/~fulltilt/lav109.jpg)
-
I dunno if this has ben mentioned/covered, or if I'm TOTALLY WRONG, but I was wondering about the amount of trim controls. I have looked at pictures etc. of planes, and the trim tabs are always TINY as compared to their relative control surface. But I have noticed also that in the game if I am flying, say, a BF-110 g2 and get it into one of those terrible stalls where it just falls toward the ground just below it's stall speed, the big ol' elevator won't do diddely crap, but the tiny little elevator trim tab can actually make a difference. Might someone correct me, or if by some mistake I am correct mabye this needs fixing.
Whatever you do please don't get mad if I'm wrong, I really don't know that much, and I apologize for all incorrect information.
Thanks
-
Brakes
Can both brakes be prssed differently - via rudder for exemple if I apply light right rudder the right brake force will be 65% and left 35% just like in WB (sorry). With this option you can taxi much easyly and when landing you can control your plane better.
Me262 Turbojet Engines
Me262 jets had some problems in real life:
If you operate you throttle too hard - at high speed and high RPM you close too fast your throttle you just get both engines cut.
At hi speeds - of 400-500 km/h you could not reduce your throttle less then 7000 rpm
-
Torgue is present in every rotating mass, and is also present in non moving objects. Anything that is that has a twisting or bending moment to it. Thats is torge.
An airliner that is sitting on the ground park no engines running just sitting there has torge affecting it. The stress of the wing bending on its own weight the fulcrum is at the fuselage and arm or bending moment is the torgue.
As in an engine the N1, and N2 is the measure of the percentage of rpm in the low and high stage axial compressors. EPR is a measure of the air as it enters the engine, and the gas pressure at the turbine discharge. The ratio between the two is read directly on the instrument dial. One of the engine variables such as compressor rpm, turbine discharge pressure or engine pressure ratio, all of which vary with thrust, should be employed as an indication of propulsive force which an engine is developing. When an engine is on its test stand all cockpit gauge and more gauges monitor the engine as its is running. Engineers can calculate anything that engines is doing through all ranges of opperation. For example how much torgue is the engine pylon taking, either from thrust, increasing or decreasing RPM of the rotation of the mass turning or gyroscopic precession. Based off the information they recieve from various gauges and the engineering calculations.
In a jet airplane we dont care about torgue that the engines produces. We want to know air density, temp, barometric pressure to determine MCT(Max continuous thrust) or for a normal rated takeoff. How much trust is available for that day,weight of the airplane, runway length, dry or wet runways. Can we go fly for that given information.
Yes turbo-props and helicopters have torge gauges. Because of only a small part of propulsive force is derived from the jet thrust, neither turbine discharge pressure nor engine pressure ratio is used as an indication of the power produced by a turbo-prop engine. Turbo-props are usually fitted with a torguemeter, operated by a torguemeter ring-gear in the engine nose-section, similar to the torguemeter provided on large reciprcation engines. The torge being developed by the engine is proportional to the horse power. Torguemeter oil pressure is used to indicate shaft horsepower.(SHP)and similar with helicopters.
-
Originally posted by LoneStarBuckeye
There has been some discussion in the past about the inability to perform proper hammerheads and tailslides due to some peculiarity in the AH flight model. I have no idea whether the claims about the flight model are correct, but I do know that I have never been able to perform a pure hammerhead or tailslide. If I kill and slam the throttle at the top of the vertical climb, I can produce sort of an ugly approximation of a hammerhead, but I don't think that this is the way it is normally done.
Anyway, I'm no expert, but if there is there is a problem with the current FM that prevents or inhibits these maneuvers, the ability to perform them properly might be a good verification of your modifications.
Thanks.
- JNOV
With a duel throttle it's possible to pull off a perfect hammerhead in a P-38, just cut throttle to one engine and let gravity do it's work. It's also possible to do it without a duel throttle but takes some practice but mine usually look really sloppy unless I'm using a duel throttle.
ack-ack
-
Originally posted by btone
I dunno if this has ben mentioned/covered, or if I'm TOTALLY WRONG, but I was wondering about the amount of trim controls. I have looked at pictures etc. of planes, and the trim tabs are always TINY as compared to their relative control surface.
The trim tabs don't work like the control surfaces themselves do, they just change the deflection of the control surfaces - trim tab down makes the control surfaces go up. So a small change has a pretty big effect.
-
My original Post on the Control Authority given the Combat Trim system in Aces High seems to have been sidetracked a bit.
The AH Combat Trim has Control Authority greater than that of the pilots control inputs in many cases. Not a situation anywhere near the desired effects or the real world design for that matter.
I Augered a P 51 in the MA recently due to "my forgeting to turn combat trim off" before starting a series of straffing run s.
The combat trim totally overcame the elevator commands and aileron commands as I manuvered low to the ground, even with throttle greatly reduced, the aircraft was responding to the Combat trim system instead of my stick inputs.. Very frustrating...
The Flight Model also seems to only recognize the reduced drag and weight of the aircraft after ordnance release - after the weapons select (backspace key), has been toggled and the guns and cannons again selected... Especially noticeable on low powered aircraft such as the Zero...
-
So lets delete this unreal feacher - lets make pilots trim their planes manualy. if you feel to much froce on stick just press I/K/J/L/M/, and all ok!!!! More reality like real trimmers.
I never use this option - more realism.
-
-there is too much visibility over the nose. Try the Corsair in FS2k2 and let me know if you see any difference :P
-every plane in AH flies like a Cessna 152-i.e. rudder is not needed for coordinated flight.
-
Too much visibility over the nose?
At 100 meters a fighter should just fit into the circle of the cross hair (of german planes). In AH if an nmy fighter is at 110 (or whatever is 100 meters) flying knifes edge part of his lower wing isn't visible because it's below the nose. I don't think the crosshair IRL was partly showing the nose...
-
Sorry to but in between the visibility issues, but I was just going to say I'm all for it if HTC wants to just rid us of the whole combat trim or whatever it's called (I disabled it as soon as I figured out what it did, which I still don't understand :-) ).
Maybe, if they like it becuase it helps begginners, they could have it as an arena option, so that it could be on for a training arena, but off at all other times, and toggleable in H2H.
Thanks
(p.s.- I know that combat trim in AH works totally different than real trim, I wasn't talking about combat trim to start with, just to clear things up.
-
Udet,
Visabilty over the nose is 100% subjective to what ever pilot or annecdote you may have read. I have numerous references for points of view on that subject.
Instead I think using photographic replications of the cockpits and there views are the way to go.
On a similiar subject 6 views are also very subective. Take a look at WB3 and compare it to AH. Both are replicating the same thing but have opposite results. How is that possible?
I have a quote from the 1944 Joint Fighter Conferance stating that in a F4U-1 you can look over your shoulder and see the virtical stab and that you can from the inside of a P-51D look over your shoulder and see the opposite horizontal stab. This is more generous than AH let alone the horrible view system in WB3.
BTW. I do feel that some of the Axis A/C such as the FW190 have a horrible view over the nose while the 109 has a rediculous 6 view allowing for an external view. I'm sure some better research from the community could help HTC change some of this.
-
I heard that spitfires are more manuverable than hurricanes. Is that true? I suspect that Hurricane 1 can turn better than spit 1 in AH during dogfights.
-
The Hurri did turn tighter than the Spitfire, but the Spitfire completed any given number of degrees of turning faster owing to its higher speed.
-
This is a little off the track of this thread, but can we get the relative fuel consumption of light and heavy fighters sorted out?
As has been explored in a number of previous threads, at least one plane (La-7) flies at all power settings as if it was run on auto-lean. The implied best specific fuel consumption was not attained in a high powered engine until decades later - and that in a turboprop.
-Blogs
-
Originally posted by btone
Maybe, if they like it becuase it helps begginners, they could have it as an arena option, so that it could be on for a training arena, but off at all other times, and toggleable in H2H.
Thanks
Combat trim is already an option, you have the option to either use it or not to use it.
Ack-Ack
-
tire blowups on hard landings :)
-
Originally posted by Fariz
It seems fixing this problems will lead to correct modeling of la7, so it will be both faster and will turn with spit V like in reality. :D
If Ah2 means a more uber la7, i'm for leaving the game the way it is.
-
So this is a tremendous amount of revision along with some additions such as working slats.
Hello Pyro!
Thanks for the update on AHII. Could you explain some more what the above quote means? Were slats, I'm assuming leading edge slats, not modeled in the FM before or are you talking about them being graphically represented?
-
Originally posted by GRUNHERZ
Hello Pyro!
Thanks for the update on AHII. Could you explain some more what the above quote means? Were slats, I'm assuming leading edge slats, not modeled in the FM before or are you talking about them being graphically represented?
I was thinking the same thing, i always thought the 109s had the slats modelled but just not represented graphically. Im sure Ive read that in some posts before as an explanation for poor zoom or over the top stall or something.
-
Just found this thread. great news! :-)
If the effect on fuel consumption of different engine control settings is modelled (at least to some degree), fuel loads are modelled (more) accurately (in buffs) and ifone can have greater control over the amount of fuel one can load (I don;tmind if themaximum amount loadable at a particular is limited by strat considerations at that field, but I'd like to be able to load any amount of fuel up to that limit) - I'll be a much happier bunny.
Add in Otto gunnery and I'll be very happy
Add in a system that allows CMs to do away with GPS and DAR in flight, and I'll be very, very happy!
Must admit, I've been going through a gloomy patch where I wondered whether WW2 flight sims were headed the right way at all. This is a ray of hope, at least for AH.
Esme
-
Originally posted by hazed-
One last thing i dont quite understand:
In 'veiw from the cockpit' by adolf galland he clearly states the effective range of the mk108 was 800 meters. Thats a lot further than 800 yards.
slightly peeved! :(:confused:
Uhm Hazed, a Yard the same as a Meter... 3 Feet... give ot take a few inches. are you referring to Kilometers?
-
Originally posted by 2Hawks
Uhm Hazed, a Yard the same as a Meter... 3 Feet... give ot take a few inches. are you referring to Kilometers?
800m=875yards
-
I'm sorry but I havent found another place to post what I'm posting now so have patience please.
What I considered often an AH fault is the ICON SYSTEM.
I think it is not much realistic to know there is an enemy SPIT XIV 6k (~10 kilometers) from you, I guess bejond visual range.
I hope not to be hit by an AIM 7 Sparrow ;) :cool: YahooOOOOOoooo.....
I'm sorry I must correct ~10 Km with ~5 Km.
-
Originally posted by clouds
I think it is not much realistic to know there is an enemy SPIT XIV 6k (~10 kilometers) from you, .
5.4864 kilometers and your right its not the subject of this thread......... to start a new thread click new post .
-
Wow sorry but......did u ever try to recognize a type of modern airplane passing over your head at 6K altitude ?
If you didn't then try to figure out a ww2 plane and compare its dimension with one of the modern airliner then tell me if you must recognize it at 6K (hawkeye) ;)
-
Originally posted by JB73
the N1k2 is a UFO
sry i had to... :D:D JK
seriously the bf110g2 has something odd happen and i dont know a ton about real flight but here goes.....
fly level @ least 200 mph on the white needle and do a hard rudder turn while climbing. around the moment of stall apply full opposite rudder and stall out the plane. im pretty sure how i accomplish this... i KNOW i can replicate it at will almost... it's all about the full rudder @ the start of the stall.
what happens is you will go into a 100mph tail first fall... you will literally be going backwards for part of the fall. all stall recovery tactics i have read dont work. the only way i have been able to get out of it is manual trim all the way nose UP and zero throttle, but this still takes about 5000k feet of freefall to recover... if you are below 5k AGL when this happens you will not get out.
just my 2¢ about it.... i may be missing something and this might be a real charertistic of this plane.
JB73, in aerobatics that maneuver is called a "tail slide". Have you tried asymetric thrust to recover?
-
Originally posted by clouds
Wow sorry but......did u ever try to recognize a type of modern airplane passing over your head at 6K altitude ?
Altitude is in feet here so that would be 1.83 kilometers.
Sorry could not resist.....but your right. Type icon at 6000 yards is unrealistic. Set icons short say I (3000 yards is an alternative arena setting altready available) and do not differentiate sub type.
-
as long as the 38 finally, after all these years, gets their DIVE FLAPS to have the accurate effects (if deployed under 250mph they do what they do now in AH, if above 300mph they would give the 38 a steady 3G nose up pull)...
and the fowlers to not autoretract...
...and gets a green model (F/G)
...and gets the option of carrying 2X2k bombs +10rockets
...and all other planes finally get some torque/slipstream/whatchammacallit effects (yeah, im sure the n1ks could be running at full wep and helicopter on their nose while firing 4 cannons continously at 10mph without any control issues)
... and the ICON SYSTEM mirrors WW2OL's
I'll be happy.
-
heheheh hey TILT when you see an enemy plane in front of you and its icon is showing 6k it is at 5,.....Km and instead when you see the same enemy above you and its icon is showing 6k it is at 1,8...Km !?!?!?!?!
WHAT'S the difference m8, in front or above you, an icon at 6K is 6K far from you :p ;) :) :D :cool:
I agree with OIO for the icon system.
-
Range on tags are in yards wether he is in fron of you behind you over you or under you even if your on the ground. A tag with a range of 6k is 15000 feet away. Altimeters in planes are in feet.
When your flying in a plane at 15000 feet and you fly over a gv at sea level he will see your tag as 6k
-
Originally posted by clouds
I'm sorry but I havent found another place to post what I'm posting now so have patience please.
What I considered often an AH fault is the ICON SYSTEM.
I think it is not much realistic to know there is an enemy SPIT XIV 6k (~10 kilometers) from you, I guess bejond visual range.
I hope not to be hit by an AIM 7 Sparrow ;) :cool: YahooOOOOOoooo.....
I'm sorry I must correct ~10 Km with ~5 Km.
The reason why flight sims such as AH have some sort of icon for the planes showing range is because of the depth perception problem inherent in all PC flight sims.
Like the previous person that complained about Combat Trim, you too have the option of using or not using icons. If you don't want to use them, just turn them off.
Ack-Ack
-
Range estimation by stereoscopic vision does not work farther out than 50 yards.
-
Originally posted by icemaw
Range on tags are in yards wether he is in fron of you behind you over you or under you even if your on the ground. A tag with a range of 6k is 15000 feet away. Altimeters in planes are in feet.
When your flying in a plane at 15000 feet and you fly over a gv at sea level he will see your tag as 6k
6x3=18. Other than that its correct.
Sorry ice:D
I agree that the icon system should be 'tweaked'.
-
I stand corrected
-
Originally posted by ccvi
Range estimation by stereoscopic vision does not work farther out than 50 yards.
Who told you that?
If it were true then stereoscopic vision wouldn't be a requirement for pilots (and many other professions where distance estimation is required).
-
Actually it’s more like 20 feet.
You would have to be one-eyed not to have stereoscopic vision, so I don’t see why it would be a requirement … except to disqualify everyone that’s half-blind of course ;).
Beyond 20 feet or so stereoscopic vision means less. Size and movement is the prime factors in determining range beyond 20 feet.
http://www.hd3dmovies.com/3d.html
-
Non-binocular vision in two eyed people is not as uncommon as you might think. Depth perception is a function of the brain - not the eyes, and theres lot of reasons for not having it.
When I was a youngen I lost the use of my right eye for a couple of years due to a severed nerve to the muscles. Many operations later I regained use of that eye, however by this time my vision development had completed and I had 'learned' to see non-binocular. Funny thing was I had no idea til I did an Air Force physical - when I found out it explained a lot of wierd **** about my vision (like being an excellent shot with both eyes open, totally unable to hit balls in tennis and stuff, no idea what 100 metres down the road was).
Stereoscopic vision does go out a lot further than 20 feet GS. And it does matter, I have to fake our drivers test which checks yours eyes for binocular vision - theres no way they'd let guys with 2D vision in the air ;)
-
Originally posted by Vulcan
Stereoscopic vision does go out a lot further than 20 feet GS.
How would you know?! (sorry, couldn't help myself ;))
Wow, you need stereoscopic vision to get a drivers license? Here they let one-eyed ppl drive. They just have to have their head on a swivel to cover their blind side.
You can't judge a 100 meter distance? I find that odd since I do that with one eye all the time, 200 meters and 50 meters too (pistol/rifle shooting).
-
Originally posted by Straiga
The horizontal stabilizer creates lift in a downward motion on all airplanes for equalibrium.
I feel bad picking on Straiga here, but this jumped out at me, and he said it more than once. The horizontal stabilizer is an airfoil, just like the wing. It creates lift, just like the wing. The only difference is the size and location. There is no such thing as lift in a downward direction. Downward force on an airplane is called weight. I don't have any handy pictures to link here and illustrate, so I'll try to draw this with words the best I can.
Imagine a side view of an airplane. Now imagine a big arrow coming up from about the middle of the wing, representing the lift generated by the wings. Imagine also a smaller arrow coming straight up from the horizontal stabilizer, representing the lift created by it. Now picture a dot somewhere between those two arrows, representing the Center of Gravity (CG). Do some simple physics-math (force x distance) and you can figure out where the equilbrium point is. Now if the CG slides too far forward, both arrows are behind it and the plane will go nose-down and start flipping. Likewise, if the CG moves too far back, the plane will go nose-up and flip. But assuming the CG stays where it should, slightly behind the lift vector from the wing, it makes sense when the empennage gets shot off that the aircraft would pitch nose-up, because the only lift remaining is in front of the CG.
Sorry, but for someone with these kind of credentials:
I have been a pilot for over 30yrs, 91/2 with the US Navy jet fighter pilot, the rest as an Airline Pilot with a major carrier flying DC10s and B767s. Im both airplane and helicopter flight instructor with ATP in both. I have a master in aeronautical engineering,with over 500 hrs in a P-51D
it just strikes me as odd that you can be that far off the mark about basic aerodynamic concepts.
-
Originally posted by mjolnir
I feel bad picking on Straiga here, but this jumped out at me, and he said it more than once. The horizontal stabilizer is an airfoil, just like the wing. It creates lift, just like the wing. .
There are some (mainly canard) designs where the tail contributes lift, but for all the designs we're interested in WWII aviation, the tail does indeed supply a downward turning moment and does not contribute lift.
-
Most planes are designed nose heavy to get the CG far enough forward to make the plane stable in the vertical, with a counteracting force (inverse lift) acting on the tail. This is why as speed increase you have to trim the nose down, the downward force acting on the tail gets stronger with speed, but the weight of the nose does not.
-
Originally posted by GScholz
Most planes are designed nose heavy to get the CG far enough forward to make the plane stable in the vertical, with a counteracting force (inverse lift) acting on the tail. This is why as speed increase you have to trim the nose down, the downward force acting on the tail gets stronger with speed, but the weight of the nose does not.
you'd have to trim the nose down as speed increases since the wings would produce more lift (proportional to the square of the speed) and you'll start climbing if you dont.
It has nothing to do with the location of the center of gravity and direction of the force induced by the elevators. the both increase propotionally and net moment is constant.
I dont know how real planes are built but having the center-of-gravity infront of the wings' center of lift is less eficient in terms of drag and maximum turnrate.
Bozon
-
Originally posted by Seeker
There are some (mainly canard) designs where the tail contributes lift, but for all the designs we're interested in WWII aviation, the tail does indeed supply a downward turning moment and does not contribute lift.
Read what I said again, and we're arguing the same point. I wasn't talking about turning moments, just straight vectors. The CG sits between the lift vector of the wing and the lift vector of the tail. Thus, the wing provides a positive (upward) turning moment, and the tail provides a negative (downward) turning moment. But both create lift. Canards create lift too, and are mainly useful in delta wing designs where there is no tail and the CG sits forward of the wing lift vector.
-
how much lift create a horizontal stabilizer compared to the wings ?
I mean the purpose of the stabilizer is more attitude control than lift or I'm mistaken ?
-
You're right straffo, it doesn't produce very much lift compared to the wings. The amount of lift produced is a function of, among other things, the surface area of the airfoil. The more air passing over it, the more lift you get. Since the horz stab is a fraction of the area of the wings, you only get a fraction of the lift. The whole purpose is just to keep the airplane in equilibrium, because if there was only one surface on the plane producing lift, the CG would have to stay right dead center on the lift vector at all times (otherwise you'd have rotation about the CG), and we all know that doesn't happen.
-
Thank you !
I know it's not directly related to this thread but I've found some nice and funny littles images to explain how the commands work :
see here : http://www.chez.com/shgente/histoire/vole1.html
-
Wow straffo, RED X in French really says a lot... :)
-
fek ...
No problem , I'll scan my crayon book tonight :p
-
Hey guys, you are talking about airplanes having a normal or positive stability design, while there are also airplanes with a relaxed stability design or Unstable (one overall the F16 Falcon) in wich the tail is used exactly opposed to the normal stable airplanes.
In theese airplanes (tending to drop their backs) the tail is used to raise the back so increasing the total lift, while the others have to pitch dn the tail to increase the AoA so loosing precious lift.
But why some are stable and others unstable planes ?
Because of the position of the CG related to the main lift vector.
If the main lift vector is applied infront the CG, then the plane tend to drop its back so it is called unstable, while if the CG is infront main lift vector the plane tends to drop its nose and it is called a stable plane.
If you can build a paper plane, you can test this soon, just moving a little weight from the nose to the tail, and you will see the more the weight comes near the main lift vector, the more the plane is transforming from a diver to a glider.
When the weight comes behind the main lift vector, the plane become uncontrollable at all (it just needs a flight control computer to fly stable to prevent it noseup tendency) just like the F16 Falcon does.
So this is the reason the F16 is one of the most meneuvering aircrafts, because it is unstable and its flying abilities are controlled by a very fast Flyght Control Computer, but if unfortunately the flight computer crashes (then the Augmentation Stability Control System = ASCS doesn functions too) the pilot will die almost instantly (someone said the accelerations doubles every quarter of a second or more so in 1 sec you hit 8G that's a kind of dive against the wall).
A fast computer controlls all the aspects of the flyght in a F16 but, a fast computer is nothing without a fast mean to transmits all the commands tho the control surfaces, so here is the Fly by Wire.
All the commands are sent to the control surfaces by means of cables that serves electrical motors (not hydraulic piping or direct connection with the stick).
I was reading of some F16 pilots get confusin seeing the tails moving constantly up and dn while the stick was held fixed for the horizontal flyght. The flight control computer were doing its job trying to maintain the aircraft inside the flight envelope.
I'm sorry for my bad english, I hope in your intelligence if I was not too much clear.
What a strange thing to talk about the F16 in a WWII forum ;) :) :D :cool:
-
Originally posted by GScholz
How would you know?! (sorry, couldn't help myself ;))
Wow, you need stereoscopic vision to get a drivers license? Here they let one-eyed ppl drive. They just have to have their head on a swivel to cover their blind side.
You can't judge a 100 meter distance? I find that odd since I do that with one eye all the time, 200 meters and 50 meters too (pistol/rifle shooting).
This is just from stuff I read (cause of my eyes). Apparently stereoscopic vision is the dominant factor out to 20 feet (ie other cues hardly get a look in). At 100 feet the balance changes to textural and other cues. However stereoscopic vision does come into play beyond 100 feet with objects in motion.
As for me not being able to judge 100 metres, yeah its wierd. But perhaps your stereoscopic vision gives you a benchmark for one eyed views. Some of the stuff I've read indicates that people with binocular vision still have way better depth perception than those who have only ever had non-binocular vision. ie if I guy is born one eyed, his vision will always suck, whereas if his eye got poked out when hes 20 he'll have a reasonable level of depth perception.
Its a complex thing, medical science still doesn't understand it fully. Take me for example, I regained vision in my right eye but never regained the stereoscopic vision.
When shooting you can hold a rule to my pattern vertically and ever hole will line up perfectly (just my breathing sucks).
-
MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?
-
Originally posted by Straiga
MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?
A proper rebutal would have been better than a personal attack/insinuation
-
(clipped out this part to respond to)
One of the major changes we’ve made is how we model the forces on the plane. We wanted to increase the number of force points by about an order of magnitude or even more if necessary. For example, prior to this the wing was split up in large chunks with the applicable forces applied to each chunk. In level steady flight this is fine, but it shows its limitations when you get outside of it. Now we have it split up into a lot of small pieces...
The biggest problem flying in WWIIOL was the number of objects apparently being sent to my FE whenever I entered a sector or overflew a town with bunches of GV's below... My framerate would literally go to 1 (thats, ONE) FPS until I cleared out of the area. This may have been a function of Cornered Rat Software trying to send me too much information/update about the relative states of all the little bitty sections of armor on a tank that they kept track of for "realistic" damage modeling purposes (x the number of GV's that were down there) --- but it truly sucked to be in a Stuka divebombing and not even be able to get a screen refresh between the time you dropped and the time you AUGURED.
Be really careful (please) about sending too much data for all the surfaces of all of the objects you are trying to make more realistic. Otherwise, it'll be even more bogged-down in a major furball than it already is...
-
Hyrax81st the problem you're experiencing is completely different.
What HTC intend to do is increase the fidelity of the flight model. Each aircrafts flight characteristics are only modelled on the local PC, with positional information being sent to the server. So no this won't kill your framerate.
In WW2OL there are many factors involved in the framerate killing. The biggest being the code itself, many believe its not very effecient (and I'd agree). The landscape and towns also load as you fly over, and I get the feeling other objects such as tanks do as well. I believe some objects also cause framerate hits because of the number of facets vs the engines effeciency (in the early versions of WW2OL you could figure out where inf or tanks were hiding by moving your gun around and watching the FPS go down). If you don't have sufficient RAM to cache objects you notice immediate framerate hits. CRS have stated the intend to address the issue with the new graphics engine they're working on, and are looking at reducing the type of object data sent to aircraft vs infantry vs tanks.
Playing ww2ol makes you appreciate HTCs effecient code and damn fine netcode (in AH cons don't disappear for 30 seconds).
-
I perfectly agree with you about WWIIOL that's the reason I didn't get the account in that game.
Friends of mine having PCs much more performing of mine had the same FPS problems of me so it seems not to be the PC causing problems like instead the code does.
-
Originally posted by Straiga
MJOLNIR your wrong I learned this stuff when I was 14 taken my private written exam. Are you a pilot? I mean a real pilot?
Straffo was right, but since you ask, yes, I am a pilot IRL. Since this line of discussion really has no bearing on what Pyro was asking for (he obviously understands aerodynamics), how about we move this to the O' Club if you want to continue your charade? I'll keep an eye out for your thread.
-
Todays jet fighters are built very unstable. The cg locations are vastly different between airplanes . Cg locations can change in flight.
Swept-wing configuration airplanes (F-14s-F-111s)on these airplanes the center of pressure moves in a far range for and aft and so can the CG. Augmentation computers make the planes able to fly correctly. The more unstable the more manuverable.
In WWII there where no such computers. Planes vary in weight, size and shape. Some airplanes where stable and easy to fly some with a lot of dihedral in the wing, some where not that easy to fly. Due to cg locations in relation to the center of pressure determines to a great extent the logitudinal stability of the airplane, either neutral, negative or positive. All airplanes have a cg moment. Some planes can fly out of there cg moment buy burning fuel off, making the planes less stable or some can fly into the cg moment becoming more stable. The horizontal stabilizers on most WWII fighter airplanes where set in an negative angle of attack and the positive camber of the horizontal stab was inverted having the negative camber on top. Producing lift in a downward moment to balance the airplane in flight. The center of pressure of the main wing can move for and aft or increase and decrease depending on the speed of the airplane or changing the camber of the wing (Slats, Flaps) or angle of attack. That is why there are pitch and trim changes associated with airspeed changes.
-
Uhm..........Straiga you'r right except for......F111 and F14 are securely not the most meneuverables of all and so not the most unstable planes actually we could have the pleasure to see over our heads and more, afther that period in wich all were fixed on the forward swept wings they understood maybe the planes could have very good flying performances withouth have to move the wings like birds does (check out for F15, F16, F18, Mig29, Su27 etc, etc).
Some others were designing planes with a sort of forward swept wing that were a one piece wing swepting digonally one tip forward and the other backward very very bad to see (fortunately this was only a prototype).
Others were designing airplanes with inverse arrow fashion (recalling LW projects newer built because of the time tecnology did not permitt that).
And......wife is playin the adunance for dinner.......bye;)
-
When going super sonic lift shifts forward. That's why modern fighters have their wings so far in the back.
-
Clouds Your right the F-111 was not made for dog fighting it was designed for all weather strike fighter using terrain following radar to fly nap of the earth to hit its target. F-14 is quite manuverable for what it is. The tomcat was design to carry the AIM-54. It can carry six and stand off over a 100 miles, than launch all six on six seperate targets. I just used the F-111 and F-14 to show that CG and center of pressure can change with the sweep of the wings.
Later Clouds
-
Uhm......ccvi......the F-14 have two little winglets deploying out from the upper part of the jet intakes and they could have to adjust the horizontal stability during SS cruises if I remember well (tell me if I'm wrong). So it seems, at least in the F-14, this sort of little canards could add a little bit forward lift positioned absolutely forward the CG. Could these devices be used to raise or down the F-14 nose ? I have no infos about this.
Bye
-
Anybody with a PPL or higher should know that the horizontal stab has a negative lift vector, and the reason being stability. With artificial stability (f-16 and other modern fighters) CG can be moved aft so that the tail produces lift.
The most complex of all flying things are birds. They are unstable in all axis (pitch, roll and yaw), can move their cg and lift vector etc.
-
arent we supposed to be giving info to pyro which might be incorperated into the new model? what the hell has F16's and F111's got to do with his request?
Its all very good that you guys know your aerodynamics but please keep things RELEVANT to WW2?
otherwise pyro will not bother reading this thread if it gets filled with irrelevant Flight dynamics. Modern jets dont bear much relation to piston engines.
For me id like to ask pyro if he has factored in the different types of aileron and control mechanisms.
For instance modern stunt aircraft that need stability in lateral and horzontal pitch and roll and yaw control used control rods to connect the joystick/yoke. Only a few WW2 aircraft used this method and the rest used the far less 'crisp' wires and pulleys.
The two aircraft i know of so far that used control rods are the F4U's and the FW190s.
It would seem according to an interveiw i saw with a modern stunt pilot that the control rods give much more precise and instant control.The pulleys and wires systems would also stretch over time and make the fighters lose their crisp handling.
So my question is why do both these aircraft behave almost identically to others when the fact that modern stunt aircraft use control rods clearly points to an added benefit of this method of control.
THe area where we would or should notice this the most is when we have to use fine and delecate control of the aircraft.In vertical climbs as the speed drops off and you allow gravity to pull you over both these aircraft should have a notably better feel to the controls.I would have thought the same thing would be noticable in suustained turning on the limit of stalls.Whereas wire controls would require a slight opersite lock to counter the give in the wires etc the control rod aircraft should have a much more precise feel. How about it pyro? has any of this been factored in?
I know its a small matter but its the small improvements that add up to a superior aircraft. Im not complaining but for the 190 already it has many of its novel features unmodeled. None are major but addded together it soon becomes a rather large chunk of what actually made them special.
For instance in WW2 there were very few aircraft with any form of auto pilot. In AH we all have auto pilot with X,alt X, shift X etc but in WW2 when 190s were introduced it came with one of the first computer autopilots. It handled mixture rates and propellor pitch control among other jobs. This took a lot of load off the pilots mind and allowed him to better concentrate on fighting,Which is what they were there for after all.In AH this clever inovation has no benefit for the 190.Whilst allied pilots were focusing on their engine management it was to the detrement of their SA, not so in AH
It also had an electric fusing sytem for its bombs which could be set whilst inflight by the pilot. This meant timed fused or impact fused bombs allowing for a choice of how the weapon was deployed. This is also irrelevan in AH but was a huge improvement at the time.
The 190 was also supposedly a very stable aircraft at all speeds needing very little trimming.It didnt have adjustable trim because it handled so well they decided to remove tham and use small tabs instead. In AH the 190 needs constant trimming as you increase speed and it also seems to take a longer period to settle from a climb trim to a level trim if you use auto level.Why is this? shouldnt it be very quick to sort out the trim if this aircraft was as good as it seems it was? (plus the control rods mentioned above)
MW50 and GM1 was used by the 190s and these were superb systems.In AH we all have a very similar system of wep for all aircraft but in WW2 many early allied and almost all russian aircraft had no such systems. The La7 for instance had a severe limit on emergency power use.It was a 2 minute limit according to the pilots manual! not so in AH eh? :) .The same applies to many aircraft.The fuel for these systems which affected how long you could use them was also a major factor in favour of 190s etc. They carried much larger supplies than even some of the latest allied types.This meant they had advantage in longer protracted fights.As the allied planes ran out of wep or additives the LW aircraft had more left.
This would make a big difference but with AH's wep system its hardly noticable as any advantage, in fact as the weights of the gm1 and mw50 systems is still modelled they actually work against the aircrafts ability.
The seating position on the 190 was distinctly cambered back to allow for greater pilot tollerance of G's because of his seating position and its used in modern fighters in a similar way,I believe P47s also had this tilted or more reclining seating position yet neither aircraft seem to have any advantage in levels where blackout occours in AH.
I know its small things but they do add up to the overall package.Im ok with the way AH is modelled in wep etc but I do feel it doesnt represent the WW2 systems too well and aircraft with metanol and nitrious in real life have little if any advantage in AH over those that didnt back then in RL.Add this to the other 'little' things and soon you have half the innovations wiped out and you get a less than representive model dont you?
Id like to see all aircraft given their full range of benefits that the real aircraft introduced factored into the model. Things like laminar flow wings or the stukas automatic pull out computer etc. OH and of course the bad things too!
109s and 110s had a sliding leading edge slats that could deploy unevenly at certain speeds and would drag the wings one way or the other and throw off the pilots aim or cause premature stalls.
The me262 throttle was an absolute squeak!! if at certain alts you used it without following the rather delicate rules you would get a flame out and you couldnt restart the engine until you got below a certain alt (19k i think it was from memory).Also slamming the throttle open could destroy the engines. In AH you can do whatever you like in the me262 and this doesnt give us the 'feel' of being in a very new and very tricky to fly and dangerous jet.We can fly like maniacs with no penalties.
just my opinion of course but i feel much has been missed out.
-
Originally posted by hazed-
The La7 for instance had a severe limit on emergency power use.It was a 2 minute limit according to the pilots manual! not so in AH eh? :)
from the pilots manual................. the Ash82FNV was field rated to run 10 mins continuously at 2500 WEP and 30 secs (upon take of) at 2600.
The only referance I have ever seen to 2 mins was recounted by Czech pilots flying the La5 FN.
Also FYI elevator and ailerons on the La7 were actuated thru tubular (rod linkages) rudder was actuated via cable linkages.
-
WOW hazed !!!!...............you post looks huge like the British Encyclopedia is :D
Anyway u said lots of interesting things 4 me.
And.....what do u think about the Me163 fuel dissolving properties had ? (dissolving the pilot I intended) :p
Some time the plane lands intact but.....afther some minutes the pilots didn't get out, why ?.....because him vanished inside the cockpit. GULP!!! :rolleyes: :p
-
Originally posted by clouds
WOW hazed !!!!...............you post looks huge like the British Encyclopedia is :D
Anyway u said lots of interesting things 4 me.
And.....what do u think about the Me163 fuel dissolving properties had ? (dissolving the pilot I intended) :p
yeah if i was HTC id model it lol. you could hear screams and stuff as your pilot dissolves after being hit in 163 :) hehe
Tilt i didnt know that! La7 had control rods too? The 2 minute limit was on a website that had the La7 in detail.I unfortunately lost all my 'favourites' so i cant post it or remember the addy but I got the link from a post in this BB if i remember right. It caused a bit of a fuss when it was discussed in here.(btw there was also a load of info on the LA7 they fitted a rocket to!! it boosted its speed tremendously! can you imagine LA7s running around with rocket boosters!?! :D
EDIT: found the site!!! http://www.btinternet.com/~fulltilt/Engine.html
EDIT:This is your website tilt ! lol I didnt realise. But as you can see
it clearly says it can be run at maximum (2600rpm) for 30 seconds. Even less than the 2 minutes i thought it was. There is a 'Duration' in the list that says 10 mins but i cant see what that duration refers to. I assume this is what you are talking about? 10 mins from the manual? what is the 30 seconds referance all about?
Ive since sort of discovered that control rods and wires would (if recently adjusted) behave similarly.Only when heavy use stretches the wires do the control rods show their benefit.As AH models all aircraft in their factory fresh condition it doesnt factor in to the model.I have to concede i have got the wrong idea about how they would effect flight. They would affect performance if we used the same aircraft over time but not in the instant renew AH spawning :)
However I still feel its a shame in a way that we dont get to see the difference that the autopilot computer and fuse selector and MW50/GM1 systems made in real life. Its not HTC's fault to be fair because faced with the almost insermountable work it would take to somehow model the lifespan of a real engine with the limits it has in real life being totally out of phase with our quick up and go type of play. Perhaps TOD could try to model the realistic lifespans of a particular engine but that would require a huge, and probably unecessary change.Engines last for years! you can overabuse them or look after them and it all affects lifespan.
Tilt now i need to ask another question. If im correct HTC said the wep limits are set as the pilot manuals recommend. Or at least when i asked about this before thats what i was told(probably a customers idea of what it was but i think HTC sort of confirmed it).
Unfortunately it doesnt tally up. Just as you have just said, 10 mins of wep for the LA7 according to the manual? why is it 5 mins now in AH? The current times for wep are incomprehendable to me im afraid.heres a few examples
109 10 mins wep 10 mins to cool
190 10 mins wep 20 mins to cool
P51 5 mins wep 10 mins to cool
P47 5 mins wep 10 mins to cool
SPIT 5 mins wep 15 mins to cool
Hurr 5 mins wep 15 mins to cool
Ive never managed to understand how its worked out.
edit: Actually this is off thread topic Tilt, never mind.
-
Originally posted by hazed-
EDIT: found the site!!! http://www.btinternet.com/~fulltilt/Engine.html
EDIT:This is your website tilt ! lol I didnt realise. But as you can see
it clearly says it can be run at maximum (2600rpm) for 30 seconds. Even less than the 2 minutes i thought it was. There is a 'Duration' in the list that says 10 mins but i cant see what that duration refers to.
Std WEP is the 2500 rpm figure............. the reference to 2600 can only be found in the La 7 manual......I doubt it was ever used in flight.......however you will note that the rev control would have permitted the pilot to set it! regardless of consequencies........
It is also my page refers to the la5FN having just 2 mins of WEP
http://www.btinternet.com/~fulltilt/Perform.html
I will admit this is contentious, if you click on the ! next to the 2min figure you will arrive at some speculation on my part and the reason it is given.
I do not know how HTC arrived at the WEP ratings given........... I do like them linked to engine temperature as IMO this would indeed have been the parameter the pilot would have watched. (in this case it {air cooled radial}would, I think, have been oil temp and pressure).
In a thread elsewhere we have discussed the niceties of WEP via over rev and WEP via additive injection (water, methanol, NO etc) and how it would be neat to have them replicated.
Re rods and wires........ I know its my imagination.... but some times it seems to me that after prolonged periods of very high G my turning ability is reduced.............. I think it probably has more to do with my inability to rid myself of what ever is on my 6;)
-
ahh ok my bad, i said La7 when i should have said La5.
I wont go over the wep business again.I had my bellybutton chewed off by hitech for asking before so id best drop it :) leave it to someone else to ask :) tilt :)
-
Originally posted by clouds
Uhm......ccvi......the F-14 have two little winglets deploying out from the upper part of the jet intakes and they could have to adjust the horizontal stability during SS cruises if I remember well (tell me if I'm wrong). So it seems, at least in the F-14, this sort of little canards could add a little bit forward lift positioned absolutely forward the CG. Could these devices be used to raise or down the F-14 nose ? I have no infos about this.
Bye
The winglets "pop out" to adjust the center of lift when the wing sweeps, and are not adjustable in any way by the pilot or flight control system.
And yes, hazed, it is off the subject.
-
He's absolutely right about the horizontal stabilizer. It does, indeed, produce a DOWN force to counteract the FORWARD CG of (almost all) planes with a tail in the back. I think the bleriot monoplane is an exception.
Look at the flight manual for any light plane. The center of lift is AFT of the center of gravity.
Canard planes like Beech Starships and Velocitys have a canard that Lifts UP, and that's one fo thereasons they are more efficient designs.
The private pilot books produced by Gleim (or is it Gliem) explain this stuff in the chapter on aerodynamics. It is published fact.
-
Tilt
Have not been to your page in a while. It is really great. Nice editions and the citations are much appreciated.
-Blogs
-
ya got autolevel, autofly (comb trim), auto speed, auto that , auto this, dive bombing buffs, buffs flying thru hangers upside down, 10 million yard killing and ya'all fighting about this topic of torque and airflows?
LOL
god knows all the other odd stuff with the fighters, who cares about the airflow
-
Hope you guys look at the A6M's drag numbers. These must be among the most lightly wingloaded aircraft in the game, yet I've never been able to glide one to a deadstick landing...
-
yet I've never been able to glide
Reduce your RPM to minimum, glides quite well ;)
Definition of a minimum: "A short British mother" :D
-
Thanks Weav, will give it a try...
-
oboe wing loading dosn't realy effect glide directly, glide distance is a function of L/D.
HiTech