Constant Speed Props

[Tilt]

Sorry if this shows my ignorance........... but if torque forces are applied forward of the  centre of lift/centre of gravity would this not produce some yaw?

Particularly if one of the wheels became the off centre axis around which the forces were balanced.


A force vector diagram would show this.

[flakbait]

HT, you're trying to explain something to the same guy who can't tell the difference between an EPR gage and a torque gage. Keep that in mind; we don't want you blowing a gasket from frustration.



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Flakbait [Delta6]
Delta Six's Flight School
Put the P-61B in Aces High

[Straiga]

Pyro,
 Go to this web sight and learn something about how the real airplanes fly. Watch this film on the characteristics of the P-51. This is an actual training film for the pilots.

This is part of the real P-51s pre-takeoff check list
< Elevator trim set to 2 degrees nose hvy
< Rudder Trim set to 7 degrees nose right
< Aileron trim set to 0 degrees

1. Listen to what the pilots say about the normal use of rudder on takeoff to counter torgue but nothing about airleron which the trim is set to 0.

2. Hitech listen to what the pilot says about prop over speed.

3. Not one time during this hole flight does he say anything about triming the airplane about the roll axis but only in a high speed dive this is because of the +1 degree on incidence on the right wing and trim he said is very little.

I have argued this point about torgue but nobody would believe me, I do know what Im talking about. I can give you technical discription of how torgue effects an airplane so you can understand it better.

After viewing this film can someone correct the aerodynamics modeling in AH 1

 Heres the web sight    http://www.zenoswarbirdvideos.com

And watch the Characteristics of the P-51

Later

[hitech]

Gasket blowing time.

have argued this point about torgue but nobody would believe me, I do know what Im talking about. I can give you technical discription of how torgue effects an airplane so you can understand it better

Please enlighten us clueless dolts. We might even belive you if you make a valid argument.



HiTech

[Straiga]

Here we have a p-51 sitting on the runway with the engine running at idle power. Now advance power smoothly and evenly and we use directional control (rudder) to maintain center line.
 Torgue ,p-factor, prop slip stream, and gyro procession are all the left turning translating tendencies on the ground. This is the definition from the book of advanced naval aerodynamics.
 Torgue trys to roll the airplane on the ground in a tail dragger, but whats happens is that the left main landing gear is the pivot point for the roll moment or leverage. The left gear is compressed somewhat because of the roll force applied this depends on the amount of torgue present, this then translates into a left turning tendency because of the friction or drag from the left landing gear. If there was not enough rudder force to counter this left turn force the airplane will ground loop.
 Hitech call those guys that gave a P-51 flight. I know they didnt let you takeoff or land due to insurance purposes and I know you dont have an LOA, but have one of those pilots discribe to you in detail a takeoff in the P-51 and show them this video and see how accurate it is. Ask them all the questions you want, ask them why they use rudder on takeoff and in the air to counter torgue, you dont have to listen to me. In fact im getting tired, I gave you prove of a training film that talks about using rudder for takeoff but I guess this goes against your religion sorry.
 Let them fly AH 1 and let them tell you how incorrect, you use aileron trim. For some reason I dowt you will contact anybody, I would if I wanted to find the truth if someone was saying something else than what I beleived.
 Torgue is a rolling moment in the air, on the ground it is a left turning moment. Both in the air and on the ground this force can be overcome by the use of rudder at graduall power changes. If rudder is at full deflection because of excessive torgue the plane will yaw and roll due to excessive sideslip. As pilots we fly the airplane we dont let the plane fly us so we manage the forces applied to the airplane.

 


Well got to go fly later

[Straiga]

Gripen,
 How do the ailerons work when a plane is in a 0 airspeed hover when there is no airflow over the wing there worthless, it like a parked airplane move the ailerons they dont do anything, same as with rudder and elevator nothing, try rudder or elevator for some control they sit in the prop stream they have an airflow going over it. But if it exceeds rudder authority the plane will roll opposite torgue with no control authority. See you can start a roll with rudder. I used to fly RCs with no aileron just elevator and rudder with a little dyhedryl.
 But this is not what were talking about, forward airflow acting on an airplane will be a yawing /rolling moment if rudder authority is exceeded due to excessive sideslip.
 If you were to just use aileron to oppose excessive torgue with out rudder you would roll right aileron in and the left wing would create more lift and drag, then the right wing and the ball would be to the inside of the turn. If you did use rudder it would be right rudder to cordinate preventing sideslip. But were not using rudder at all at this time. So were not cordinated, if you were to use more aileron in this situation it would get worse in the sideslip.
 The nose of the airplane at this time has been moving to the left with a left wing high slowing down because of lift and drag and the right wing speeding up because of less lift and less drag turning the nose of the airplane to the left in a yawing or left turning motion because of sideslip, and because of torgue moment in front of the CG and because of no directional control (Rudder).
 Now if torgue exceeds the full aileron deflection or control authority you are already in a yawing motion, and also at a high bank angle at a given time, and airspeed is probably decaying, torgue is exceeding aileron control and it will start to roll the airplane opposite to the rotation of the prop. Now you have probably stalled one wing because of excessive sideslip. When this happens  you will get into a rolling motion, and the plane would roll over on its back and get way out of control. Controlling the airplane at this time would be to stop developing torgue, (reduce power) so you can have aerodynamic authority again.        
 Pilots dont let there airplane get out of control like this, if they cant help it.
 A pilot during a managable power increase or power decrease would just use rudder to cordinate the ball, and aileron would not have even be been needed.
 Remember when you use aileron you have to use rudder in the same direction to be cordinated. This is directional control.
 If there is a power change and rudder can cordinate the ball, you should not even feel a roll moment.

[hitech]

Never mind, getting tired of the subject changing.  Because in that whole disertation you have said.

1. Eng torque produces a roll moment.
2. Correcting with ailaron produces adverse yaw .
3. Advserse yaw is controled by rudder.

 
HiTech

[Straiga]

Im sorry Hitech, in the last string I was trying to talk gripen, to give him my view about what he was talking about.

 People told me it would be a lost cause, I have talked to other pilots who fly for a living and do play AH which I have met them on a regular basis when I have flown in and seen them during work and we will sit at lunch or just hang out or something and talk about AH. Truthfully we laugh alot of the time about a lot of things that happen in AH. I have been told from these guys that they have been flying for years and that things will never change. I was told there making there money and what do they care. In there view. I try not to believe this. But we play, because of the friendship and to kill time when Im at work.
 
 I have been sending all the E-mails to my dad to get his take on this and ask If he wanted to address this subject he said he was retired and didnt have time for games.
 
 Im just trying to have a discussion about something and  being open mined about this and see if there is something I can learn from it. By talking about it, it makes you think and you can learn from it. The last string was mostly taken out of the book. If Im wrong im wrong and I would stand up and say Im wrong, Id rather be open minded then close minded.
 It would be better to demonstrate hands on and actually see the outcome, better then typing over the internet and trying to visualize what would happen or have some one else like a professional mustang pilot can explain it better.

 Hey did you ever talk to someone about this? Something tells me you didnt.

 Hey you know, you havent explained in your own words what you think what happens, may be I can learn something. Please tell me indetail. I have no Idea what you think, let me know were your coming from. Explain.

 Why are you trying to be defensive or negative. I havent been, its feals like Im treading on your territory. You must be reading an inflection coming from my script. Thats far from it. Just trying to have a discussion. Sorry!

[gripen]

Straiga,
The hovering capable RC-planes have large ailerons which start directly from the fuselage and the ailerons are usually wider near fuselage to have better controll using propeller slipstream. Basicly you are continoysly mixing together tourque effects and slipstream effects.

gripen

[Straiga]

Gripen, Not RC airplanes I fly. I have two yellow aircraft one F-16 and F-14 both with rossi .91s the f-14 having two, a byron P-51 and a scratch built spit 14 with a five bladed prop running a quadra 3.5 same as the p-51.

 Torgue, P-Factor, prop-slipstream, gyro-precession are all left turning tendancies on the ground. Thats right out of the book for advanced aerodynamics for naval aviation. So you use rudder to counter left turning tendancies. Right!
 Torgue in the air is a roll moment but the way a plane is designed to fly, it can be countered by rudder havent you ever rolled your RC with rudder only I have, so what makes you think rudder cant prevented torgue rolls?  If you use aileron you still have to use rudder to cordinate the plane due to sideslip. Using aileron is a waisted flight controll against torgue, when all you need is rudder when torgue is applied. When an airplane is in striaght and level unexccelerated flight ailerons shoulnd be neutral. Rudder and elevator is a different story. Where do you set your aileron trim on your RCs?

[gripen]

Straiga,
Well, none of the planes you mentioned is so called 3D capable (ie capable to maintain controll during hovering). As an example Shock Flyer is a good example of current 3D RC-plane generation.

The tourque caused by propeller mass and engine moving parts mass causes just rolling moment. The tourque caused by air particles hitting propeller blades causes just rolling moment (which depends on speed and angle of the propeller blade and the plane itself). After that slipstream might cause rolling and yawing moments due to assymmetrical shape of the plane or ground effect (or due to various other reasons; like thrust line and so on).

Seems that you can't see the difference between  tourque and sliptream effects.

gripen

[RRAM]

Originally posted by hitech
...can go both wayes, because I can assue that I have done 4 g accelerated stalls in real dog fights and had the plane snap both ways, including in a p51...

when I grow up I wanna be Hitech . But with better typing skills



Straiga: I don't doubt you might have flown a lot of RC or real planes, and that you think you know a lot about aircraft...but,really, you should FORGET all you think you "know" because, to put it sharply, you're wrong in most of the topics you've raised here.

I would point out where are you wrong on most of them...but it seems it ain't neccesary...just clear your mind about everything you think you 'know' and read what hitech, Hohun and others have written in this thread. And then ask yourself if it makes sense or not...and if it does, then ask yourself if what YOU say makes sense or not.

It's quite a challenging exercise (I know, have had to go through that before and it's hard just to admit you 'may' not know as much as you think, not to talk about admitting that others have been right all the time), but in the end you'll get all your questions answered. And that is what matters.


BTW, accept this advice...don't try to teach Pyro or hitech about aircraft...and certainly don't tell them to read webpages about how do aircraft fly. Because bassically, I think they went past that stage some decades ago





P.D. Amazing thread, very informative. There should be a link in the main page with the best and most informative messages written in the forums about the mechanics of flying. Should help people a lot to better understand what's flying about.

and I'm serious, I think it's worth a thought  

[moot]

I'd do some digging in each forum for a list like that if Skuzzy'd sticky it RRAM.

[Straiga]

Gripen,

 The blade torgue is found to be proportional to a nodimensional torgue coefficient, the air density, the disk area, the square of the tip speed, and the blade radius.  The torgue coefficient is dependent upon the average profile drag coefficient of the blades, the blades pitch angle, and the average lift coefficient of the blades.  The torgue can be thought to result from components of profile and induced drag forces acting on the blades.

 Slip stream is a by product of the average profile and induced drag of the blades, proportional to the blade area, blade radius, air density and the square of the tip speed.  The resultent  acceleration of the volume of air along the fuselage in a flow rotation at the vertical tail.

 Of course I know the difference.  You cant have one with out the other thats why they blend together. The one big disadvantage you have in not understanding the force acting on an airplane is not being able to be at the controls to see and feal the effects of the forces acting on the airframe and what controll actions needed for a given flight maneuver.  Just reading and not applying what you learn about aerdynamics is a disadvantage.

 Go rent a airplane get behind the controls and talk to a instructors about what you believe and see what they say.  You dont have to believe me, but find out from another experienced sorce and see what they say.

 I have been flying for 30 yrs now and I would not say something that I dont know about. Im not lying to you about this, this is what happens.  Dont just read from a book go experience it your self. RCs dont count your not in the driver seat.

 Dont get hook while your flying, its expensive for a pilots certificate.
 Have a good flight!

[Straiga]

RRAM,
 Its what is taught to stundents pilot obtaining a pilot certificate and what I had to discuss as parts of my check ride for becaming a newly FAA designator examiner and check pilot for the company I fly for, now I give the check rides for the company pilots to pass a 135, 121 and ATP check rides.

 Tell us all of the extent of your flying experiences please, so we have a bases for your knowledge, and be more direct on the things that Im wrong on.  So I can give you an appropriate responce.

 Later!