Trim!

[straffo]

I don't think so, if the designer of a plane spend time and money designing a aileron trim it's certainly because it has a purpose.

I don't know IRL but in AH when diving the 190 show a tendancy to roll and ailreon trim is very usefull to counter act this roll.

[Straiga]

Stop the roll with rudder. So why does it roll to begin with. I dont think its modeled right.

Airleron trim is useful for fuel embalance, one bombing hanging on the plane, good for multi-engines with an engine out. Alot of WWII planes did not have certain trims at all.

 Straiga

[Kaz]

All planes are different. You should check out what the Combat Trim is doing in all the different planes in varying situations.

[Straiga]

Iam sorry I dont fly combat trim on, so I dont know.

Straffo one prob you might have is you dont know IRL. I know different airplanes fly differently. But I also know, that a plane that has to fly with aileron trim to keep it flying true, wings level creates a lot of drag on the airframe.
  So here we have a plane in straight and level flight with right aileron trim induced to counter torque, which makes the plane yaw to the left because of the aileron deflection.
  Now understand the right aileron is deflected up, which decreases lift on that wing which inturns increases in airspeed, because a decrease in lift,  is a decrease in drag. So the wing moves forward, and pushing the nose to the left. The left airleron is deflected down which increases the lift on that wing, a increase in lift is also a increase in drag, which also decreases airspeed, so the wing moves rearward, which also moves the nose to the left.
  So now the planes yaws to the left,  just because of aileron deflection. Now to counter the yaw you need to use right rudder to center the ball.

 Now in real life, aircraft maufactures try to design airplane to fly with little trim as nessasary which decrease drag because of induced drag from the flight controls. The less trim needed is good for a more efficeint airframe. Plus at cruise airspeeds and unaccelerated flight the airframe is rigged to fly as straight as possable with out trim, it still might need some rudder trim and elevator trim for a given pitch or airspeed. The airframe should counter the torque as much as possible which is at it lowest point in straight and level unaccelerated flight.

 Wouldnt it be more efficeint to have the ailerons nuetral and to counter torque with rudder alone, if torque was increased or decreased. What I described above is ailerons deflected and more rudder then nessasary being used to counter the ailerons and the torque. Think about that, the planes yawing to the left because of the aileron thats countering the torque and now you have to add more rudder then nessasary to counter the torque and the aileron deflection together, just to have directional stability. Look at all the induced drag. Why not just use rudder alone.  

 Just a reminder torque is at its greatest on takeoff and at anykind of power increase to a varying degree. In straight and level flight unaccelerated, torque is at its lowest point. The airframe is designed to fly true, at the airplanes best cruise airspeed with little trim.

 I have read that ME-109 pilots had no rudder trim tabs at all in some models, so how tired do you think his right foot gets, but theres no mention of aileron deflection to counter torque to keep directional stability. I guess these guys turn more to left and desended then climbing right turns, I guess because of there dead right feet.

 Straiga

[stantond]

Here is a relevant article I looked up on the F4U flight characteristics detailed by a former pilot.

http://www.museumofflight.org/news/newsletter/Aloft_MayJun04_p09.pdf

Torque roll causes a plane to roll in the direction of the engine rotation.  For single engine aircraft, such as the F4U, that is along the longitudinal axis.  Ailerons on the wings counteract that motion by creating aerodynamic forces to cancel the torque forces.  Yaw is created because of the aileron positions, as described above.  

Torque roll will cause a plane to bank without aileron input and more rudder would be needed to get the plane to 'crab' through the air and maintain a straight course.  That would cause more drag than applying ailerons to cancel the roll with rudder to correct for the yaw offset.

I will offer a suggestion.  Adjust the dead zone on your stick.  Adjustments are available in AH and under the games controllers section.   All controllers drift slightly and the 'dead zone' adjustment is to compensate for the drift.

The 'problems' you are seeing in AH are most likely due to your setup.  High end controllers, such at Thrustmaster, CH Products, etc. offer alternate ways to trim out your controller.  After all, that is what you are doing.  The only piece of hardware available to adjust is your controller.  The plane is virtual.

Regards,

Malta

[straffo]

Straiga  from an complete unscientific view (and backed only with my intuition ) wouldn't it be more efficient to counter roll with aileron trim than rudder ?

[muerto]

Wouldnt it be more efficeint to have the ailerons nuetral and to counter torque with rudder alone, if torque was increased or decreased. What I described above is ailerons deflected and more rudder then nessasary being used to counter the ailerons and the torque. Think about that, the planes yawing to the left because of the aileron thats countering the torque and now you have to add more rudder then nessasary to counter the torque and the aileron deflection together, just to have directional stability. Look at all the induced drag. Why not just use rudder alone.

Whether it's rudder trim or aileron trim, using trim creates drag.
Torque creates a rolling effect that would be counteracted with aileron, and aileron trim if it were available.
P-factor and slipstream effects would normally be corrected with rudder.
Rudder can be used on some aircraft to correct for rolling moments, but this is dependent on the aircrafts stability about the longitudnal axis and if this means yawing the aircraft to counteract roll it can be far less efficient than correcting with aileron (the slip skid indicator can give you an idea of whether or not rudder is efficient.)

Ideally an aircraft will be rigged so as to need only minimal amounts of trim; but only in one phase of flight (usually at normal cruise speed) and obviously an aircraft can only be perfectly rigged at one pressure altitude, airspeed, weight configuration; so trim is a neccessary evil.

I don't agree with your evaluation of AH trim. Compared to any other PC based flight sim I've used (and the list is extensive)  my opinion is  the AH flight model, overall, is the best I seen in any flight sim; especially when compared in the slow flight and stall regimes.

I would suggest that the trim position indicators actual position be ignored and the aircraft trimmed so it flies straight with minimal control input.

I don't use combat trim.  I usually autotrim most aircraft on speed = 220 before entering into combat.  I rarely ever need to touch the trim again after that unless I'm going on an extended climb or level cruise (and either case usually only requries elevator trim, or minor aileron trim if the speed has changed dramaticaly.)

[Straiga]

The later models 0f the F4U had the engine mounted nose down and to the right which is offset from the logitudenal axis (the crank shaft is not inline with the longitudinal axis), this is why aileron and aileron trim is not needed for takeoff. This was another way to rigg the airframe to counter torque. There is a lot of airframes designed this way.

 Yes Torque is a rolling motion counter clock wise to the prop rotation, not in the same rotation of the prop [stantond]. But how do you counter torque on the ground (were torque is high), when at a zero airspeed there is no airflow across the airlerons(w/rudder). Airlerons become effective, only when enough airflow moves across the wing, this happens at about 45 -50 MPH, so until this happens how do you counter torque on the ground (w/ Rudder) and also an even application of power.
  Also you can not roll an airplane over on the ground. You can only ground loop it. You will compress the left landing gear strut which creats friction on the tire and pulls the airplane to the left and ground looping it, with to much torque.

Using rudder alone to counter torque is not crabbing its called directional control. Rudder can be used to roll an airplane very well with out aileron. It can also be used to counter torque roll well.

  Do I understand, would you guys only use aileron only to counter torque?

  Then how can you hold a heading?

  How do you counter yaw due to aileron deflection?



 I have taken a P-51D and set the trim for takeoff based of the POH (pilots opperating hand book), which is
Aileron trim Nuetral
Rudder Trim 6 degrees right
Elevator trim 2 degrees up

Then I go fly.
 
  In AH the trim setting should reflect this but look at it on autotakeoff, its not even close. The trim shows elevator nuetral (no torque countering at all) Airleron trim, it should be nuetral but its trying to counter torque (so it shows to the right), but how can this be if theres no airflow across the ailerons to be effective to counter torque. Elevator trim goes full up when trimmed for autoclimb for Vy.
 In a real P-51D if you trim for Vy you would still have 7 trim wheel revolutions nose up left, but not full up like in AH. The real P-51 Vy, its only about 1 degree up trim. The Vy on my dads P-51 dosent match Vy in the book. Its gross weight is less than that of a factory P-51, so it has a better Vy.

 I wish you guys could fly the real P-51D, I have, and my experiences flying it is what im telling you about. Yes torque is a rolling moment, and when your in cruise and adding power, and increasing torque, believe me it can be countered by rudder only.

 This is what the trim is set at for a real P-51D at cruise
Rudder 3 1/2 right
Elevator 4 down
Aileron nuetral

Look what AH shows.  This is what I dont understand. If this is supposed to be a real accurate sim about WWII fighters than explain something like this. I cant get any body who can explain this. The turn cordinator and ball with the trim tabs should show accurately what the plane is doing in flight. Shouldnt it?

After I trim the P-51 for cruise, now I can go dog fighting and use rudder pedals, some elevator trim and just move the stick were I want to go.

 Straiga

[muerto]

The later models 0f the F4U had the engine mounted nose down and to the right which is offset from the logitudenal axis (the crank shaft is not inline with the longitudinal axis), this is why aileron and aileron trim is not needed for takeoff. This was another way to rigg the airframe to counter torque. There is a lot of airframes designed this way.

I don't know for sure, but I thought the down and right canting of engines in their mounts was to off set to combined left turning forces of torque, p-factor, slipstream, and the canting is set to balance the forces at cruise airspeeds.

Yes Torque is a rolling motion counter clock wise to the prop rotation, not in the same rotation of the prop [stantond]. But how do you counter torque on the ground (were torque is high), when at a zero airspeed there is no airflow across the airlerons(w/rudder). Airlerons become effective, only when enough airflow moves across the wing, this happens at about 45 -50 MPH, so until this happens how do you counter torque on the ground (w/ Rudder) and also an even application of power.
Also you can not roll an airplane over on the ground. You can only ground loop it. You will compress the left landing gear strut which creats friction on the tire and pulls the airplane to the left and ground looping it, with to much torque.

Agreed, you counter left turning forces on the ground with rudder.  The propeller slipstream over the rudder is your only method of controlling direction at the start of the takeoff roll.' With the wheels planted firmly on the ground the aircraft isn't prone to roll.  (Although I know I read somewhere in some very high power aircraft, such as the P-51, a sudden application of full power could produce enough torque to flip you over when the aircraft is sitting on the ground.)  Proper use of controls in taildragger aircraft do have you use aileron deflection as well as rudder to counter crosswinds (something we don't have to deal with in AH.)

Using rudder alone to counter torque is not crabbing its called directional control.

On the ground this is true

Rudder can be used to roll an airplane very well with out aileron. It can also be used to counter torque roll well.

Depends on the aircraft.  Rudder can be used to roll most aircraft and is the recommended method at certain times (while recovering from a stall for instance) but in most aircraft I've flown (and I have never flown a WWII fighter) rudder is not an efficient way to roll into or out of a turn.  However, some of the older aircraft I have flown do like you to lead the turn with rudder and use only enough aileron to keep the turn coordinated (as compared to most modern GA aircraft which like you to turn using aileron and keep it coordinated with rudder.)

Do I understand, would you guys only use aileron only to counter torque?

Then how can you hold a heading?

How do you counter yaw due to aileron deflection?

In the air its all a matter of aileron and rudder coordination.  If something is out of trim and is causing the aircraft to roll, correct with aileron and/or aileron trim.  If it's necessary to use rudder or rudder trim as well to keep everything coordinated adjust that as well.  Likewise if something is out of trim and the aircraft is yawing, correct with rudder and/or rudder trim, and again, it might be neccessary to also adjust aileron trim.

I've heard some people talk "aileron does this and rudder does that" and the truth is that each control has a unique function, but nothing is ever cut and dry where you can change one and not have to change the other, however minutely.

On the ground, use rudder to track straight during takeoff and after landing.  In the air, use both all the time to keep the plane flying coordinated.

I have taken a P-51D and set the trim for takeoff based of the POH (pilots opperating hand book), which is
Aileron trim Nuetral
Rudder Trim 6 degrees right
Elevator trim 2 degrees up

Then I go fly.

In AH the trim setting should reflect this but look at it on autotakeoff, its not even close. The trim shows elevator nuetral (no torque countering at all) Airleron trim, it should be nuetral but its trying to counter torque (so it shows to the right), but how can this be if theres no airflow across the ailerons to be effective to counter torque. Elevator trim goes full up when trimmed for autoclimb for Vy.
In a real P-51D if you trim for Vy you would still have 7 trim wheel revolutions nose up left, but not full up like in AH. The real P-51 Vy, its only about 1 degree up trim. The Vy on my dads P-51 dosent match Vy in the book. Its gross weight is less than that of a factory P-51, so it has a better Vy.

I wish you guys could fly the real P-51D, I have, and my experiences flying it is what im telling you about. Yes torque is a rolling moment, and when your in cruise and adding power, and increasing torque, believe me it can be countered by rudder only.

I wish I could fly a real p-51 too!  Do you have access to one? Are you offering?

This is what the trim is set at for a real P-51D at cruise
Rudder 3 1/2 right
Elevator 4 down
Aileron nuetral

Look what AH shows. This is what I dont understand. If this is supposed to be a real accurate sim about WWII fighters than explain something like this. I cant get any body who can explain this. The turn cordinator and ball with the trim tabs should show accurately what the plane is doing in flight. Shouldnt it?

After I trim the P-51 for cruise, now I can go dog fighting and use rudder pedals, some elevator trim and just move the stick were I want to go.

Straiga

As I said earlier, I'd ignore what the trim indicator settings look like, and make whatever adjustments need to be made to make the aircraft fly right (both in AH and in real life)

AH isn't a perfect P-51 simulator (or simulator of any particular aircraft.)  I think you are expecting too much of it.
IMHO, Hitech and company have done a great job with the flight model as a whole.  I think they've also done a great job with relative aircraft performance. Then they took these simulated aircraft and put them together in a way that allows huge numbers of people to get together and kill each other in them on a fairly level playing field despite the vast differences in internet connection types and PC performance.

I guess what I'm saying Straiga is that while I see your point about the AH P-51 not operating exactly as the real P-51 POH says it should, over all though it still performs like a P-51 (or that I'd imagine it does.)  There is a place in Florida that will let you fly a P-51, but it is thousands of $$$ for a 1 hour flight.  Too rich for my blood.  I asked them what you can do while flying it.  The responce was "anything you like."  I guess its a tough aircraft to break.

[Straiga]

I just trying to find answers about my questions this was said to be avery accurate flight sim. They spend more time a guess on the roll rates and other things, but showing what the trim does in the airplanes I guess it wasnt aprority.

 Yes my dad owns a P-51D and I have about 560 in it. It takes about $3400 an hour to fly w/ fuel, maintainance, insurance.

 Straiga

[Kaz]

Straiga I noticed something while taking off in a 109. I was watching the control surfaces and combat trim movements.

They did not correspond to what was actually happening. CT showed almost full right aileron deflection but the ailerons showed little movement.

What was interesting about this was the rudder movement, I looked out back and the rudder was almost fully deflected as was expected to counter torque as speed built up CT showed rudder neutral or almost neutral.

Try it out with the P51 maybe you'll get similar results. In other words as muerto hinted at (if I read correctly). The trim position may not be showing what's actually happening.

I don't agree with your evaluation of AH trim. Compared to any other PC based flight sim I've used (and the list is extensive) my opinion is the AH flight model, overall, is the best I seen in any flight sim; especially when compared in the slow flight and stall regimes.

I would suggest that the trim position indicators actual position be ignored and the aircraft trimmed so it flies straight with minimal control input.

[Straiga]

Thanks Kaz

Thought it was just me.

[stantond]

Stragia,

I never meant to imply you were wrong (although only using rudder to counter cruise torque I still don't understand).  AH has a flight model where trim is incorporated.  It is not perfect.

Picking on the flight model will not make it better.  Providing information from the pilot’s flight handbook for the P51 may be useful in making an argument for a change.  Also, and I mean this sincerely Straiga, have you ever considered taking a creative writing course?

One thing I have found for all Military Generals, such as your dad, they can communicate very effectively!  Your writing skills could be better.  I know mine can improve and I am working on that.

It would be nice to see the AH flight model become even more realistic.  However, I have neither the time nor energy to pursue that goal.  Seeing torque roll would be really cool, but it's an isolated aerobatic maneuver that I can live without.

The trim indicators can have a visual effect on the control surfaces.  One of the ways to get a damaged plane back to base is to use full trim to compensate for a loss of aileron and wing surface.  You can look out the window and see the (remaining) elevator physically deflected under those conditions due to trim.  

Having aircraft flight manual information and comparing it to what is seen in AH could make for a compelling argument.  Conveying the information may be the most challenging part of that goal.  Fwiw, I am pretty sure the F4U ‘torque’ rotation is backwards in AH.  However, since torque is not modeled to affect the roll rate or vertical stabilizer offset for normal cruise, rotational direction is not important.

I would be happy to see the trim system revised, but like torque direction, its imperfections do not significantly affect the flight model.  That is not to say it is not important when flying a real plane. The AH flight model is not perfect, but as I have said many times before, it’s the best I have found.



Regards,

Malta

[hitech]

Stantond: Torque is completely modeled and is not backwards on the f4.

HiTech

[muerto]

HiTech, do you have a list of the V speeds used for the AH aircraft that you could publish?  It would be nice to know Vy for all AH aircraft.