Posted by a P-51 Pilot (real pilot) - couple of issues worth a mention

from Dudley Henriques, a real life P-51 pilot and instructor... posted on another forum..

 

"There is one overwhelming point about the rudder trim on the 51 that should be completely understood by everyone. That 6 degrees of right rudder trim is NOT pre-set before takeoff to solve the forces acting on the aircraft during the takeoff run. You do that with rudder and aileron used in conjunction with a COMPLETE understanding of airspeed and how increasing airspeed increases dynamic pressure on the control surfaces.

What that 6 degrees right trim ACTUALLY gives you is an optimally trimmed out airplane at 46 inches and 2700RPM which is your first power reduction AFTER takeoff. "

 

now... In DCS the trim doesnt really work as a real life trim, what it does and acording to the control viewer (R-ctrl C) is to move the actual control surfaces (aleron elevator rudder).

 

So in DCS moving a trim is like actually moving the rudder. wich is another limitation of DCS

if you look externally all that it is actually moving is the trim

its a limitation of the right ctrl + enter display

nothing more

Just would like to add the rudder preset suggested is not an absolute requirement. I do not touch the trims at all until I have the Mustang in the air. I do virtual airshows and formation take offs all the time and have just gotten used to using rudder input (Saiteks) as needed and can take off in a straight line with the best of them. Its a matter of practice and smooth control.

/Salute

While I haven't read over this entire thread, it is good to keep in mind that if the DCS simulator was able to accurately model aircraft flight in 100% of circumstances then every company and government would be using it for training. There are limitations with anything and with the complexity of aerodynamics I doubt there will ever be anything that can incorporate all aerodynamic phenomenon acting on the aircraft. The Runga-Kutta equation is not even solvable except by supercomputers and even then there is no discrete solution that could be used for an entire aircraft.

I've set a curve of 25 on my rudder axis and never looked back. There are mixed opinions to the takeoff rudder trim setting. Some say 6 degrees, some say 6.5.. I always takeoff 3 point with flaps down and stick held back. When I detect the beginnings of stall, I relax stick forward gently, and up she goes...

I've set a curve of 25 on my rudder axis and never looked back. There are mixed opinions to the takeoff rudder trim setting. Some say 6 degrees, some say 6.5.. I always takeoff 3 point with flaps down and stick held back. When I detect the beginnings of stall, I relax stick forward gently, and up she goes...

I don't find much need for flaps on takeoff unless you are carrying near max weight. Airspeed is much more important while pushing the engine during takeoff.

From what I've seen, THE most important thing to master during take-off roll in the P-51D is the rudder movement. You really just need to get used to anticipating the movement of the nose and feeling out the amount of rudder correction needed. After enough practice it's second nature. (pretty much spot-on with notes from the actual pilots)

from Dudley Henriques, a real life P-51 pilot and instructor... posted on another forum..

 

"There is one overwhelming point about the rudder trim on the 51 that should be completely understood by everyone. That 6 degrees of right rudder trim is NOT pre-set before takeoff to solve the forces acting on the aircraft during the takeoff run. You do that with rudder and aileron used in conjunction with a COMPLETE understanding of airspeed and how increasing airspeed increases dynamic pressure on the control surfaces.

What that 6 degrees right trim ACTUALLY gives you is an optimally trimmed out airplane at 46 inches and 2700RPM which is your first power reduction AFTER takeoff. "

 

now... In DCS the trim doesnt really work as a real life trim, what it does and acording to the control viewer (R-ctrl C) is to move the actual control surfaces (aleron elevator rudder).

 

So in DCS moving a trim is like actually moving the rudder. wich is another limitation of DCS

ive read that comment a while ago already as well....personally i dont touch the trim wheels at all and have no problems at all to get it airborne.

its really only a matter of practice...i still remember the days where it was actually a challenge to take off in the p51,...those days are long gone, and even though it was confirmed several times by Yo-Yo that this is not the case, thinking about those days, it feels as if they have tuned the flight model to make it more easy.

the interesting part of that quote though for me is, that it claims that the plane should be trimmed out with 6° right rudder trim @ 2700rpm and 46Hg mp...well, ill have to try that now, but if i remember correctly, i tried that already a while ago, and with those 6°, the plane is everything but trimmed out...

it feels as if they have tuned the flight model to make it more easy.

It's just you having gotten more proficient with it. Because if they say they haven't touched the FM, they probably haven't.

I just saw this! Great post and thanks for the education. Makes perfect sense and I appreciate the energy you put in it to explain it all. :thumbup:

Just wondering if there had been any follow up on this? I know the wheel covers dropping due to lack of hydraulic may sound 'insignificant', but it should happen but doesn't. Is there any way of getting a ticket raised on this so it can be corrected?

Cheers, MP

Attached is a wartime Technical Order 01-60J-28 on the P-51D/K's flight restrictions.

I have other Mustang T.Os I'll dig out...

ive read that comment a while ago already as well....personally i dont touch the trim wheels at all and have no problems at all to get it airborne.

its really only a matter of practice...i still remember the days where it was actually a challenge to take off in the p51,...those days are long gone, and even though it was confirmed several times by Yo-Yo that this is not the case, thinking about those days, it feels as if they have tuned the flight model to make it more easy.

 

the interesting part of that quote though for me is, that it claims that the plane should be trimmed out with 6° right rudder trim @ 2700rpm and 46Hg mp...well, ill have to try that now, but if i remember correctly, i tried that already a while ago, and with those 6°, the plane is everything but trimmed out...

To me it feels like the ground actually has some friction now. Before it was like the aircraft just slid on ice. I asked not too long ago if something changed (with the WWII aircraft in particular) to affect takeoff but Yo-Yo said nothing. Dunno, maybe we're all just better virtual pilots...

When I serviced a Spitfire during an air show in Germany, the crew said it was all original, except no guns and they a added a modern radio...

so, the info about not being original wartime configuration... just had me thinking about that....

and...re: P-51 in IL-2, the fuel tank behind the seat caused us great problems in IL-2. Oleg flat out refused to fix the fuel problems and totally ruined the flight model.. regarding the fuel load, balance, and order of fuel tank draining...

MP

I found a WW II Training video for transition into the P51B/C. Some of these guys keep referring to the Wartime configuration vs current Peace time. Give me a break! they need to take heed to you guys that have actually flown them and pay attention to these films out here about the P51. I've complained about the characteristics. my big issue is every time I'm I a dog fight either on the offensive or defensive the aircraft goes into a stall even at 300 knots (conducting the Scissors maneuver) WTF, either I'm doing something wrong or like I keep saying which I believe is the actual issue is the programing for their P51 model. I only have a 4 hours in a Piper and 3 1/2 on the ground. but I believe I do understand basic flight and what's happening with this bird make no sense. (

See the video Wolf Rider posted)

the programing for their P51 model.

The DCS P-51? My guess is you're pulling too hard on the stick and thus find yourself in an accelerated stall.

DISCLAIMER: I'm in no way, shape or form affiliated with ED and have absolutely nothing to do with DCS development (and thus can't and won't speak on their behalf), but for various reasons, still have some knowledge about how these kind of processes work. So please read the following carefully:

Of course the FM _can_ be wrong, but in order to get it looked at, you have to come up with something tangible; or in other words, you need to present some unambiguous proof about what you feel is wrong. We've all heard complaints like yours - and they're a dime a dozen, because shouting "this is wrong!" is just whining no-one pays any attention to.

So if you want this to be taken further, first of all present measurements and explain how the data was arrived at.

 

now... In DCS the trim doesnt really work as a real life trim, what it does and acording to the control viewer (R-ctrl C) is to move the actual control surfaces (aleron elevator rudder).

 

So in DCS moving a trim is like actually moving the rudder. wich is another limitation of DCS

Actually, this is not true of DCS, but rather of FSX :-) and that's how the p51d by A2A does it in FSX.

In DCS the correct effects of using the trim tabs are correctly modeled. In one of the axis you can even observe the effect when standing on the ground, stopped.

Set a situation with mild headwind, and apply aileron trim. Your stick will NOT move. Now, save that situation and load it with a strong headwind. You will now be able to observe the stick deflecting.

Just like IRL, the control surfaces will deflect with the trim settings, and that will be felt by the pilot, and, if he leaves the controls by free, they'll move!

MP

I found a WW II Training video for transition into the P51B/C. Some of these guys keep referring to the Wartime configuration vs current Peace time. Give me a break! they need to take heed to you guys that have actually flown them and pay attention to these films out here about the P51. I've complained about the characteristics. my big issue is every time I'm I a dog fight either on the offensive or defensive the aircraft goes into a stall even at 300 knots (conducting the Scissors maneuver) WTF, either I'm doing something wrong or like I keep saying which I believe is the actual issue is the programing for their P51 model. I only have a 4 hours in a Piper and 3 1/2 on the ground. but I believe I do understand basic flight and what's happening with this bird make no sense. (

 

See the video Wolf Rider posted)

How many years have you flown in other simulations?

You see. In simulation, you can't feel what pilot feels. So you can't tell early enough that plane is on edge of stalling. There are light vibrations present. We can only see the strong ones in the sim, and only if we pay attention to the cockpit itself. P-51 gives not too much vibration before stalling. Compared to 190 as an example (because thats what we have) The P-51 doesn't whip over, just drops the wing slightly. When that happens release the pressue on the stick and you continue to fly. Of course all planes are not too prone to spining... but thats another topic that covered that made my Kwiatek in K4 section.

Fly in MPH. The plane was designed for MPH, so you shouldn't switch to knots. It is more 'natural' that way. You can stall your airplane at even high speeds, speed is not going to make you stall-proof. You need to work on your muscle memory.

Is Piper built with semi-laminar flow wing? You can't take your experience of small and very low-powered planes and apply it to monsters like P-51D.

ive read that comment a while ago already as well....personally i dont touch the trim wheels at all and have no problems at all to get it airborne.

its really only a matter of practice...i still remember the days where it was actually a challenge to take off in the p51,...those days are long gone, and even though it was confirmed several times by Yo-Yo that this is not the case, thinking about those days, it feels as if they have tuned the flight model to make it more easy.

 

the interesting part of that quote though for me is, that it claims that the plane should be trimmed out with 6° right rudder trim @ 2700rpm and 46Hg mp...well, ill have to try that now, but if i remember correctly, i tried that already a while ago, and with those 6°, the plane is everything but trimmed out...

I've never dialed in the recommended 6 degrees. I knew about it but I prefer to use my own method.

Prior to take off I trim the pitch to neutral and adjust the aileron dial clockwise until the L mark is lined up with the screw fitting in the bottom right corner of the aileron trim panel. Then I counter the torque reaction manually with right rudder input while building take off speed. Once airborne, slowly reduce right rudder input to neutral and climb out as normal adjusting trim as necesary.

I've also read somewhere you're not supposed to trim aircraft out during a high speed dive but rather control the plane by countering the reaction of the out of trim aircraft by hand but for how long it takes (got my trims bound to POV switch), I always trim out when I can - even during dogfights sometimes.

Quite often during my climb to crusie altitude I'll trim the aircraft out and fly it with nothing but trim.