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

From another thread Swoop73 posted the following:

I only have a very few problems I couldn't fix with the control setup. One is the speed the handbook says to raise the tail at... I think it's a typo in converting from metric, maybe. Why would it say raise the tail at 100 mph when the Mustang comes off the ground at around 80? Then there's the bad swerving that goes out of control when you're up on the mains for take off or trying to wheel land it.

The inner gear doors come down on the ramp after shut down when you pull the T handle, which is correct, but the flaps stay up. They should drop down too as hydraulic pressure is removed from the system. Easy fix, I would think.

I'm well aware of the differences between a real plane and flying at one's desktop with the short sticks we use. That said, here is my wish list to put this amazing P-51 sim over the top and make it unbeatable.

Tweek the steering to be more controllable on take off and landing for those of us who aren't running 50 fps. Most Mustangs now days are wheel landed to keep better aileron control... These planes are close to 2 million dollars now. Yes, everybody landed 3-point in the War but they didn't have to pay for the occasional ground loop.

Every crash including ground loops seems to end in an explosion and fire... Come on, guys... :-)

Accelerated stalls are close but the real P-51 has more pronounced buffet. Also, for all of you saying the Mustang had vicious stall behavior- Not really. It would snap roll in the direction the ball was off but at least in normal stalls, if the ball was centered it would break straight ahead. This sim does model recovery beautifully... just relax the back pressure and you're flying again.

Just a bunch of notes after flying the DCS Mustang for the past 3 weeks. Again, don't jump on me.. I love it and am going to work with darn little sleep some days.

By the way, I'm not saying all this as theory. I have 7.5 hours in a P-51 at Stallion 51 in Florida and the first hour was with Ed Shippley.. Ever hear of him? :-) He'd be the first to tell you you can get the tail up at 60 on take off and track the centerline with razor precision. I have done split S's from altitude, holding Crazy Horse in the stall buffet all the way through. That's an exercise they teach. Take off's and landings? Probably close to 20.

I'll never be able to go back... Burned through my savings... but absolutely love this sim because it comes so close to the real thing. Sure wish it didn't swerve so much on the runway though. :-)

Thought I'd post it here as this I presume is the best place for these issues to be looked at?

Cheers, MP

Great to hear all this, and great to hear someone with _REAL_ Stang experience posting. But was the bird you flew in wartime configuration, because AFAIK that makes a big difference as regards how she behaves too?

Nice read. Thanks MP

But was the bird you flew in wartime configuration, because AFAIK that makes a big difference as regards how she behaves too?

None of the Mustangs flying today are in a 'wartime' configuration.

None of the Mustangs flying today are in a 'wartime' configuration.

Nope because it is not allowed to be by the FAA or the CAA in the UK due to instability in the airframe with the rear tank in place and filled

All the Mustangs I have been in have had it removed.

Pman

Then there's the bad swerving that goes out of control when you're up on the mains for take off or trying to wheel land it.

This was actually toned down to accord for not being able to feel the airframe moving. The feedback you get through just being able to watch the airframe react is a lot slower and less precise than being subjected to the force. Back during the closed beta, it used to be really hard. Now it's just a matter of training.

Nope because it is not allowed to be by the FAA or the CAA in the UK due to instability in the airframe with the rear tank in place and filled

 

All the Mustangs I have been in have had it removed.

 

Pman

I know of one P51 in a wartime configuration. Even the gun heaters. (major fire hazard) I have no idea how its approved by the FAA. I do know it flies regularly.

I would think there is more then one out there in the USA.

I would think there is more then one out there in the USA.

Perhaps, but it is highly unlikely that the one flown by the OP, in a commercial environment, was one of them.

EDIT: I don't mean to take anything away from the OP or his experience.

Arrr, why did I enter this thread :P

Definitely now booking Stallion 51 Crazy Horse flight!

it was restored to North American standards as a TF-51 so not wartime configuration.

but having asked a couple of wartime pilots...the landing flaps did drop when the hydraulic t-handle was pulled after the engine closed down :)

Crazy Horse being a two seater, will have a CoG a bit further back than a regular civvy Mustang, but given our DCS variant has a fuel tank (filled or not, that plumbing all adds pounds) and also has some hefty WW2 vintage radio equipment and IFF gear sat in that position I'd call it about even.

It's the taller fin and rudder which will improve yaw stability and rudder response and make a stock Mustang more squirrelly in comparison.

but having asked a couple of wartime pilots...the landing flaps did drop when the hydraulic t-handle was pulled after the engine closed down

This is good to know. So in the future when I pull the handle to get the gear down with battle damage I will also be prepared for full flaps. Sounds like it might be a bad feature if you are just trying to get the gear down but don't have a lot of airspeed to sacrifice. Everything I had read about the T-handle suggested it was to release the fairing doors.

@Merlin. I understand that the hydraulic pressure keeps the flaps in the selected position. If I am not mistaken, without hydraulic pressure the flaps will be "loose" so they'll probably stay, up or "up-ish" while you have airspeed and come down after landing.

Some thoughts....

Re: the flaps thing, Merlin.... No, they wouldn't come down if you're in flight trying to get the gear down by pulling the T handle. It removes hydraulic pressure from the system. This pressure is what holds the flaps up and also the gear doors. It used to hold the gear itself up until a tragic accident with the 325th FG during dive bombing tests. The left main came partially out in the pull out and yawed the plane at high speed causing loss of the vertical stab and other parts. The plane went in at 400 mph. After that, uplocks were installed to hold the gear up. So.. Sorry if I'm wandering, here, but on the ground, pulling the T handle, also called the hydraulic dump, opens the system and nothing is left to hold the flaps or gear doors "clamshells" up. They slowly open from gravity. In flight, The flaps would stay up from aerodynamic forces. It takes a lot of force to drive them down in flight. There is a 450 psi accumulator bottle in the right side gear well that is supposed to be good for one flap cycle in an emergency...otherwise you simply land without flaps.

As to "configuration" Just about all modern Mustangs have the rear tank removed. A Mustang is too valuable to most owners not to have a rear seat. That rarely means rear controls. Taking out the tank, armor plating, very heavy old-fashioned radio gear, etc. and adding a seat generally all evens out. Understand that modifying any airplane does not mean that you have to change the CG. You would just move stuff like the heavy battery around to keep it in range. Crazy Horse is indeed the bird I got to fly "3 trips to Kissimmee over 3 years and most of my life savings". It cost me any chance at retiring and I consider it a fair deal. First flight in the back seat with Ed Shipley and subsequent ones with Lee Lauderback culminating in three hour and a half flights in the front seat where I had to start the Merlin and handle the gear and flaps. First flight in 2005. This was actually the P-51 checkout syllabus we were using. While I knew I couldn't afford the complete checkout, I made it half way. That just left high altitude training, various advanced emergency procedures, etc. What we did included about a million stalls since these are the killer in the Mustang. I got to do stalls with flaps and gear down "which the sim models just about perfectly" It was all about stall recognition and I was made to fly in and out of the pre-stall buffet constantly. One drill was to roll inverted at around 270 mph and pull into a split S but pull aggressively enough to keep the bird in the buffet all the way through the split S. Called "tracking the buffet". Lots of accelerated stalls at 250 and above. No big deal... Like this sim, just relax the back pressure and you're flying again. At high speed, the turbulence off the wing was severe enough to make the skin on the stab oil can and you not only felt the buffeting, you could hear it. We did many "dozens" of touch an go's and this is why you hear me saying how easy and controllable the Mustang was on the runway. Touching down at around 90 on the mains, tail up, and then adding power "40 inches at first and then 55 with prop at 2,700" it was a little swervy due to my inexperience but never close to out of control. The rudder on the Mustang is VERY powerful and is effective at low speeds where the ailerons are totally ineffective and the elevator marginal.

By the way... we were taught to start the Merlin with the oil and coolant doors closed and on auto... they would get the engine warm faster and then open up to maintain temps. just a different policy.. Not done everywhere. Just saying it worked well.

Going over some points about war mustangs versus modern configs, Just some thoughts. It' been almost a decade, so go easy on me.. I'm just repeating some of the stuff I was told while training. People wonder about take off's in contemporary Mustangs where 100 octane gas generally dictates 55 inches MP instead of 60 and nobody would ever use WEP... It all balances out. Today's Mustangs are several thousand lbs lighter and take off and climb at 55 inches works out to at least as good as a WWII bird. Crazy Horse and the TF-51's are not tail heavy due to the added rear cockpit. They balance pretty much normally. If it was tail heavy, we never would have done all the aerobatics and stalls. The several inch taller vertical fin does not change the flight characteristics over the stock Mustang...It keeps them the same. The TF canopy is said to come from a T-33 but that could just be rumor. It does have added head room in back and this kills some of the airflow over the vertical tail, thus the added area. According to my instructors there is no significant difference between the TF-51 and regular Mustangs other than the fact that they are all at least slightly different. You will probably never see any two civilian Mustangs with identical cockpits. In Crazy Horse, the oil and coolant door switches are on the right where the ancient WWII radio controls used to be.

Well... That's it. Sorry if I kind of went all over the place but I've been reading all the reasons and theories for different things in this thread and others and just wanted to, hopefully, throw a little light on the subject. I'm no Mustang expert but just want people to know what a beautiful flying bird the real plane is and that it is nowhere near as hard to fly as most sims. I think the DCS Mustang is the best ever done but there are a few things that could be made better and that would make it unassailable. I personally have little interest in playing a "game". To me, this DCS bird is a terrific P-51 simulation and I use it to recapture a time I can never go back to. :-)

great post Swoop73! appreciate you sharing that info! :thumbup:

I am able to do very straight takeoff with tail up at 80 mph (not with full fuel mind u) and very straight 2 point landings with my $20 dollar Extreme 3D pro..... Maybe add bigger curves and deadzones to your control axies

Re: the flaps thing, Merlin.... No, they wouldn't come down if you're in flight trying to get the gear down by pulling the T handle. It removes hydraulic pressure from the system. This pressure is what holds the flaps up and also the gear doors. It used to hold the gear itself up until a tragic accident with the 325th FG during dive bombing tests. The left main came partially out in the pull out and yawed the plane at high speed causing loss of the vertical stab and other parts. The plane went in at 400 mph. After that, uplocks were installed to hold the gear up. So.. Sorry if I'm wandering, here, but on the ground, pulling the T handle, also called the hydraulic dump, opens the system and nothing is left to hold the flaps or gear doors "clamshells" up. They slowly open from gravity. In flight, The flaps would stay up from aerodynamic forces. It takes a lot of force to drive them down in flight....

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:

From the flight manual:

"The P-51D is equipped with two separate hydraulic systems. One is the main power system for the operation of the landing gear and wing flaps. The other system is the foot pedal-operated brake system. The only connection between the two systems is that they receive their supply of fluid from the same reservoir in which a 3 cubic in. capacity cup is arranged so that in the event all the hydraulic fluid from the main power system might be lost, the brakes may still be operated."

"In the main power system, a pump is permanently geared to the engine and maintains a pressure of 800-1100 lbs/sq.in. As long as the engine is running, the engine unloading valve loads the hydraulic system when hydraulic pressure drops to 800-850 lbs. It unloads the system when hydraulic pressure reaches 1050-1100 lbs. In the event of hydraulic pump failure, no provision is made for emergency operation of the wing flaps."

"Incorporated into the hydraulic system on all P-51 model aircraft is an Landing Gear Fairing Door Emergency Release handle. The purpose of this handle when pulled out is to release or bypass hydraulic pressure from the fairing door cylinders and lines back directly to the reservoir. After the knob has been pulled out and has served its purpose, pushing it back in will once again restore normal operation of the hydraulic system. Therefore, if emergency landing gear procedure has been followed, push the knob back to attempt normal operation of the flaps. If flaps fail to extend, no emergency procedure is available."

Hi Mike, The 51 was a work in progress and depending on the year various items may or may not have been installed... Not to mention the way contemporary birds are all a little different as their owners put in dozens of different radios and nav equipment as well as change the location of many controls and switches. My Mustang manual is US Air Force publication T.O. No. 1F51D-1 (Formerly AN 01-60JE-1) Published in 20 January, 1954. This would be for late model Mustangs and you're probably correct that, in the DCS Mustang, there probably is not an accumulator bottle in the right wheel well. I don't know when that would have been installed. I did try cycling the flaps while shut down and parked on the ramp in the DCS sim and I could raise and lower the flaps through about 4 cycles before the hydraulic gauge suddenly dropped to zero and the flaps froze. That seems to mean the DCS people are modeling some kind of pressure accumulator. Don't put too much faith in any manual as there are many places where the DCS model doesn't necessarily follow. Some of this will get fixed and some won't. I have no real problem with that since most P51's are at least a little different from each other. Many times during the War, North American made little changes. My friend, Barrie Davis, of the 325th FG had a D model with no dorsal fin one week and then it was added as a field mod.

I was writing from memory last week, but finally located my manual. In section III, Hydraulic Power System Failure: "If the engine driven pump fails and the rest of the system is intact, enough pressure will be supplied by the accumulator to lower flaps fully provided the pressure gauge shows at least 800 psi."

Again, I'm not trying to come across as some kind of Mustang expert. If you want experts, go to Duxford, UK, or Kissimmee, FL, where the Lauderback Brothers crank out prize winning P-51's by the truckload. I'm just a guy who LIKES Mustangs and wishes he was a millionaire. :-)

Understood. Where I typed "From the manual" was referencing the DCS flight manual.

or Kissimmee, FL, where the Lauderback Brothers crank out prize winning P-51's by the truckload.

I don't understand; you mean that a company Lauderback Brothers is mass-producting full-size P-51s now? Surely even approximate replicas aren't nearly popular enough for that. I did an Internet search for Lauderback Brothers and couldn't find a single thing. Mind expounding?

Echo, what I was saying is Stallion51, in Kissimmee, FL, along with David Gray at the Fighter Collection are among the very best at rebuilding and maintaining P-51's. Stallion 51 is owned and run by Lee Lauderback and his Brothers. Mustangs are pretty much what they do. No, they aren't producing factory new Mustangs, that I know of, but now that you mention it, I wouldn't be surprised if they or somebody else was thinking about it. Eventually this will be absolutely necessary.

Ah, yes. I believe Flugwerk is currently producing small quantities of full-size approximate-replica P-51s. Not sure if there are any others.

Hey,

when you say the P-51 was more easy to handle while accelerating down the runway, how much right rudder trim had you dialed in in Real World take-offs ?

I am no real world P-51 Pilot and if I don't win 10 mil in the lottery I never will be but I found out that when you dial in 5-5.5° right rudder for take-off the Mustang tracks down the strip like an arrow, only slight corrections needed. Before I found that out, OH BOY, I messed up every other take-off resulting in a crash.

When I fuel her up all he way incl. drop tanks I tend to give it 0.5° more and set it to 5.5° to compensate for the higher MP that I need to apply to compensate for the higher mass.

It just tracks down like an arrow and I would rather think that is too easy and not RL like than the other way round if you set the dials somewhere at 5°. It is no bad idea to also add some elevator down trim or be on alert that she wants to get airborne very quickly once on the mains. The DCS manual states 2° down afair. I usually don't trim her down and control her by hand on the elevator. She does need the elevator trim once airborne when fully fueled with 2 drop tanks, that is out of question from what I learned.

I wish I had the money to go to Duxford, put some 25k on the table and say " Let`s Rock'N'Roll" ;)

Bit

Hey,

 

when you say the P-51 was more easy to handle while accelerating down the runway, how much right rudder trim had you dialed in in Real World take-offs ?

 

I am no real world P-51 Pilot and if I don't win 10 mil in the lottery I never will be but I found out that when you dial in 5-5.5° right rudder for take-off the Mustang tracks down the strip like an arrow, only slight corrections needed. Before I found that out, OH BOY, I messed up every other take-off resulting in a crash.

Rock'N'Roll" ;)

 

Bit

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