P-40 unstable?

[SteveBennett]

P-40 Accu-Sim: I have a couple of thousand hours in all types on the MFS from the Apple II tape version to FSX. I find the P-40 almost unflyable. Do I have something set up wrong? The plane wants to nose up and stall immediately on takeoff and is pretty much impossible to trim out. If this is accurate, so be it. If not, I need some help from anyone who finds the plane friendly. Thanks for any assistance you can give.

[FlyingsCool]

Nope, haven't had any issues like that for me. Plane is very stable in flight. No trimming issues for me either. My issue is getting over the top in a loop without going into a flat spin, but I'm sure that's me (I almost got it the other day ). I had an issue like that when I was flying the HD OZx Goose in Steam. Turned out it was because it was using the wrong aircraft.cfg file because it was using the .cfg file from the A2A lights files in a different directory (a quirk of Steam and its DLC for default planes). Point being, have you made any changes in the aircraft.cfg file? Are you trying to use the FSX version in P3Dv.4 or vice versa (I understand there are some differences there in the programming)?

[Jacques]

Steve, if this is your first A2A aircraft, they are different from other stock or payware aircraft you may have flown or purchased previously. Setting up the aircraft on the ground correctly using the checklist provided with the manual and paying close attention to trim, engine power settings and speed for takeoff could be an answer.

[Paughco]

RTFM. The checklist is pretty easy to memorize, but use the Shift+2 panel and look at startup, runup, and takeoff procedures. Make sure elevator and rudder trims are set correctly. No fuel in the fuselage tank until you get the feel for the airplane and then only if you're going on a long flight. For takeoff, start with the stick back to keep the tailwheel on the ground until you get rudder authority. Apply throttle smoothly, so that you're moving at about 50 mph by the time you get to 30 inches MP. By this time you should have applied some forward stick to get the tail off the ground. Keep the throttle coming in to the redline on the MP gauge. By this time you're really moving. Keep her on the centerline. Ease back on the stick at about 110 mph or so, and bring up the gear.

Gear and flaps: Use the Shift+1 feature to see positions of the gear and flap levers. I have the hydraulic pump mapped to the trigger on my stick (guns don't work, so why not?), so I press the G key, then hold down the trigger until the gear is coming up. Back to climb power/rpm (see Shift+2 panel for recommended settings).

The whole takeoff thing as described takes maybe ten seconds. Here's a video of a real P-40: https://www.youtube.com/watch?v=V-kCeuxMBoQ. The A2A P-40 flies just like the real deal!

Seeya
ATB

[FlyingsCool]

No fuel in the Fuselage tank? I've been meaning to discuss this, but, the USAAF P-40 training manual (1943) states that it's required to use the Fuselage tank for take off as it's the only tank which is vented, IOW, it's got an overflow fuel line between the tank and the carburetor which carries excess fuel back to the fuselage tank (pg 19). "Always use the fuselage tank for takeoff. During takeoff the chance of fuel overflow is especially high, and unless you are using the fuselage tank - the only one built to handle overflow gas, the overflow is lost." (pg 19)

I also am a little confused by A2A's terminology, as the training manual states "All P-40's (except a few early P-40N's) contain a front wing tank, main wing tank, and fuselage tank" (pg 18), and doesn't mention a "Reserve" tank. I assume the "Reserve" in A2A terminology is the front wing tank, since they also have a Fuselage tank, although the USAAF training manual calls the Fuselage tank "Fus. Res." on the selector. So perhaps A2A is using different terminology? In the manual, the tanks on the selector are, counterclockwise from the top Off - Belly - Fuselage Res. (Reserve?) - Rear Wing - Front Wing (- Off). I haven't had a chance to review this since I read the training manual last week with the A2A plane's selector, and they don't have a picture in their manual of it, so maybe I'm missing something.

But main point is, the P-40 isn't a P-51. I don't believe it's as sensitive to fuel tanks as the P-51 is. When I fly the P-40, I've always had fuel in the fuselage tank and never had a problem with pitch. As I noted, I find the P-40 a very stable platform.

[Paughco]

I don't have the real manual, but I do have the Periscope Film reprint, which seems to have a lot of the original info. The fuel system is described on pages 18 and 19. Only thing is, the system described is for the P-40M and P-40N, which appears to be way different from the systems in our P-40B (what I fly) and P-40C aircraft. My P-40B has a reserve tank, wing tank, and a fuselage tank. I just did an "advanced search" for "reserve tank" on the P-40 board and found some early posts. Here is one with what looks like fuel system diagrams for the early P-40s: viewtopic.php?f=82&t=28896&p=219788&hil ... nk#p219788.

I usually take off on the reserve tank, then switch to the wing tank. I have checked fuel level in the Shft+4 panel once at altitude on a long flight, and while I haven't done this in a while, I really do believe that I could see an increase in the level of the reserve tank while flying on the wing or the fuselage tank. Also, in my manual for the P-40M/N, there's a picture of the fuel selector valve and tank positions, and the fuselage tank is labeled "Fus. Res." I will have to take the P-40 out on a flight to see if any fuel actually does return to the reserve tank.

EDIT: OK, looks like they added the fuel return in update 1.4: viewtopic.php?f=82&t=29906&p=231168&hil ... nk#p231168.

Seeya
ATB

[FlyingsCool]

The Periscope manual is a reprint of the Training manual I have. It's actually a training manual for all versions of the P-40, which was up to N by 1943. In comparing, what A2A calls the "Reserve" tank is the "Front Wing Tank" in the manuals.

Thanks for the links to the threads, I'd searched but not found those threads. I'm thinking I need to get the 01-25CE-1 manual.

Interesting the training manual states the vent from the carb to the Fuselage tank for ALL P-40 models (except for some early P-40N's), but the earlier images of the fuel system (shown in the threads you mention) from the British Tomahawk I manual show a line going to the Front Wing Tank.

I'll have to check how A2A modeled it.

This is a great training video produced by Curtiss on how to fly the P-40 (In this case they are using a P-40F as an example, but they say it's applicable to all models, except for expicitly defined concepts such as the two stage supercharger on the F.

https://youtu.be/TOIg7JxHQBk?t=180

I do notice that the A2A fuel selector is reversed in orientation from the D and later models. I don't have the B/C manual (01-25CE-1) to see if it changed with the D model.

[Paughco]

Thanks for that very cool video. I watched the similar video about how to work the hydraulic system many times. Will have to save this one as a favorite. More P-40 trivia! No, wait - essential knowledge!

More of the A2A MP Misfit Squadron are discovering the P-40. Next time I'm in charge of a MP flight maybe I'll come up with something for the P-40. We've already flown the Hump, the Hawaiian Islands, and a Pearl Harbor commemorative. Gotta come up with something good - something worthy. Next Sunday is another "Doctor's Adventure," in which we'll fly our Bonanzas around Denali. I pre-ran it in the P-40, and the P-40 is definitely where it's at.

Every once in a while I ride my motorcycle up to FHCAM in Everett, WA and look at their original P-40B/C, and sometimes even watch it fly.

Seeya
ATB

[FlyingsCool]

Nice!

The Bonanza's one of the few I don't have... yet.

Yes, loving the P-40. Just complex enough to be fun, but still capable of a short flight after work before bed. I was reading the training manual for the B-26 Invader on a flight to Chicago last week. Man, that plane's got a LOT of systems to understand in depth.

[SteveBennett]

Thanks everyone. I got it sorted out and find it a fun plane to fly.

My new problem is that my P-40, T-6, P-51 and Spitfire all cause FSX to quit when they load.
It doesn't hang -- it just quits to the desktop. I am running FSX in Admin mode to fly the Milviz F-86.
My other A2A planes work fine (Cub, Coursair, Bf-109). This really acts like a anti-piracy event.
I have tried to uninstall and re-install the P-40 but no joy.

Any ideas?

[Dogsbody55]

When you load flight sim, be it FS9, FSX or P3D, always load the sim with a stock sim plane such as the Cessna 172, at a place which has little or no addon scenery. Once everything has loaded and you see your AI sinking, then load your flight. All these sims take a while to load all their components and adding an A2A plane, and many other addon planes, will cause problems either with CTD's or something else such as DLL files not loading.

Try this first then get back to us.


Good luck,
Mike

[SteveBennett]

Tried to start with a stock plane. No joy. Switching to one of the A2A AcuSim planes causes FSX to stop.
Thanks for the try though.

[Lewis - A2A]

Hello,

Sorry you have experienced some issues, lets see if we can't get you up and flying.

First up we need to get you back to square one and updated. We never advise a reinstall as a first step troubleshooting as it simple wipes the issue away or hides it making it harder to find and solve and often simply results in more frustration or kicking the can down the road.

So lets get you back to square one.

Step 1;
Go into your FSX root directory and delete the update folder in the A2A folder for all of your A2A Aircraft. For example for the T-6 the directory is;
\FSX\A2A\T6\Update_fsx

You will want to delete either the entire Update_fsx folder or the client.wyc file inside it.

Step 2;
(warning this will delete your persistent hours for your aircraft)
Go to your Documents folder, to the A2A > FSX folder and then in the aircraft you are having issues with go into the respective folders and delete the .dat files. For example the directory of the Spitfire is;
\Documents\A2A\FSX\Spitfire

Step 3;
Restart your PC

Step 4;
Run the latest Accu-sim Updater here. This might take a little while and will require you to press and OK certain dialogue boxes as the update searches for and updates your A2A aircraft in FSX;
viewtopic.php?f=23&t=57819

Step 5;
Restart your PC

Step 6;
Load up FSX, from the free flight menu start a new flight.

Let us know how you get on, that should get you all updated and hopefully ready to roll. So at least any further troubleshooting is from the latest versions. (Remember everytime you install an A2A Aircraft, you should run the updater after the installation)

thanks,
Lewis - A2A

[SteveBennett]

Thanks for the help.
I've gone through the steps and no joy. Everything updated etc.
If it tries to go from free flight to start the flight, FSX shuts down.
This happens with the P-40, T-6, Spitfire and P-51.
The P-47, Cub, Coursair, and and Bf-109 all work fine.
The Spitfire will load and let you fly one flight if configured as the default flight.
Then FSX quits.
All my other aircraft work fine.

Any ideas are welcome.
-Steve

[Jacques]

Steve are you using FSX boxed version or FSX Steam Edition?