Unrecoverable left flat spin

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Lewis - A2A
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Re: Unrecoverable left flat spin

Post by Lewis - A2A »

Hello,

just to confirm folder wise you are deleting the update folder in the A2A folder for the mustang?

Can you also please 100% confirm you have the P-51 + the Accu-sim pack for the P-51 and not just Accu-feel?

thanks,
Lewis
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Nick - A2A
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Re: Unrecoverable left flat spin

Post by Nick - A2A »

Hello Stephan,

Just a few more points which may help to get to the borrow of the issue you're encountering.
Stephan wrote: https://www.dropbox.com/s/ebfg3lp3sb8sc ... l.jpg?dl=0

[...] Here are the following trim tabs, which I have left at what you get by default on cold and dark. I believe:
Rudder : 6.1 right
elevator : 0
Aileron : 0
Looking at the picture you posted above, the fuel distribution is likely part of the problem. Your fuselage tank is virtually full, with very little fuel in the wing tanks. With fuselage fuel, you'd benefit from nose down trim, but you mention nose up trim earlier in the thread. It's probably a good idea to start by removing the fuselage tank entirely whilst trying to get airborne.
Stephan wrote:[...] as usual at a few hundred feet, while as I was flying level gear up, no flaps, throttle about 80%, not touching the controls, the left wing started to drop and I entered a fast spin.
The "not touching the controls" bit is likely part the problem here. During take off and climb out, the P-51 just can't be flown without control inputs. Judicious rudder input as you accelerate and clean up the aircraft is perhaps the main thing that's needed here.
Stephan wrote:As soon as I took off, I activated the AP to force the aircraft level, raised the gear, and guess what happened about 40 seconds in? The left wing dropped and the aircraft entered a wild spin, with the AP ROLL ON and without me touching any of the controls!
Again, manual control inputs are essential during this phase of flight. The autopilot in the P-51 doesn't move the rudder so you need to do this yourself. I guess it's important to remember that autopilot is there to relieve workload during cruise flight, not for use during take off at high power settings when loads of complex aerodynamic forces are at work, trying to turn the aircraft towards the left.

Maybe try capturing a few more screenshots showing the flight instrument during one of your take off attempts? This would give an idea of airspeed, ball deflection and so on. Better still, a video. :)

Nick
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Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Lewis - A2A wrote:Hello,

just to confirm folder wise you are deleting the update folder in the A2A folder for the mustang?

Can you also please 100% confirm you have the P-51 + the Accu-sim pack for the P-51 and not just Accu-feel?

thanks,
Lewis
Yes Lewis, I have accu sim P51 civilian. To try and get the cleanest reinstall I did the following:

1. Used the uninstall from Windows
2. Deleted the P51civ folder in Sim Objects
3. deleted the P5civ folder in the A2A folder at the root of FSX
4. Installed the P5civ
5. installed the accusim P5civ
6. Installed the latest Accusim combined update

Thank you
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Nick M wrote:Hello Stephan,

Just a few more points which may help to get to the borrow of the issue you're encountering.
Stephan wrote: https://www.dropbox.com/s/ebfg3lp3sb8sc ... l.jpg?dl=0

[...] Here are the following trim tabs, which I have left at what you get by default on cold and dark. I believe:
Rudder : 6.1 right
elevator : 0
Aileron : 0
Looking at the picture you posted above, the fuel distribution is likely part of the problem. Your fuselage tank is virtually full, with very little fuel in the wing tanks. With fuselage fuel, you'd benefit from nose down trim, but you mention nose up trim earlier in the thread. It's probably a good idea to start by removing the fuselage tank entirely whilst trying to get airborne.
Stephan wrote:[...] as usual at a few hundred feet, while as I was flying level gear up, no flaps, throttle about 80%, not touching the controls, the left wing started to drop and I entered a fast spin.
The "not touching the controls" bit is likely part the problem here. During take off and climb out, the P-51 just can't be flown without control inputs. Judicious rudder input as you accelerate and clean up the aircraft is perhaps the main thing that's needed here.
Stephan wrote:As soon as I took off, I activated the AP to force the aircraft level, raised the gear, and guess what happened about 40 seconds in? The left wing dropped and the aircraft entered a wild spin, with the AP ROLL ON and without me touching any of the controls!
Again, manual control inputs are essential during this phase of flight. The autopilot in the P-51 doesn't move the rudder so you need to do this yourself. I guess it's important to remember that autopilot is there to relieve workload during cruise flight, not for use during take off at high power settings when loads of complex aerodynamic forces are at work, trying to turn the aircraft towards the left.

Maybe try capturing a few more screenshots showing the flight instrument during one of your take off attempts? This would give an idea of airspeed, ball deflection and so on. Better still, a video. :)

Nick
Hey Nick

I guess I didn't explain right. Of course I "fly" the aircraft all through out. When I mention not touching I simply mean that I didn't apply strong rudder left or aileron left to induce the spin.
I guess you would agree that the P51, once leveled, trimmed, gear up, shouldn't go into a strong left spin out of nowhere, especially when you have the AP on Roll and in zero wind conditions.
And something important: when the left wing starts to dip, a right aileron should prevent the situation from aggravating. That's not the case here. As soon as this spin of death starts, whatever right rudder or right aileron I apply doesn't do anything.
All your piloting advices are sound, and I hate to repeat myself but I think I know all of this, otherwise how can one explain that I'm able to take off, cruise, and land without problems on a clean install, 100% of the time? As for the fuel distribution well I guess that would have been a problem with the clean install too, don't you think? Yet I was able to fly with this configuration.

What's puzzling is that nothing has ever been a problem on the clean install. I mean you've seen these screenshots of the landing and the plane flying leveled I just made when I reinstalled without the latest update. I'm sure a2a has improved the flight model in recent updates, but has it become so sophisticated that a pilot who was able to fly the aircraft very reliably until now just couldn't maintain it in the air for more than 2 minutes now? That seems like a really extreme difference.
When I install the latest accusim combined update, then all my work as a pilot is moot. The aircraft drops left, very strongly, in spite of all my efforts and my experience.
Still, I'll see if I can find a way to record all this. I know it's hard to believe but I swear I don't invent anything. Thanks!
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

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Dominique
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Re: Unrecoverable left flat spin

Post by Dominique »

Stephan wrote: As for the fuel distribution well I guess that would have been a problem with the clean install too, don't you think? Yet I was able to fly with this configuration.
!
No, not necessarily ! If the FDE has been upgraded, bad practices (like a full aft tank and empty wing tanks) may be "punished" now (after the upgrade) harsher than they were before (what you call a clean install) ! That goes for any sloppy piloting. The 51 is an unforgiving aircraft and any upgrade that brings her more closer to the real thing would make her more unforgiving :mrgreen: !

It is not hard to believe you, Stephan, nobody says that you invent anything, the point is it is hard to help you as we cannot replicate the issue you have except by doing known no-noes ! Or you have a hardware problem that is amplified after the upgrade for some reason or you need to improve how you drive your unruly Mustang :) !

BTW , could you remind us your sim, OS and controllers.
Dominique
i7-4770 /Nvidia 1080 and MSFS
Proud ownerin FS9 of the P-47 and P-51, in FSX/P3D of the Piper Cub, Cherokee, Comanche, P-40, P-51 civ., Texan, Boeing Stratocruiser, Cessna Skylane and in MSFS of the Comanche

Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Dominique wrote:
Stephan wrote: As for the fuel distribution well I guess that would have been a problem with the clean install too, don't you think? Yet I was able to fly with this configuration.
!
No, not necessarily ! If the FDE has been upgraded, bad practices (like a full aft tank and empty wing tanks) may be "punished" now (after the upgrade) harsher than they were before (what you call a clean install) ! That goes for any sloppy piloting. The 51 is an unforgiving aircraft and any upgrade that brings her more closer to the real thing would make her more unforgiving :mrgreen: !

It is not hard to believe you, Stephan, nobody says that you invent anything, the point is it is hard to help you as we cannot replicate the issue you have except by doing known no-noes ! Or you have a hardware problem that is amplified after the upgrade for some reason or you need to improve how you drive your unruly Mustang :) !

BTW , could you remind us your sim, OS and controllers.
Unforgiving yes I agree with you, and I actually like it a lot. But a wing dropping when you have plenty of speed, power, and the aircraft has been flying level and trimmed for 30 seconds? Just like that? If that was the real behavior then not one single P51 pilot would have seen the end of the war, not even the Tuskegee airmen...
Still, I truly appreciate the time you guys spend helping me. :)

I use FSX accelerated (not the steam edition) on Windows 7. I have Saitek Yoke, pedals, and throttle/prop/mixture/elevator trim controls. I also have a Mpanel, TrackIR, and Active Sky Next.
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

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Lewis - A2A
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Re: Unrecoverable left flat spin

Post by Lewis - A2A »

Hey Stephan,

last thing, can you delete the .dat file also please.

thanks,
Lewis
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Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Lewis - A2A wrote:Hey Stephan,

last thing, can you delete the .dat file also please.

thanks,
Lewis
Oh sure. I'll try tonight after work and I'll let you know. Where is the .dat file located?
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

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Lewis - A2A
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Re: Unrecoverable left flat spin

Post by Lewis - A2A »

In your my documents, it'll look something like this;
\Documents\A2A\FSX\P51civ

Also just to check you are first loading a default aircraft and then loading into the P-51?

thanks,
Lewis
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Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Lewis - A2A wrote:In your my documents, it'll look something like this;
\Documents\A2A\FSX\P51civ

Also just to check you are first loading a default aircraft and then loading into the P-51?

thanks,
Lewis
Will do and will get back to you. Thank you!
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

Stephan
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Re: Unrecoverable left flat spin

Post by Stephan »

Hey Lewis,

I'm so glad to report that my problem is now fixed! I don't know if that is simply the deletion of the dat file that did the trick, but the strong left roll is gone! It feels good to know that I wasn't going crazy after all. So I was able to spend some quality time with the bird and I can attest that it feels very different from what I was used to, but not to the point where I can't understand the behavior. It's now without a doubt quite more challenging. The left roll introduced at take off is very noticeable and quite dangerous, so I really had to read carefully and follow sir Henriques real life advice. The aircraft has also a nose up tendency now, that can play tricks if you don't pay attention.
But if anything I like the added realism and extra challenge. It makes clean landings and take offs even more rewarding. I did about a dozen take offs and landings and the Mustang deserves her name now more than ever. You can feel her bucking and rolling and jumping, and it takes quite a grip to tame her.
Anyway I love it. Still my favorite warbird from A2A.
So anyway I just waned to thank everyone here who really did everything they could to try and find a solution to my problem, Lewis especially.
B377 / B-17 / Spitfire / P-51 Civilian / Piper J-3 Cub / C172 / C182 / Cherokee / Comanche / Avro 504k / F4U Corsair / BF109

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Re: Unrecoverable left flat spin

Post by Piper_EEWL »

Good stuff. I guess deleting the dat file would have helped all along. Good to know!

Happy flying
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Lewis - A2A
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Re: Unrecoverable left flat spin

Post by Lewis - A2A »

Good to hear, sounds like the .dat file had an issue all along, good your now up and running.

thanks and happy flying,
Lewis
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Dominique
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Re: Unrecoverable left flat spin

Post by Dominique »

Glad you got it sorted out and can enjoy this great aircraft now !
Dominique
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Re: Unrecoverable left flat spin

Post by sloppysmusic »

I have the same problem. Glad I found this thread because having miserable time with this aircraft. Every single flight ends with left spin and crash and then all my saves dont work. Doesnt help that all liveries seem to share the same persistent data so even loading up a new livery its still the same plane :(
Look out windows at wings. All surfaces neutral, plane huge pull to left. Eventually I counteracted and even landed by realizing
that even with neutral calibrated controls the plane was rolling hard so could counteract with 'extreme' right aileron. The amount you'd need to make a 60 degree or higher turn. Wings showed this silly amount of control surface was being deployed just to keep aircraft
steady.
1st step deleted dat files. No effect.
Its late at night and yet another Twitch stream Ive canceled to be dealing with this. Had no problem whatsoever with the fantastic Comanche and Cherokees as my joyous videos posted here show.
I'm going to remove aircraft and reinstall ONCE.
If that doesnt work I will have to ask for a refund for a non-functioning prod cut which would make me very sad as I researched and planned to buy this plane for the last month to fill a gap. Fingers crossed my fresh install (last new one was fresh too!) will sort this otherwise its back to the RealAir Spit for speed and no more A2A purchases. I want to fly not suffer like this!
Will post/report back the results.
Being a diagnostic chap Im going to reinstall with ORIGINAL Accusim exe NOT the global update. See if that works first.

Not looking good unless the real plane is this hard to fly,,,

After takeoff roll to left. To climb/cruise I need 10 degree right aileron. This works for 5 -10 seconds then plane starts to
roll right smoothly towards death spin. Remove all trim to 0 degrees. Plane flies dead straight then a few seconds later...starts to left again. 10 right fixes it for few seconds then roll right again. This repeats over and over.
I could get to my destination like this but its no fun at all and cant be realistic.
34 MP and 2250RPM steady cruise--IF you can call steady cruise at 145kts steady!

Going to continue and land then complete overhaul. Something messed up my power after a very careful and slow climb.
More later....

Coming in to land..LOL ignore the speed problems...i had been so busy keeping the plane from spinning out during climb i ummm.left the gear down...approach is smooth at moment no rolling at all..\

No problems landing. Hanger report LIKE NEW. For diagnostics reasons Im going to attempt another flight still running original accusim install. If I get left and right rolling after takeoff I will quit and install the update.

Took off..usual left deathroll until 4000 feet then it went away...this time no trim just held yoke over to right the whole time.
Trimmed out smooth at 7000. Went to bathroom for 60 seconds came back plane in the dirt. Reloaded in flight and serviced with hanger in the air...when this flight is done i will load the accusim update as last attempt to get plane safe to fly.

..update..plane very stable above 250kts..i understand torque effect..been very careful with throttle adjustments.

..interesting note...fus tank full before flight...used CD/auto start for this test..just checked fuel- fus tank selected
and it has ZERO fuel..popup shows 0 and gauge on left shows 0 too..been flying on 0 for 15 mins at least..just switched
to left tank to be cautious...

Landing smooth as silk..flaps that didnt work during tax test worked fine for landing...greased it!

Ran latest AS update...found P51 Civvy said was up to date..guess files retained somewhere...ok back to try flying again!

Loaded last flight. To test the fuel 'thing' I unloaded all fuel from plane all tanks and selected fus tank. Panel shows 0% all tanks.
Used auto start. Plane started perfectly. Gauges showing zero fuel. Will fly this whole flight without adding fuel...at least me weights are super low! IF i make it will try start plane with zero fuel manually at destination.

OK I am seriously DONE! Im using FSX Steam Edition BTW. Gonna load up another plane now and enjoy myself before bed.

Plane engine didnt need fuel. Got tickover sample but it throttled up fine but sounded silly. Control lock OFF but behaved like it was on (i could see control surfaces fine in views). Loaded fuel next time, no difference. Plane acted same as if C lock was on. Impossible to take off. Will be asking for refund could someone tell me where to go for that? I hope my recorded efforts from another wasted night here will suffice to show I REALLY tried to get this working.
Im going to finish the night with the Comanche. I HAVE to know before bed that that AS update didnt mess with that too..Fingers crossed for my sweet Piper combo..so much pleasure compared to this...\

Loaded up the glorious Comanche..start up/take off fine planned to do gear down circuit. NOT POSSIBLE! Plane death rolled to left until the moment I raised gear. Flies perfectly now...I could cry if that AS update (that i didnt run till had the Mustang) messed up my favorite planes...:( :(

PS after landing and taking off again Comanche didnt roll left...bedtime now with some relief. I DO want to get Mustang off my system ASAP now though.

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