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aircraft stall

this4dave2

this4dave2

Members +
I was wondering if it is possible to have the aircraft fall off on one wing and/or then spin after entering a stall?

David wooster
 
Reactions to a stall can be set for left/right wing drop, or slow nose drop, with varying severity levels.

Unfortunately I do not know the mechanics of it to do by hand in the .air file. I use Sparky's FDWB to get the desired response.
 
I am assuming that you are talking within FS9 ... since that is of course entirely possible in the real thing :D
Within FS there are some aircraft that model the aerodynamics quite well and do a plausible job of the traditional stall-spin transition. Most of them are acrobatic aircraft that need that sort of thing in order to come close to realistic behavior when doing acro.

I think the freeware Christen Eagle was one of the better examples.

Cheers
Stefan
 
Unfortunately I have difficulty getting Jerry Beckwiths freeware FDWB to come up with the goods for spinning, so I resort to experimenting in the air file, but sometimes I find it necessary to increase the MoI's a lot greater than simple calcs say.
Keith
 
Dev One said:
Unfortunately I have difficulty getting Jerry Beckwiths freeware FDWB to come up with the goods for spinning, so I resort to experimenting in the air file, but sometimes I find it necessary to increase the MoI's a lot greater than simple calcs say.
Keith
Click to expand...

LOL Keith ... can't say I have done the spin thing, just the stall responses. Most of the aircraft I build, the MFRs recommend against any kinds of intentional spins.
 
Now thats a thought - programme the escape key to eject from the aircraft!!!LOL

BTW; I did manage to get my Provost T1 to spin out of a max rate turn, which I believe the real thing would do....not sure how I did it though, I (or the designer) must have got the numbers just right, because none of my other kites will do it!

Keith
 
Dev One said:
Unfortunately I have difficulty getting Jerry Beckwiths freeware FDWB to come up with the goods for spinning, so I resort to experimenting in the air file, but sometimes I find it necessary to increase the MoI's a lot greater than simple calcs say.
Keith
Click to expand...

That's interesting, as I've usually found the opposite.

I do seem to recall however (IIRC) Jerry saying something along the lines that there were a few cheats & tweaks in the workbook code to get accurate spin/departure behavior - maybe the way the FM is set up has a bearing on spin results.

Anyway. here's a quick video of the Alphasim Boston spinning with an FM I created using the 2005.18 Workbook: -


And here's one of your Piston Provost with a 2005.18 FM, showing it depart in turns to the left & right, and it also spinning : -


Whilst the spin behaviour might not truly reflect the real aircraft the FM is for, I think the Workbook does quite a good job, and should at least satisfy folk who thought the MS series of sims couldn't do spins.

Cheers

Paul
 
Thanks for that video of the Boston, a very nice spin!! The Zivco Edge spins nicely too.
I did run the CriCri through the FDW but it made no improvement in FS9 or FSX to its 'spinability' until I did increase the MoI, it now sort-of spins for a couple of turns, but before it just tumbled as most sims do. BTW I try my spins without in or out aileron, just full elevator & rudder.
I find some aircraft have too much elevator authority & one or two sim a/c I know will loop at the stall!!!
BTW I did find a spin report on the real Provost by Cranfield, as its spins are classified 'unstable' & some brave souls were conducting instrumented tests of inverted spins!!! This report did include calculated MoI's too!
Keith
[edit] I notice that you seem to be missing some texture from the bottom of the pilots panel as well as the throttles?
[edit2] I also note that my version is earlier at V2005.14 - wonder if that makes the difference?
 
456 and 460 entries in the .air file affect the yaw stability vrs AOA. Usually there has to be a trigger, or imballance at the stall to cause a drop off one way or another, supplied by rudder or trim input, or prop "torque". Milton's F7F Tigercat, for which I did the FD, really likes to flip out of an accelerated stall into a spin. Numerous example abound. It does take a lot of experimentation to achieve the desired post stall dynamics!

To tune these .Air file entries one must ether be a hex wizzard or use an editor such as Aircraft Airfile Manager. Available at Simviation and several other sources.

T
 
Dev One said:
Now thats a thought - programme the escape key to eject from the aircraft!!!LOL
Click to expand...

Been done, the Mirage 2000 by Roland Laborie and co

BTW; I did manage to get my Provost T1 to spin out of a max rate turn, which I believe the real thing would do....not sure how I did it though, I (or the designer) must have got the numbers just right, because none of my other kites will do it!

Keith
Click to expand...

The T6 (Harvard) in real world also does this; as I can vouch for,having flown one a couple of times; most disconcerting to find it drop out of turn opposite way to what you were turning (ie it unloads the upper wing in the turn) as no doubt Martin (T6 Flyer) will affirm.

ttfn

Pete
 
Thanks Motormouse, I believe the Harvard has caught quite a lot of pilots out & had/has a bit of a reputation - did they have originally rounded wingtips which was cured by changing them to squared off ones?
I also believe the P51 could catch one unawares in some aeros - I seem to remember my father quoting some caution on both those aircraft. (he was an ATA ferry pilot in the latter part of WWII).
Keith
 
Dev One said:
Thanks Motormouse, I believe the Harvard has caught quite a lot of pilots out & had/has a bit of a reputation - did they have originally rounded wingtips which was cured by changing them to squared off ones?
I also believe the P51 could catch one unawares in some aeros - I seem to remember my father quoting some caution on both those aircraft. (he was an ATA ferry pilot in the latter part of WWII).
Keith
Click to expand...

Not sure on the wingtips, as the one I flew has square tips, and does/did unload in the turn!
Never having had the chance to try a P51; the only comment I can make come from a now deceased gentleman I had a discussion with a few years ago now; basically said if you could fly a Harvard (T6 for the transatlantics!) well, then you would find a P51 easier.

ttfn

Pete
 
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