Spinning the Spit (and other warbirds)

[=Pedro=]

The WWII warbirds are inherently all very stable aircraft, with straight very high lifting wings. The Spitfire in particular has a very high critical angle of attack.

 

I personally don't think the modelling is wrong.

 

It's still in beta so lets wait and see what will happen in future development ;)

[OnlyforDCS]

Of course it's in beta, but I've been here since before the Mustang days. Yo-Yo's FMs have always been pretty much feature complete by the beta phase. Yes things have been improved upon, some changed, and there could very well be a bug. But I don't think this is the case.

 

I can pretty much initiate every spin in the Spitfire, though it comes out of some them easier then it does others, and some are very HARD to get into intentionally. The OP's original post claims that he can not enter spins, that there is something wrong with the FM based on his experience.

 

I am stating the opposite, spins are possible, and not even that, but the aircraft behaves differently in different spins. To me this shows signs of a mature and well behaved flight model. Besides spin behavior is the first thing they test when they do test flight models, before we even get our hands on the modules. (I am talking about Eagle Dynamics here, not third party developers).

Edited May 24, 2017 by OnlyforDCS

[philstyle]

Phil, what type of spin is talked about in the excerpt you provided there? It seems to start halfway through? The corkscrew spin I did yesterday required centering the stick, adding power, and applying reverse pedal.

 

 

 

The manual does not say, it just starts with "If an accidental spin occurs.." on the previous page.

[philstyle]

I can pretty much initiate every spin in the Spitfire, though it comes out of some them easier then it does others, and some are very HARD to get into intentionally. The OP's original post claims that he can not enter spins, that there is something wrong with the FM based on his experience.

I will happily recant my position, if you throw a vid up of some spin entries and the subsequent spinning. Ideally showing third person also.

 

Incidentally, a discussion about the spitfire's Spinning characteristics in DCS came up on ATAG soon after it was first released. Comments inlcuded the following:

while it is up to DCS on how they want to model their aircraft, I would wonder about the modeling of a Spitfire which seems incapable of entering a spin, no matter how hard it is pulled into a stall... especially an accelerated one

That thread, incidentally, is also where Bounder first posted his stall/ spin video.

Source: https://theairtacticalassaultgroup.com/forum/showthread.php?t=23900

 

If anything, this whole discussion has made me want to go make a new YT video of spins and stalls in the spitfire!

 

 

Woohoo!

[Sulaco]

I will happily recant my position, if you throw a vid up of some spin entries and the subsequent spinning. Ideally showing third person also.

 

Incidentally, a discussion about the spitfire's Spinning characteristics in DCS came up on ATAG soon after it was first released. Comments inlcuded the following:

while it is up to DCS on how they want to model their aircraft, I would wonder about the modeling of a Spitfire which seems incapable of entering a spin, no matter how hard it is pulled into a stall... especially an accelerated one

That thread, incidentally, is also where Bounder first posted his stall/ spin video.

Source: https://theairtacticalassaultgroup.com/forum/showthread.php?t=23900

 

If anything, this whole discussion has made me want to go make a new YT video of spins and stalls in the spitfire!

 

 

Woohoo!

 

Hey Phil, if you do make that vid, maybe include some footage from CloD so people can see the comparisons between the spins you're describing. Looking forward to watching your take on all of it!

[Bounder]

Orginally Posted by Bounder

Having said that... I tried the same test tonight on current 1.5 patch and had more trouble

 

So it's different for DCS 1.5 and 2.0? Interesting...

 

To clarify, I wasn't saying there is a difference between 1.5 and 2.0 (I haven't tested that).

 

My comparison was the behaviour of the Spitfire in December 2016 (see linked video in my post) and behaviour now (will try and get a video of this). Both tests were carried out in the standard DCS release of the time (1.2 / 1.5x back in december and 1.56 now). There have been patches in between the two and I noticed the Spitfire is more difficult to stall now and more interesting in the context of this thread, ceased spinning far faster now compared with previous tests in December.

[OnlyforDCS]

I will happily recant my position, if you throw a vid up of some spin entries and the subsequent spinning. Ideally showing third person also.

 

I don't bother with video making and recording. It's not something I do, for fun or to prove a point. I hardly have the time I wish I had to fly these days, let alone record videos and upload them to youtube or wherever. (Yesterday all I had time for was to try and do a few spins) Im tempted to try now, since it's appears that my word appears to be worthless here...

Edited May 24, 2017 by OnlyforDCS

[philstyle]

Hey Phil, if you do make that vid, maybe include some footage from CloD so people can see the comparisons between the spins you're describing. Looking forward to watching your take on all of it!

 

 

 

That means I'd have to reinstall CloD...

But.. yeah.. in the interests of science! . . lol

[philstyle]

Im tempted to try now, since it's appears that my word appears to be worthless here...

 

 

 

It wasn't meant like that (i.e. prove it!), the request for a video was meant in order to see exactly what you are doing. That will help me understand why I seem to be getting different results.

 

 

Still if you don't have time, then don't bother. I'll try and work it out...

[OnlyforDCS]

No worries. I might be doing things wrong or incorrectly interpreting whether Im in a developed spin at all, so it's not like it wouldn't have value. If I find the time Ill and try and record a video using Nvidia's shadowplay. Need to set it up first, I can choose the drive and folder it outputs to right?

[Pocket Sized]

So it's different for DCS 1.5 and 2.0? Interesting...

 

What I tried to do with Spitfire in DCS 1.5. I also have some reduced pitch control saturation (~75% of max) and I tried to roll 90 degrees left and fully pull the stick, just like in the video above. I resulted in just a flat maneuver without any spins with Angle of Attack = 30 degrees! How realistic is it? I'm not sure but from what i read, usually stall AoA is about 15-20 degrees for many aircraft.

 

During tests I managed to aquire even greater angles of attack for Spitfire, up to +35 degress for short time.

 

 

Also today i tried the same with Bf.109 without the reduced saturation: same story, stable flat maneuver with AoA ~20+ dergees.

:joystick:

 

The spitfire wing stalls at about 15° in my experience. The airplane just has enough elevator authority to push the wing far, far past stall AoA (large, high deflection elevator and aft CG)

[Art-J]

I don't think recording vids of developed spins is crucial, because, as far as I know, all DCS warbirds have always been self-recovering sooner or later after centering controls, so it seems to be intended behaviour of flight models in this sim and it's here to stay.

 

We've got a very interesting discussion here, though!

[Yo-Yo]

So it's different for DCS 1.5 and 2.0? Interesting...

 

What I tried to do with Spitfire in DCS 1.5. I also have some reduced pitch control saturation (~75% of max) and I tried to roll 90 degrees left and fully pull the stick, just like in the video above. I resulted in just a flat maneuver without any spins with Angle of Attack = 30 degrees! How realistic is it? I'm not sure but from what i read, usually stall AoA is about 15-20 degrees for many aircraft.

 

During tests I managed to aquire even greater angles of attack for Spitfire, up to +35 degress for short time.

 

 

Also today i tried the same with Bf.109 without the reduced saturation: same story, stable flat maneuver with AoA ~20+ dergees.

:joystick:

 

Congratulations! You just found the feature NACA described in its wartime report on Spitfire stall...

[Holbeach]

I tried several spins in accordance with the MkII trials of 1940 and all looked OK including the recovery.

 

Then I tried a turn to the right with right rudder, full aft stick, no power for 3 turns, returned the stick and rudder to centre and the spins continued for another 4 turns, when it stopped abruptly and entered a vertical dive.

 

..

Edited May 25, 2017 by Holbeach
Changed stalls for spins

[skliff13]

I restored the pitch saturation and carried out some minor tests of spin and recovery.

 

Small video:

 

 

And the description:

 

* Test #1. Only pitch used, no rudder. The behaviour doesn't look like a spin at all. No visible tendency to Autorotation. To recover - simply release the stick.

* Test #2. Pitch + 50% left rudder. The plane spins nicely. Pushing the stick forward leads to an immediate recover.

* Test #3. Pitch + 50% right rudder. The plane spins. I released the stick and after 3-4 turns the plane recovered automatically.

* Test #4. Pitch + 50% left rudder. Same as in (3), the plane recovered by itself after 3-4 turns with stick centered.

Edited May 24, 2017 by skliff13

[=Pedro=]

Cheers for the effort ;)

[philstyle]

Thanks Skliff. Very nice.

[OnlyforDCS]

Yes very nice. Will try and do some inverted spins and try to record them when I get the time. Hopefully over Normandy :)

[Holbeach]

I repeated an earlier spin test.

 

11,000' AGL. Started spin with right rudder and aft stick, throttle back.

 

After 4 turns centred rudder and stick and sat back.

 

Auto spinning continued for 13 turns until it hit the ground at 108 kts.

 

Opposite rudder would of course stop the spin.

 

 

 

..

Edited May 25, 2017 by Holbeach

[Yo-Yo]

It can spin if you are unlucky...

 

[Bounder]

I don't think recording vids of developed spins is crucial, because, as far as I know, all DCS warbirds have always been self-recovering sooner or later after centering controls, so it seems to be intended behaviour of flight models in this sim and it's here to stay.

 

We've got a very interesting discussion here, though!

 

But is this self-recovery after centering the controls correct for the Spitfire?

Philstyle links to a copy of a Spitfire (mkI?) manual which states:

 

"There is no difficulty in recovery, provided the standard method is correctly used - full opposite rudder, maintained until the spin stops; stick fully forward."

 

If the real Spitfire manual states this there must surely be a reason for it? It may be that the standard recovery method isn't always (or ever) needed and simply centering the controls works as well but I've not seen any literature/ evidence of that shared here (for the Spitfire) and it begs the question, why go through the trouble of opposite rudder and stick forward when centring works just fine? Is it speed of recovery? If so, the Spitfire recovers extremely quickly in DCS currently with centred controls - opposite rudder and stick forward seems redundant. Don't mean to be a pain but have to ask why the DCS Spit differs in behavior from what is described in the real Spitfire manual.

 

Posted from my phone.

[Art-J]

But is this self-recovery after centering the controls correct for the Spitfire?

Philstyle links to a copy of a Spitfire (mkI?) manual which states:

 

"There is no difficulty in recovery, provided the standard method is correctly used - full opposite rudder, maintained until the spin stops; stick fully forward."

 

If the real Spitfire manual states this there must surely be a reason for it? It may be that the standard recovery method isn't always (or ever) needed and simply centering the controls works as well but I've not seen any literature/ evidence of that shared here (for the Spitfire) and it begs the question, why go through the trouble of opposite rudder and stick forward when centring works just fine? Is it speed of recovery? If so, the Spitfire recovers extremely quickly in DCS currently with centred controls - opposite rudder and stick forward seems redundant. Don't mean to be a pain but have to ask why the DCS Spit differs in behavior from what is described in the real Spitfire manual.

 

Posted from my phone.

 

I'm not qualified to say how correct it is, just noticed how it's always been working in DCS.

 

Note, however, that using proper recovery method still helps a lot when one needs to recover as fast as possible. Centering only works, but it takes noticeably longer, especially in left spins (for the Spit) - yesterday when testing and waiting for the spins to fully develop, then centering controls, I was loosing on average unacceptable 5000 ft of altitude.

[OnlyforDCS]

But is this self-recovery after centering the controls correct for the Spitfire?

Philstyle links to a copy of a Spitfire (mkI?) manual which states:

 

"There is no difficulty in recovery, provided the standard method is correctly used - full opposite rudder, maintained until the spin stops; stick fully forward."

 

If the real Spitfire manual states this there must surely be a reason for it? It may be that the standard recovery method isn't always (or ever) needed and simply centering the controls works as well but I've not seen any literature/ evidence of that shared here (for the Spitfire) and it begs the question, why go through the trouble of opposite rudder and stick forward when centring works just fine? Is it speed of recovery? If so, the Spitfire recovers extremely quickly in DCS currently with centred controls - opposite rudder and stick forward seems redundant. Don't mean to be a pain but have to ask why the DCS Spit differs in behavior from what is described in the real Spitfire manual.

 

Posted from my phone.

 

Just a thought, but maybe just maybe the proper procedure is stated since it is the fastest way to correct for the spin. Fastest == Safest.

 

Man I hope I get some time to play with the Spit tomorrow. Long day at work today. :(

 

*sniped by Art-J :) (tired and still got a long day ahead of me)

[Yo-Yo]

I'm not qualified to say how correct it is, just noticed how it's always been working in DCS.

 

Note, however, that using proper recovery method still helps a lot when one needs to recover as fast as possible. Centering only works, but it takes noticeably longer, especially in left spins (for the Spit) - yesterday when testing and waiting for the spins to fully develop, then centering controls, I was loosing on average unacceptable 5000 ft of altitude.

 

Some planes of WWII had the ultimate mean of recover directed in the manuals: controls to neutral, pray and wait... :)

[Bounder]

Those replies make a lot of sense and I guess it's a lot easier to centre our toy controls with their centre springs than the real thing, which don't have centre springs and all the while being disorientated spinning under G with the fear of real consequences of crashing. Thanks.

 

Posted from my phone