Spinning the Spit (and other warbirds)

[philstyle]

Just a general note really...

 

I've noticed a perculiar absence of spinning aircraft in DCS. This includes aircraft which are damaged, or undamaged.

I've tried myself to flick and stall the spitfire into a spin, but I find it hard to get the aircraft to start auto-rotating, no matter what I do. It always seems to want to adopt a generally stable attitude.

 

I've also noted that I don't see other aircraft going into spins very often, if at all. In fact the only time I see aicraft auto-rotating seems to be when they are badly shot up and, essentially, no longer flight-capable machines.

 

 

The Spitfire 9 Manual says that, should the pilot get into an accidental spin, the recovery process is full opposite rudder, with a little forward stick. However, I've never seen the need for this procedure in DCS.

 

 

EDIT: For clarity, In patricular I am not talking about simply "stalls" nor "insipid spins", but rather a fully developed spin (the self-sustaining maneuver).

 

 

Has any one else noticed this? Is there a fundamental aerodynamic problem with the DCS physics engine, or are these aicraft really that hard to mishandle?

Edited May 24, 2017 by philstyle

[imacken]

Funnily enough, Phil, I have been thinking the opposite! Certainly I can't remember any other aircraft spinning, but this happens regularly to me when practising dogfighting.

I'll try later to see how I bring it on and report back.

[OnlyforDCS]

I've tried myself to flick and stall the spitfire into a spin, but I find it hard to get the aircraft to start auto-rotating, no matter what I do.

 

So, how are you going about doing that?

 

I find it's pretty easy to put any aircraft in DCS into a spin. Pull the throttle to idle, and try and keep the nose level with the horizon by slowly pulling the stick back as the speed drops. Start slowly applying left or right rudder, all the while keeping the nose on the horizon with liberal aielron use. That should pretty much do it.

 

Im thinking that maybe you're not having enough surface control authority with all of that saturation you are using with your config.

[philstyle]

So, how are you going about doing that? .

 

I've tried multiple methods:

Nose-up stalls & level stalls with rudder

Nose up and level stalls with aileron

Nose up and level stalls with rudder+aileron (opposite) combination

Max-rate turn with de-satbilizing rudder thrown in

Max-rate turn with opposite rudder+aileron combination thrown in

 

 

I've tried the same at high speeds too (well above stall speed) to try and unduce a flight.

 

 

All I can manage is abrupt wing drops. But the aircraft recovers before it will go into a sustained auto-rotation.

 

Im thinking that maybe you're not having enough surface control authority with all of that saturation you are using with your config.

 

I've only had the low saturation for 2 to 3 weeks. I've been flying the spit since Decermbar last year. The two cannot be correlated.

[OnlyforDCS]

You tried stalling that bird before you changed your settings? Maybe they changed something in the flight model. I will try and stall her today and report back.

[philstyle]

You tried stalling that bird before you changed your settings? Maybe they changed something in the flight model. I will try and stall her today and report back.

 

 

 

I tried is waaay back in dEcember when I first had the sim. I think I even showed some attempts in my very first ever DCS spitfire video.. can't quite recall.

 

Either way, I hardly ever see anyone else spinning either.

Stalling, sure, but not spinning

[OnlyforDCS]

Yeah thats what I meant, the classic spin stall. The Spitfire might be naturally resistant to entering the spin. But Im sure I've done it a few times. Ill try and reproduce today after work and report back.

[=Pedro=]

Try to reset your trim first, than try it again at high angels ;)

[imacken]

Funnily enough, Phil, I have been thinking the opposite! Certainly I can't remember any other aircraft spinning, but this happens regularly to me when practising dogfighting.

I'll try later to see how I bring it on and report back.

Actually, having tried it for a while today, I'm beginning to see what you mean, Phil.

Whenever I get into a spin, letting go of the joystick for a few seconds seems to get the plane stable again!

I'm sure it didn't used to behave like that.

[Holbeach]

Today I tried at 10,000', several, power off, power on and gear and flaps down spins.

 

All were perfectly normal, including standard recovery

 

Regards.

 

..

[OnlyforDCS]

Actually, having tried it for a while today, I'm beginning to see what you mean, Phil.

Whenever I get into a spin, letting go of the joystick for a few seconds seems to get the plane stable again!

I'm sure it didn't used to behave like that.

 

But you did manage to get it into a spin first?

 

Centering controls usually does the trick (depending on the type of spin). Remember most joysticks have a centering spring, something that the real airplane controls don't have.

[Pocket Sized]

Most WWII birds, to my knowledge, have good enough stability margins that a self sustaining spin is very difficult to enter.

 

As for DCS in general, the only aircraft I can really spin are the F-15 and F-5E (with a bit of practice, that is).

 

Edit: good point, OnlyForDCS. To fully center the controls In a spin, you need to apply a considerable amount of pressure IRL.

[OnlyforDCS]

Ok just tried it at home. Free flight mission, Nevada. (for kicks) Altitude somewhere above 10k feet. Managed to get into a corckscrew spin on the first try from level flight. Though the Spit seems very, very resistant to it. I needed full right stick deflection and full left rudder, then switched to full right rudder to get it to spin. As soon as I centered the controls and applied opposite rudder and added power I managed to get out of the spin, though it was pretty close to the ground by then.

 

It's actually amazing how much lift those big wings provide, and how high the critical AoA of the Spit is. No wonder it is one of the best turnfighters of the war. It really needs very, very little airflow over the wing to provide lift.

Edited May 23, 2017 by OnlyforDCS

[philstyle]

Today I tried at 10,000', several, power off, power on and gear and flaps down spins.

All were perfectly normal, including standard recovery

Regards.

..

 

any chance of a video of it?

[Holbeach]

any chance of a video of it?

 

Are you looking for the flat spin, which is self sustaining?

 

I doubt that it's possible with a Spit, except with the loss of a wing, or maybe a full aft fuel tank.

 

The type I'm doing is pilot sustained, such as you would get on the approach, or in cloud.

 

..

[Perfesser]

Agreed.

The only thing more resistant to a spin seems to be the 109.

[bongodriver]

Agreed.

The only thing more resistant to a spin seems to be the 109.

 

Which makes some sense, the leading edge slats give a margin of stability that make it more resistant to spinning, not impossible to spin but certainly more forgiving.

 

On the wider issue, there were very few aircraft that would not recover from a spin if the controls were put at least to neutral (effectively just letting go) one of my old flying instructors told me the only aircraft he could think of that wouldn't self recover that way was the EE lightning, and he spent his entire RAF career on the machine apart from a brief stint in the Red Arrows on the Gnat.

When doing intentional spins it is required to hold pro-spin input in order to maintain and I have rarely seen a case where recovery didn't start to happed as soon as the controls were moved to neutral and fully recovered before full anti-spin inputs reached. on occasion some spins wind up nicely and it takes a few turns to recover mainly because the aircraft has built up some inertia in the spin. I find DCS has all this modelled very well, spinning is a doddle and the Spits pre stall buffet is absolutely magic using FFB, just ride the buffet and watch everyone else flop around trying to turn with you.

[Bounder]

Just a question to those testing, are you using modified joystick settings i.e. curves & decreased saturation? Bringing it up as there were threads very recently describing reducing saturation and using curves to improve the sensitive Spitfire controls and I thought it might have an effect on these results if still being used?

 

[edit] reading back through the thread again I'm not sure I'm understanding fully "Spinning the Spit" - are we talking about the ability to get the aircraft to enter a stall (e.g. accelerated stall), enter a flat spin, about behavior once in a stall, or all three? If we are talking about pulling enough AoA to get the aircraft to enter a stall your controls (or lack of them with limited joystick saturation) will most likely have an effect for obvious reasons.

 

I posted a video before on this subject and can post it again, the Spit will enter an accelerated stall. I don't use any saturation or curves and it will do it:

 

 

Having said that... I tried the same test tonight on current 1.5 patch and had more trouble. I did enter a stall but not as easily. Further I had a lot more trouble entering a stall in a right turn than left. It is almost a struggle to get the Spit to stall in a right turn now. Furthermore, once in the stall and with hands off the stick and pedals, the Spitfire seems to settle out very quickly, stop spinning and then gradually nose up. Seems a bit wrong to me (but whatdoiknow)? I can post a new video for comparison with the above (filmed back in December) compared with now where it does seem far more difficult to enter a stall and far quicker hands off recovery.

 

If I've got the wrong end of the stick please ignore but very interesting thread.

Edited May 23, 2017 by Bounder
testing

[philstyle]

Just a question to those testing...

Having said that... I tried the same test tonight on current 1.5 patch and had more trouble. I did enter a stall but not as easily. .

 

 

 

Hi Bounder, a couple of things;

 

 

1. I've ony very recently lowered my saturation in control inputs. I had the same observations prior to doing this as I have now. In addition I can still stall the aircraft with saturation as low as 20%. I am confident I can rule out the saturation curves as haviong anything to do with it on those two grounds.

 

 

2. "Stalling" is not the issue being raised in this thread by the OP. The issue here is Spinning. No all stalls result in a spin, I am aware of that.

 

 

In patricular I am not talking about insipid spins, but rather a fully dveloped spin ( self-sustaining maneuver).

 

I have also updated the OP for clarity, seems the "definition" of spins/stalls has created some confusion in the thread.

[OnlyforDCS]

What is an insipid spin? Doesn't the example in the video Bounder posted qualify as a self sustaining spin stall?

Edited May 24, 2017 by OnlyforDCS

[Art-J]

Wait, maybe let's narrow something down first - Phil, what do you mean as self-sustaining spin? Do you ask whether the warbirds in DCS can go into fully-developed spin, in which they continue to rotate even with controls centered and stop rotating only after counter-spin controls are applied?

 

That's indeed how planes behave in Il-2:CloD for example, but not in DCS - here, centering controls is enough for the planes to recover relatively easily, though it takes a bit longer compared to applying dedicated recovery input. How realistic it is, I do not know.

[OnlyforDCS]

Has anyone tried to do an inverted flat spin? Im pretty sure that it happened to me in the Spit on at least one ocassion. If entered in specific conditions it is very hard to recover from that one. Will try and do one today.

[skliff13]

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...

 

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:

[philstyle]

Wait, maybe let's narrow something down first - Phil, what do you mean as self-sustaining spin? Do you ask whether the warbirds in DCS can go into fully-developed spin, in which they continue to rotate even with controls centered and stop rotating only after counter-spin controls are applied?

That's indeed how planes behave in Il-2:CloD for example, but not in DCS - here, centering controls is enough for the planes to recover relatively easily, though it takes a bit longer compared to applying dedicated recovery input. How realistic it is, I do not know.

 

Exactly...

This description is almost a match to the definition of the "fully dveloped spin" ( self-sustaining maneuver) that is repeated in a lot of literature (I've clarified this two or thgree times in this thread already now.. am surprised people keep asking TBH), and it matches the description of the Spin in the Spitfire IX Manual, which requires the pilot to input conuter-spin controls.

http://i.imgur.com/J80I0wb.png

Full disclosure: I am comparing, in-part- to IL2:CloD, where seeing an aircraft spinning out of control was a regular occurrence. Manhanding the aircraft too aggressively could often result in a spin, which would not be nearly as easy to recover from as we see in DCS. Recovery from a fully developed spin in CloD required the opposite rudder, idle throttle and a small amount of forward pitch, exactly as described in the Manual for the spitfires right the way through the war.

 

That's not so say that CloD was MORE historical than DCS. Also the CloD aicraft are early war, despite having largely the same aerodynamics. However, CloD seems to match the manual more closely.

Edited May 24, 2017 by philstyle

[OnlyforDCS]

How realistic is it?

 

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.

 

*edit*

 

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.

Edited May 24, 2017 by OnlyforDCS
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