Recovering from a FLAT spin.

[Keygrip]

Ok - most prints say it can't be done.

Anybody want to argue with that? What actions would you take to attempt a recovery from a flat spin.

(I wonder what percentage of answers will be smartae rather than constructive?)

[Blackshift]

Get as much weight forward as you can pronto - slide seats forward and move any items with much weight foward if you can - and hope that this is enough to nudge the nose down towards a conventional spin in time for you to recover normally when (and if!) the flight controls regain their effectiveness.

Could also try applying power with control column fully forward to induce a pitch down I suppose.

That's all I can really think of ... although I suspect that I might also suddenly find religion and pray furiously as a back up plan in such circumstances!

... but only after completing the above actions as best I could.

[VFE]

Could also try applying power with control column fully forward to induce a pitch down I suppose.

So power causes the aircraft to pitch down eh? How's that work then chief? Inverted flat spin.... now you might wanna try the power, I guess?

What would also be of good use here would be to discuss how we avoid the flat spin.

VFE.

[Final 3 Greens]

In retract, I suppose that you could drop the gear.

Who knows what it might do, but it couldn't make things much worse.

[Keygrip]

VFE - you almost made the percentage 50/50 at that point.

But - the pitch up with power doesn't happen any more after exercise 4 ('cause we don't let it) - so MAYBE full power, full forward pressure (to prevent nose rising) MIGHT get enough airspeed increase to allow the relevant control surfaces to become effective again?

[FlyingForFun]

Ok - most prints say it can't be done

I've said before on these forums that I don't claim to be particularly knowledgeable about aeros, and that applies here too, so maybe I've got the wrong end of the stick. But when I did my aerobatics training, I entered and recovered from what my instructor called a "flat spin". Basically, enter a normal spin, then add power. The more power you add, the flatter the spin becomes - from the pilots perceptive, the nose was noticeably higher, almost as high as the S+L attitude.

Recovery was the "standard" spin recovery as for a normal spin, including reducing power to idle first (which is part of the normal recovery anyway).

This was in a Great Lakes bi-plane. If my memory serves me correctly, we also did the same thing in a Pitts S2B. And also if my memory serves me correctly, we did this both upright and inverted.

FFF
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[VFE]

It's a fair point Keygrip. Slipstream over rudder might be a possibility but it ain't gonna pitch the nose down. Wouldn't increased power also affect the gryoscopic properties of the spinning aircraft in some way?

Where's your test pilots when ya need 'em eh?!

VFE.

[Say again s l o w l y]

The power helping the spin will also depend on which way the a/c is spinning.

Adding power my help, it certainly won't make it worse! It may give you enough airflow over the rudder and elevators to do something.

I think the key is, if it ain't working with the standard recovery for that machine, then try anything!

[VFE]

Not forgetting that many a good man has been killed "trying anything" during a spin when the aircraft does not respond to the standard recovery action after 3 or more rotations.

They get worried, panic, and try something else.... then it's "hello terror firma" [sic].

VFE.

[greeners]

Sorry guys, but if you want to learn how to do this properly, go to a suitable training organisation that will show you how.

In most GA aircraft a flat spin should be recoverable, given correct technique and enough height.

[Speed Twelve]

I'd reach up, pull the canopy handle, call 'jump, jump, jump' to the stude then unstrap and go over the side with my left hand on the d-ring.

[Blackshift]

.... but not from 10,000ft presumably - c'mon mate give us yer tuppensworth... you know you want to!

[Speed Twelve]

Ok Blackie...

The Firefly will enter a flat-ish high-rotational spin mode if the normal spin recovery is mishandled even slightly. Us chaps are required to do a dual high-rot spin sortie annually in which this spin mode is deliberately induced and the instructor left to sort it out.

Delayed spin recovery is pretty straightforward, reapply pro-spin controls and recommence the normal recovery technique. In a high-rot spin the stick tends to go pretty much all the way to the forward stop. The aircraft snaps out of the spin pretty abruptly and if you aren't circumspect with centralising the control column then an outside loop tends to commence!

There are no other published spin recovery drills that we use. Prevention is quite good, and a lot of emphasis is placed on incipient spin recovery technique in the mil. Applying this promptly and correctly will sort things out no matter how wild the initial departure, as long as you are quick and accurate with the controls.

First item on the Immediate Action Drill for a full spin incidentally is 'check height'. If you are approaching your pre-calculated minimum abandonment height (transition level + height of ground) then you'd just throw the aircraft away. At minimum abandon (normally FL35-FL40) there's just enough time to get rid of the sunroof, unstrap, step outside, get clear the aircraft and pull the d-ring. Incidentally, the last time a mil crew had to throw away a Firefly in a spin the instructor had to physically crawl over the side of the cockpit against rotational 'g' before jumping clear AFAIK.

I wouldn't be keen to deliberately spin an aircraft without a parachute. Even C152s can bite. An ex-Perth CFI managed to recover (at 1500' agl IIRC) from a high-rot spin in one a few years back. I think a CAA test pilot became involved with that one.

[LD Max]

I'm generally inclined to agree with Blackshift's original post about getting the weight forward pronto.

Interesting post from Speed Twelve, however, since the principle there is clearly to re-establish a bog-standard (non-flat) spin before implementing the correct recovery. All very sensible really.

However, if we are talking about an unintentional flat spin in something like a PA-28 for example, I would start by saying a Flat spin is defined as "Rate of Yaw exceeding Rate of Roll in any attitude including inverted". Unintentional Flat spins are usually, (I accept not always), caused by an AFT CG.

Flat spins around the CG are considered impossible to recover from, therefore your primary task will be to move the CG forward and initiate or increase Rate of Roll so that it at least equals or exceeds the existing rate of Yaw.

I would suggest a suitable Recovery procedure is Power OFF, (since power tends to flatten a spin), move the CG forward, (seats, bags, POH, Extinguisher, lean forward), while applying PRO SPIN Aileron. I would tend to suggest Neutral on the rudder, because although the secondary effect of the rudder is to induce Roll, clearly one wishes to reduce the dominant yaw without necessarily impeding any roll being commanded by the ailerons.

When, (or if), Rate of Roll equals or exceeds Rate of Yaw, the spin is no longer considered "Flat" and you can then execute a standard spin recovery.

Thing is - if this were a test question - an FAA examiner can't really say any of this is particularly wrong, because INTENTIONAL flat spins are limited to very few aircraft types and the recovery procedure is pretty much as as above, (without considering how to change the CG).

UNINTENTIONAL flat spins, however, require you to be a "test pilot" because the aircraft almost certainly won't be certified for it, since being well outside the utility category is probably what got you into the situation in the first place! So I don't suppose there is a definitive answer. But if it were me, I'd start with the above and work from there.

I have heard of people rocking the aircraft, "pumping" the control column etc etc. Who knows what will work on your type of plane? One only hopes you figure something out in time. If you don't have a parachute, let's hope there's a lake nearby and you might be able to bale out!

[DFC]

Originally Posted by VFE

It's a fair point Keygrip. Slipstream over rudder might be a possibility but it ain't gonna pitch the nose down. Wouldn't increased power also affect the gryoscopic properties of the spinning aircraft in some way?
Where's your test pilots when ya need 'em eh?!
VFE.

I have flown at least 3 types that pitch down when power is applied. The pitching direction depends on the position of the engine and the thrust line and drag line.

Regards,

DFC

[LD Max]

Originally Posted by DFC

The pitching direction depends on the position of the engine and the thrust line and drag line.

DFC is, of course, quite correct. However increased slipstream over a bottom mounted elevator (i.e. not a T-tail) is likely to increase elevator authority. Therefore pushing forward on the control column with an increased slipstream will tend to lower the nose (relative to the pilot) on most aircraft.

Of course this also ignores the effect of the CG around which all the moments will rotate. If the CG is too far aft, then no amount of elevator authority will lower the nose, which is probably why an aft CG is cited as the most common reason for entering an inadvertant flat spin.

Any spin can be defined as autorotation in any three axes. Whether it is "flat" or not depends only upon the relationship between Roll and Yaw, since the attitude of the aircraft is immaterial. The trick to getting out of a flat spin is to ensure rate of roll >= to rate of yaw. You can do what you like with pitch! Unless this leads to an increase in the rate of roll, your spin is still flat.

For my money, I could live with a pitch up just as easily as a pitch down upon closing the throttle. A pitch down is likely to enter a normal spin. A pitch up is likely to enter an inverted spin. Both are equally likely to promote roll, and therefore permit a standard spin recovery.

[7gcbc]

Adding power my help, it certainly won't make it worse! It may give you enough airflow over the rudder and elevators to do something.

or in the case of the Pitts S2b adding power will raise the nose , accelerate more, and flatten the spin even further. (which puts you further away again from recovery), it actually depends on the type.

I think Greeners has made the only point worth making.

Sorry guys, but if you want to learn how to do this properly, go to a suitable training organisation that will show you how.

[Capt Pit Bull]

I have flown at least 3 types that pitch down when power is applied. The pitching direction depends on the position of the engine and the thrust line and drag line.

Point of information.

It is thrust line related to vertical CofG. Very common misconception regarding the drag line. Remember, force couples are a convenient short cut that can be used to quickly determine the effect of two forces when they are equal.

If T <> D then the combined pitching effect could be either way.

If anyone feels the inclination to tell me I'm talking rubbish, please check your basic physics first

pb

[JonWhitehouse]

Not intending to suggest any rubbish, just adding my tuppence worth.If I remember my basic physics you can replace any a force acting from any point by a force acting from any other point plus a moment acting.
The forces do not have to be equal, if they are not you would simply get an additional force acting through the rotation point which would not affect the pitch up (or down) as there is no moment from it.
Thus the pitching moment will not be either way if the forces are not equal, it can be calculated, and as was said, depends on the a/c type.

BTW it would make sense to calculate the effect of combined forces by shifting them to the vertical CG as you said.

Regards
JW

[rmcdonal]

unintentional flat spin in something like a PA-28

Good luck, I find it a bit of an effort to intentionaly get even a wing to drop at the stall, let alone spin.
Me +Airobatics=