Spins - How dangerous?

[secks]

I've got a few questions regarding spins:

1) Can spins only be caused by stalling and applying rudder? Are there other ways to induce a spin?

2) Are some spins unrecoverable?

3) Are some aircraft incapable of entering a spin?

4) Is spin recovery part of a typical PPL training program?

5) How dangerous is your typical spin?

6) Ever had a close call while attempting to leave a spin?

Thanks

 

[katanabob]

1. A spin is the direct result of exceeding a wing's critical angle of attack while slipping/skidding. The aircraft descends in a helical path while maintaining the aforementioned high alpha condition. This can occur at any combination of airspeed, attitude, and altitude.
LAYMAN'S TERMS: You stalled and were uncoordinated.

2. Spin recoverability depends most highly upon aircraft design and rate of descent as compared altitude vs. altitude required to exact recovery. Some airplanes are more difficult to recover from a stalled condition and thus more difficult to recover from a spin. A simple example of this that you should see in training is the effect of CG movement upon stall recovery.

3. As long as there have been airplanes, there have been designers claiming to have created 'stall-proof' designs. If it can stall, it can spin. A canard design is configured such that the control surface stalls prior to the wing, exacting a recovery before the wing can exceed its critical angle of attack.

4. Yes.

5. This depends highly upon how much experience your instructor has with regard to performing them. A properly-executed spin in the training environment is no more dangerous than the performance of stall series, and statistically less dangerous than some ground reference manuevers.

6. Yes, but only because I was young and stupid. Multiple successive snaprolls (a snaproll is essentially a spin on a horizontal line) at low altitude are not possible in a Supercub unless you recover after each revolution. Loose articles in the cockpit are not a good idea, and neither are unsuspecting girlfriends in the back seat. Loose girlfriends in the cockpit during unannounced enroute snaprolling procedures in a Supercub.. well, don't try that one at home.

 

[Iceman21]

4) Is spin recovery part of a typical PPL training program?

Spin recovery is not required of a PPL program and it not included in the PTS.

However, Stall/Spin awareness is required. You will never have to recover from a spin during your private training or you commerical training for that matter.

In reference to canards, the canard is designed so the canard itself stalls before the wing does. It can lead to a false sense of security. When a canard stalls, the rate of descent experience can be close to what would be experienced with an actual stall, and the aircraft will feel as if it is under control, but in fact the airplane is on its way to making a pancake on the neighborhood lawn. Essentially, you can hold back on the yoke and the nose will pitch down once the canard stalls, but in order for the aircraft to fly correctly the canard must be taken out of the stall condition. Otherwise, you will descend all the way to the terrain in a relatively flat attitude at an excessive rate of descent.

 

[Flyingtoohigh]

1) Can spins only be caused by stalling and applying rudder? Are there other ways to induce a spin?

If you are in uncoordinated flight during the stall, you will spin.

Some aircraft are more forgiving than others. The Cessna 152 that I spun with my instructor while working toward my CFI took full opposite controls to reliably develop into a full spin. If I closed the throttle, neutralized the rudder, or neutralized back pressure on the elevator, the spin would stop. The 152 is a very docile airplane in a spin and you must hold it in the spin yourself!

 

[Timebuilder]

I agree about the 152. I had to hold the yoke all the way back to keep the airplane spinning. After the first time, I said "hey, let's do that again!!"

Back to number 2.

A number of aircraft are unrecoverable in a spin. The typical attitude for these aircraft in a spin is "flat", where there is no or little nose-down attitude, which prevents the airflow over the wings and controls from being restored, breaking the stall.

I would never stall a multiengine airplane.

Jets have stick shakers and "pushers" to help prevent the aircraft from entering an unrecoverable condition.

Stalls are for training.

 

[bigD]

I would never stall a multiengine airplane.

Do you mean *spin* a Multi-engine airplane?

 

[flywithastick]

Re: Re: Spins - How dangerous?

If you are in uncoordinated flight during the stall, you will spin.

Not sure I agree with this. I don't believe every instance uncoordinated stall will result in a spin. A snap, maybe.

One other thought. don't think it would be neat to load up a -172 with your buddies and go try some spins. get a couple of big people in the back seat, and the stability (aft cg) gets real marginal.

2¢

 

[Timebuilder]

Well, BigD, you got me.

Do you mean *spin* a Multi-engine airplane?

Yes. That's what I ws going for this morning with only one eye open. In fact, you must be careful when and how you stall a twin. If you inadventently stall during a Vmc demo, for example, you are in trouble.

 

[Vector4fun]

1) Can spins only be caused by stalling and applying rudder? Are there other ways to induce a spin?

Depends on the airplane. Some will spin with your feet flat on the floor in the right circumstances.

2) Are some spins unrecoverable?

Yes. I knew two pilots personally that died in aerobatic aircraft conducting inverted spins. In both cases, the spin went flat, and in both cases, they never recovered, or got out.

3) Are some aircraft incapable of entering a spin?

I wouldn't want to be the test pilot that proved that fact.

4) Is spin recovery part of a typical PPL training program?

I believe it is, or should be part of the typical ground school discussion of stall/spin awareness. I doubt it's actually practiced in flight at most flight schools.

5) How dangerous is your typical spin?

MINE are quite safe, as I won't do one unless it's in an aircraft that's been certified for such, and I'm comfortable with THAT particular aircraft. I also adhere to the published limitations and procedures for doing them. I also like to have a chute, and LOTS of altitude.

6) Ever had a close call while attempting to leave a spin?

NO. I think the danger comes when people try them in strange aircraft, with little preflight planning or review of the aircraft's own published limitations and standards. Just because you successfully spun a C-152 once does not make you safe to spin a Luscombe because somebody said "they spin real good". Unfortunately, that seems to be all the necessary info some folks need to play test pilot.

I also have a BIG problem with folks spinning someone else's aircraft for no reason other than a "thrill", and screwing up the gyros....

 

[dmspilot00]

Re: Re: Re: Spins - How dangerous?

don't think it would be neat to load up a -172 with your buddies and go try some spins. get a couple of big people in the back seat, and the stability (aft cg) gets real marginal.

...not to mention it's illegal to spin a 172 with people or objects in the back seat or baggage compartment, I believe.

 

[Iceman21]

172's are certified to spin in the utility category only. No backseaters.

The 172R model is not certified to spin at all.