Since I learned to fly (in Canada) in 1976, I can think of a couple of training spinning accidents. But, in terms of things gone wrong causing accidents, I don’t have the sense that spin training accidents are high on the list. More common than instructor + student spinning (only two come to my mind in recent decades), I can recall many more spin in accidents with new pilots out fooling around, particularly in 172’s with four aboard. (And let’s recall that an all up 172 is spin recoverable, but more skill and effort will be required, and getting it right out is vital – don’t go more than a turn).
So perhaps new pilots felt emboldened with a little knowledge about spinning, and went out on their own. I certainly did. I recall my instructor demonstrating spins, asking me to demonstrate my ability to enter an recover, and then telling me to go an practice on my own, he did not like spinning. He did not spin with me again until my practice flight test.
I doubt that there are persuasive statistics about the spin training risks Canada vs US. But I certainly have had many American visiting pilots ask me to show them spins!
Canada and Alaska may have a higher proportion of low level manoeuvring in their statistics – not sure any interesting conclusion might be drawn, statistically speaking.
Spinning was taken out of the FAA syllabus to reduce training accidents I thought. Does Canada have a higher incidence of stall/spin accidents in training? This would be more apples to apples?
Fuji_Abound wrote:
What we dont know is how many pilots have recovered from an inadvertent spin (or spiral)
Yes. That is why it is so interesting to compare Canadian and US accident rates, because spin recovery training seems to be the major difference between the two countries. It seems that there is no benefit in Canada where spin recovery training still is part of the PPL syllabus (or was until recently), which it has not been in the US for many years.
It appears there is a difference in the effect from doing spin recovery training and doing e.g. training landings. It seems that some landing accidents could have been prevented by better stick-and-rudder skills, whereas spin accidents generally only could have been prevented by recognition and avoidance training, but not by recovery training.
LeSving wrote:
That is very creative statistics to say the least. It only shows that if you initiate a spin at an alt where you cannot recover, you will crash.
What we dont know is how many pilots have recovered from an inadvertent spin (or spiral). That would be interesting. In the commercial world reporting is mandatory. There might be a safety case for reporting in the non commercial arena – even if not everyone would comply. Not than I am suggesting it is very likely in the type of aircraft used for CAT!
I use to fly unlimited, first in a Pitts then a Sukhoi 31. I have seen every type of spin imaginable in an airplane with normal spin characteristics.
Power off always. Neutral ailerons. Opposite rudder. Wait for the rotation to stop, elevator forward (how much depends on airplane, what you want the spin to look like, and CofG).
Occasionally you may need inspin aileron, especially when recovering from what was a full power flat spin (where the nose position in the spin is above the horizon) – especially if your CofG is aft. (This lowers the angle of attack on the inside wing and gets it flying early).
Another unlimited pilot told me that he told his students that you cant spin if all the controls are neutral – in other words if you are not in a spin, and you are unsure what is going on, might be better to think about what is happening rather than start moving things around. (Not strictly true, with enough torque or precession from a big prop, anything is possible).
Once the spin has developed, the opposite is not true. Center the controls and something really interesting might happen.
huv wrote:
Studies of spin accidents all tell the same story – once the spin was a reality, so was the accident. Hardly any of the spin accidents could have been saved by better recovery technique – they all started too low.
That is very creative statistics to say the least. It only shows that if you initiate a spin at an alt where you cannot recover, you will crash. It’s like saying you shall not teach people to push the stick fwd because they may hit the ground (which is dead certain when you do that at 10 ft). Seriously, it’s exactly the same thing, totally koo koo logics. Training spins, you will learn how to handle the aircraft better. This will make you a better pilot. Will it make you a safer pilot? who knows? using the creative statistics logics, the only safe pilot is the one with both feet firmly plated on the ground – always. Only problem is, he will no longer be a pilot.
The tolerance for overspeed is 10%, which is a certification requirement. This is mostly a buffet/flutter margin, though also an opportunity to assess trim and handling entering and recovering from the 10% overspeed. That’s what I was doing, while flying the DA-42 at 110% Vne, assessing externally mounted survey booms for buffet. Don’t worry, I had a flight permit to allow it. The tolerance for overstress is 150%. BUT, beyond 100%, you may be damaging the airframe, and that damage may not be immediately apparent.
I believe in stall and spin training, with proper aircraft, in a proper environment. This belief was reinforced to me last fall, when I waterlooped my flying boat. I was turning on the step as I had done hundreds of times before. The rudder pedal forces were exactly as they had always been, and suddenly a gust of wind, as I turned out of the wind was enough to reduce rudder effect, and around I went. A small amount of damage, and some embarrassment with my passenger. I had never waterlooped before. But, now that I had, I realized how close I had come to waterlooping so many times before. On all those previous occasions, I assumed that I had lots of reserve control. Nope, with my new, hard won wisdom, in hind sight, I was at 99% of the control I had available, and could waterlooped on earlier occasions – when getting a damaged plane home would have been a very much greater problem. I was lucky, my bad event happened in about the most convenient body of water possible for me.
Sometimes, the learning is not only about the event, but more importantly, the approach to the event. How far can you push something? Maybe not as far as your adventurous mind thinks! Losing control, in a safe environment, is an important part of learning how one should maintain control. It should not be the vague fear of the unknown, but rather the informed fear of the known. Yes, most spin accidents are fatal, because they are allowed to occur in the circuit, by an unaware, or unfearing pilot.
Having been taught spins 38 years ago as just another part of the glider flight training’s syllabus, and having performed them occasionally in Decathlon, Cub and C172 since then, I would like to say that it is valuable training to all pilots. But statistics does not seem to support that.
Studies of spin accidents all tell the same story – once the spin was a reality, so was the accident. Hardly any of the spin accidents could have been saved by better recovery technique – they all started too low. Additionally statistics comparing the US and Canada find that there is no difference in the rate of spin accidents despite the fact that Canada train PPL’s (i.e. all pilots) to spin, while the US has not done that for a very long time.
I love to train pilots to spin and recover, but I cannot honestly say it makes them safer pilots.
Spiral dives are quite another matter. They are much easier to get into unintentionally, and unlike spins the can destroy the aircraft long before you hit the ground. Vne can be reached and exceeded very fast, and the tolerance for overspeeding is relatively much smaller than for g overstressing. (The picture above is really distressing.)
Knowing how to recognize and avoid stalls will prevent any spins. But knowing how to avoid spiral dives is what matters when it comes to staying alive.
RobertL18C wrote:
however in normal stall recovery, ie at first indication, pushing over into 1/2 G (the new stall speed being 70% of 1 G stall), will set you up for a secondary stall.
Yes, at the first indication of a normal stall, a slight “check forward” would be all that is required to prevent the stall. Apparently a few pilots are not sensitive to the first indication. If the stall has become aggravated, or a spin, pushing forward to unload G may be required in some circumstances. This is the background for the phrase “move control wheel briskly forward” which can be found in some flight manuals.
RobertL18C wrote:
When the wings are rolled level, and the IAS has stopped increasing, the aircraft is flying level and will want to return to trim speed. It shouldn’t require a 2.8G pull, but just some initial back pressure, and stop. You shouldn’t pull on the elevator/stabilator, the aircraft will recover more safely to trimmed speed on its own.
Yes, the trimmed aircraft will want to return to its trim speed, but it could easily exceed Vne during the process, if the pilot does not intercede. A dive which has had a roll component or upset, usually requires a pilot pull to recover. The key is to apply the pull without overstressing the aircraft. Under spiral dive recovery, Cessna says for the Caravan:
Cautiously apply elevator back pressure to slowly reduce the airspeed to 115 KIAS.Quote
Any clean aircraft pointed near straight down from a cruise speed entry will accelerate a lot before it finds its trimmed speed again.
If the pilot has forced the plane into a less pitch down (than near vertical) dive from level flight, without retrimming, then yes, a push will be required to maintain the dive, and the aircraft will try to return to trim speed on its own. The pilot will then have to be careful to assure that the nose is not allowed to come up too quickly, or the aircraft might overstress itself, or overshoot the level flight attitude into a high pitch up.
Unloading G is correct, however in normal stall recovery, ie at first indication, pushing over into 1/2 G (the new stall speed being 70% of 1 G stall), will set you up for a secondary stall. At zero G your stall speed is helpfully zero 
and in a stall turn you are pulling around 3 to 4 G in the recovery. Releasing back pressure to eliminate the symptom of the stall is recommended, to avoid setting up for a secondary stall. Pushing over towards zero G sets you up for requiring more of a dive, and more G in the recovery.
In a spiral dive a reasonable assumption is that the aircraft would be trimmed for a speed in the green arc. After bringing power to idle, you should ensure you are releasing back pressure as you roll wings level. When the wings are rolled level, and the IAS has stopped increasing, the aircraft is flying level and will want to return to trim speed. It shouldn’t require a 2.8G pull, but just some initial back pressure, and stop. You shouldn’t pull on the elevator/stabilator, the aircraft will recover more safely to trimmed speed on its own. Rich Stowell calls this the Power-Push-Roll hierarchy.
Hardly any modern aircraft have Turn/Slip indicators, which ARE reliable for spin recovery, both upright and inverted. The tilted gyro of the Turn Coordinator, is NOT reliable for spin recovery. Spin training requires clear ground features, hence the HASELL check to not carry out stall exercises over large expanse of water or an undercast.
