SEARCH What's New

Emphasize awareness in stall/spin training

 

In a recent Transport Canada newsletter, the Transport Canada Civil Aviation Standards Branch outlined a recent study of stall/spin training. They concluded that in all of the spin accidents studied, the spin occurred at too low an altitude for recovery and therefore we should put more emphasis in our training on stall/spin awareness.

This is something I have been advocating for some time. The way we have been teaching stalls and spins bears little, if any relation to how they develop in the real world. We become very proficient in our recovery actions, but don’t learn well how to avoid the situations in the first place.

The Standards Branch is suggesting that we train our flight instructors on how to better teach stall/spin awareness.

This may take some time and most of you have your licences and won’t benefit from this change.

To start with, we must learn the situations where we are most likely to get into trouble.

One of the most likely scenarios is when we rapidly add power in an overshoot or bounce recovery and we allow the aircraft pitch attitude to increase too quickly and we do not correct for yaw.

We must always remember that we may have to overcome the pitch-up tendency that comes from a sudden addition of power and we must correct for the yaw. We have been taught that when we add power, we must add rudder to correct for the yawing tendency.

Let’s back up and think about adding rudder as the power is added. We shouldn’t have to be correcting for anything if we coordinate our control inputs.

A second scenario occurs when we attempt to turn back to a runway or strip if the engine starts to lose power. Even a docile aircraft like a Cessna needs approximately 800 feet to successfully complete a 180 degree turn. If we don’t have that we tend to tighten the turn and stall. It is likely that we don’t have enough rudder input as well.

We should not turn back to a runway unless we have less than 90 degrees to turn and at least 500 feet of air under us.

The third scenario is when we let the airspeed get too low on final approach and raise the aircraft pitch attitude to correct the rate of descent. The addition of power at the stall warning is likely to be rapid and we end up in a similar situation to the overshoot described above.

The forth scenario is when we overshoot final approach and tighten the turn back to the runway. Again, we likely do not have appropriate rudder input when we stall.

In all of these situations, the entry into the stall is likely to be very aggressive, not at all like we practiced.

These situations need to be practised at altitude so that we learn to recognize them and avoid them at low altitude. We can go one step farther at altitude and let the situation develop into a spin so we can see how a spin actually develops.

The current method of practicing spin entries bears no relation to reality.

A Cessna 150, 152 or 172 aircraft can enter into a spin if we enter a climb with partial to full power and let the pitch attitude increase until the aircraft stalls.

No rudder input is required; in fact we should keep our feet off the rudder pedals. The aircraft yaws itself as the airspeed decreases and at the stall, it will fall nicely into a spin. This is realistic practice.

A Piper product doesn’t enter quite so nicely and might take just a little coaxing but the idea is there. We can practice the same kind of entry from slow flight by just letting the speed bleed off and keep our feet off the rudders.

The next problem with our training is nowhere does it say we should reduce power in the recovery. Almost all spins in the real world are entered with power on.

This power must be reduced to idle to allow for recovery, just before or as we are applying full opposite rudder.

The fifth scenario is losing control in cloud and entering a spin.

Most likely it will be a spiral dive, but we will leave realistic spiral dive training and recovery for another column.

How do we know we are in a spin if we are in cloud? The instruments. We must take a moment to see what they are telling us. If the airspeed is low, the altimeter is showing a rapid descent and the turn coordinator (turn and bank indicator) is showing a turn, we are in a spin.

We should also think about stalls and spins and how they might behave at different forward and aft C of G loads and near gross weight. Due to aircraft limitations, it may not be possible or safe to practice this.

If an aircraft is loaded too far forward, the aircraft nose at the stall may drop farther and faster than expected.

We may not have enough rudder input available to stop spinning or enough elevator input available to raise the aircraft pitch attitude high enough to stop the descent in time.

If we stall with an aircraft loaded too far aft, we may not have enough elevator input to lower the aircraft pitch attitude enough to recover from the stall or spin.

We can load an aircraft to near its gross weight and get used to the feel of how the aircraft handles and how it reacts to attitude, airspeed and power changes. This may help awareness of how it might react in a stall.

The way to avoid a stall or spin is to always be aware of what we are attempting to do and what pitch and bank attitudes we have in relation to our airspeed, and to always fly with the correct rudder inputs.

Modern Cessna and Piper aircraft have made us lazy in the use of our feet. Whenever power is added or reduced, a foot should be moving with the hand on the power lever and an eye should be kept on the ball.

Dale Nielsen is an ex-Armed Forces pilot and aerial photography pilot. He lives in Abbotsford, B.C., and currently flies medevacs from Victoria in a Lear 25. Nielsen is also the author of seven flight training manuals published by Canuck West Holdings.