I just had a nightmare. It was watching an inexperienced Cessna pilot toying with aerobatics, with deadly result after a piece of plane fell off in an over-zealous spin recovery.
I am a member of the Gliding Federation of Australia and a glider pilot.
In the GFA Pilot training program, spin training is mandatory. In fact, all pilots must demonstrate correct spin recovery at their annual checkflight.
Any GFA pilot may practice spinning at any time provided the aircraft is suitable and there are no specific Club Rules preventing aerobatics in a hired club plane.
There are pre-requisites to spin safety.
1. The aircraft must be certified for spinning.
2. the aircraft must be within weight and balance limitations for the spin. (which it usually is in certified types)
2. the Pilot is thoroughly briefed in the procedure, and an instructor current in spin training present.
3. A pre-aerobatic check is done before commencement of the spin.
An understanding of the difference between a spin and a spiral dive is essential, as is correct spin recovery procedure for the particular aircraft flown.
Both spins and spiral dives have steep nose down attitudes. (flat spins are beyond my experience sorry....)
A spiral dive is sometimes allowed to develop accidently, by the pilot believing he is in a spin and not recognising the build up in airspeed. The wings are unstalled in a spiral dive. A spiral dive is characterised by a rapidly increasing airspeed and slower rate of rotation than the spin.
If a spiral dive develops, it is imperative that recovery action is taken quickly, as destructive speeds are very quickly reached. The aircraft needs to be rolled level and the nose raised to decrease speed.
In a spin, the inner wing is stalled, and airspeed usually reaches a limit quickly. Rotation is usually quite rapid.
A spin occurs when one wing stalls before the other, usually in a turn at low airspeed, we call this early spin stage an "incipient spin". The outer wing remains unstalled in a spin, but it's aileron is useless against the forces of the spin.
A spin is rotation in all three axis, PITCH, ROLL and YAW.
Hence the wild ride!
If corrective action is not taken immediately upon the incipient stage of the spin, a full blown spin with it's unnerving rotations quickly ensues.
Spins can usually be corrected at the incipient stage by relaxing back pressure on the controls, (even forward pressure is needed in some types of aircraft). This reduces the angle of attack on the stalled inner wing,
allows airspeed to build up and the stalled wing begins to fly again.
Opposite rudder to the direction of the spin must be applied to stop rotation in the yaw axis, this rudder force is applied at the same time as the elevator control is put forward.
It is IMPORTANT to recognise the DIRECTION of the spin and apply the correct OPPOSITE rudder control or recovery may not be possible.
Once the yaw rotation slows or stops, and the wing is unstalled, roll the wings level with aileron then recover from any resultant dive with steady back pressure on the controls while monitoring airspeed. It is important not to over stress the airframe at this stage of recovery. Avoid a panic pullup at high airspeed, you may lose a wing or something else.
So, in a nutshell, the basic spin recovery procedure is:
1. STICK FORWARD OF NUETRAL
(Don't invert - just enough to get the wing flying again)
2. FULL OPPOSITE RUDDER UNTIL ROTATION CEASES
( then center the rudder, you might spin the other way)
3. ROLL LEVEL AND RECOVER FROM RESULTANT DIVE
(You must get the nose up. Be gentle, dont break it.)
Spins are dangerous and deadly for the unprepared, particularly at low altitude where there is insufficient recovery height. Unfortunately this low altitude flight is where they often occur.
In a landing circuit, while turning onto crosswind or final,
an aircraft is vulnerable if airspeed is low. That is why proper landing speeds must be flown.
A gust can induce a slow turning plane into a spin. That is why glider pilot's are trained in spin recognition and recovery. A glider turning in a rough thermal close to stall speed is a spin waiting to happen! In reality it rarely happens because the pilot is very tuned into the feel of the plane. But It happens.
It is very unfortunate that the current flight simulations offer such poor spin emulation, because this is a manuever that could be perfected in the comfort of an armchair, rather than risking life and limb, not to mention the stress caused to aircraft when they are mishandled during training or genuine emergency.
Airspeed is everything. Watch your Attitude!
Sweet Dreams!