A few points on the matters that Whatunion has mentioned on the subject of stalling and spinning.
1. C of G. The position of the C of G makes no difference at all to the stalling characteristics, so why there should be any “surprise stall accidents” I do not understand. Perhaps he would enlighten us mere current mortals by providing some examples. However, the more rearward the C of G the lower the stalling speed will be. The reason is that with a rear C of G the nose down pitching moment of the C of P and the C of G is reduced. This means that a lower downward force from the tailplane is required to balance it. Since total lift in level flight must balance the aircraft weight plus the tailplane down force, a lower total lift from the wings results in a lower stalling speed. As far as spinning characteristics are concerned, a rear C of G can make the recovery more difficult since the moment arms of the elevators and rudder are reduced thereby cutting down their effectiveness.
2. Use of Power. Full power should always be used as a means of reducing the height loss. This is easily demonstrated on the first stalling exercise by showing the height loss on a fully developed stall with and without using any power. On average it will at least halve the amount of height loss. Subject to any engine limitations there is no good reason not to use full power.
3. Wing Drop. The position of the flaps is irrelevant. Given symmetrical wings in balanced flight it does not matter whether the inboard or outboard sections of the wings stall first. The point is that both wingtips should stall at the same time, so there will be no wing drop. The use of stall strips on the inboard leading edge is not necessarily to make the inboard part of the wing stall first. They are very useful for promoting an early breakaway of the airflow and causing the buffet over the tailplane that we use as a recognisable stall symptom. Wing drop will, however, be caused if there is any difference in lift over the wings. Causes of this can be as simple as slight irregularities [dents, dirt, insects etc], and more usually not being in balanced flight. Any sideslip will cause a blanking effect over the downwind wing. It is therefore not so much a case of wing drop as the fact that the downwind wing is producing less lift than the upwind one.
4. Ailerons. Whether or not ailerons will still work at the stall depends on the design of the aeroplane. Vortex generators ahead of the ailerons or a smooth wing surface such as can be provided with composite wings will prevent or delay the transition to turbulence and the separation point. However, a cambered airfoil has a lower stalling angle than a non cambered one, so the application of ailerons in an attempt to raise a down going wing has the effect of putting that wing well beyond the stalling angle of attack. It also increases the coefficient of drag. These two effects give rise to autorotation and a spin, hence the dictate not to use ailerons at the point of a stall.
5. Standard Stall Recovery. Ever since I learnt to fly in 1965 I have been taught, and teach, that the Standard Stall Recovery is “Control column centrally forward to unstall the wings, full power and rudder to prevent further yaw [see previous paragraph].” How do we know that the aircraft is unstalled? Either when the buffet has stopped or, in the case of aircraft such as the Cessna 172 which has no real buffet, when the stall warner has stopped. You cannot use the same argument for a spin recovery because that depends entirely on the characteristics of the aeroplane. I have spun aircraft in which the fully developed spin recovery is merely to centralise the controls. Others require the stick to be moved to the neutral position at the same time as full opposite rudder is applied, others after a pause of about one second. Others need the stick to be progressively moved forward until the autorotation has stopped and some even need inspin ailerons. So to state blandly “Move the CC forward until flying control is regained” is not necessarily correct and most certainly cannot be used as a standard for both stall and spin recoveries.
So, in reply to Whatunion, I would say that nothing much has changed over the years. However, since he has on his own admission not instructed for 14 years, perhaps he could refrain from telling those of us who are still current in the matter all the causes and effects. By and large we already know the answers and are constantly in the habit of teaching them, and being tested on them every three years, practically and without “downloading a set of diagrams.” Nor do we need to complicate the subject in search of an ego trip. We do, however, need to make sure that our students fully understand what is happening, or might happen, and the consequences.
To Paulo I would like to say “Good call.”