Reviewing the stall series can be very educational. Today's instructors do not let the aircraft stall completely; when the stall warning sounds, they start the recovery process. Together we examine the power on and power off, departure, trim and accelerated stalls. By incrementally approaching the stall, the pilot learns every aspect of how the stall happens and how to extract himself from it. Stalls usually occur during maneuvering in the airport traffic pattern.
Spinning the airplane is not something demonstrated by most instructors. There are a couple of reasons for this. The first is most training aircraft are no longer certificated for spins. The second is that most instructors don't have confidence in demonstrating the maneuver. Their exposure to it was minimal in their training. The reason for this is that the training regulations only require basic spin training for the CFI endorsement, and most instructors never revisit the spin again.
These are called unusual because they are not normal. The upsetting of an aircraft can be due to winds, wake turbulence, stalls and emergency maneuvering. Hazards can be an overstressed airplane that has exceeded Vne or maximum "G" load. Knowledge of your attitude and power settings can eliminate the stress on the airplane and minimize altitude loss. This is very important when close to the ground as in an approach to landing or shortly after takeoff.
