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Old 3rd Jul 2014, 22:40
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john_tullamarine
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(a) basic certification stall and recovery (as in the AFM) is not concerned with ground contact ergo it is all about unstalling (ie alpha reduction), getting the speed to a comfortable margin above stall (1.2Vs is normally quoted) and then recovering back to normal flight.

(b) in the real world (excluding real world military operations and like higher risk civil activities), the risk of stalling principally is in the circuit while manoeuvring for a landing, especially the IFR bad weather circuit case whilst hooking around to final and overbanking to adjust a misjudged base.

Hence, the operational Regulatory process traditionally was concerned with minimum height loss during the recovery. The result was that the typical recovery trained and demonstrated in endorsement and recurrent training had scant resemblance to the certification animal .. this could, on occasion, result in unexpected frights.

One notes that there have been numerous deltas between the design/certification and operational sides of the table over the years ...

Mishaps, such as AF447, clearly demonstrated that the system possibly had missed the point of the difference between design/certification (ie what the aircraft should reasonably be presumed capable of doing) and operational (ie what was going to kill us most of the time in short order) reality.

As an Industry we are in the process of recalibrating our thinking .. so far this has evolved at airline level and progressively will filter down to the GA area in due course.

The aim now is to unstall FIRST .. then worry about recovering to normally controlled flight and avoiding ground contact.

As in all things (other than death and, possibly, taxes) there are no guarantees .. only probabilities .. and the aim is to load the dice in favour of survival. That might not work ALL the time but it will work MOST of the time.
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