Wednesday, 1 June 2016
(Acknowledgments: Nigel Everett, GASCO Flight Safety)
Hi Folks! The following is taken from an excellent editorial by Nigel in the current edition of the GFS Magazine, based on the GASCO Stall & Spin Study of 2010.
A Student pilot can be led to believe that a large, perfect field is essential, because the instructor always opts for such a one when demonstrating emergency landings. As a survivable deceleration (9G) from 50 mph requires just under 10 feet of landing space, it is often better to select a clear approach zone, even if the field is small and rough.
In itself this is no protection. In stall/spin accidents, a fatal outcome is more common amongst qualified PPL/CPL holders than amongst Student pilots, and 22% of all such accidents occur with an instructor on board.
Ditching, when the aircraft is flown to a conventional wings-level touchdown and occupants are wearing life jackets, is very likely to end in survival. Of 179 ditching cases studied over four years, only 12% involved fatalities. Bear in mind, however, that in most water landings an aircraft will not remain upright, leading to injuries and an immediate survival situation.
Flying an aircraft under control into treetops is very survivable, often with no or only minor injuries. Only 6% of landings into trees involved fatalities.
Better odds than water or trees, as only 3% of field landings resulted in fatalities, and these almost always involved inattention to airspeed leading to Loss of Control (LOC) whilst manoeuvring for landing. Striving to reach perfectly level ground, or an airfield beyond realistic gliding distance, will very likely end in LOC.
Whatever surface is available, the goal is to achieve the lowest forward speed whilst minimising the rate of descent. The human body is better able to absorb forward speed than vertical speed, which is what compresses spines and ruptures diaphragms.
It is prudent therefore, whilst staying well clear of LOC parameters, to practice glide approaches regularly by making a proportion of normal landings completely power off, both to achieve slow arrival and to remain familiar with the aircraft’s glide capability.
One thing is relatively certain. The aircraft will probably be a write-off, so if a forced landing situation arises the pilot must forget sentiment and consider the aeroplane to be nothing but an expendable collection of aluminium, steel, rubber and fluids.
Forced landings are frightening but they can be made without serious injury provided that the pilot remembers the first rule of aviation:
“No matter what, always fly the aeroplane!”