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Old 4th Jun 2011, 12:58
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A37575
 
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the optimum short field technique requires power to be on until the aircraft is in the landing attitude and near the ground - when it's removed the aircraft promptly lands.
This is true if you have reduced the final approach speed to barely above the stall with the stall warning sounding. This was a wartime technique for landing into unknown length strips. Of course there was no stall warning horn although in a Tiger Moth the slats would flutter in and out and were a reliable stall warning. Nowadays we would call it a minimum ground roll landing - which after all is why the former short field landing or precautionary landing was all about in the first place.

But where light aircraft flight manuals landing distance are usually predicated on a min speed of 1.3 VS at 50 feet with power off, the true short landing technique (1.05 VS) is a thing of the past. One often reads of flying instructors talking about using the correct 1.3Vs landing speed as a short landing and then brief the effect as if it is on the point of stall and no float. That is incorrect. However, because most instructors teach their students to approach somewhat faster than is needed (presumably to allow for error and give a longer float for smoother touch down), then the faster approach is considered a `normal` approach - while approaching at the flight manual recommended speed is seen as a `short field` landing and to be undertaken with extreme care...

Interesting that jet airliners cross the fence at the flight manual recommended speed for a normal landing. There may be wind component additives but nothing extra thrown in for mum and the kids. But Cessna would call it a short field landing...

By definition, today's short field landings are flown at the same speeds as normal landings even though the Cessna Manufacturer's Information Manuals label their landing distance charts "Short field".

Confusing I know but it helps to know one's history.

P.S. Extract from RAF Pilot's Notes for Chipmunk. AP 4308A - PN Date 1950. Part 2 sub-para 30. Approach and Landing:
"It is recommended for all conditions that the airfield boundary be crossed at a speed of 55-60 knots. The initial glide or powered approach should be made at 60 knots.
For a precautionary landing an initial approach with full flap under power at 55 knots is recommended, aiming to cross the airfield boundary at about 50 knots". Unquote.

Stalling speed under typical approach conditions, flaps fully down is 35 knots. That applies whether power is on or off.

Last edited by A37575; 4th Jun 2011 at 13:17.
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