Short Field Landing -Definition Please

[de La Valette]

Scenario: B737 requires (say) 1700 metres landing length from Flight Manual. Flight Manual also provides correct Vref for weight in order to satisfy the distance needed. This is for normal landing because the term "short field" is not defined in the manual. The speed used is generally 1.3 Vs, depending on certification parameters.

Most Cessna manuals give tables with a specific speed entitled Short Field Distances, which are also based on a flight manual chart speed of 1.3Vs. Why therefore is one called normal landing, and the other short field when the speeds are both based on the Flight Manual figures?

If 1.3Vs speeds are safe (30% above the power off stall), then why do flying schools teach faster speeds over the fence as a normal landing while reserving the 1.3Vs speed for short field landings. How long must a field be in GA parlance to deserve the title Short Field?

And if 747's, and other jet transports use 1.3Vs as normal procedure, are these then short field landings?

I read somewhere that true short field landings, sometimes known as Precautionary landings, were a military combat landing approaching just above the stall at 1.1VS power on stall.There was no float, the aircraft was flared with power on then cut - same as an aircraft carrier approach. Obviously not appropriate to civil flying schools.

Would it be correct to assume therefore, that the flying school syllabus short field landing at 1.3Vs over the fence is really a normal landing as used routinely in jet transport landings, and that short fields are in the eye of the beholder. Confusing, isn't it?

[Angle of Attack]

It is interesting is'nt it. Firstly I think it's a lot easier for the jets to use a predetermined Vref speed without too much worries regardless of conditions, whereas its a little more difficult for a C152 to come in on final at the short field approach speed in gusty turbulent windshear conditions. I think flying the aircraft at slightly higher speed during a normal approach is just an increase in the safety margin if unexpected gusts are encountered. As for differences in a normal landing and a short field landing even though one might be approaching at the same speed, remember that the technique upon touchdown is going to be quite different ie. maximum braking in a short field landing. As for the "military style" approach I practise that one myself. For example the C152's short field approach speed is 54 knots but on a smooth day it is quite feasible to come down to 40 knots over the fence driving it in on power and coming to a stop before the end of the piano keys! Assuming there is a bit of headwind of course!