Original Posted By: Michael D Cuy
As taken from the book Aircraft Design - Volume Two - Aerostrctures by C. H.Latimer Needham in 1939, I quote the following passage about these twosubjects. My comments are added in the :"The airscrew clearance should be about 6 inches with the aeroplane inrigging position, tyres flat, and shock aborbers compressed to their maximumvertical travel ."The point of wheel contact with the ground should make an angle with thevertical through the CG in side elevation (aircraft in rigging position) ofnot less than 10 degrees, and may increase with wheel brakes up to a maximumof 14 degrees."The tendency of aircraft to overturn when landing with wheel brakes may beprovided against by arranging for the brakes to be released as the tailskidleaves the ground . It has beenfound, however, that if the angle, made by the line joining the point ofwheel contact to the CG with the vertical line through the CG when the tailskid is touching, is at least 20 degrees, no overturning is likely. Anangle much greater than 20 degrees results in excessive tail loads atlanding and difficulty in taxi-ing and at takeoff ."It may be noted that the overturning tendency is not great at the moment oftouchdown since the aircraft is still largely airborne and skidding of thewheels takes place. Towards the end of the run both aerodynamic lift andcontrol are negligible, the braking effect increases and for safety thebraking load should be decreased.________________________________________________________________________________Date: Tue, 05 Feb 2002 12:10:04 -0500