Undercarriages for Deck Landing: Special Design Features with Particular Reference to the Vertical Velocity of Descent at Touch‐Down

FOR landing on aerodromes, aircraft under‐carriages are now designed to give a certain safety factor on strength for specified conditions. These conditions have been determined after considerable investigations and represent the most severe landings that aircraft can reasonably be subjected to, and are defined in terms of the ground reaction applied to the wheels when the aircraft touches down at a specified arbitrary vertical velocity of descent in an airborne landing; i.e. the aircraft weight balanced by the aero‐dynamic lift on the wings. In a normal landing, of course, the aircraft is seldom 100 per cent airborne, but this assumption is a sufficiently accurate approximation. The vertical component of this ground reaction may be associated with various components of drag and side load, to cover for example the drag loads due to spinning up the wheels on surfaces with various coefficients of friction, ground ‘bumps’, drift, etc.