Patent ID: 6564142
Filing Date: 2003-05-13
Classification: G01M

Abstract:
A method for determining the location of the longitudinal center of gravity of an aircraft of the type having a landing gear arrangement including a pair of transversely spaced apart main landing gear units and a third ground support member located substantially on the longitudinal axis of the aircraft forward or aft of the main landing gear units, said method comprising the steps of:a. determining the aircraft inclination; b. determining total aircraft weight; c. attaching a lever apparatus to a selected lifting point located substantially on the longitudinal axis of the aircraft; d. determining the horizontal distance between the selected lifting point and the main landing gear wheels; e. lifting the third ground support member from the ground using the lever apparatus by applying a force to one end of the apparatus; f. measuring the reactive load at a point along the length of the lever apparatus; g. relating the measured reactive load to the load on the nose wheel to determine aircraft nose wheel load; and h. relating the nose wheel load to aircraft center of gravity according to the relationship Lm&it;â€ƒ=â€ƒ&it;Pn&it;â€ƒ&it;L(WT)&it;â€ƒ&it;cos2&it;â€ƒ&it;Î¸&it;â€ƒ+â€ƒ&it;Lzm&it;â€ƒ&it;tan&it;â€ƒ&it;Î¸â€ƒâ€ƒwhere WT equals total aircraft weight; Pn equals the load on the third ground support member when the member has been raised from the ground; &thgr; equals aircraft angle of inclination; L equals the horizontal distance between the third ground support member and the main landing gear units; Lzm equals the vertical position of CG above the main landing gear units; and Lm equals the horizontal distance between CG and main landing gear.