Weight and balance computer apparatus for aircraft
AssigneeSperry Rand Corporation
InventorHarry Miller
Life of this patent
Estimating the term…
Abstract
Aircraft weight and balance computer apparatus processes sensor outputs to generate an electrical signal that is proportional to aircraft gross weight at the time take-off thrust is initially applied to the aircraft on the runway and continually updates the weight signal when airborne to account for burn off of fuel or other weight loss and also provides a measure of the location of the aircraft center of gravity position. This is achieved by computing the aerodynamic forces on the aircraft in its longitudinal plane and the thrust generated by the engines and relating these computations to the corresponding acceleration components measured by a pair of linear accelerometers that are mounted orthogonally in this longitudinal plane.
Claims28
Apparatus for providing a measure of the gross weight of an aircraft having engines for providing propelling thrust therefor comprising
- a. means responsive to an operating characteristic of the engines for providing a measure of the thrust thereof,
- b. means responsive to aerodynamic forces acting on said aircraft and said measure of thrust for providing a measure of a function of the angle of attack of said aircraft, and
- c. means responsive to said angle of attack function measure for providing an output measure of the gross weight of said aircraft.
Apparatus for providing a measure of the take-off weight of an aircraft comprising
- a. means for providing a measure of an operating characteristic of the aircraft engines for providing a measure of the take-off thrust thereof,
- b. means for providing a measure of the longitudinal acceleration of the aircraft,
- c. means for providing a measure of the rolling friction of the aircraft,
- d. means responsive to said measures for providing an output measure of the take-off weight of said aircraft as a predetermined function of said signals,
- e. switch means for rendering said means responsive to said measures effective, and
- f. means responsive to a predetermined value of said engine operating characteristic for operating said switch means.
Apparatus for providing a measure of the gross weight of an engine powered aircraft comprising
- a. means responsive to an operating characteristic of each of the aircraft engines at the Mach number speed and static pressure environment of the aircraft for providing a signal corresponding to the thrust produced on the aircraft by each of the engines and means for summing all of said thrust signals for providing a resultant signal corresponding to the total thrust produced by all of the engines,
- b. means responsive to accelerations of the aircraft along mutually perpendicualr axes corresponding to the vertical and longitudinal axes of the aircraft and for providing signals corresponding thereto,
- c. means responsive to the Mach number speed of the aircraft and the static pressure environment of the aircraft for providing signals corresponding thereto,
- d. means responsive to the positions of aerodynamic surfaces of the aircraft affecting the lift and drag characteristics thereof, and
- e. computer means responsive to all of said signals for providing an output signal corresponding to the solution of the pair of equations ##EQU38## wherein W = the gross weight of the aircraft
- T = the total thrust of the engines
- a.sub.x = longitudinal acceleration of the aircraft
- a.sub.z = normal acceleration of the aircraft
- M = the Mach number speed of the aircraft
- P.sub.s = the static air pressure at the aircraft
- .alpha. = the angle of attack of the aircraft
- C.sub.l = the coefficient of lift of the aircraft
- C.sub.d = the coefficient of drag of the aircraft
- S = the wing area of the aircraft
- g = the gravity acceleration of the earth,
- said output signal corresponding to the simultaneous solution of said equations for said gross weight term W.
Apparatus for providing a measure of the position of the center of gravity of an aircraft having a main sustaining wing, wing flags, horizontal stabilizer and elevator, relative to the mean aerodynamic chord of said wing comprising
- a. means for providing a signal proportional to the effective position of the horizontal stabilizer in producing a pitching movement on said aircraft,
- b. means for providing a signal proportional to a function of the horizontal and normal accelerations of the aircraft and the thrust-to-weight ratio of said aircraft, and
- c. means responsive to said signals for providing a signal proportional to the position of the center of gravity of the aircraft about which said pitching moment is effective.
Dependencies are inferred from the claim text.