| Patent Number |
Title Of Patent |
Date Issued |
| 4890284 |
Backup control system (BUCS) |
December 26, 1989 |
| A backup software program is installed in an isolated portion in the memory of at least one of redundant computers. The backup program performs basically the same functions as the prime program but is dissimilarly programmed to prevent a common software error. Switchover to the backup |
| 4741501 |
Preventing augmenting vertical load induced oscillations in a helicopter |
May 3, 1988 |
| Collective stick inputs are provided (18) to a high pass filter (24) when collective stick reversals in excess of a threshold collective authority rate (15%/sec) and in excess of a threshold frequency (3 stick reversals per second) are sensed. The output of the high pass filter (24) is s |
| 4580223 |
Incorporation of pitch bias actuator function into an existing AFCS |
April 1, 1986 |
| An aircraft automatic flight control system (AFCS) includes a pair of fast, limited authority inner loop actuators responsive to signals indicative of aircraft attitude or other flight parameters such as airspeed, the inner loop being recentered by an outer loop actuator responsive to at |
| 4566101 |
Oscillatory failure monitor |
January 21, 1986 |
| An oscillatory-failure monitor (101) compares a parameter of a plurality of signals (A, B) within a tolerance (TOL) to determine agreement or disparity among the signals. Each discrete miscompare occurrence (i.e., singular disparity following full agreement) is counted by incrementing |
| 4564908 |
Automatic limiting of helicopter engine torque |
January 14, 1986 |
| A torque limiting altitude hold system for a helicopter engages torque limiting (56, 203) when excessive torque is anticipated (138, 202) as determined by the summation of present torque and torque rate times a reference value (126, 194) exceeds maximum torque with torque limiting en |
| 4563743 |
Maneuver-force gradient system |
January 7, 1986 |
| A maneuver force gradient system causes a helicopter, that otherwise tends to pitch up in a banked turn, to pitch nose-down. A command signal (25) is provided as a function of the roll angle to operate the longitudinal trim actuator (27) which automatically moves the cyclic control (50) |
| 4500967 |
Aircraft short-term roll attitude retention system |
February 19, 1985 |
| An automatic flight control system, for an aircraft having a roll attitude retention outer loop actuator (29), a roll stability inner loop actuator (25) and a control stick (26) for positioning control surfaces of the aircraft to control its roll attitude, includes means (54, 55) to prov |
| 4382283 |
Helicopter attitude and airspeed acquisition and retention system |
May 3, 1983 |
| A helicopter pitch axis autopilot system, including airspeed hold at cruise speeds and pitch attitude hold below cruise speeds, includes integrated longitudinal acceleration drift corrected by heavily filtered Pitot static airspeed as a filtered airspeed reference, use of a beeper to nud |
| 4337516 |
Sensor fault detection by activity monitoring |
June 29, 1982 |
| Faults in a sensor (10) are detected by excess rate fault determination by taking the differentiated (58, 107), rate limited (60, 100, 111) integral (64, 112) from the raw sensor output (72, 113) and indicating a fault (15, 117) in the event that the difference exceeds a predetermined ma |
