Abstract: A method and system for braking aircraft landing gear wheels after initialization of landing gear retraction. The system includes monitors, controlling components, measurement components, a fault recording memory, fault annunciation components, wheel braking system and brakes. The monitors monitor speed of the landing gear wheels and landing gear position. The control component generates braking instructions based on the monitored speed of the wheels and position of the landing gear.

Abstract: A low-speed antiskid control for a multigain hydraulic valve brake system for an airplane is disclosed. The antiskid control includes low- and high-pressure bias modulation (PBM) high step thresholds. At high speeds the low PBM threshold is used to control a PBM high step firing. At low speeds, the high PBM threshold is used to prevent a PBM high step firing unless a deep skid is occurring. The use of a high threshold at low airplane speeds prevents a low speed control loss due to PBM high step firing reducing brake pressure to below minimum brake contact pressure.

Abstract: At low speeds, an antiskid/autobrake control system applies a brake release current to the antiskid valves of the brake system associated with selected wheels of an airplane to prevent brake shudder caused by gear walk. The control system obtains a measured wheelspeed value from each of the selected wheels and calculates a reference wheelspeed based the measured wheelspeed. Tests are made to determine if the reference wheelspeed is below some predetermined magnitude, e.g., 15 knots, and if the airplane ground speed is below some predetermined magnitude, e.g., 50 knots. If the tests are passed, the value of a low-speed brake release current to be applied to the antiskid valves of the airplane's brake system is determined. In order to prevent an abrupt change in braking, the low-speed brake release value ramps off as the airplane slows to a stop. Releasing some of the brakes results in the pilot increasing pressure on the remaining brakes, thereby eliminating brake shudder due to gear walk.