“GEAR” CAS message during take-off
Effectivity: Global 7500 series aircraft
ATA 32
By: Jonathan Couture – Technical ServicesSome operators recently reported having a momentary “GEAR” CAS message during take-off.
It is important to know that this warning is not related to a system malfunction, but rather meeting the logic that prevents landing with inadvertent gear-up condition. The logic is based on the following parameters:
L/H OR R/H Aircraft Radio Altitude below 600 ft.
Landing gear not down and locked
Throttle Lever Angle (TLA) below 25 degrees or Slat/Flap Control Lever (SFCL) detent 4
If all these conditions are met, the landing gear system will conclude that a landing is about to happen without the gear being extended. The “GEAR” CAS message will be posted until one of the conditions is no longer present.
During investigation of the reported events, the warning was triggered when the crew pulled back the TLA below 25 degrees after selecting “gear-up” while they were still between 500 and 600 ft. (rad-alt). A few seconds later, the message was cleared as the aircraft climbed above the 600 ft. (rad-alt) threshold.
To avoid a false “GEAR” CAS warning, it is important to fly the aircraft outside of those parameters and be aware that this warning will be posted if doing so is not possible.