STUDENT GUIDE FOR T-1A AIRCRAFT SYSTEMS
Landing Gear Warning Tone
The landing gear warning tone is initiated if one or more of the landing gear are not down and
locked and either one of the following conditions exist:
Flaps are at the 0 or 10 degree flap position and either or both throttles are retarded to a
position corresponding to approximately 70% N2.
Flaps are extended beyond the 10° position regardless of throttle position.
Landing Gear Position Indicators
Three green indicators and one red indicator are located on the face of the landing gear control
unit to the right of the LDG GR handle. Each green indicator corresponds to one of the landing
gears (NOSE, LH, and RH), and when illuminated indicates the gear is in the down-and-locked
position. An illuminated red UNLOCKED indicator indicates one of the following:
Landing gear is in transit.
One or more landing gear is not locked.
Main gear fuselage doors are not closed and locked.
A safe up-and-locked condition is indicated when all three green and the red unlocked indicators
are extinguished. Pressing the face of the light may test these lights.
Each main gear wheel is equipped with a hydraulically operated disc brake assembly. Pressure
for operation of the wheel brakes (with the exception of the emergency brake system) is provided
by the aircraft hydraulic system and is initiated by the brake pedal master cylinders.
The power brake anti-skid control valve is used to release and apply hydraulic pressure to the
main gear brake assemblies and has three modes of operation:
In the manual mode, the power brake anti-skid control valve is open and the anti-skid system is
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