FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsMedium
A technician overhauling a main landing gear brake assembly finds alternating rotating and stationary friction discs that are compressed together by hydraulic pistons to produce braking force. This describes which type of brake?
- AMultiple-disc brake
- BExpander-tube brake
- CSingle-disc brake
- DShoe-and-drum brake
Show answer & explanationAnswer & explanation
Correct answer: A. Multiple-disc brake
A multiple-disc brake uses several rotating discs (keyed to the wheel) alternated with stationary discs (keyed to the torque tube), all squeezed together by hydraulic pistons to generate friction. This design is common on transport-category aircraft for greater heat capacity and braking surface.
Why the other options are wrong
- B. An expander-tube brake uses a rubber tube expanded by hydraulic pressure against brake blocks, not discs.
- C. A single-disc brake has only one rotating disc, not alternating multiple discs.
- D. Shoe-and-drum brakes use curved shoes pressed against a rotating drum, found on light aircraft.
Multiple-Disc Brake
A brake assembly using several alternating rotating and stationary discs compressed by hydraulic pistons to create braking friction, common on transport aircraft.
- Rotating discs are splined to the wheel
- Stationary discs are keyed to the torque tube
- Provides greater surface area and heat capacity
- Used on most large jet transport main gear
Memory trick: Many discs, many hands squeezing together = multiple-disc brake.