FAA Aviation Mechanic Airframe (AMA)Landing Gear SystemsHard
An aircraft's normal hydraulic brake system has failed completely. The pilot pulls an emergency brake handle, which releases compressed nitrogen from a storage bottle through a metering/relief valve directly to the brake pistons, bypassing the hydraulic power system. This describes a
- Aexpander-tube brake system
- Bpower brake control valve system
- Canti-skid modulation system
- Dpneumatic emergency brake system
Show answer & explanationAnswer & explanation
Correct answer: D. pneumatic emergency brake system
A pneumatic emergency brake system stores compressed air or nitrogen in a bottle and, when activated, routes it through a relief and metering valve directly to the brakes, providing braking capability independent of the hydraulic system in case of total hydraulic failure.
Why the other options are wrong
- A. An expander-tube brake is a brake design type, not an emergency backup power source.
- B. A power brake valve is part of the normal hydraulic braking system, not the backup.
- C. Anti-skid modulates brake pressure electronically and requires hydraulic pressure to function.
Pneumatic Emergency Brake System
A backup braking system using stored compressed air or nitrogen, released through a metering/relief valve directly to the brakes when normal hydraulic braking fails.
- Stores gas in a charged bottle
- Bypasses failed hydraulic power system
- Metering valve controls pressure applied to brakes
- Provides braking capability without normal hydraulic power
Memory trick: When hydraulics quit, compressed air steps in to stop.