How is the AMAD connected to the Auxiliary Power Unit (APU)?

How is the AMAD connected to the Auxiliary Power Unit (APU)?

• A. Thermally connected to the APU through a heat exchanger
• B. Pneumatically connected to the APU through the air turbine starter (ATS).
• C. Electrically connected to the APU through a generator
• D. Hydraulically connected to the APU through a pump

Answer: (B)

AMAD is the Aircraft Mounted Accessory Drive, the central shaft that powers the aircraft’s accessories. To start an engine, the APU provides bleed air to the air turbine starter. The ATS uses that pneumatic energy to spin the AMAD, which then drives the engine’s accessories (like pumps and generators) long enough to bring the engine up to speed and start. This is a pneumatic link via the ATS, not a heat-exchanger, electrical, or hydraulic connection. The other options don’t supply the initial drive needed to rotate the AMAD during start.

AMAD is the Aircraft Mounted Accessory Drive, the central shaft that powers the aircraft’s accessories. To start an engine, the APU provides bleed air to the air turbine starter. The ATS uses that pneumatic energy to spin the AMAD, which then drives the engine’s accessories (like pumps and generators) long enough to bring the engine up to speed and start. This is a pneumatic link via the ATS, not a heat-exchanger, electrical, or hydraulic connection. The other options don’t supply the initial drive needed to rotate the AMAD during start.