Final answer:
The APU fire extinguisher does not automatically discharge if a fire is detected on the ground. The ground crew must manually activate the fire extinguisher. Proper procedures and guidelines should be followed to handle fires on the ground safely.
Step-by-step explanation:
The Automatic Fire Extinguishing System (AFES) on an Auxiliary Power Unit (APU) does not automatically discharge if a fire is detected on the ground.
When a fire is detected, the AFES activates a fire warning annunciator and shuts off the APU fuel supply. The ground crew must manually discharge the fire extinguisher by pulling the APU fire handle to suppress the fire.
It is important for the ground crew to follow proper procedures and guidelines provided by the aircraft manufacturer or the airline to ensure the safe handling and suppression of fires on the ground.