The APU pneumatic supply connects to which system?

The APU (Auxiliary Power Unit) pneumatic supply connects to the aircraft bleed air manifold system. The primary function of the APU is to provide bleed air that is used for various essential aircraft systems, such as starting the main engines, environmental control systems, and for cabin pressurization.

When the APU operates, it generates pneumatic pressure that can be diverted to the bleed air manifold. This supply of high-pressure air is crucial for starting the engines and supporting the operation of air conditioning and pressurization systems while the aircraft is on the ground, particularly when the engines are not running.

In summary, the connection of the APU to the aircraft bleed air manifold system highlights its role in providing necessary pneumatic power for vital aircraft functions, especially during ground operations.