In the manual start procedure, how is the start valve opened?

In the manual start procedure, how is the start valve opened?

• A. By selecting the MAN START pb to ON
• B. By pressing the ENG START button
• C. By turning the ENG mode selector to IGN START
• D. By pressing the APU start switch

Answer: (A)

Opening the start valve in a manual start is done by selecting the MAN START pushbutton to ON. This command directly opens the engine’s start valve, allowing bleed air (from the APU or another source) to flow to the start port and spin the engine up with ignition. The normal engine start button starts the engine via the standard start sequence but does not manually open the start valve in the same way. Turning the engine mode selector to IGN START simply enables ignition; it does not by itself open the start valve. The APU start switch only starts the APU, not the engine being started.

Opening the start valve in a manual start is done by selecting the MAN START pushbutton to ON. This command directly opens the engine’s start valve, allowing bleed air (from the APU or another source) to flow to the start port and spin the engine up with ignition. The normal engine start button starts the engine via the standard start sequence but does not manually open the start valve in the same way. Turning the engine mode selector to IGN START simply enables ignition; it does not by itself open the start valve. The APU start switch only starts the APU, not the engine being started.