Ground PTU operation

Check the PTU selector

At a stand, display HYDR and inspect the PTU selector. ^[54]

Compare the PTU control position with the synoptic while the airplane is on the ground.

Ground PTU logic

PTU vs pump pressure

FSS: PTU not working on ground

Look for the PTU and associated hydraulic pressure indications.

The FSS hydraulic page explicitly states that the PTU does not work on the ground.

Build and ground state

Ground state / build

Record the ground/air state and exact build; do not confuse pump pressure with PTU operation.