The purpose of the PTU is to supply the additional volume of hydraulic fluid
needed to operate the autoslats and leading edge flaps and slats at the normal rate
when system B engine–driven hydraulic pump volume is lost. The PTU uses
system A pressure to power a hydraulic motor–driven pump, which pressurizes
system B hydraulic fluid. The PTU operates automatically when all of the
following conditions exist:
• airborne
• system B engine–driven pump hydraulic pressure drops below limits
• flaps are less than 15 but not up.
The questions are:
-OPERATE means retraction AND extension?
-Could you make an example of a scenario where the PTU will start working?(a/c configuration, flap lever position and movement)
Thanks a lot!!!