B-737 Airstair

83 pages in a maintenance manual. 11/16" wrenches, 94 turns for manual retraction. Requires 115 V AC, 3 phase to run the motor to retract the rear airstair. It also requires 24-28 V DC for the control system that actuates the relays that control the motor.

There is also a torsion bar that unwinds to power the airstair in emergency mode. Once the airstair has been deployed in emergency mode, the torsion bar must be reset by moving a lever to ‘SET’ and then extending and retracting the airstair under power.