@ (optional) Send List of Aircraft Help Us C/NModBuiltID In this OrganisationIn other Org 1974 73-21656: US Army f/f 29nov74 1975 73-21657: US Army f/f 19feb75 1975 73-21658: US Army f/f 28may75
Helicopter Boys: True Tales from Operators of Military and Civilian Rotorcraft
The Official FAA Helicopter Flying Handbook