Operation " Rock " Parachutists of the 503rd RCT make last minute adjustments inside a Fairchild C119 Boxcar transport plane. The markings on the Griswold containers in which the weapons are carried along the side of the body are not identification of the unit making the jump . They were loaned to the 503rd on MR for the jump . The equipment consists of reserve parachute , combat pack underneath reserve chute , weapons in Griswold container , and the main chute , T7 , on the back . 17 April 1953