B757-200
Maintenance Powerplant; Maintenance Airframe
Situational Awareness
No Specific Anomaly Occurred All Types
General None Reported / Taken
Equipment / Tooling; Human Factors
At approximately mid-morning; February 2013; I performed a Safety Check on a Hyster Boom Lift; which included a walk around for general condition; and fluid checks. I then got on to the vehicle; started it and moved all controls to make sure they worked. I moved the Hyster Lift from the north end of the hangar ramp to position the Hyster Lift at the Thrust Reverser (T/R) cowl in front of the hangar. Satisfied that the lift was in good working condition I signed-off the Daily User Check. After lunch I lowered the hoist by hand and attached the T/R sling. With the aid of other team members we moved sling in position over T/R cowl; I drove while team members guided. Once sling was attached to T/R cowl we started the process of moving it from the pallet to a chair cart [flatbed]; again I was driving while team members guided and steadied the cowl. Without warning the cowl fell to the ground with a loud thud; and I saw an object fly across the Hangar floor approximately 15 to 20 FT. I put the lift in park; set the parking brake and turned lift 'Off'. I then retrieved the object which turned out to be the clevis attach bolt; which connects the hoist to the boom which is a threaded bolt.
Myself and other Aircraft Maintenance Technicians (AMTs) were transfering a Thrust Reverser half from a shipping crate to a [flatbed] cart when the reverser and sling separated.
Three Aircraft Maintenance Technicians (AMTs) report about a B757 Thrust Reverser (T/R) half that separated and fell from a sling and chain pulley assembly attached to a boom on a forklift. AMTs were attempting to move T/R from shipping crate to a flatbed chair cart.