B777 Undifferentiated or Other Model
Maintenance Powerplant; Maintenance Airframe
Training / Qualification; Situational Awareness; Communication Breakdown; Confusion
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Aircraft Damaged; General Maintenance Action
Human Factors; Procedure; Equipment / Tooling; Chart Or Publication
Improper hoist equipment used during disassembly procedure. Communication issue; maintenance flow issue; jobcards; workcards and maintenance practices. [Recommend] updating job card with a less confusing description for proper use of hoist equipment.
Reporter stated their Engine Shop was already in the Tear-Down process on the PW-4000 Engine when a 1/2' Eyebolt suddenly broke that had been  attached to the top 'ear' of a round; flat; fixture plate at the forward flange of the High Pressure Compressor (HPC) section. The engine rotated downward; approximately two feet; striking the shop floor. Fortunately; no one was working under that area at that moment. The engine was not damaged because the same flat; round fixture plate attached to the front of the HPC also extended down below the HPC and contacted the cement floor. Reporter stated that part of a Step-4 procedure in their Job Card that instructs mechanics to install a 'Spreader Bar' was missed; not 100% completed. The spreader bar should have been connected to an overhead hoist capable of lifting over 5000 tons.  Cables from the spreader bar drop down on both sides of the HPC section of the engine and are suppose to be attached to 'ears' on the edges of the flat round fixture plate. That procedure was not accomplished. As a result; the 1/2' inch Eyebolt that was only suppose to be used to position the flat; round plate to allow for the plate to be bolted to the front section of the HPC; ended up carrying a 9;000 pound engine; which exceeded the shear strength of the bolt. That same PW-4000 Engine had been elevated much higher earlier. The potential for a fatal accident was very high.Reporter stated current Revisions to their Job Card for hoisting the engine; now include bold Caution Notes 'before' and 'after' the Step 4 procedure for attaching the Spreader Bars at the HPC and aft Diffuser Case sections; warning mechanics to make sure the Spreader Bar and cables are attached to the engine and hoist assembly; prior to lifting the engine. He wanted a Lead or Inspection item added for verification of Spreader Bar installation. That 'Second Set of Eyes' sign-off was not been included in the Job Card revision.
While lifting engine; improper connection of hoist caused engine to drop. [Recommend] installing 'Cautions' on job card to alert mechanic of possibilty of this ocurring prior to lifting engine.
Two Aircraft Maintenance Technicians (AMTs) recommend adding 'Caution' notes and updating a job card for attachment of Engine Hoist Equipment PW-4000 Engines used on their B777 aircraft. Aircraft engine had been dropped due to improper connection of hoist equipment.