B737 Undifferentiated or Other Model
Communication Breakdown; Workload; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Company Policy; Procedure; Human Factors; Chart Or Publication
B737 aircraft was docked in ZZZ in Bay-X at approximately XA:30pm. At XB:15pm the mechanics started working on the aircraft. The normal procedure is to do all the Hydraulic Checks first; although I am not aware if this is policy anywhere. On this night; the Hydraulic Checks were started in accordance with the General Maintenance Manual (GMM) and there was no one or equipment around the aircraft. Within 45 minutes there were eight ladders and three scissor lifts under the aircraft and the Checks had to stop on four occasions: Once; as an individual climbed onto the jackscrew compartment as the Rudder Checks were being accomplished. Once; as a ladder was moved under a flap canoe. Once as a Mechanic rolled his toolbox under a flap and once as an individual tried working in the Leading edges as the Flap Checks were being accomplished. I am unclear if this is acceptable or unacceptable procedure or not. Even following the GMM procedure for clearing flight controls prior to moving them; there is just too much happening at once and too quickly for one or sometimes even two ground personnel to clear the area. There is just too much at risk with aircraft damage or personnel injury and puts too much responsibility on the one individual giving the clearance. Several of the Checks are done with a BITE Check (i.e. uncommanded Flap Check) and once the BITE Check has started there is not a way to exit it to stop the test if someone or something moves in the way. Recommend having Lead [Mechanics] coordinate jobs and job cards; according to a sequence. NO one is to start any work until all the Hydraulic Checks are complete and tagged out.
An Aircraft Maintenance Technician (AMT) describes his efforts to accomplish Hydraulic Checks in a chaotic work environment at a company maintenance hangar. Concerns also raised about the lack of Job Card coordination for sequencing maintenance work and the potential for personnel injury.