perchè allora il meccanico, non abilitato, ha eseguito il lavoro per cui non era stato addestrato?
Human Factor?
Pressioni da parte del Supervisore in turno?
E' la struttura "Maintenance" della Air Wisconsin da mettere sotto accusa non il meccanico, questo prevede la normativa.
La sua parte di responsabilità nella catena degli eventi è solo perchè non ha denunciato il fatto.
On December 14, 2008, about 1700 eastern standard time (EST),1 a Bombardier CRJ CL-600-2B19, N407AW, operated as Air Wisconsin Airlines Corporation (AWAC) flight 3919, landed with the left main landing gear (MLG) in the retracted position at Philadelphia International Airport (PHL), Philadelphia, Pennsylvania.2 The two flight crewmembers and one flight attendant aboard the airplane were uninjured, and the airplane sustained damage to the left wing, aileron, and flap. The flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 121 as a nonscheduled positioning flight from Norfolk International Airport (ORF), Norfolk, Virginia, to PHL. An instrument flight rules (IFR) flight plan was filed.
The National Transportation Safety Board’s (NTSB) investigation of this incident is ongoing. However, based on preliminary findings from this investigation, as well as prior investigative findings, the NTSB is concerned about training for mechanics and inspectors.
Training for Mechanics
On December 13 and 14, 2008, the incident airplane underwent extensive maintenance at the AWAC maintenance facility at ORF, including the removal, replacement, and visual inspection of the left and right MLG uplock assemblies (see figure).3 The work order indicated that this task was a required inspection item (RII).4 Mechanics were only able to work on one assembly at a time due to the confined space in the wheel well, so the work was divided between two mechanics. The NTSB’s investigation revealed that the mechanic who replaced the left uplock assembly (the incident mechanic) had not replaced an uplock assembly prior to working on the incident airplane, had not received on-the-job training (OJT) for this task (it was not required for this task), and was not being supervised during the procedure.5 In a postincident interview, the incident mechanic stated that he relied on AWAC’s General Maintenance Manual (GMM) and the mechanic who was replacing the right uplock assembly for guidance.6 However, when the incident mechanic replaced the left uplock assembly, the upper attachment bolt, nut, and cotter pin assembly used to mount the left MLG uplock assembly to the structure were installed but did not engage the uplock assembly, which allowed the uplock assembly to pivot about the lower bolt. Because the upper attachment bolt did not engage the uplock assembly, the left MLG remained in the up-and-locked position and did not respond to the pilot’s commands to lower prior to landing.
The NTSB’s investigation revealed that AWAC did not offer formal training or OJT specific to the uplock assembly removal and installation procedure. According to the AWAC GMM Volume 1, Chapter 2, personnel who perform maintenance, preventive maintenance, and RII tasks will be trained in accordance with the training program described in the Maintenance Training Program manual, which provides comprehensive training information for AWAC mechanics, technicians, inspectors, and other employees. The curricula in the training manual and modules covered are intended to ensure that maintenance personnel are qualified for operations under 14 CFR 121.375. However, neither the training manual nor the GMM specifies when this training must be completed and what operational limitations exist for mechanics who have yet to complete training.7 For example, even if a mechanic has not completed the 32 OJT tasks, the mechanic may still perform maintenance tasks without limitations or restrictions. No formal supervision process exists, but mechanics are encouraged to request guidance from a more experienced mechanic if performing a task for the first time.
The NTSB concludes that the AWAC incident mechanic was not properly trained or supervised when he replaced the uplock assembly on the incident airplane for the first time, which led to the error in installation. Further, the error was not detected by the inspector.
The NTSB is concerned that the Federal Aviation Administration (FAA) does not currently require mechanics to receive OJT or be supervised while performing RII tasks for the first time.
