It was supposed to be an easy trip to Dallas. The 737-300 only had 40 people on board. They were just about ready to push back when an FAA inspector discovered that the jump seat oxygen mask was inoperative. Maintenance was called, but no replacement mask was available. The technician called maintenance and the on-duty technician checked the MEL manual under ATA Chapter 35 Oxygen and found that there was no MEL listed for the jump seat oxygen mask. The maintenance technician could not release the airplane. The technician ordered an oxygen mask and the flight was cancelled.
Shortly afterward, the maintenance supervisor finished his shift and his replacement took over. The new supervisor realized that the jump seat was listed under ATA Chapter 25 Equipment and Furnishings, so he called maintenance in Kansas City and reversed the order, issuing an MEL for the jump seat.
The maintenance supervisor reasoned that the mask served no purpose if the jump seat could not be occupied, so it could be included in the jump seat MEL as an accessory to the jump seat, although the MEL manual didn’t specifically state that accessories were included. This same logic had been used in the past.
FAA and the courts
The FAA disagreed and proposed to fine the technician. The maintenance supervisor stood his ground, insisting that his interpretation was correct, so the case ended up in administrative court.
The trial judge found that the maintenance supervisor had violated FAR 43.13(a) because the MEL did not state that it included “associated equipment”. The trial judge noted that the airline had submitted a request to the FAA after this incident to change the MEL manual so that it would include accessories in the jump seat MEL. The judge apparently believed that the change was requested because the MEL did not previously include accessories, rather than to make it clear that it did include accessories.
The maintenance supervisor appealed, arguing that there was a broad understanding in the airline industry that associated equipment was included in the MEL, even without a statement to that effect. He relied on the testimony of the airline’s FAA liaison manager who testified that he had checked with three other airlines and the FAA inspectors for those airlines. According to his testimony, they all had concurred that the oxygen mask was an accessory to the jump seat and was therefore included in the jump seat MEL.
The appeals court judge discounted this testimony because the witness had not identified the airlines, the airline officials, or the FAA inspectors he got his information from and the testimony was vague and self-serving. The judge relied instead on the testimony of the FAA inspector who made the complaint and the maintenance technician who had made the original decision not to issue an MEL.
The judge also noted that MEL manuals for other models of airplanes in the airline’s fleet did specify that accessories were included.
Possibly the most convincing evidence the appeals court had to consider was a letter to the airline from the FAA, dated about six months prior to the incident which stated unequivocally that the oxygen mask was not covered in the jump seat MEL.
The maintenance supervisor also argued that he could not have violated FAR 43.13(a) because he did not perform maintenance. FAR 43.13(a) says: “Each person performing maintenance, alteration, or preventative maintenance on an aircraft ... shall use the methods, techniques, and practices prescribed...”
The appeals court judge found that although he did not perform physical maintenance on the aircraft, his decision to defer the broken oxygen mask was a maintenance decision and that to hold otherwise would restrict the FAR to the person in physical contact with the aircraft although important maintenance decisions, including the decision not to perform maintenance, are made by supervisors and other officials. He noted that the maintenance supervisor overrode the decision of the on-scene mechanic. In effect, the supervisor took over the maintenance and had become the mechanic albeit from a distance. The appeals court upheld the trial court and the maintenance supervisor was fined.