Looking at the passenger service units that had come unlatched and dangled from the overhead compartment, I couldn’t help but think of the number of times I had re-installed these units myself. I never thought how important double-checking the latches could be. The maintenance manual required a visual check to make sure the latch was in the proper place, but not the on-the-job shortcut. The way we all re-installed these units was to walk down the aircraft aisle pushing the PSUs manually and feeling them click. I can’t remember anyone ever taking the time to sit in the passenger seat and look up into the little slot that would visually confirm that the latch was in fact latched. There were always too many things to do and too little time.
But here I was, part of a team investigating why passengers suffered injuries when the Allegheny BAC-111 aircraft landed long, going off the runway into a field at Rochester Airport in upstate New York. It was apparent pretty quickly that the aircraft travelling over bumpy terrain had dislodged several of these improperly secured PSUs and a number of passengers suffered injuries when their heads collided with these dangling units. It doesn’t take a very heavy object to cause head injuries when combined with a wildly careening aircraft.
PSUs are certainly not the most critical components of an aircraft. I certainly didn’t think they were in 1974 when I was assigned by the IAM to participate in the review of maintenance issues that might have contributed to passenger injuries from this runway excursion. This was in the early days of the union’s Flight Safety Committee and my first experience with air carrier accident investigation. Loosely patterned after ALPA’s accident investigation committee, the IAM’s Committee was formed so that maintenance expertise from the mechanics’ perspective could contribute to a better understanding of the reasons for accidents and help develop recommendations to prevent future accidents. And here, these not-so-critical components caused the majority of the non-evacuation injuries.
Even in the days before words like human factors or complacency were bandied about by accident investigators, and the term Dirty Dozen had not yet been coined, it was clear that a mechanic’s handling of a routine job in a routine but improper fashion was a cause of some of the injuries. An important lesson for me; but not important enough to make it into the accident report. In those days, little attention was paid to maintenance issues if they did not contribute directly to the cause of the accident. (Okay, they don’t pay proper attention to maintenance issues today even when they contribute directly to aircraft accidents, but that’s another story for another day.)
This accident started me thinking about the importance of routine maintenance tasks in not-so-critical areas and the consequences of doing them incorrectly.
Moral of the Story: There are no unimportant maintenance tasks in aviation. Small jobs can have big consequences if not performed properly. Even a mundane coffee maker, improperly repaired, can cause an in-flight fire.