I was lead counsel to American Airlines in the NTSB investigation of the 25 May 1979 DC-10 crash of Flight 191 at O'Hare and in the FAA investigation and subsequent grounding of all DC-10 aircraft. In light of the latest articles and emails referring to that crash, I probably should repeat some points I've made previously.
The MDC manuals were not dispositive on the use of a fork-lift engine-replacement procedure, and there was some controversy about what had been orally said (and meant) by MDC personnel to AA about the proposed fork-lift procedure that was blamed for the cracks in the engine pylon aft bulkhead (not a bearing) that led to the loss of the engine and, in turn, the airplane. AA was under the impression that MDC thought the procedure was acceptable, in part because, as reflected in the written record described in the NTSB report, MDC was aware of AA's proposed fork-lift procedure and, without objection, supplied requested C.G. data so AA could use this procedure. MDC apparently also did not object to Continental's use of this procedure. I tried three cases (one against lawyer/aviator F. Lee Bailey) in which some details of the flight were at issue. The pilots followed the manual's engine-out procedure; they had no way of knowing that not only had they lost power on the left engine but that they had also lost the nacelle, the pylon, and part of the leading edge of the wing. All this damaged some hydraulic lines and caused a loss of hydraulic pressure and retraction of outboard leading-edge slats on the left wing, which increased the left wing's stall speed to a speed above the speed called for in the engine-out procedure. Seconds after lift-off, the left wing started entering into a stall, causing the airplane to begin rolling to the left. Impact with the ground occurred eleven seconds or so after that roll began. As for the DC-10 grounding, it should be noted that the grounding was based on the FAA's mistaken conclusion that the cracks in the pylon aft bulkhead that were discovered in a series of post-accident AD-directed fleet inspections had actually grown during the inspection period. Before the grounding, I spoke by telephone and met in person with the AA inspection team that found the pylon bulkhead cracks, and their view was that the bulkhead cracks had not developed or grown during the series of post-accident inspections of the fleet. They pointed out that the cracks in question had not been found in the earlier inspections because the earlier ADs had not called for inspections in the area where these cracks were later found. Indeed, a chief reason why there was a series of ADs was that the areas to be inspected kept being clarified and expanded. It was a later AD in the series that called for inspections of the location where the cracks in question were found. My understanding was that this information was passed on to the FAA but was discounted. The grounding followed. A pre-grounding internal FAA inspection report indicated that the local (SFO) FAA inspectors agreed with AA that the cracks in question were pre-existing and were in a location that was not to be inspected in the original rounds of post-accident inspections (and this was confirmed in subsequent testimony of FAA personnel). I understand that AA's head of maintenance also argued to Craig Beard of the FAA that the cracks were pre-existing and not an appropriate basis for a grounding. I believe there was even a much-later FAA report that concluded that the FAA's instructions in the initial ADs were not adequate to reveal the cracks found later in the pylon aft bulkhead. Accordingly, in my view the grounding of the DC-10 was not justified. Bob Randal Craft Email: randalrobertcraft@gmailcom Mobile: 646-226-2299 (USA)
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