On 25 May 1979 the worst airline crash in America’s history occurred during take-off at Chicago O’Hare airport, killing all 271 people on board. Now, on 4 November at Louisville, Kentucky, an unnervingly similar disaster has occurred, also immediately after take-off.

But because the Louisville crash involved a freighter, far fewer people died, and for that reason the event has not received the same international wall-to-wall coverage in the media as the 1979 catastrophe.

Some 46 years may have passed since the crash of American Airlines Flight 191 at Chicago O’Hare, but it remains the worst aviation accident ever to take place on US soil. It also happens to be the first major accident upon which I had to report as a rookie aviation journalist with Flight International magazine, so my memories of it remain vivid.

The similarities between the two accidents were these: both aircraft were McDonnell Douglas (MDC) DC-10 trijet variants; both, late in the take-off run when the aircraft were already committed to take off, suffered complete detachment from the left wing of the No 1 engine.

Flight 191 involved an MDC DC-10-10 passenger aircraft, whereas the Louisville accident involved the most recent variant of the DC-10 series, known as the MD-11, and it was a freighter version operated by UPS with only three crew on board.

The UPS MD-11F engines were Pratt & Whitney PW4460s and Flight 191’s power units were General Electric CF6-6Ds, but the common factor in both cases was that they ripped themselves off their wing mountings, damaging the wings disastrously in the process and making the aircraft completely unflyable. Nobody on board either aeroplane had a chance of survival. At O’Hare two people on the ground were killed, and at Louisville the death toll of third parties is estimated at nine, with at least 11 injured.

The National Transportation Safety Board (NTSB) investigation of the 1979 accident found that improper maintenance practices by American Airlines when they re-mounted the left engine on the wing following overhaul had resulted in damage to the wing mountings where the engine pylon attached to the wing itself. The report says that, when the engine detached, it pivoted upward and passed over the top of the wing as it departed, the separation causing physical damage to the wing leading edge and to hydraulic systems, resulting in the retraction of the left wing leading edge slats which dramatically reduced the lift that wing was able to produce at low speed. The wing dropped uncontrollably, and the aircraft hit the ground inverted.

At this stage all we know about the UPS accident is that the NTSB have recovered the flight data and cockpit voice recorders, and that witness from the ground and wreckage disposion at the site makes it certain that the left engine separated, causing damage to the wing, which then dropped and hit the roof of an industrial unit beyond the runway end. So far there is no evidence to suggest that the separation took place in exactly the same manner that it occurred on Flight 191, nor for the same reason. Additional video information showing the No 2 (tail) engine emitting flame suggests debris from the No 1 engine separation damaged it, making it impossible to maintain level flight.

Additions to detail since the NTSB released a preliminary factual report: the Lousville departure was Flight 2976 for Honolulu, and it took off from runway 17R reaching a maximum height of 100ft (the original statement said 475ft, but the NTSB has now reviewed the ADS-B data from which that was derived) and airspeed of 183Kt. Also, most of the No 1 engine’s pylon was still attached to the engine when the NTSB found it, but probably received additional damage when hitting the ground after detaching from the wing. The separation process began with a fatigue failure of the left engine pylon’s aft attachment lugs, so the engine and pylon detached as a unit from the wing underside. The engine twisted upward and passed over the top of the aircraft, gyroscopic precession causing it to fall to the right of the aircraft’s path, and debris entered the tail engine causing a reduction in power, making descent inevitable.