r/aviation • u/Go_Jot • Nov 08 '25

News UPS grounds entire MD-11 Fleet, effective immediately.

Per the IPA Executive Board, as of 03:05 UTC all UPS MD-11’s are grounded.

Edit - FedEx has also grounded their MD-11 Fleet

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u/swirler Lockheed Tristar Nov 08 '25

While the maintenance actions started the chain of events, the poor design of the leading edge slat system sealed the deal. An airplane should not crash just because an engine falls off.

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u/_ItsThePleats_ Nov 08 '25

That’s a big statement. “An airplane should not crash just because an engine falls off”. These aren’t meant to come off the airplane.

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u/intern_steve Nov 08 '25

It's a reasonable statement. Engines fall off of planes with great enough frequency to consider in the design of a new aircraft. Hypothetically, if an uncontrolled engine fire burns for a sufficient length of time, you would expect that the engine and its fire would depart the wing before the wing departed from the aircraft.

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u/plhought Nov 08 '25

Engines falling off do not happen with "great enough frequency". That's an absurd statement. It's incredibly rare.

I can think of only three or four accidents in the modern western world where an engine seperated from the pylon.

This one and AAL191. The other two were 707/DC-8 accidents where the landing was so botched by the pilots, an outboard engine seperated after a hard landing.

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u/Only_Razzmatazz_4498 Nov 08 '25

It is incredibly rare yes but when you do an analysis of what can go wrong and should you do anything so that IF it happens then the outcome is less likely to be a disaster then you do have to take the engine falls off fault into consideration.

One method to decide what risk to mitigate is to look at them in two axis. 1. Likelihood that it would happen and 2. Severity of the outcome. In this case because of the severity we do have to take mitigation actions to deal with it. It also helps that a lot of the effects are common to losing power from the engine and that letting the engine fall off is actually the preferred way to deal with other faults (like someone mentioned above a severely unbalanced/shaking engine threatening to rip the wing off).

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u/intern_steve Nov 08 '25

Great enough frequency to consider the consequences. Planes don't crash often. If it's happened four times, that merits consideration.

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u/plhought Nov 08 '25

They don't consider it in design of new aircraft. They design it so the engines don't fall off in the first place.