United Eyes 2022 Return For 777s With PW4000 Engines

By Spyros Georgilidakis | October 21, 2021

Confirming earlier reports, United Airlines said that it does not expect to operate its Boeing 777s with PW4000 engines before Q1 2022.

A United Airlines Boeing 777-200 had a very high-profile incident earlier in the year when one of its engines failed after take-off over Denver. Contrary to some reports at the time, the occurrence was apparently a contained failure. This was because the engine itself contained the high-energy components within. However, large parts of the engine cowling and other aircraft components rained onto the ground below.

United Eyes 2022 Return For 777s With PW4000 Engines
Image: NTSB

The FAA and other aviation authorities grounded all 777s with PW4000 engines, after the United incident. Worryingly, this wasn’t the first one. A JAL 777 had a similar failure the previous December. And another United 777 with the same engines had a very similar failure a few years earlier.

Ironically, that first United 777 (long-repaired) flew the Denver passengers to their destination, after the latest failure! United is the only airline in the United States that flies 777s with PW4000 engines. Most Boeing 777 aircraft in service today have GE90 engines. That said, a JAL 777-300ER with GE90s had an interesting failure over Los Angeles, less than a week ago.

Image: NTSB

However, that aircraft did not rain parts over Los Angeles – as far as we know. The FAA and others grounded 777s with PW4000 engines after the United incident, because of the way it developed. Authorities are putting pressure on Boeing, who is responsible for the engine cowling, and Pratt & Whitney, for the cause(s) of the engine failure.


United 777s, The PW4000 And Boeing’s Engine Cowling Design

United Airlines states that it has not heard from the FAA about new developments around its 777s with PW4000 engines. But work is ongoing with both Boeing and Pratt & Whitney. The engine manufacturer is inspecting the hollow fan blades of these engines. For more information on the details of these parts, you can see our previous article, HERE. Boeing is working on strengthening its cowling design.

United Eyes 2022 Return For 777s With PW4000 Engines
Photo: tjdarmstadt, CC BY 2.0

United has 52 777s with PW4000 engines. Unlike other operators, they don’t plan to retire them early. This is what JAL did because they were planning to retire their jets in early 2022 anyway. By contrast, United is planning to increase international capacity by 10% from 2022. So they need these 777-200s and want to see them back from the first quarter of next year. And it now seems they have reason to expect that this will indeed happen.

It will be interesting to see what the cost will be, to return these aircraft to service. The United 777s that have these PW4000 engines now have an average age of over 22 years. But perhaps more importantly, the issue could potentially affect more aircraft. Some opine that we could see new standards for engine testing come as a result of this investigation. Or perhaps, standards for testing engine installations, rather than the engines themselves.


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