Yesterday a United Airlines Boeing 777-200 flying from Denver to Honolulu suffered a major engine failure shortly after takeoff. Significant chunks of the right engine fell to the ground, with one part of the engine falling through the roof of a house, just a couple of feet from someone who was in their kitchen. Thanks to the great work of the pilots (and some luck based on where the debris fell), no one seems to have been seriously injured.
While this is without a doubt a coincidence, I can’t help but point out the interesting plane that ended up replacing the original 777, after the first plane returned to Denver.
United Airlines replaces N772UA with N773UA
The plane that was supposed to operate the original Denver to Honolulu flight yesterday had the registration code N772UA. This was the fifth Boeing 777 ever produced, and it joined United’s fleet in 1994.
After the emergency the plane returned to Denver, and United operated a replacement Denver to Honolulu flight for those who still wanted to travel (I imagine some people chose not to fly). This flight operated without issues, and landed in Honolulu about six hours after the originally scheduled flight was supposed to arrive.
The replacement flight used the flight number UA3025. The aircraft that United used for this flight was also a Boeing 777-200, and it had the registration code N773UA. This was the fourth 777 ever produced, and it joined United’s fleet in 1994 as well.
Why is this noteworthy? Because this exact plane had a similar incident in February 2018, also on a flight to Honolulu (though out of San Francisco, rather than Denver). Parts of the right engine fell off over the Pacific. The major difference in the appearance of the engines was that in 2018 there weren’t flames coming from the right engine.
— Maria Falaschi (@mfalaschi) February 13, 2018
Here’s video footage of that incident at the time:
And here’s the ATC audio:
What an investigation of that incident revealed
The National Transportation Safety Board (NTSB) investigation into the February 2018 incident found that inspections of the engines had failed to spot signs that the fan blades were weak. It was decided that Pratt & Whitney didn’t provide a formal program for training inspectors who examined fan blades.
One of the reasons aviation is so safe is because aviation authorities, airlines, and aircraft and engine manufacturers, learn from each incident. It’s way too early to know what happened with UA328 yesterday, though hopefully it wasn’t caused by a similar issue (in the sense that hopefully something was learned from the 2018 incident).
Let me be clear about what I’m not saying…
I just want to be very clear, I’m not in any way suggesting that there’s anything unsafe about the replacement aircraft, or that either plane is cursed, or that 25+ year old 777s are bad, or anything. Rather I’m just pointing out that:
- United had a similar(ish) incident back in 2018, in terms of a significant chunk of the right engine of a 777 falling off during flight; this was the only other time something like this happened on a United 777
- The exact aircraft that had the incident back in 2018 was used as the replacement aircraft, and was a plane that United took delivery of around the same time
- I’ll be curious to see what the NTSB determines the cause of this incident to be; hopefully it’s not the same as the cause of the 2018 incident
I should also mention that while United has 74 Boeing 777-200s, about a quarter of them belong to a subfleet used primarily for high-density domestic flights. So presumably when United was looking for a replacement aircraft, it wanted a 777 with a similar layout.
Following the incident on UA328 yesterday, United quickly found a replacement aircraft with the same configuration. What’s interesting is that the replacement 777-200 suffered a similar incident about three years ago, also on a flight to Hawaii.
That’s obviously just a coincidence. The NTSB investigation into the previous incident wrapped up in 2020, and determined that the incident occurred due to fan blades not being properly inspected. I’ll be curious to see what the cause of this incident is determined to be… though we may have to wait a couple of years to get a final report.