Yesterday a United Airlines Boeing 777-200 flying from Denver to Honolulu suffered a serious engine failure shortly after takeoff. Significant parts of the right engine fell to the floor, and part of the engine fell through the roof of a house just a few feet from someone in their kitchen. Thanks to the great work of the pilots (and a little luck depending on where the rubble fell), nobody seems to have been seriously injured.
While this is undoubtedly a coincidence, I can’t help but point out the interesting plane that replaced the original 777 after the first plane returned to Denver.
United Airlines is replacing N772UA with N773UA
The aircraft that was scheduled to make the original Denver to Honolulu flight yesterday had registration code N772UA. This was the fifth Boeing 777 ever produced and it was added to United’s fleet in 1994.
After the emergency, the plane returned to Denver, and United operated a replacement flight from Denver to Honolulu for those who still wanted to travel (I imagine some people chose not to fly). This flight went smoothly and landed in Honolulu about six hours after the scheduled arrival of the originally scheduled flight.
The replacement flight used flight number UA3025. The aircraft United used for this flight was also a Boeing 777-200 and had the registration code N773UA. This was the fourth 777 ever produced and it was also added to United’s fleet in 1994.
Why is that remarkable? Because exactly this plane had a similar incident in February 2018, also on a flight to Honolulu (not in San Francisco, but in San Francisco). Parts of the right engine fell off over the Pacific. The main difference in the appearance of the engines was that in 2018 no flames came from the correct engine.
– Maria Falaschi (@mfalaschi) February 13, 2018
Here is video footage of the incident:
And here is the ATC audio:
What an investigation into this incident revealed
The National Transportation Safety Board (NTSB) investigation into the incident in February 2018 found that inspections of the engines did not reveal any signs of weak fan blades. It was decided that Pratt & Whitney was not providing a formal program for training inspectors to inspect fan blades.
One of the reasons aviation is so safe is because aviation authorities, airlines, and aircraft and engine manufacturers learn from every incident. It’s far too early to know what happened to the UA328 yesterday, although hopefully it wasn’t caused by a similar problem (in the sense that hopefully something was learned from the 2018 incident).
Let me make it clear what I am not saying …
Just want to be very clear, I am in no way claiming that the replacement plane is unsafe, or that any of the planes are cursed, or that over 25 year old 777s are bad or anything. Rather, I just point out that:
- United had a similar (ish) incident back in 2018 regarding a significant portion of the right engine of a 777 that fell off in flight. This was the only time something like this had happened on a United 777
- The exact plane that had the incident in 2018 was used as a replacement plane and was one that United delivered around the same time
- I am curious to see how the NTSB determines the cause of this incident. 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 those are part of a sub-fleet primarily used for high-density domestic flights. Presumably when United was looking for a replacement aircraft they wanted a 777 with a similar layout.
Following yesterday’s UA328 incident, United quickly found a replacement aircraft with the same configuration. Interestingly, the replacement 777-200 suffered a similar incident about three years ago, including on a flight to Hawaii.
It’s just a coincidence, of course. The NTSB investigation into the previous incident was completed in 2020 and revealed that the incident was due to an improper inspection of the fan blades. I am curious what caused this incident … although we may have to wait a couple of years to get a final report.