A United Airlines Boeing 777 suffered an uncontained engine failure over Broomfield, Colorado, on Saturday afternoon, spreading debris over a mile on the ground. There were no injuries on the aircraft or on the ground. There were 229 passengers and 10 crew onboard. Meanwhile, what appeared to be turbine blades fell from a Boeing 747-400 cargo plane over a Dutch village on Saturday, injuring two people on the ground, although not seriously. Images from that village show about a dozen broken blades collected in the community and one piece piercing the roof of a car.

In the Colorado incident, the 777 had just taken off for Hawaii from Denver International Airport about 1 p.m. local time when the engine came apart. The aircraft was at about 14,000 feet. The crew declared a mayday (audio here) and returned to the airport for a safe landing. Debris also went through the roofs of buildings. Video shot from the cabin shows the nacelle and most of the rear fairings missing from the engine as it wobbles while windmilling on the return trip to the airport. First reports from the scene showed parts in yards and in a park that had reportedly been full of locals enjoying a warm early spring day. In a rare move during the pandemic, the NTSB is sending investigators to the scene. More details as they become available.

The Dutch mishap involved a Longtail Aviation 747 that took off from Maastricht Airport in the Netherlands for New York. Initial speculation is that the engine ingested an “object” taking out the turbine blades. The aircraft stayed in the air for more than 90 minutes before diverting to Liege in Belgium. Longtail Aviation is based in Bermuda and has two 747-400s.


    • Most of the performance improvement (especially economic) of modern types is coming from the engines. And in order to deliver these improvements, engines and the materials they are made from are being pushed to the limits. The on-going and often serious problems with the latest generation(s?) of airliner engines is evidence of this.

    • This is a trick of the mind. The stats continue to trend towards lower rates of failure. The availability of timely news on accidents has increased however. It can therefore appear that accidents and failures have become more common but they have not.

      Aside from this covid period and even with progressively fewer crashes it is projected that the equivalent of a full 767 will be crashing ever two weeks by mid century. Yet air travel will actually be safer then than it already is now. The difference is the projected massive increase in passenger numbers, particularly in India, China and the rest of Asia.

      • I think the history on countries like Communist China foretells a higher rate of accidents. So, I disagree. Of course, I’m a conspiracy nut who doesn’t believe the propaganda on the source of COVID being natural, so what do I know?

        • There is a respected body of opinion in intelligence services ( eg British counter terrorism ) that Covid did escape from a laboratory, probably not deliberately tho. No absolute proof, but smoking guns.
          Looking at the engine clip, can’t see much thrust coming out of that mess so why not turn the fuel off? Welcome to the newest aviation hazard, passengers wielding phone cameras.

    • Oh, please. My day job involves jet engine certification. These events are rare; you are thousands of times more likely to die of COVID than in an accident caused by uncontained failure of a passenger jet engine. Your teenage kid is much more likely to kill someone whilst driving than any given PW4000 engine.
      It can [and does] cost over a billion dollars to certify a large turbofan in today’s world. Billion, with a ‘B’. And the engines on the two planes that shed blades weren’t certified in today’s world. Yet these engines fly for tens of thousands of hours, and it’s very rare to have them fail.
      I suppose you can have more government if you really want it. I recommend North Korea.

    • Yeah. Automation of cars appears to be inbound with likely huge reductions in crashes. But we can be sure that failures will lead to previously unseen kinds of crashes. These will be occurring in populations that have quickly become used to lower crash rates so they will be seen as significantly more worrying than even bad crashes are now. I can see the breathless headlines now.

    • Not one in a billion. And the salient question is not whether it is newsworthy. The proper question is: is it action-worthy? Or is it just “stuff happens?”
      The lack of fatalities (Southwest’s recent event being an exception) is misplaced comfort. The Quantas event is evidence of the possibility of significant airframe damage. When an uncontained disassembly occurs, the likelihood of an airframe strike is mostly a matter of DSL.
      From an engineering perspective, DSL is a very unreliable strategy for mitigation.

  1. Although not a common occurrence, the uncontained failures that have happened makes you wonder about the validity of the certification tests. The nacelles are supposed to keep the parts contained during a failure and it looks to me like that is not happening.