Video of flight track and atc recording : https://www.youtube.com/watch?v=G7-zh7Sebr8
United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
391–400 of 483 posts
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#392Earlier quoted context omitted.
https://en.wikipedia.org/wiki/Clustering_illusion
I read on the German news about the Dutch incident and came to HN because I knew that somebody would've posted about it here. Found this thread and didn't fully read the headline, just "Boeing" and "engine failure". It took me a few seconds to realize that this was a completely different incident.
The Dutch incident is a relatively common one, the reason it's in the news is that turbine blades fell down on a residential area and someone got minor burns from picking one up.
It's more typical to have this kind of failure early in the take off where the parts would fall on the airport and nobody would talk about it.
All the rest of the news about circling at 10,000ft and then landing at a nearby airport is completely standard procedure that gets practiced all the time in the 6 months simulator checks. Basically you climb high enough to be able to dump fuel without it reaching the ground (minimum 6000ft, preferably higher) and still not too high such that you're burning a lot of fuel quickly because at 10,000 ft fuel usage is way higher than at 30,000. Then when the fuel dump is complete, engine secured, checklists done it's a relatively normal landing. Especially if you have 4 engines but even with 2 it's a landing every pilot can do and is trained for all the time.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#393Earlier quoted context omitted.
It looks like they've got plenty of time to move out of the way.
I'd guess looking upwards at some awkward shaped objects falling down, it's not easy to guess where they will come down.
If this ever happens to you and it seems like the falling object is not moving in your field of view: run away at a 90 degree angle.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#394Earlier quoted context omitted.
It's good airmanship to turn into your "good" engine.
Why? Surely it's easier to turn the other way? Then again, it's not a dogfight, so maybe less chance of losing control if turning into the working engine?
Because you may not be able to get out of your turn that way. The aircraft 'wants' to turn over the bad engine so you could easily get caught in a feed-forward situation.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#395Earlier quoted context omitted.
Aircraft undergo regular preventative maintenance checks, with letter codes A - D. The D check being the most comprehensive, it occurs every 6-10 years and basically the entire aircraft is taken apart and inspected, looking for among other things anything like stress fractures, corrosion, unusual wear, etc. https://en.wikipedia.org/wiki/Aircraft_maintenance_checks#D_... A commercial aircraft does not just accumulate…
Beware of the dangers of preventative maintenance, where sometimes while replacing or inspecting or re-mounting inspected parts, the maintenance crew breaks something that was OK and probably going to be working fine for years. But yeah, a D check is so expensive I've heard there's a habit of dumping the aircraft on less observing flying companies some thousand miles before it comes up...
A minor point, it's not based on miles, but cycles (takeoffs/landings) for structural parts or hours for engines.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#396Probably a dumb question, but why don't the pilots cut the fuel to the right engine after they know it's on fire?
What is burning is probably leftover oil.
Fanned by a couple of 100 mile/hour winds. It would take a small miracle for the fire to go out by itself under those conditions, they may have tried to flood it with CO2 but it's so open to the elements even that may no longer work.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#397That quoted ground observer. Do they work for the NTSB or something? I am 110% certain that if I saw a plane on fire in the sky, I would not have the presence of mind to remember the term "cloud deck", let alone the rest of those details. Ground observer: "Good sir, I do say that the cloud deck was quite low so I didn't get a good look, but the engine was mildly louder than usual, and possibly had smoke, but perhaps…
It's very likely that they're an AvHerald reader. It's the absolute de facto gold standard website in its field, and sensationalism and drama is not appreciated -- a large chunk of the usual audience are aviation professionals. My dad was a pilot, and I've got some few hours myself. You can bet that if either of us watched this event happen, we'd mentally be documenting it as best as we possibly can, both to try to p…
There is a now a comment on that article where the ground observer identifies himself and gives a few more details, so looks like you're right.
> 1) I was giving Simon a heads up to look for a report out of DEN - if it was anything, I thought it was just something like a (big) compressor stall. That was why so many caveats were there - I wasn't sure at the time that the aircraft had had a problem. I didn't realize it was going to be widely reported until my mother texted me a couple of hours later asking if any of the plane parts came down close to me
> 2) Something I omitted that I should have put in: After I got home I imagined how many thumb-widths at arm's length it would take to occlude it (from memory), and plugged that into similar triangles and the length of a 737 (didn't realize it was a 777) to get an estimated altitude and got 2-4 thousand meters. I thought the cloud deck was only 2000 feet AGL or so, so I didn't believe the numbers. I did change "a couple" to "a few" though. Turns out it was ~8000 feet AGL. I should have believed more in the math!
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#398less than 30 days ago. I made a comment[0] here on HN that Boeing planes safety records make your bowels shift, if you look up their safety records before you fly.
glad everyone on that flight was safe. but yeah airlines need to have a disclaimer when you fly certain planes.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#399less than 30 days ago. I made a comment[0] here on HN that Boeing planes safety records make your bowels shift, if you look up their safety records before you fly. glad everyone on that flight was safe. but yeah airlines need to have a disclaimer when you fly certain planes. [0]: https://news.ycombinator.com/item?id=25904047
In that comment you assert 777s “break in half”. Where did you get this from? There has been 8 hull losses and only one “broke in half” (Asiana) after it was basically flown into the ground.
https://en.m.wikipedia.org/wiki/Boeing_777#777-200ER
Your comment, which implies the 777 is unsafe, is nonsense. The 777 has a great record.
Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine
#400Earlier quoted context omitted.
"Mayday" is the internationally agreed code, so that's one reason to use that - but US accident investigators also noticed a pattern that American pilots are often too reluctant to declare emergency status when it's appropriate as it is here, because they feel it's "not that bad" yet. Having them say it's an emergency without saying "Mayday" is good enough and might mean a few more cases that should have been emergen…
Listening to the audio, the pilot first says, "We've experienced an engine failure, need a turn." ATC does not respond, so he calls again and says "Mayday" in order to unequivocally get their attention. There are actually two different emergency calls. There is "mayday", and there is "pan-pan", which is a less urgent version of "mayday", but that is hardly ever used.
PAN-PAN is used more often than you might think, at least outside the US. In particular, any medical emergency would be a PAN-PAN.
Here's an interesting example where two aircraft had declared PAN-PAN for quite different reasons, while coming into Sydney. https://www.youtube.com/watch?v=DfidHywKmZI