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United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

avherald.com

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Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#321

Post by tjohns »

willyt wrote: post #186
hnburnsy wrote: post #81

Earlier quoted context omitted.

EMERGENCY- A distress or an urgency condition. DISTRESS (MAYDAY)- A condition of being threatened by serious and/or imminent danger and of requiring immediate assistance. URGENCY (PAN-PAN)- A condition of being concerned about safety and of requiring timely but not immediate assistance; a potential distress condition.

“Declaring an emergency” is US specific. The rest of the world doesn’t recognise this phrase you have to use either “Mayday” for immediate danger to life or “Pan Pan” for less severe problems. As I understand it, “Declaring an emergency” is the equivalent of a Mayday and the US is very slowly switching away from this non standard phraseology.

"Declaring an emergency" isn't even correct in the US. The FAR/AIM only lists "mayday" and "pan pan". (Yes, it's oddly common here in the US for some reason. I think some pilots are afraid to say the "m" word.)

That said, controllers are human. As long as you get the message across somehow they'll do everything they can to help, even with non-standard phraseology.

Of course, the risk of non-standard phraseology is that you might be misunderstood - especially in countries where English isn't the primary language. It's still good to stick to standard ICAO phraseology whenever possible.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#322

Post by zerocrates »

xvf22 wrote: post #126
snuxoll wrote: post #115

Earlier quoted context omitted.

For the uninformed: V1: Speed at which the take off attempt should no longer be aborted Vr: Speed at which the plane should be pitched up (rotated) V2: Speed at which the plane can safely climb with one engine If an engine fails after V1 the runway is supposed to have sufficient length that you can hit Vr, rotate, and be 35 feet off the ground and traveling at V2 before you run out of tarmac even with a single engine…

Fair enough and my memory may be fuzzy but I see quite a few references to V1 as being the minimum single engine takeoff speed. https://skybrary.aero/bookshelf/books/493.pdf (page 2)

I don't have any specialist knowledge here, but that seems to make sense. If you're under V1 then you can still abort takeoff. Having that be the minimum for single-engine takeoff essentially sets up the rule that if you lose an engine while you can safely abort, then you must.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#324

Post by dboreham »

willyt wrote: post #175
dmoy wrote: post #134

That 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…

I expect the person interviewed is a pilot?

Or an engineer?

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#325

Post by repiret »

EE84M3i wrote: post #254
throw0101a wrote: post #222

Earlier quoted context omitted.

Animated recreation with audio: * https://www.youtube.com/watch?v=G7-zh7Sebr8 * Via: https://forums.liveatc.net/atcaviation-audio-clips/ual-328-u...

If anyone else is wondering what ZIMMR means in this context, it is a specific feature of the Denver airport: https://ja.flightaware.com/resources/airport/DEN/DP/ZIMMR+TW...

A specific location. Waypoints used in IFR approaches are given unique, 5-letter, usually pronounceable, names.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#326

Post by kwertyoowiyop »

lrossi wrote: post #233
azalemeth wrote: post #184

Earlier quoted context omitted.

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…

I can draw some parallels between that and a healthy SRE culture. Except for the casualties, of course. Wondering if the first SREs who created the guidelines had aviation industry experience.

Aviation regulations are written in blood. SRE regulations are written in lost weekends.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#327

Post by interestica »

kortilla wrote: post #308
interestica wrote: post #253

Earlier quoted context omitted.

> As well as two demonstrations that the aircraft meets the design specification that even a catastrophic failure in the worst stage of flight is easily recoverable. But in that type of failure, you can't control where the pieces go. https://abc7ny.com/philadelphia-emergency-landing-southwest-... It resulted in depressurization and partial ejection/death.

That’s a different type of failure. Uncontained vs contained.

Kinda. While the 2018 incident was "contained", it still resulted in damage to the fuselage.

"Two small punctures were found in the right side fuselage just below the window belt with material transfer consistent with impact from pieces of an engine fan blade"

(From the link in parent to this thread https://avherald.com/h?article=4b4e8ca7&opt=0)

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#328

Post by AdamJacobMuller »

viraptor wrote: post #174
jfk13 wrote: post #124

Earlier quoted context omitted.

At least it's unlikely to be that 777-200.

That specific plane will go through a lot of rebuilding, checks, thorough investigation, etc. Given a choice, I'd take that plane over another one.

Yeah but not if they rush the rebuilding and complete it in a few days. I suspect that's gonna require too much duct tape and bubble gum.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#329

Post by colechristensen »

hazeii wrote: post #121
terramex wrote: post #113

Almost identical incident happened 3 years ago - the same type (B777-200), the same engine (PW4077), the same operator (United Airlines), the same side (right engine), the same failure (unconfined engine failure). https://avherald.com/h?article=4b4e8ca7&opt=0 I would not be surprised if the whole fleet of this type/engine gets grounded for some time.

I thought it was 'confined' if the containment ring did its job? If it had failed (like not supposed to) it would have been a whole lot worse.

The plane landed and didn’t blast enormous holes with ejected compressor blades. That’s a successful failure.

Re: United B772 at Denver on Feb 20th 2021, engine inlet separates from engine

#330

Post by aklein »

Dirlewanger wrote: post #158
just_steve_h wrote: post #65

Earlier quoted context omitted.

I'm wading into waters that are way over my head here, but my understanding is that it is possible for software to be provably correct, in the mathematical sense of "proof." I'm well aware of the admixture of folklore, experience, and caffeine-fueled inspiration that constitutes much of the software that runs our world.

I think being able to prove that a program can be correct is getting close to P=NP territory.

Cannot prove some program is correct, in general, because that’s effectively the halting problem. But in practice it is sufficient to enforce (prove) the absence of behaviors via constraints like types or contracts.
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