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-   -   United B777 engine failure (https://www.pprune.org/rumours-news/638797-united-b777-engine-failure.html)

FlightCosting 21st Feb 2021 15:09

lomapaseo

when the airframe manufacturer sets up an engine selection process they always require the powerplant supplier to provide an engine /nacelle that provides the performance to meet the spec. If the engine supplier fails to meet the spec they do not get on the airframe. Only the Russians build an airframe around an engine as they dud with the IL62 and IL76. I spent years negotiating with GE on the SF340 powerplant.

Dave Therhino 21st Feb 2021 15:21

I think we will find that damage was from the separated thrust reverser outer wall, fan cowl door, or inlet pieces. That damage is to the composite wing-to-body fairing parts. No penetration of the wing plank or spar. There was no high energy uncontained rotor debris from the initial reports and photos I have seen.

MLHeliwrench 21st Feb 2021 15:22

is that an ‘exit wound’ at three o’clock (from this view) lined up with the ‘entry wound’ at the wing root!

Longtimer 21st Feb 2021 15:24

NDI Process Failures Preceded B777 PW4077 Engine FBO - Aerossurance

mnttech 21st Feb 2021 15:26

silverstrata

Based on the weather in the video/and what it was like yesterday here, they had a pretty good view of the front range that was right in front of them before the turn. Lots of rough stuff in the 12K or higher range in front of them. The ground track shows them turning before reaching the front range. Dont disagree with the rest of the post.
Interesting they came within a couple of miles of my place!

Feathers McGraw 21st Feb 2021 15:26

MLHeliwrench

The in-flight footage didn't indicate anything in the fan cowl area on the fuselage side.

silverstrata 21st Feb 2021 15:27

fergusd

Yes, really.
Engine manufacturers test a whole blade separation, as that is the worst case scenario for the containment-ring. But a blade tip has much more forward pressure when it breaks, than the whole blade, and can spin out to the front of the engine. And then return and perhaps hit another blade.

I note in another image that there is wing-root damage on the aircraft, so a blade must have spun out of the engine somehow. If there is no breach of the containment-ring (difficult to see), then it must have gone through the forward cowling, taking the whole cowling with it.

Even a blade tip has a lot of energy. I saw a turbine blade from an ALF507, which is only 2 cm long, go straight through the back of the engine and embed itself in the fuselage (over 2 m away).

Update: Looking again at the video, I see no breach of the containment ring on the port side (nearest the fuselage). And I cannot believe that a piece of cowling could stray so far as to hit and damage the wing root. Thus the most likely scenario at present, is the blade missed the containment ring, took out the cowling, and penetrated the wing-root.

An unusual result for sure. But when you set this high velocity debris in motion, it is like making a forceful break on a billiards table - you have no idea where the balls will go...

Alpine Flyer 21st Feb 2021 16:08

ACMS

As a maintenance guy recently put it, to them the aircraft is more of a formation of valuable components (engines, APU, gear, other swappable spares) held together by the airframe.

Dave Therhino 21st Feb 2021 16:10

MLHeliwrench

No. That's a remnant of the aft bulkhead of the inlet still attached to the fan case front flange. Other views clearly show no penetration of the containment ring by blade fragments.

Alpine Flyer 21st Feb 2021 16:14


Originally Posted by silverstrata (Post 10994761)
The request for an ATC-determined turn was natural and logical, and for ATC to then overload the pilots with a “which way” request was stupid in the extreme. The crew may not even instantly know where the airport is (it being behind them), nor where any prohibited areas, terrain restrictions, or conflicting traffic may be.

Stupid is a bit of an overstatement. As they said "turn" rather than "return" it is not entirely obvious to ATC where they need to go and having stated an engine failure and depending on the circumstances there might be a preferential side to turn. In a perfect world they might have said "return" or said "turn right or left" but calling ATC stupid for asking feels inappropriate


Originally Posted by silverstrata (Post 10994761)
ATC should have kept things simple, and just given a normal traffic pattern back to the departure runway: “this will be a left-hand circuit for rwy 26”. And perhaps for reassurance added: “other options available, if you require”.

(Remember, the crew need to know the runway to set up the ILS - they don’t need a guessing-game for which approach, while dealing with an engine fire.)

I've never been to Denver but with the number of runways they seem to have according to the Radar display, it seems a bit unlikely that the departure runway would also be the arrival runway. They might have briefed a different runway for an eventual return and in any case they need to calculate landing figures. ATC offered them a runway and added that they could have any other. I'd say that's what you want to hear in a case like this.

Alpine Flyer 21st Feb 2021 16:27

silverstrata

I'd say because their procedures require them to ask and while it's on a load sheet somewhere retrieving that load sheet for a flight originating in a different country may take some time (or will have taken some time when these procedures were devised in the age of telex). And there are lots of GA planes around that don't have a load sheet filed somewhere.

As for the fuel it might be useful for the fire department to know whether to prepare equipment for a fully loaded 777 or a Dash 8 fuelled for 90 minutes.

silverstrata 21st Feb 2021 16:51

I have never been to Denver either. But at most airfields you can expect a left-right split between take-off and landing. That is pretty axiomatic, but it gives you an idea of the circuit pattern.

And Billy Boeing (and Andy Airbus) have a helpful generalisation - if you can take off from a runway (whatever the performance figures), you can do a single-engine landing on the same runway. (Presumably post fuel-dump if fitted, but not flown those types.). So no calculations required. Although the landing performance figures don’t give you much margin for error.

Chris2303 21st Feb 2021 18:28

Is "Aviate, Navigate, Communicate" no longer relevant?

Zeffy 21st Feb 2021 19:13

NTSB Docket
N773UA, BOEING 777 222
Date of Accident: 02/13/2018

DaveReidUK 21st Feb 2021 19:41

And Final Report: DCA18IA092 N773UA Boeing 777-222, Honolulu

lomapaseo 21st Feb 2021 20:56

So what changes were made or not justified to address the engine nacelle cowl?

and that leaves the latest failure with a fire issue in the reverser much farther aft

Personally I can't get very excited with an engine alone fire as long as it doesn't threaten the pylon and has limited fuel

JPJP 21st Feb 2021 21:41


Originally Posted by Lockhart (Post 10994491)
The only indication of a uncontained engine failure to the flight crew, is when they rotate the fire switch a second time to release the squib.
If the fire light remains on for approximately 30sec, then the engine is considered uncontained then you need to return ASAP.
If the light goes out it's an engine severe damage as per the QRH, t
hough sometimes you need to look outside the square to asses the situation.
They did declare a mayday so that fire light would of stayed on or if it went out then a CC member only need to communicate a fire is still visible.

I’m curious about your statement above. Do you have some form of reference, from anywhere ? I’ve never heard of it, and it doesn’t make much sense. Caveat - I don’t know everything and I haven’t heard everything.

The fire light remaining illuminated on a Boeing, indicates that the temperature at the sensor remains above a specified threshold.

visibility3miles 21st Feb 2021 21:45


Originally Posted by Grav (Post 10994345)
https://www.youtube.com/watch?v=XnSj...ople%27sElixir

The video you mentioned was also posted on YT few moments ago

What struck my phone savvy spouse immediately when watching this video is that although the engine is in rock steady focus, the edge of the window in the picture is moving around.

It is the smart feature of the phone camera that makes it look like a steady view out the window, when in fact the plane and the passengers were bouncing due to engine vibration.

If you don’t believe me, watch the video again and focus your eyes on the lower right corner of the photo which shows the edge of the window.

Zeffy 21st Feb 2021 22:05

https://cimg8.ibsrv.net/gimg/pprune....34d6ea366a.png

GlobalNav 22nd Feb 2021 00:04

United pulls 24 777 with same engine out of service
 
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