777 Engine Failure

[Tim Wescott]

Wowzers.  I usually like a window seat overlooking an engine -- I guess I would have gotten to participate in some drama had I been on this flight!

http://www.dailymail.co.uk/news/article-3228323/Dramatic-new-images-British-Airways-jet-caught-fire-Vegas-engine-EXPLODED-spraying-cabin-pieces-burning-shrapnel.html

[REX1945]

I like to sit over the wing because it is the smoothest ride in the house.

Rex

[john ohnimus]

I like to sit over the wing because I'm a licensed Airframe and Powerplant mechanic and I know how to work the escape hatch.... That seat row also has more legroom :-))

[FLOYD CARTER]

I always try for a window seat.  I tell the attendant that the pilot can't find his way without my help.
Floyd

[Steve Fitton]

I thought uncontained engine failures were not supposed to happen anymore.

[Steve Helmick]

My guess is that Pete Ferguson had to go to Los Vegas immediately. I hope he got to Florida (driving) in time to catch his flight back out West.  Steve 

[john ohnimus]

Most of the stuff you see on engine failures deal with fan blade (C-1 disk) separation. The videos that circulate usually show the blade separate and then be contained by the fan frame. However when a turbine wheel fails it sometimes will exit the case. It is located near the aft end of the engine. This unit is spinning quite fast and at take off power settings it surely will exit. American had a 767 with CF6's on it dam near burned LAX down. The turbine wheel exited #1 and skipped across the bottom of the plane and stuck into #2 engine. Other parts ruptured the fuel tanks huge fire ball etc...

[Bill Johnson]

Most of the stuff you see on engine failures deal with fan blade (C-1 disk) separation. The videos that circulate usually show the blade separate and then be contained by the fan frame. However when a turbine wheel fails it sometimes will exit the case. It is located near the aft end of the engine. This unit is spinning quite fast and at take off power settings it surely will exit. American had a 767 with CF6's on it dam near burned LAX down. The turbine wheel exited #1 and skipped across the bottom of the plane and stuck into #2 engine. Other parts ruptured the fuel tanks huge fire ball etc...

That was a bad one.

Turbine failures are much more difficult to contain then the compressor/fan. 2/3rds of the energy produced by the engine is extracted by the turbines just to spin the compressor.

RR Trents have an issue with the intermediate turbine which turns the mid-speed compressor. It sometimes shifts aft contacting the next turbine nozzle. This is a little more difficult to design then single or 2-spool engines. Each shaft, in this case 3 of them, must have at least one set of thrust and radial bearings. If the turbine shifts aft and the mid-speed spool seizes, the bearing support housing can rupture leading to an oil fire.  Meanwhile, the low and high speed spools are still spinning full speed.

[john ohnimus]

Bill,

  We dont see too many RR engines here. Mostly GE's and Pratt's. Which maintenance facility do you work at?

Tony O.

[Bill Johnson]

Tony,
I'm in an office in Huntsville now but have worked in facilities all over the country. Now I have quality and AS9100/9110 oversight on 24 programs in 15 countries. Lots of travel, little time on the flightline for the last 2 years. Even less time to fly C/L, much less build anything. Fortunately, I have friends with plenty of hand-me-downs and used planes for sale. 

[Scott Richlen]

What is amazing is the high level of design/maintenance of these airplanes resulting in their safety.  Thus, why this particular failure is so noticeable.  Years ago we were funding R&D on CFCCs (continuous fiber ceramic composites) for use in turbines.  Not sure where that is now.  Maybe the economics didn't work.

[john ohnimus]

If a blade at the front of the engine fails, the casing is designed to retain it. The NTSB's findings therefore suggest that the failure was within the internal part of the engine.

"Initial examination of the left engine revealed multiple breaches of the engine case in the area around the high pressure compressor," the NTSB said in a statement.

[Tim Wescott]

Here's what the NTSB said yesterday: http://www.ntsb.gov/news/press-releases/Pages/PR20150910.aspx.

[Bill Johnson]

Here's what the NTSB said yesterday: http://www.ntsb.gov/news/press-releases/Pages/PR20150910.aspx.

So BA has some 777s with GE90s! That's interesting. I thought they were RR throughout the fleet.

[john ohnimus]

Bill,

Ever work at TIMCO (now HAECO) in GSO?  I've been off of the "floor" now for two years. Work in tech training. Indoc, Human Factors, I teach a couple of GenFams. Just finished my systems and engine run on the B777 with GE90's. Spent the last 8 years as an A&P lead. Good Times...

Tony O

[Bill Johnson]

I did, John, back in 1992 and 3. I was working heavy structures then. The typical Boeing and Douglas airplanes. In fact, I was there when Piedmont was started back up.

[john ohnimus]

I'll ask around and see if anyone remembers you. I know a lot of folks there been there since. 99'

[Peter Ferguson]

It may surprise a fw people to learn that the BA 777 fleet has GE engines not RR. This was a decision made around the launch of the program. To get the order GE bought the BA facility in Preswick Scotland (formally British Caledonia airlines). That is now the OH facility for GE 90"s and is probably where this engine will go for teardown and investigation. Most of the engine non contained failures from the compressors originate with inclusions in the castings. It will be interesting to see if this is something different.