B-777 short landing at Heathrow

Ah yes ! The prince of darkness !
I had an Austin 100-6 and experienced the prince of darkness many times.
Switches

 

I was in class this past week and we were talking about the accident. Apparently the rout the flight was on is a some what polar route. Well Other planes on similar flight had to descend because of their fuel temps. Some say that it was -70C at FL300. Well all the planes had to lower their flight altitude because of this. Jet A starts to congeal at low temps.

 

I always wondered why they had such a bad rep.....

I owned two different Jag's ( both were XJ-6 )
Never had an electrical problem! And the first car,
was scheduled for the wrecker, when I bought her...
for restoration. Had lots of tranny issues.....

Hmmmm.... Did Lucas make Tranny's too???

Charlie

 

I didn't mean to wax flippant about the 777 engine failure. I am too far out of the picture now to offer a lucid comment about this incident. I know that the experts at Boeing are looking at fuel icing or waxing.
Switches

 

thats what i have heard as well, fuel waxing... that it possibly could have cogged the censors in the fuel tanks that the FADEC control uses in reading fuel temps... but knows its all speculation at the moment...

 

So this brings to mind some more questions,
*Why are we hearing about this just now? The plane has been in service for over 10 years.
*Have there been other occurrences that never made into press?
*How long have these planes been in service? Does it make a difference?
*Are these problems the result of incorrect or poor maintenance practices?
*Is this anomaly the result smaller accumulative factors/system age/contamination?.

I'm sure these items are being considered but the questions remain.

 

Darn good analysis. Why is this popping up now after 10 years of flawless service ? Gotta be something that somebody did differently and wrong.
Switches

 

Im going say its just another link in the chain. By the Chain i mean the links that lead up to the crash, break a link and the crash or accident wont happen. The idea is to see the chain an break a link bore it get too long.

Also from what I have heard the pilots did a wonderful job just to make the fence at the airport. Apparently the raised the flaps from approach position to a more upper position, therein reducing the drag on the AC enough to glide it to the airport.

 

The latest from the local paper.

Blog: Update on Heathrow 777 crash
Seattle Post-Intelligencer 05/16/2008




Even though investigators have a complete plane to examine, they still have not been able to determine why a British Airways 777-200ER lost power in both engines and crashed just short of a Heathrow runway in January.

The UK's Air Accidents Investigation Branch this week issued an update of its investigation of the January 17 accident. You can find the report here.

"This is a great mystery, and I never expected this accident to be this difficult to solve, given the state-of-art tools on the plane and the fact that the aircraft was largely intact," Bill Voss, president of the Flight Safety Foundation, told the Washington Post this week. "This has potentially broad implications that go beyond this one airplane, depending on what they find."

From the Post story:

As the hulking passenger jet approached London's busiest airport after a long flight from China, the inexplicable happened: Both of the plane's engines sputtered and essentially died.

There was little the British Airways pilots could do to keep the Boeing 777 in the air. Within seconds, the twin-engine jet pancaked spectacularly to the ground. The plane was wrecked beyond repair.

Although no one was killed in the Jan. 17 crash, investigators are facing extreme pressure to determine what brought down the 777 in an accident that has quickly become one of aviation's modern mysteries.

The wide-body 777 is one of the world's most popular long-haul jets, ferrying tens of thousands of passengers a day across the globe. The crash has also raised questions about how airlines operate an increasing number of long flights over remote and harsh areas of the world.

British authorities have not said much publicly about the accident. They released a report yesterday saying they suspected that the plane's fuel flow became restricted somewhere between the engines and the fuel tanks. They did not indicate what they thought caused the blockage. Ice collecting in or near an engine component has emerged as the prime suspect, according to sources familiar with the investigation who spoke on condition of anonymity because they were not authorized to discuss the probe.

It is ironic, outside experts said, that investigators have not figured out what caused the jet to crash about 1,000 feet short of a runway at Heathrow Airport. Investigators expected a quick resolution because they have obtained more data and information about the accident than any they can recall in aviation history, according to sources and outside experts.

They have interviewed passengers and crew members. They recovered every key part of the plane, allowing them to test the jet's components. They retrieved the plane's flight data recorder, cockpit voice recorder and a separate data recorder installed by British Airways.

 

A brief article I read a few weeks ago mentioned that the probabilities focused on icing of the fuel lines C/T the engines themselves, inside the cowlings, not the struts or wings. Rolls Royce engines in particular. There was serious talk of of fuel line heater mods.

 

Click Here Air Accidents Investigation Branch AAIB (UK version of NTSB) October 08 report.

 

Thanks, interesting read.

 

Update on fuel icing issues.

NTSB Faults Rolls Engines
The Wall Street Journal 03/13/2009
Author: Andy Pasztor
(Copyright (c) 2008, Dow Jones & Company, Inc.)



Prompted by two instances of sudden thrust reductions involving Boeing 777 engines built by Rolls-Royce Group PLC, the U.S. National Transportation Safety Board issued urgent recommendations for the manufacturer to redesign part of the engines to prevent ice from blocking fuel flow during flight.

The high-profile move, which comes despite quiet but ongoing redesign efforts by Rolls-Royce, indicates the board's concern over potential hazards stemming from the current design of the oil-cooler system on Rolls-Royce's widely used Trent 800 engine model. The board said Wednesday that without swift action, it remains concerned that "additional failure events may occur and could result in accidents and injuries."

Once the redesign is tested, and approved by regulators, the board's recommendation letter to the Federal Aviation Administration urges the new part to be installed within six months. Over the past few months, Rolls-Royce has declined to comment on the specifics of the oil-cooler or its redesign.

The NTSB recommendations come after a pair of operational changes distributed by Boeing and mandated by regulators on both sides of the Atlantic. The changes, among other things, instruct Boeing 777 pilots to temporarily increase the thrust settings on Rolls-Royce engines after a long periods of cruise and before starting descents, with the goal of preventing ice from blocking fuel flow to the engines. Under cold temperatures and other factors, ice particles can build up on the surfaces of the oil-cooler and potentially restrict fuel flow to the engines. The oil cooler is a heat-exchanger that warms up fuel while cooling engine oil.

Twice since January 2008, Boeing 777 jetliners equipped with Rolls-Royce engines have experienced so-called thrust rollbacks, or uncommanded thrust reductions. A British Airways jet crashed short of a runway last year at London's Heathrow International Airport, after both of its engines reduced thrust substantially without any command from the pilots. the plane was badly damaged but there were no fatalities.

In November 2006, a Delta Air Lines Boeing 777 suffered a temporary thrust reduction from one of its engines at 39,000 feet during a flight from Shanghai to Atlanta. The flight crew descended and the engine resumed normal operation.

The safety board's letter, which goes beyond previous safety information released by British crash investigators, provides detailed explanation about the subtle process that allows ice particles to build up, disable engines and prevent pilots from being able to increase thrust as necessary. Without a new design, airlines must follow certain pre-flight fueling procedures at low temperatures and pilots must use brief high-thrust settings to essentially blow built-up ice particles out of the system before they can create a safety threat.

 

http://www.flightglobal.com/articles/2009/03/12/323769/rolls-royce-to-modify-trent-as-tests-replicate-ba-777.html


http://www.flightglobal.com/articles/2009/03/12/323794/rolls-royce-trent-800-fix-only-part-of-broader-icing.html