BA Glide at Heathrow

[Garry Emanuel]

Any update/news on the investigation and cause of the near disaster at Heathrow with the 777 some months back now ?

Tried to search, however, came up dry.

Thanks in advance.

[Montague S]

tail has been removed, I know that much...

[Ash W]

tail has been removed, I know that much...

Yeah it is still sitting at Heathrow, as you said sans the tail. I am surprised someone hasn't painted out the BA markings as it is in full view of every arriving and departing flight into the hell hole that is LHR.

[Matt D]

The interim report was published in the last day or so. Paraphrasing (extensively):

..Ice formed in the fuel system due to extended periods in an unusually cold environment (fuel temp got to -34C for a period of time) at low fuel flows. On approach the fuel temp was still -22C, low but not unique for this acft/engine combination.

..Fuel tests show the fuel was within normal quality contraints.

..Ice restricted flow of fuel to the engines

..Unique in that it is the only recorded case of fuel flow restriction of this type and then that it happened to both engines within 7 secs of each other.

..Impact with the ground was at 1400fpm

The summary is on page 19
http://www.aaib.dft.gov.uk/sites/aaib/cms_resources/G-YMMM%20Interim%20Report.pdf

[Neil Hogbin]

Latest report and video from BBC News in London ..
http://news.bbc.co.uk/1/hi/england/london/7598267.stm

[Nigel C]

And another report found in good ol' www.news.com.au

http://www.news.com.au/travel/story/0,26058,24297757-5014090,00.html

[Andrew M]

What amazes me is "Investigators said: "This is the first such event in 6.5 million flight hours," referring to the flight time of all Boeing 777s powered by the Trent 800 engine since they entered service in 1996."

[David Ramsay]

From NZ Herald (http://www.nzherald.co.nz/section/1/story.cfm?c_id=1&objectid=10530874)

Pilots warned to rev up Boeing 777s
4:00AM Saturday September 06, 2008
By Grant Bradley


Air New Zealand will urgently introduce new procedures for its Boeing 777s after a report found frozen jet fuel caused a British Airways plane to crash-land on approach to Heathrow Airport in London.

Boeing suggests 777 pilots be told to rev up their engines before landing to clear ice from fuel lines and to change altitude periodically when flying through very cold air after the crash in January.

The worldwide alert covers 220 777s with Rolls-Royce Trent 800 engines in service with 11 airlines. Air New Zealand has eight of the aircraft.

Air NZ's general manager of airline operations, Captain David Morgan, said additional operational and maintenance requirements would immediately become standard operating procedure for the airline.

The British Airways plane with 152 passengers and crew crash-landed on January 17 after the engines could not provide enough thrust while approaching Heathrow Airport.

There were no deaths and no one was seriously injured, but the aircraft was destroyed. The 777 flew from Beijing through temperatures of minus 73C over Siberia, possibly thickening the fuel and reducing its flow, Britain's Air Accidents Investigation Branch said in an interim report.

Although the exact mechanism in which the ice has caused the restriction is still unknown, it has been proven that ice could cause a restriction in the fuel-feed system," the report said. "The risk of recurrence needs to be addressed in the short term, while the investigation continues."

Boeing's initial instructions are to periodically vary altitude when fuel in the main tank is below minus 10C, and to advance the throttle to maximum for 10 seconds before the final descent when fuel has been below that temperature for more than three hours, clearing out any water build-up.

For 777 aircraft on the ground in freezing conditions, fuel pumps must be run at maximum for one minute each to prevent water build-up.

A design change would make the fuel system more "resilient", the US National Transportation Safety Board said, but such a move would take time, so interim measures were needed.

New Zealand Airline Pilots Association technical director Hugh Faris said the crash-landing was "extraordinary" for a plane with such a good reputation for reliability and safety.

Operating the aircraft in line with the directive would be "relatively straightforward".

[Philip Argy]

What amazes me is "Investigators said: "This is the first such event in 6.5 million flight hours," referring to the flight time of all Boeing 777s powered by the Trent 800 engine since they entered service in 1996."

That reference was not to the bare phenomenon of fuel waxing/clogging, Andrew, but to a unique permutation of events/conditions, which the report expressed in these terms:



The accident flight was therefore unique in that this has been the only recorded case of a restricted fuel flow affecting the engine performance to the extent of causing HP pump cavitation, Control Loop 17, Control Loop 14 and a mismatch between FMV position and fuel flow demand, and this occurred on both engines within 7 seconds of each other. This is the first such event in 6.5 million flight hours and places the probability of the failure as being ‘remote’ as defined in EASA CS 25.1309.

[Radi K]

Looks like another incident.

DATE:10/12/08
SOURCE:Air Transport Intelligence
NTSB investigates Heathrow-like Trent 800 engine issue
By John Croft

US NTSB senior investigator Bill English is meeting with Boeing regarding an in-flight power rollback on the right-hand Rolls-Royce Trent 895 engine powering a Delta Air Lines Boeing 777-200ER during a 26 November flight.

English earlier this year took part in the UK air accident investigation branch's analysis of a Trent-powered British Airways 777-200ER landing accident at London Heathrow International Airport. The gliding touchdown 300m short of the runway destroyed the aircraft but caused no fatalities among the 136 passengers and 16 crew. An NTSB spokesman says English is "looking into the incident" with an eye on seeing if there are similarities with the BA accident.

Investigators in that case have identified water icing as the likely cause of the fuel restriction and dual-engine rollback in that accident, though the final report is not yet complete.

FAA in September issued an airworthiness directive calling on operators of 777-200 and -300 aircraft equipped with Trent engines to revise flight manuals to include in-flight procedures for pilots to follow during certain cold-weather conditions and for operations on the ground.

In the latest incident, the NTSB says Delta Flight 18, enroute from Shanghai to Atlanta at 39,000ft, experienced an "uncommanded rollback" on the right hand Rolls-Royce Trent 895 engine.

"Initial data indicates that following the rollback, the crew descended to FL310 (approximately 31,000ft) and executed applicable flight manual procedures," according to the agency's preliminary report. "The engine recovered and responded normally thereafter," investigators state, adding, "The flight continued to Atlanta where it landed without further incident."

English and his team are analyzing the aircraft's flight data recorder "and other applicable data and components" retrieved from the aircraft, according to the report.

A Delta spokesman says the airline "will partner closely with (the NTSB) and comply with any recommended actions as soon as possible to ensure that there is no operational impact to our customers or communities."

[Philip Argy]

This BBC news report has just been posted:



Hundreds of Boeing 777s could be faulty: investigators

Air accident investigators in the US say there is a "high probability" that a fault, which apparently caused a British Airways airliner to crash land at London Heathrow airport a year ago, could affect about 200 other Boeing 777s.
It is thought the accident could have been caused by a build-up of ice in the fuel delivery system which leaves the plane without enough power.
A second incident 10 months later is believed to have been caused by a similar problem in a Delta Airlines plane.
American air accident investigators say there is a high probability it could happen again and have called for a component in the engine of the 777s to be redesigned.
The makers, Rolls Royce, say a new part is being made and will be available as soon as possible.