Aircraft News Weblog

Tag: heathrow

  • Dreamliner Nightmare.

    Dreamliner fire at Heathrow.

    How much bad luck can an aircraft type have before the orders dry up and the the public wont fly on it? The one thing which can kill an aircraft is the tendency to have fires. The public will not want to be on an airliner which is periodically filling with smoke.

    When this aircraft concept was announced many years ago I knew that this would be a unique design and be, to use the over worked cliche, cutting edge.There would be huge challenges with the extensive use of composites, the reduction of traditional, proven hydraulic systems and the complete exclusion of the use of bleed air from the engines. All of these were completely different from the traditional method of constructing and operating an airliner.

    There were numerous set backs in the development which raised costs into billions of dollars. Then after the aircraft went into service the aircraft lithium ion batteries failed to operate correctly resulting in a worldwide grounding of the Dreamliner. With this problem resolved, but not solved, we now find ourselves with a fire in an Ethiopian Airlines aircraft at Heathrow which is being attributed to the ELT, the device which transmits an emergency location signal when triggered by a high G situation. This problem, if proven, is as unique as the aircraft due to the scarcity of any other incidents related to this component. The most common failure is an unintentional transmission due to a faulty ELT, but a fire is not something that anyone can recall being reported before.

    I hesitate to mention it but the ELT is powered by lithium ion batteries and that could really be the only source of power to start a fire. The British investigators have now called for all B787 ELT’s to be removed or set inert during the investigation.

    The technology in the Dreamliner is unique and Boeing are taking the lead, and the hits, for this innovation. Maybe, like Concorde before it, the Dreamliner will be a fantastic one off airliner when all the problems are resolved. There is no doubt that composite will be used in other aircraft, but the extensive use of new electrical systems will need more development before other manufactures jump on that band wagon.

    I can only imagine the stress being felt in the boardroom of Boeing in Seattle but I think there is nothing left to do but work with the regulators and get this Boeing going.

  • Boeing 777 Trent engine problems with ice.

    The US Federal Aviation Authority have now issued an Airworthiness Directive (AD) concerning the problems with ice in the fuel system of Boeing 777-200 and 300 airplanes fitted with Rolls Royce Trent 800 engines. The AD requires the crew to monitor the fuel temperature within 3 hours of top of descent and if it is below a certain temperature they must increase the engine power to prevent the formation of ice in the main tank fuel supply system. They can do this by stepping up to a higher altitude or increase the airspeed. There is no requirement to carry out this procedure if the aircraft is not fitted with Trent 800 engines.

    There is also a procedure for the circulation of the fuel on the ground by a certified mechanic to prevent the formation of ice.

    This AD is a result of the problems encountered in January 2008 by a British Airways Boeing 777 which failed to respond to a command for increased thrust while the aircraft was on approach to London Heathrow airport and landed short of the runway. The interim report suggested ice formed in the main fuel tank supply system during low fuel flow conditions in cruise flight. The ice then dislodged and caused a restriction in the fuel supply because of high flow conditions due to the lower altitude during approach.

    No doubt there will be more measures to prevent the formation of ice from the engine and aircraft manufacturers but in the mean time the FAA are counting on this procedure to prevent the recurrence of the fuel restriction and loss of engine power.