Autopilot malfunction?
Posted on 01/19/2008 8:39:33 AM PST by GovernmentShrinker
THE pilot of the British Airways aircraft that crash-landed at Heathrow said he feared the flight would end in “catastrophe” as he struggled to cope with a double engine failure just two miles from touchdown. First Officer John Coward, 41, said both engines lost power simultaneously, leaving him with just seconds to bring the aircraft down.
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Investigators examining the wreckage of flight BA038 are now focusing on the theory that the crash was caused by a failure in the avionics and electronics systems that control the plane’s engines. . . . A senior industry source said: “. . . The AAIB has identified that the problem seems to be connected with the avionics and and electrics which link the flight deck to the engines.
-- snip --
A former 777 pilot said that it was extremely unlikely that both engines would have suffered failure at the same time. “For two engines to fail at that stage of the flight - it’s not lack of fuel or contamination,” he said. “It’s got to have been commanded \[by the automatic control systems\]. We are all aghast.”
(Excerpt) Read more at timesonline.co.uk ...
He dropped the nose of the aircraft , got up some speed, and then brought the nose up so she would drift in.
If he had pulled up for a go around, they all would be dead.
WOW!
Question: Electronic interference ( cell phone, microwave, etc. ruled out?)
Could be some Tangos out there , shooting their electro-nuts.
Any landing you can walk away from . . . . . . .
Right Stuff Ping
Autothrottle malfunction ?
WTH do avionics have to do with the engines shutting down?
Still sounds like the fuel was cut off.
But, too early to tell.
Fortunately, we have the remains intact, so we will only have to wait a year or so for the report. /s
....With no actual mechanical linkage to the throttle body??
THISsssss.....
....Is the worst case scenario!!
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Also see this thread if you haven’t already — http://www.freerepublic.com/focus/news/1956225/posts?page=1 (posted by Virginia Ridgerunner) — an article from the Daily Mail including the tidbit:
“Inquiries by the Air Accidents Investigation Branch appear to rule out any form of pilot error in the approach for landing. One area of specific interest will be the electrical system after it emerged yesterday that there had been at least 12 serious incidents of overheating, causing “major damage” to power panels on at least four occasions.”
The fancier they make the plumbing...?
Flight comming from Bejing. Makes ya wonder who was fooling around with what last?
I think that President Bush was secretly on board and demanded to fly the airplane, thus leading to the crash.
(Or has the DU’ies already claimed this?)
Good picture. I didn’t know Mitt flew commercial jets.
If anyone thinks that avionics software is somehow built better than your average computer software, think again. It has more paperwork involved but that paperwork is pencilwhipped.
Honeywell's Airplane Information Management System (AIMS) project consists of the largest central computer on the jetliner; it runs 613,000 new lines of code (defined as body semicolons), taking up 15,656 kilobytes (KB) of disk space and 4,854 KB of random-access memory (RAM). With redundancy, the software runs to 46,191 KB and 10,732 KB of RAM. A multiprocessor, rack-mounted system, the AIMS replaced many of the line-replaceable units and reduced hardware and software redundancy.Two AIMS boxes handle the six primary flight and navigation displays: two sets are located in front of both the captain and copilot so that they can move from one seat to the other, and two central sets of engine parameters are shared by the pilots. The primary flight instruments indicate pitch and roll attitude, direction, air speed, rate of climb, altitude, etc. The AIMS also includes the central maintenance function, which receives reports from the 777's other computers and then gathers the data into a central maintenance report for the mechanic. Its monitoring system gathers data on how other functions are doing, and can determine, for example, that an engine is degrading, before it actually fails. Other AIMS functions include a data-conversion gateway, flight data acquisition, data loading, an Ada conversion gateway, and thrust management.
Honeywell's massive effort on the 777 involved over 550 software developers. The company built the AIMS computer as a custom platform based on the AMD 29050 processor. It was unique among aviation systems for integrating the other computers' functions; in other systems, each function resides in a different box [the central maintenance had its own box with its own input/output (I/O), its own central processing unit (CPU), etc.]. AIMS combines all these functions and shares the CPU and I/O among them: it uses the same signals for flight management and for displays, so that the data comes in only once instead of twice; one input circuit provides data to all of the functions; each of the functions gets a piece of the CPU, as in a mainframe computer, where systems use part of the CPU but not all of it; and every function is guaranteed its time slot. Engineer Jeff Greeson said that "The federated system is obsolete. Putting all the functions in one box is a jump ahead in technology that we've brought to the industry."
Another innovation is that the disk drive can read files formatted for the Microsoft Disk Operating System, which provides maintenance with access to the terminal communications. The mechanics can transfer files for data loading over the airplane bus, because Honeywell built the program to accept new data and to change the software. In fact, most of the equipment on the airplane has that ability, only a few classic systems do not (such as the ground-proximity warning system, which has proven sufficiently trustworthy and not in need of change).
Designing a new architecture simultaneously with a new language was "quite exciting," Greeson said. "The organizational details were difficult to put together." With Ada, managers were able to delegate the seven main functions to groups of 60-100 software engineers. The separate software entities have minimal interface with other parts of the software, and not all of the software is integrated. By working with loosely coupled pieces, the project leaders were able to farm out the functions to other groups. The loose integration, however, does not tie the software to the 777 platform, and will assist in Honeywell's using the code for other targets. "We needed the maximum ability to port it to other places," Greeson said.
Ronald Ostrowski, director of Engineering, claims that the Boeing twinjet is already the most tested airplane in history. For more than a year before the flight, Boeing tested the reliability of the 777's avionics and flight-control systems around the clock, in laboratories simulating flight. Design changes were made only after six months of testing the endurance of three engine types (Pratt & Whitney, Rolls Royce, and General Electric).
One compelling reason behind the extensive pre-testing was Boeing's desire to meet the Federal Aviation Agency's (FAA's) Extended Twin Operations (ETOPS) standards ahead of schedule. The original ETOPS rule was drafted in 1953 to protect against the chance of dual, unrelated engine failures. Unless a newly designed and produced aircraft has at least three engines, it usually had to wait, sometimes as long as four years, before the FAA and the Joint Airworthiness Authorities (JAA) will allow it to fly more than one hour from an airport; after a time, the new aircraft is deemed a "veteran" and is allowed to fly three hours away. A shortened trial period would drastically increase Boeing's sales.
Granville Fraser, a propulsion engineer at Boeing, said that a company protects itself better from engine failure by preventing in-flight problems {outside} the engine, such as faulty warning lights, than by concentrating solely on the engine's mechanics. "Over 50 percent of engine shutdown is irrelevant to the core engine," he said. "It has to do with electrical, fire systems, etc." On the 777, those outside systems are programmed in Ada.
Pratt & Whitney laboratories can, therefore, test the engines, but the quality of the software will have an equal role in determining the reliability of the 777's engines and its conformation to the ETOPS standards.
On the maiden flight, with the Boeing Telemetry room in constant contact with the plane, the engines performed better than expected. The 777 proved itself an ETOPS "veteran" on its first flight out, becoming the first twin-engine plane to win FAA approval for "ETOPS out of the box." The trend towards more reliable hardware and software are revolutionizing aviation and can be found in aircrafts other than the 777.
Sounds like some good flying on the part of the pilots!
Good Find, guess we'll just have to wait now.
More correctly, I should have said it looks like the “out of fuel” explanation is off the table. The cessation of fuel getting to the engines, for for some other reason than there not being any, is still on the table, but avionics/electrical problems could well be the cause of that.
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