Transponder Options The fact that it happened at all is astonishing to John Nance, a broadcast aviation analyst and veteran pilot. "It is hard to conceive of a situation in which a triple seven would lose all ability to have its transponder on and the crew would not find some way to communicate," he told CNN.
Kit Darby, a long time pilot, said Tuesday it was not clear whether the transponder was turned off intentionally. A power failure would have turned off the main transponder and its backup, and the plane could have flown for more than an hour with such a power failure, the president of Aviation Information Resources told CNN's Wolf Blitzer. But Nance expressed doubt that that could have been the case. The electrical system aboard the plane is so robust and the transponder draws so little power that it would be one of the last pieces of equipment to go dark, even after a catastrophic event like an engine explosion or a breach of the cabin and rapid decompression, he said. "I'm in a head-scratching mode," Nance said. "The most likely probability is that a human hand turned that off. Then you get into the logic tree of who and why and there aren't that many channels in that tree." He added, "This is beginning to look very, very much like a hijacking." A former Federal Aviation Administration safety inspector agreed. David Soucie, author of "Why Planes Crash," cited the redundant electrical, charging, battery and communications systems on Boeing 777s. Much had to go wrong for the aircraft to lose its transponder and then to veer off course, he said, adding that it stands to reason "that someone forced those pilots to take control of the aircraft and take it off course." Turning off a transponder requires a deliberative process, said Peter Goelz, former managing director of the National Transportation Safety Board. "If someone did that in the cockpit, they were doing it to disguise the route of the plane," he told CNN. "There might still be mechanical explanations on what was going on, but those mechanical explanations are narrowing quickly." As for the plane turning around, there is some questioning of the reliability of Malaysian radar systems. The military system that was used to speculate on a turn-around of the plane is only as sophisticated as that used 75 years ago in London during World War II. ---In FairfieldLife@yahoogroups.com, <authfriend@...> wrote : Why did the transponder stop transmitting? http://www.nytimes.com/2014/03/13/world/asia/malaysia-plane-transponder.html http://www.nytimes.com/2014/03/13/world/asia/malaysia-plane-transponder.html My bet is that the plane experienced a sudden decompression, the pilot tried to turn around to get back to Kuala Lumpur, but the pilots both blacked out because they failed to put on face masks in time. The debris is far out in the South China Sea somewhere. That's my bet also. Except the pilots were turning the plane back after the decompression event (they should have donned the oxygen mask as first priority) so the plane could be in the Indian Ocean.
