As a frequent flyer and private pilot with some knowledge of EMC, I'll throw in a few comments:
It is clear to me that consumer electronics can interfere with aircraft electronics, and I've probably heard all the same horror stories -- DC10 finds itself off course on landing, false engine warnings, interrupted communications, etc... It isn't clear to me how prevalent this problem is or if it happens often enough to be considered a problem. One instance of electronic interference is enough to have everyone up in arms against the use of ANY electronics in ANY airplane. On a 747 flight to the Pacific, I'd bet there are as many as 30 to 40 lap top computers operating together at some point during the flight. Additionally, there are probably another 40 to 50 walkman tape players or CD players in operation, plus the on-board entertainment systems and a few in-flight telephones being used. On shorter flights, there may still be a large number of laptops being used by business people plus tape/CD players and air phones and the like in use during the flight. I don't think this is a general problems for aircraft electronics. HOWEVER; if radio or television receivers or cell phones were allowed, I believe the level of interference could easily reach the level of being at least disruptive to aircraft systems if not downright dangerous. I have personally seen commercial scanners and FM broadcast receivers that will interfere with voice comms -- 118MHz to 136MHz -- which means they could certainly interfere with nav equipment operating between 108MHz and 118MHz (VOR's and ILS's, specifically). I also have a Garmin hand held GPS system that I cannot find anything that it will interfere with nor have I found anything that interferes with it (except things getting in the way of the antenna - Maybe I'm just lucky?). My sense is the following: Interference with nav stuff is the most likely -- a VOR indicator off, or something like that. With GPS back-up (or getting to be primary) in most aircraft, a faulty Nav indication would likely be caught before it was a problem (NOT so if you're on an ILS approach in IMC (Instrument meteorological conditions) where a faulty indication can run you into terrain -- this is why no electronics should be operated on the aircraft below 10,000 feet on take-off or approach). I doubt a cell phone caused the Saab to crash -- most airplanes will still fly even with all electronics blocked out (don't know if the Saab is fly by wire or not, but I don't think so). Horizontal situation indicators and gyro's are driven by vacuum and in larger airplanes, there's back-up vacuum, red flashlights in the cockpit, etc... Upsetting autopilot controls might cause the airplane to do something erratic, but that sort of thing should be recoverable as long as someone in the cockpit is paying attention. Enough of that -- need to get back to my real job.... Mike Hopkins KeyTek -----Original Message----- From: Colgan, Chris [mailto:[email protected]] Sent: Wednesday, January 24, 2001 6:15 AM To: 'Emc-Pstc' (E-mail) Subject: consumer electronics used on board aircraft There is growing concern amongst professional aircrew about the use of consumer electronics (CD players, mobile phones, hand held GPS etc) on board aircraft. Some claim that passenger electronics has definitely interfered with navigation systems, primary flight displays or engine warning systems. There are rumours that a mobile phone contributed to the demise of a Crossair Saab 340 on 10 Jan 2000 killing all passengers and crew. Some pilots reckon that it is absolute nonsense. Knowing what you do, about how EM disturbance can affect electronics equipment, that it is almost impossible to make electronics equipment completely immune to EM effects, that FCC class B or CE marked equipment has not been tested (presumably) with avionics in mind etc, etc, how do you feel when the guy next to you on your flight gets his Minidisc player or laptop out? Remember, when you are descending through a cloud layer, the pilot is relying solely on electronics receiving equipment to get the aircraft on the runway. Do you think all consumer electronics should be banned from aircraft, that FCC or CE equipment is okay or that the whole issue is scaremongering piffle. Any comments gratefully received, I will post a summary on a professional pilots forum and let you know that results. 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