Like many readers in the industry, I'm pretty skeptical that mobile handsets can cause problems with aircraft electronics. I always thought the laws were a legacy of the old, more powerful analog phones of the past. At worst, I thought there might be the sort of "dum di di dum" sounds in poorly-shielded headphones - the type you get through the sound systems at conferences when the speaker's phone rings in his pocket close to the microphone.
Which is why I was rather surprised to hear an announcement this afternoon, midway back from Barcelona on an Iberia Airbus A320 saying;
"The pilot has requested that all passengers check again that their mobile phones are switched off, as the aircraft systems are registering interference"
and again 15 minutes later
"The aircraft systems are still experiencing interference. Would passengers please switch off all electronic products now"
Anyone else ever heard something similar? I'm guessing that a flight back from Barca today after 3GSM would have a higher than usual number of cellular gizmos.... and perhaps some precertification prototypes, but this still really surprised me.
Dean Bubley's Disruptive Wireless: Thought-leading wireless industry analysis
yes. had same thing today, but before take off. Also in MWC-land en route to Madrid.
ReplyDeleteIn one flight a pilot came on before take off and said he knew two phones were still on...I figured he had some form of CellBuster he carried around...
ReplyDeletejust a s frustrating I could use my GPS chip on Southwest for 2 years...pilots would kid I had better maps than they did. 2 months ago they banned it. I asked one of the pilots dead heading on a flight and he said the FAA mandated the ban. I checked FAA and they say it is an airline's choice. So I have a letter into SW ops to try and reverse - since this is a receive only chip which via UPS I connect to my laptop...but some of this stuff appears so arbitrary
ReplyDeleteHi Dean,
ReplyDeleteA few years back I had a discussion with a senior VP of engineering at Boeing. We were at a CEPT meeting on GSM on aircraft, and this guy was Boeing's chief technical delegate. W had dinner with a bunch of similar aviation-RF geeks, including people from Airbus and the other consortium partners pushing GSMoA. The universal opinion was that mobiles pose absolutely no threat to any aircraft system.
Think about it - the systems are shielded/hardened against lightning strike. The amount of RF power in one strike would cover the entire RF spectrum, at power levels beyond the wildest imaginings of the most ardent mobiles-on-planes doomsayer.
LORAN / GPS etc work at different frequencies to GSM/3G. That said, the possible permutations of intermodulation products between RF, IF and baseband stages in any electronic devices onboard would be legion. I believe there will always be a worst-case to put for things interfering, so it's in good shielding design and mechanical integrity / redundancy we trust.
Cheers,
Mike