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Air Traffic Controller Lands Stricken Plane By SMS
There's a new reason to hope that the no-cell-chatter bill now under consideration in the US doesn't bring with it a Faraday-cage mandate, and that reason is landing safely. Reader ma11achy writes with an excerpt from a scary story (with an SMS-based happy ending) from the Irish Times: "Five people on a flight from Kerry to Jersey received mobile phone text instructions from a quick-thinking air traffic controller when he guided them in to a safe landing at Cork, after the plane lost all onboard electrical power, communications and weather radar soon after take-off from Kerry airport."
Because cellphone voice communications requires a constant link between the cellphone and the tower, where SMS is transmitted in bursts when the cellphone and the tower can hear each other.
You'll find in situtations where the cell towers are jammed with calls of people calling each other to see if everything is OK after a major storm, a SMS will get through even if you can't make a call.
What would make a phone lose audio but not SMS ability?
Shite signal. An SMS is sent in a single frame of GSM data. Audio needs 50 frames per second.
So a 4 passenger light aircraft landed with no electric power. Big whoop. Electrical failure on an aircraft like that means the radios go out, you lose a couple instruments, and that's it. Most of the important instruments for maneuvering are either powered by the pitot static system or an engine driven vacuum pump. Speaking of the engines, their ignition systems are powered by a fully redundant engine driven system and don't require any external electric power.
If the pilot wouldn't have had the cell phone, he would have been given signals from a light gun as he approached the airport. Losing radios isn't exactly all that uncommon, especially in older aircraft, so pilots and controllers have come up with ways to handle the situation.