Air Traffic Controller Lands Stricken Plane By SMS 177
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."
Re:Why didn't he just call them? (Score:5, Informative)
Why didn't he just call them?
He did. FTA:
Eventually he [the pilot] managed to contact Cork [the air traffic controller] on his phone, telling them about his problem and his intention to approach the airport from the sea.
He then lost audio telephone contact but the air traffic controller switched to texting and told the pilot that he had a primary radar signal on the aircraft and that Cork would allow them to land there. He then used texts to guide the 30-year-old plane in.
Re:Why didn't he just call them? (Score:2, Informative)
[The pilot] then lost audio telephone contact but the air traffic controller switched to texting and told the pilot that he had a primary radar signal on the aircraft and that Cork would allow them to land there. He then used texts to guide the 30-year-old plane in.
Re:Why didn't he just call them? (Score:3, Informative)
Re:Why didn't he just call them? (Score:5, Informative)
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.
Re:Whats the tech hubub about cell phones? (Score:4, Informative)
Re:Why didn't he just call them? (Score:5, Informative)
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.
Non-Story (Score:5, Informative)
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.
Re: Air Traffic Controller Lands Stricken Plane (Score:2, Informative)
Sheesh! Air controllers don't land planes, stricken or otherwise. Aircrews land airplanes. The airplane will land (and fly) just fine without an "air controller".
Air traffic controllers _clear_ airplanes to land. This involves traffic de-confliction and statistically improves safety but there are plenty of non-towered airports where the aircrew routinely lands without benefit of Air Traffic Control.
For instance: http://flightaware.com/live/airport/KPUW [flightaware.com]
At Pullman/Moscow Regional Airport, a non-towered field near Pullman, WA, Horizon Airlines makes almost a dozen arrivals and departures a day _after_ they leave air traffic control.
Re:Why didn't he just call them? (Score:2, Informative)
GSM uses time division multiplexing, which means that the "constant link between the cellphone and the tower" is infact a set of short and frequent bursts. A burst sent from a phone from further than 30km will cause the tower to receive the burst out of its allocated time slot and as a result the call couldn't be maintained.
The pilot actually landed the plane (Score:3, Informative)
The controller doesn't land the plane. The controller works with pilots to keep the airspace and runway coordinated and air traffic moving smoothly. That's an essential job, but it doesn't include flying.
After all, there's no way (in a short time) to MacGyver a cell phone SMS to an autopilot. And this plane may not have an autopilot anyhow.
The pilot followed standard lost contact procedures and augmented them with the call to the controller. The controller wisely used SMS when voice was lost.
Anyhow, the article writer's hook for large commercial aircraft is nonsensical since this is a four-seat aircraft and wouldn't fall under those rules anyhow.
Re:Whats the tech hubub about cell phones? (Score:4, Informative)
Carnegie Mellon University good enough for you? [sciam.com]
Misleading, a bit (Score:3, Informative)
There have been pretty good rules around for over 60 years regarding what the pilot should do when they can't contact the tower. Similarly the tower has an old red/green light gun for communicating with planes that can't hear.
It's unlikely there was any safety added by the cell phone sms messages. In fact, bypassing the usual no-radio procedures may have compromised safety. There may be some flags dropped on this play.
Re:Why didn't he just call them? (Score:2, Informative)
The reliability isn't generally there. They got lucky that the messages went through so quickly.
SMS services are inexpensive to provide and don't consume much bandwidth -- although they consume some storage.
The reason providers get away with charging so much for them is because they can, because enough customers perceive SMS as having value, being an extra feature, and tolerating the ridiculous, exhorbitant pricing.
Re:Whats the tech hubub about cell phones? (Score:3, Informative)
Cell phones, certainly GSM cell phones *DO* interfere with aircraft communication systems.
It was a dark and stormy night (OK, it wasn't stormy, just light rain, with a cloud base at 600 feet, and it was very dark). I was returning from the UK with a friend in his light aircraft. It was my friend's first IFR approach for real - in the clouds, at night. The air was smooth though, so the conditions weren't too bad for a first time.
Unfortuantely he had forgotten to turn off his phone.
ATC cleared us for the approach, giving us a final vector to the localiser (the localiser is what gives you horizontal guidance on an instrument landing) - the vector is a heading ATC gives you such that you intercept the localiser course sufficiently far out on the approach and at a shallow enough angle that it's practical to start your approach. Just as the localiser needle started moving towards the centre, *all* audio was blocked by this noise:
Bip-bip bip-bip b b b bip-bip bip-bip brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
It was very loud and very distracting. We could no longer hear any instructions from ATC. Fortunately, I could take over flying the approach while my friend hunted down his cell phone and turned it off, and fortunately, while this racket was going on, ATC didn't give us any new instructions.
If you have a GSM phone, chances you'll know exactly the sound I describe above. They are terrible at interfering with all kinds of stuff.