Cell Phones and Air Safety

Cutie Pi writes "On the heels of this recent Slashdot story discussing Wi-Fi use on airplanes, the BBC is reporting about new evidence indicating that cell phones can interfere with airplanes' navigation systems. From the article: "In tests, compasses froze or overshot, navigation bearings were inaccurate and there was interference on radio channels." Look like like Wi-Fi and airplanes just don't mix."

Comments

compass?

[Faust]

I sure hope they are using more than a compass to navigate a commercial plane.

Re:compass?

[rbbs]

In answer to your question: Civil Aircraft navigate using a variety of methods. Depending on where in the flight programme these are, this could be anything from VOR (Very High frequency Omni Directional Range) system to a Heading Select system ILS system or ADF. The Nav system itself functions using a variety of inputs including VOR (Military systems operate on TACAN (Tacital Area Navigation) which uses UHF rather than the mid band frequencies that VOR uses), Compasses, Accelerometers, Gimballs, Gyros as well as Ground Mapping RADAR fixes, GPS (these days), JTIDS (Joint Tactical Information Distribution System -Military again), On-Top fixes, HUD fixes and Offset fixes in addition to ADF (automatic direction finding) These inputs are used for comparison within the autopilot which uses a triplex (usually) voting system to decide what to show and what to do. (obv this various from system to system) So, finally, in response to your question, yes the plane does use a compass to navigate and whilst all these sub-systems are designed to promote redundancies within the larger system, they are taken into account and in the event of a larger systems failure, may be relied upon more than the pilot may realise - hence one of the major problems in over reliance on redundant systems...your perceived level of safety increases thereby causing you to change your actions accordingly and hence reducing the overall safety of the craft. - But thats another story. Incidentally, the reasons for not using cell phones on planes are neatly put at this link Airborne operation of PEDs [PDF] (I am not a pilot)

ok, but...

[dwgranth]

The article does NOT mention the age of these airplanes.... which does make a big difference since Boeing and Airbus have started shielding their equipment better in their recent airplanes

Re:Aren't they already banned?

[Verence]

Cell phones are banned from gate to gate. You are not allowed to use them during flight.

I recall an anecdote of a lady. She used her phone while approaching the airport (coverage in the air would be absolutely amazing) and was met at the gate by law enforcement.

They are *not* allowed in the air.