Originally Posted by dannyr
On The FCC love to scare us with stuff like "if you use your cell phone, it will interfere with navigational instruments and cause aircraft instability". My question is - Did it?
If one person using one cell phone can apparently affect the stability and avionics on an aircraft, what can 30 pax using 30 cell phones do ? Did these phone calls at all affect the stability of the flights?
I still think it is 50-50 if cell phones pose a real problem. I am much more worried by someone using a FM radio. The FM band is right next to the ILS localizer band. A FM radio is a known hazard to pointing your landing in the wrong direction. Not a good thing.
If the cell signals cause instrument errors, it will most likely show up on those instruments that rely on radio signal reception such as the ILS and VOR and GPS. The pilot must either be using these readouts, or, as in most flying, the autopilot is programmed to fly the plane using the received signals.
The autopilot programming pad has more buttons than your crackberry, and must be programmed correctly with the routes and radio frequencies and responses the plane is to follow. It is one of the most sophisticated things to learn in the cockpit. Punch one button wrong and it does not work correctly. Of course, commercial flights follow similar routes every day and the routine route info and SIDs and navaid radio frequency and such are all programmed in. The locations of navaids and airports are preprogrammed, the longitude and latitude of the WTC is not.
The 9/11 hijackers, from what I have read, barely knew how to hand fly the planes. There is no way they could have learned to program the autopilot to fly to an off airport site. I bet an experienced pilot could not do it in the 30 minutes or so their whole flight took after takeover. It could take hours.
The hijackers hand flew the planes VFR looking out the windows using maps to navigate. That's why they picked a time of year with a high probability of clear weather in the NE. One movie showed they carried hand held GPS receivers which they could program in advance even if it took a week.
It is my opinion the cell phones could have completely whacked the radio based navigation systems but it did not matter as the hijackers were not using any them. OTOH, every ordinary everyday flight uses these systems continuously and if cell phones interfere it would be a problem.
If cell phones are a problem, the 9/11 post hijack flight phase is not a representative test.