Why? They don't prohibit any other electronic devices which can clearly interfere. They only prohibit their use in flight.

Are you being deliberately obtuse? Isn't it obvious to you and anyone else who flies frequently that people cannot be expected to turn their phones off? Just like we don't trust people to not fire their guns in the cabin, nor trust them to not blow up their bottles of water :rolleyes:, etc.

Forget the FAA and airlines. It's the pilots life on the line too. They would not allow phones on board if they were worried about any problems.

There are many strong radiation sources impacting commercial aircraft throughout a flight:

- AM and FM radio towers pumping out tens of thousands of watts of energy
- Police/fire radio repeaters
- Active Cell towers that aircraft fly near and over (especially on landing)
- Radar

It seems like these sources of potential interference would be a much larger problem than a cellphone in the cabin.

I am one of those pilots. I've been an airline pilot for more than 20 years.

Cell phones can interfere with aircraft systems. I have seen such interference first hand. When everything is working properly, a single cell phone shouldn't interfere but things don't always work properly and we aren't talking about a single cell phone. The risk of having some phones on, but not on an active call, is relatively low but low doesn't mean non-existent. When interference occurs, it will not normally cause an accident, but it could. Things as simple as a burnt out light bulb have started a chain of events which led to airline crashes in the past. Reports of interference from passenger electronic devices are submitted regularly to the aviation safety reporting system (ASRS).

Aviation safety is about identifying and managing risks. There is a risk associated with the passenger's electronic devices, including phones. Measures are taken to minimize these risks in ways which are practical for the passengers. Confiscating all cell phones, computers, DVD players, etc. prior to flight is not practical and is not necessary. The risks can be managed in other, less onerous ways. The current policy doesn't result in 100% compliance but without it there would be a hundred, or more, active cell phones on many flights and nobody can predict what that much RF in the cabin might do. It would certainly result in a significantly higher risk of interference than what we have now and there's no reason to take the additional risk.

This idea that if there was any risk at all the activity would be banned demonstrates a naive view of risk-management philosophy. If such a strict risk-avoidance policy was used we wouldn't fly as there are always risks.

Those sources are much farther away than are RF sources in the cabin. The strength of the signals from the outside sources are much lower due to that distance.

Yet interference from those sources does occasionally occur...

I think you mean "unsubstantiated claims" about interference are submitted regularly. Without proper testing equipment on board and someone to perform those tests all you are left with is an unsubstantiated claim, not evidence.

I have personally seen Cat III testing (and a full range of avionics tests) being performed and troubleshot in a maintenance environment with the person in the flight deck talking on a cell phone with a remote engineer. If cell phones were such a risk to avionics equipment they would also be banned from all maintenance hangars where such certification testing occurred. They are not banned in such situations, even though you, as a pilot, are relying on those certifications to ensure that your equipment is working properly.

This pretty much throws out the window the concept that the ban on cell phones is anything other than an outmoded "safety" concept.



By the way, during the certification of major cabin upgrades a test flight is typically conducted with a large quantity of various consumer electronics spread throughout the passenger cabin, all operating in their normal modes, to test for just this type of problem. In the last test I was involved in there were over 100 devices spread throughout the cabin and no impact was observed by the flight crew. This was with 80 in-seat video systems up and running and 100+ portable consumer devices, including cell phones carried by the multitude of in-flight observers with no impact during the entire flight. Again, pretty much throws this concern out the window.

This is real world experience with testing equipment and test pilots on board, not some subjective "report" from a crew with no real evidence.

Yes, on every report I have seen of pilots claims of cell phone interference, it has never been proven in followup tests on the same airplane.

As for risk management and the impracticably, no one has answered my point about water, toothpaste and jelly doughnuts?

I mean exactly what I said. Few, if any, of the incidents are investigated further.

As a pilot, I would say that more than half of the avionics write ups that I see in the aircraft logbooks are not reproducible by the mechanics and are subsequently written up multiple times before the mechanics are able to get it fixed. Does that mean that the three, four, etc., previous anomalies were the pilot's imagination? No, it means that these things are unpredictable and very difficult to reproduce.

Yet they continue to occur, again, and again, and again. From that you conclude that they do not exist.

The only risk of using a cell phone during maintenance work is that an otherwise perfectly good airplane will fail a diagnostic test and the mechanics will waste time trying to find the non-existent problem.

Ah, that's the key to why the airplanes aren't crashing. We don't rely on the equipment working properly, we expect it to fail so that we are prepared on the relatively rare occasions that it does.

Re-read what I wrote on risk-management.

One successful test only shows that everything was working correctly on that airplane, on that flight. One test doesn't tell you anything about what can happen when things aren't working perfectly. If a successful test ensured perfect performance then there would never be any write-ups. Everything always works fine--until it doesn't.

And if a phenomenon can't be reproduced in a controlled experiment then it's what? Anyone? Bueller?

They should shut off the sun. It's a source of electromagnetic interference :)

I don't have the link handy, but I have seen on an FAA web site, confirmed cases of loss of ILS glide slope lock, and numerous cases of interference to intercom and air to ground radio communications from cell phones. I'll try and relocate the link.

+1,000,000

Banning cell phones in flight is the best idea ever... nobody is that important that they need to use a cell phone aboard a flight. People shouting loudly that they are on the plane is the most annoying piece of conversation!!! Do people need to communicate every piece of useless detail to everyone else? really?

If you have something that critically important to be communicated (life or death situation) i'm sure the pilot can radio that communication!

Intermittent.

I'm not going to defend inane conversation, but as a business traveler I dislike being cut off for the duration of the flight. Given that on most airlines in coach I can barely open my laptop, and I can't make phone calls, the flight time becomes wasted time.

If I could make calls I could use that time to advance my projects forward, attend conference calls and meetings, even sit in on training sessions - thinks I have to miss out on now if I happen to have travel that conflicts.

I agree. You know that EK allows phones to be used in flight, right?