Mobile phones.
 

Am I correct in thinking that no airline ever modified their aircraft to accept the now common practice of mobile phone usage on board?

How many times do people forget (and I mean genuinely forget) to turn their phones off??

I suspect most flights have at least one fully active phone running

Link to research please

almost all articles I've seen say its precautionary and there is little or no evidence a Mobile phone screws up electronics - especially on modern aircraft

That may be true with newer AC and phones, but it wasn't always the case. Many years ago (early to mid 90's maybe), I brought two mobile phones (Audiovox bag and Motorola MicroTac) with encryption gear on board companies new glass cockpit G IV to determine feasibility of encrypting execs communications after the company lost a couple of large lucrative contracts. Corporate chief pilot gave me a quick tour and powered her up.

He had already told me that on just about every flight they were getting random and frequent display messages forcing the crew to instruct Pax to turn off all electronic devices - mostly laptops. Spent quite some time on board (the G IV and two other AC) making calls with both phones and moving around the cabin. Location didn't seem to make a difference but both the 3W and .6W phones caused the messages to start scrolling. Not surprisingly the 3W phones generated a larger number of alerts but both ultimately did the job. It was always an added burden on the crew to determine what was real and what wasn't particularly since glass cockpits were realtively new to them - a distraction at least that could occur at times when the crew really didn't need to be distracted.

I realize that RF emmissions have changed and shielding has gotten much better, but I always turned my phone off after that and it annoyed me when I saw people leaving them on. It still annoys me today simply from the perspective of not following crew instructions.

Does not Flight Mode ensure the phone while 'on' for games and videos etc already in it's memory does not have RF emissions to potentially screw up Aircraft electronics?

Am still not sure that when using the Aircraft's wi fi to use your own device to act as the IFE screen is 'Safe'

In the old days the command Turn off Devices was quite clear, however now devices are 'on' how do other passengers and CC know that the device it not affecting aircraft performance?

"the perspective of not following crew instructions"

regretfully those days of respect are long gone - the SLF are too used to thinking of it as a bus service with worse seats

Kiltrash

Yes, but you can turn wifi back on above 10,000 feet separately while the device's other transmitters remains in airplane mode. I personally doubt most people turn-off their wifi on descent. Most phones run between 1-2Watts in cellular mode but less than .02Watt in wifi and the frequency bands are different. Large difference in power output.

Even if you don't use your phone's wifi, there is still a wifi access point on aircraft that offer such service and that is transmitting in and of itself. The FCC is considering rule changes allowing cell phone calls at altitude and below 10,000 feet due to 'advancements in technology'. Get a good set of noise cancelling headphones or ear plugs if they relax that rule. I got a taste of that back in the 90s when much of United's fleet had a GTE Airfone on the back of every seat. The only reason it wasn't more objectionable is that it rarely worked and was incredibly expensive.

Just FYI, there were two parts to the original issue of cell phone use on planes - possible interference with aircraft instrumentaion (shielding on older equipment just wasn't made to filter out spurious RF from the newer frequencies) but also confusing ground cell towers due to the rapid hand-offs as you cruise past towers every few miles. I don't think today's mobile infrastructure (ground) would be able to handle everyone on every plane on their phones.

And yet some airlines allow and indeed facilitate use of mobile phones in flight just about everywhere. That is except in US airspace. Their aéroplanes do not fall out of the sky.

Do the mobile carriers (or the airlines) charge a premium for in flight calls? I don't think our ground infrastructure would be up the task in large metro areas such as the Boston to DC corridor unless the AC had a concentrator that relayed the signals similar to wifi.

Like I said, United used to have cellular - so did USAir if memory serves. But I suspect they made some profit from the wireless provider (originally GTE for UAL). They didn't fall out of the sky either though having tested and forced messages to appear on the G IV, I'm still concerned about crew distraction trying to diagnose spurious and incorrect display messages during the more critical phases of flight.

I fly Southwest every week and they have pretty much given up on any enforcement at all except large devices not being on your lap or in the seat back pocket for take off and landing. I bet there are 20 people or more on every flight who have not switched off.

And not that I would ever have a phone on in flight intentionally or otherwise but if I had I might have noticed that there is never any signal at cruising altitude even over relatively populated areas.

In 2008 AeroMobile launched a system.
AeroMobile's first customer was Emirates became when their 777 started to be modified.

sherburn2LA

You might be surprised. Developed a cellular fraud mitigation system at a large wireless carrier years ago. A side effect was we could track the route in real time coast-to-coast for our customers who accidently left their phones on in flight as the phone registered in a new roaming environments. For kicks we'd plot on a map and get the old OAG guide out and were able to determine airline and flight based on path of roaming registrations - before the flight landed. OK so we had some extra time on our hands. It was very tempting to leave a voicemail reminding them to turn their phone off.:E

The ones I'm aware of have a 'cell tower' on the plane which tells the phones to transmit at low power, and forwards calls to the ground from the plane. An acquaintance of mine worked on one of those systems a few years back.

So far less of a problem than dozens of phones transmitting at maximum power and switching between towers every couple of minutes.

I don't know if it's still an issue, but at one time the cell phone providers didn't want people using their phones on aircraft because at cruise speeds the phones switched between towers too frequently to be reliably tracked (and of course billed, which was the real concern).
Modern aircraft are rather well shielded for Electro Magnetic Interference (EMI) - initially it was done by FAA "Special Conditions" (and the JAA equivalent) - now days it's been incorporated into the FAA FARs and EASA CSs. Since I worried about engines and FADEC (which are outside the pressure vessel) we had to meet higher levels than stuff inside the fuselage (which helps shield external sources) but the EMI limits are still high enough for flight critical systems that a 1 or 2 watt cell phone transmission inside the fuselage is still insignificant (unless the shielding hasn't been properly maintained, which is a concern and not just for cell phones).

Years ago, Boeing received many reports of 'unusual' flight deck effects or displays that went away when the cabin crew told some passenger to turn off their electronic device (often reported to be video games). Thing is, the Boeing EMI group worked with various operators, and would have the airline buy the (apparently) offending device from the passenger and return it to Boeing. According to my friends in the EMI group, they never were able duplicate the problem or even find unusual emissions from the returned devices.

One important reason (for me) to switch the phone off, or onto Air Mode - is to save battery. Yes, I could faff around with yet another cable to charge the phone, but there might not be a USB.

If there is a delay, or diversion, or problem on arrival, I want every bit of battery I can. I have seen folks out of phone battery in power outages and they are headless chickens. I also have a power booster battery in my carry-on bag.

Chinese airlines enforce the rule of no mobile phone use at all even in flight mode.if you don't follow cabin crew instructions the next step is the onboard security staff.

I accept that I retired before cellphones or glass cockpits really took hold, so can't comment, but do recall a Captain advising me, the Navigator, that his compass was giving obviously erroneous readings, and asking me to go back into the cabin and investigate the First Class baggage rack above rows 2 and 3 both sides. This was where the master compass fluxgate senses ( correct name ? ) were stowed in the sidewall construction on the 707, along with a large notice asking that no baggage containing magnetic material be stowed in these two compartments - ( thinks ? why didn't we just block those compartments off.)

I discovered a large tape recorder, about the size of a Remington portable typewriter - remember those ? - stowed in the Port side locker, belonging to the passenger sat underneath. The magnet as part of the loudspeaker was affecting the compass system. Tape recorder removed and confiscated for the rest of the flight. Problem solved.

It would seem aircraft fitted with pico-cells, designed to communicate with cell-phones would be much better than those not fitted.

Swissair had seat backed phones. Was on flight from GVA to LHR, when the Burger King in T1 burst into flames. I was able to call Avis and rebook my car rental.

I do hope using mobile phones on flights doesn't catch on - imagine 100 people all talking at once "I'M ON THE PLANE"

I have a memory somewhere that the bias frequency used by the Nagra portable tape recorder (once the recorder of choice for broadcast journalists) was an exact match for one of the frequencies used by the Victoria Line Automatic Train Control system on the London Underground.
So if you had one of these recorders on a Victoria Line train and you switched it to record the train would do an emergency stop at every signal.