Using electronics on commercial flights

[DarkSarcasm]

Just a question out of curiosity.

 

I can understand why you can use mp3 players during takeoff/landing because (I assume) they don't want people with music turned up so they can't hear announcements etc (I'm guessing that's their motivation behind it?)

 

But what about digital cameras? I don't mean video cameras, just still picture cameras. As far as I know, they don't send out a signal that will mess with the instruments or anything (or do they?), so can you use them during takeoff/landing? Or is there some other reason why you can't?

 

 

[sseeker]

As far as I'm aware still cameras are fine, some video cameras that use MiniDV tapes have a magnet in them which can send the compass off (if it's close enough).

 

-Andrew

 

 

[Al B]

Cameras, and most electronics, don't intentionally transmit anything. Unfortunately it is possible for electronics to unintentionally emit noise on a variety of frequencies. Certain design methods are used to minimise this noise, and most countries have limits on the maximum permitted amount.

 

I guess one concern is that it _may_ be possible for some really badly designed device to unintentionally radiate enough noise to mess up the aircrafts navigation systems (which should be very noise immune anyway). Since aircrew cannot possibly check every single device, it's safer to err on the side of paranonia during the critical parts of the flight.

 

Disclaimer: IAAEE (I Am An Electronics Engineer)

 

 

[Sloper]

Makes you think, would you want to fly in a computer contolled aircraft.

 

And yes l to will claim IAAEE

 

Seem to remember about a microwave transmitting on aircraft freqencies a few years ago cuased all types of havoc.

 

regards Bruce

 

 

[Admin]

One thing about a camera could be that you may take a snap with the flash which could effect a pax's eyes just when they will need to use them to see the escape lines - just a thought!

 

Many people don't know why they turn the lights off when taking off and landing - this is simply for the pax to acclimatise their vision in the case of an accident

 

 

[Tomo]

Many people don't know why they turn the lights off when taking off and landing - this is simply for the pax to acclimatise their vision in the case of an accident

Makes the view so much better too! nothing like seeing the city lights on take off/landing!

 

I asked permission to video/photograph taking off landing on one of my flights, they checked my camera out, and said I could. Then en-route I pulled out the car GPS and turned it on, hold it up to the window to get signal (I asked permission to do this also btw) was pretty cool until the battery went flat. Signal is pretty intermittent though, but I got it briefly, I wanted ground speed at the time.

 

 

[Guest Wigg]

on my last domestic flight a young girl next to me had her mobile phone on the whole 2 hours she texted the whole time including take off & landing. The flight crew said nothing to her so am I to assume that it is ok to use your mobile during a flight now? Sue

 

 

[Tomo]

I heard some gossip that some airlines now have/or going to have WiFi.... now that would be handy.

 

 

[Spriteah]

To the best of my knowledge phones are still banned. We know they emit noise and RF at several watts.

 

Jim

 

Austec.

 

 

[Ding]

Phones etc.

 

Your right Jim,

 

We flew back from Tasmania recently, and everyone was aked to turn off their electronic devices including mobiles.

 

Didn't mean that everone did, nor did the crew ask anyone who hadn't. It was pretty obvious from where I was sitting who was using their phone.

 

Regarding cameras, all cameras these days have some form of microprocessor in them to drive the light metering etc, and all microprocessors have a clock that keeps them syncronised. Sometimes these electronic clocks run at a frequency that either directly interferes with on board systems or generates a harmonic that interferes. So they ask all people to please turn off electronic equipment. The chances of interference are billions to one these days, but would you want to be on the one flight where it happens.

 

Cheers,

 

Ding.

 

 

[jetjr]

Could it be that say 10 phones running during a flight isnt too bad - 2 W each ~ 20 Watt RF noise

 

150 phones all on could generate 300W which could stuff up all sorts of things,

 

Even 1 phone in the Jab is generates a ticking noise though headset. Other interesting thing is that they dont track cell locations very well in the air - it will stay attached to cell tower 50nm away then just drop out as it changes to nearer one, next it will be linked to distant one again

 

 

[Guest Andys@coffs]

The Mobile GSM system (2G) is based on cells, where each cell is about 10kms wide. In an aircraft that is traveling at 800km's per hour, how often will it enter and leave a cell? about every 45 seconds. As it leaves and enters a cell its transmits to the old cell and the new. For those with GSM phones you've all heard the noise as they update the cell.

 

Think of the extra telco network traffic if planes full of 100 plus 2G cell phones all on, flew over a city, compared to the expected traffic from those 100 handsets if they were moving at the usual speed in the city....Does wonders for your battery life....Not!

 

3G is the same, though the cell size is not protocol physically limited to 10km's rather reception in that cell vs reception in another cell determines when a switch occurs. Where a 3G phone at altitude, switches from one cell to the next, a similar 2G phone might have switched cells orders of magnitudes more times, each time relying on a handover takeover transmission that generates interference and eats battery life while stressing the telco networks.(assuming there is a cell to take over...which in Australia is probably only true along the east coast and then only where the highway runs...)

 

In fact the new mini cells that are likely to find there way onto aircraft shortly have the benefit to the airline that because they are in the aircraft the phone doesn't have to shout, where shout = long distance = greater power = more likelihood of interference (The power output of a mobile isnt fixed, it very much depends on what reception is like wherever it is. this is why sometimes a phone will last on a single charge significantly longer than it does at other times when in different locations). The mini cell location doesn't change relative to the handset so it doesn't need to transition to another cell. The mini cell in the aircraft is connected back to the ground via a satellite connection which is tested and known not to interfere and best of all for the airlines, they get to charge you, indirectly for the call, and as such it becomes a money making enterprise.

 

Andy

 

 

[Tomo]

A lot of mobile phones can be put into 'travel' (aircraft) mode. Which allows operation of mobile phone, but must switch off signal. Basically for the likes of iPhone and Blackberry (many others!) type mobiles that you can use for more than just ringing people.

 

Though using your mobile while flying (in the airlines) will flatten it rather fast... unless signal searching is switched off.

 

 

[GraemeK]

Further to Andy's post, it's the FCC (the communications regulator) in the US that bans mobiles in planes, not the FAA (the aviation regulator). Reason? As Andy suggests, the cell system really wasn't built to handle a rapidly moving transceiver that is pretty much equidistant to maybe 30 or 40 towers at any one time.

 

There's really no evidence to support interference to aircraft systems, despite investigations by Boeing and others.

 

As for cameras Darky, it just depends. Some of the newer sensors are so sensitive that they literally suck photons out of the air. So if the camera is pointed towards the engines, it can create a photon deficiency in the transmogrifier bypass amplifier, leading to turbo encabulator failure at the nofer trunnion and hence compressor stall. So be warned!!

 

 

[flie43]

WHAT THE !!!! Well said Graeme

 

 

[Bill Hamilton]

Folks,

 

It is not only phones or other devices that have a transmit function that can cause problems/interactions with aircraft equipment.

 

No names, no pack drill, but certain mobile phones can cause a malfunction in the pressurization outflow valves in a particular quite common aircraft, causeing anything from cabin pressure "bumps" to an emergency descent.

 

For another example, until relatively recently, many Apple computers had the same series of Motorola microprocessor chips as a number of Flight Management Computer Systems (FMCS) in aircraft. If you were sitting in the area of a B747 which was near or directly above the main electronic compartment, unintended consequences could and do eventuate.

 

Mobile phones have also been shown to cause interference with VHF comms radios.

 

I have has personal experience with both the above, so, please, please follow the airline rules and turn of what you are asked, when you are asked.

 

Regards,

 

 

[DarkSarcasm]

. Some of the newer sensors are so sensitive that they literally suck photons out of the air. So if the camera is pointed towards the engines, it can create a photon deficiency in the transmogrifier bypass amplifier, leading to turbo encabulator failure at the nofer trunnion and hence compressor stall.

That sounds like something Doctor Who would say to confuse the aliens

 

(In other words, I haven't a clue what any of that means, but I'll take your word for it)

 

 

[Al B]

[...] many Apple computers had the same series of Motorola microprocessor chips as a number of Flight Management Computer Systems (FMCS) in aircraft. If you were sitting in the area of a B747 which was near or directly above the main electronic compartment, unintended consequences could and do eventuate.

I'll believe that certain computers may cause problems, but I'm puzzled how a common processor with the avionics could be the cause. What kind of glitches were you seeing?Darky: When it comes to the trunnion, you don't want to muck around. As well as possible compressor stalls each failure increases the possibility of carburettor blockage in the APU - not what you want on a hot day!

 

 

[Bryon]

Some of the newer sensors are so sensitive that they literally suck photons out of the air. So if the camera is pointed towards the engines, it can create a photon deficiency in the transmogrifier bypass amplifier, leading to turbo encabulator failure at the nofer trunnion and hence compressor stall. So be warned!!

And that is the simple answer, he can get real testicle if needed:hittinghead::hittinghead::hittinghead:

 

 

[Guest Wigg]

thanks for the answer guys. John told me the part about the telecom relays being to often, but there has been quite a bit of extra info in here as well. Sue

 

 

[Bill Hamilton]

Al B,

 

A gentle dutch roll, with the nose making a small figure 8 on the horizon on the B744.

 

The pressurization problem --- seems to vary from aircraft to aircraft.

 

There has been no cast iron technical explanation, just speculative causes. In my cases, getting the cabin crew to look for anybody with a then model of the Powerbook, and asking the pax. to turn it off always immediately solved the problem.

 

With all due respect to GraemeK, he is not correct, an extensive series of tests by United Airlines also showed a range of problems, in one case enough to preclude a Cat 11/111 coupled approach, with corresponding misleading displays of commands on the ADI and HSI.

 

What makes it so tricky is that the results are not consistent across a range of supposedly identical models, this is where airline results across a fleet have shown results, whereas Boeing (can't say for Airbus) only subjected (an) individual aircraft to tests.

 

The old analogue phones seemed to cause a lot more problems than present generation, high powered TV transmissions also cause problems (see TSO requirements for VHF radios in Europe) and there has been much speculation over "radiation hardening" of Airbus flight control systems.

 

Regards,

 

 

[Guest basscheffers]

Just they other day I heard a QF flight cue their mike to answer ATC and there it went: "di didi di didi di di..."

 

Good to know the pilots turn off their cell phones as well!

 

 

[Thx1137]

I read once (and unverified) that there was an airliner incident where they could not find a cause so it was thought that it might have been someones personal electronics device. So, it wasn't proven it was a "just to be safe".

 

The devices do emit RF however they need to be approved for sale and part of that approval is limiting the possible interference.

 

Another article I read some time ago said that phone off restrictions may be removed because there was no actuall evidence of aircraft system interference though voice calls were still to be banned. (thank god!)

 

I really wouldn't have thought it would be that hard to verify once and for all.

 

 

[Gibbo]

Ask Telstra about the mess it can make of someone's bill.

 

Had a couple of doubled / tripled up calls made at the exact same time.. One in Queensland and one in SA. The billing system could not cope with the concept and it took them 3 months to sort it out.

 

I use a 6db car antenna attached to my samsung phone and you can get reception everywhere in Australia as soon as you hit 3000'. Middle of the Simpson and Gibson Deserts is not a problem (except to Tel$tra's billing engine).

 

G

 

 

[dazza 38]

Makes the view so much better too! nothing like seeing the city lights on take off/landing!I asked permission to video/photograph taking off landing on one of my flights, they checked my camera out, and said I could. Then en-route I pulled out the car GPS and turned it on, hold it up to the window to get signal (I asked permission to do this also btw) was pretty cool until the battery went flat. Signal is pretty intermittent though, but I got it briefly, I wanted ground speed at the time.

Hi Tomo, my Garmin Nuvi, shows a top speed of 1242 kmph, my patrol doesnt go that fast LOL, i shook it in my hand when turned on.Its still on their i have proof LOL:big_grin: