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CD Players  
User currently offlineLMML 14/32 From Malta, joined Jan 2001, 2565 posts, RR: 6
Posted (11 years 6 months 2 weeks 2 days 17 hours ago) and read 2079 times:

Seriously, what are the risks of playing CD's, audio or laptop CD-ROM, or DVD in flight? At AirMalta it is not permitted. Although as FA I have to enforce this rule, I am not sure of whether there is concrete proof that CD's actually interfere with flight computers.
What other airlines have this restriction and what have the others that don't done to allow CD's on board?

18 replies: All unread, jump to last
 
User currently offlineRick767 From United Kingdom, joined Jan 2000, 2662 posts, RR: 51
Reply 1, posted (11 years 6 months 2 weeks 2 days 16 hours ago) and read 2061 times:

We allow CD players & laptops to be used on our flights at all times, except when the seatbelt sign is on for the purposes of takeoff and landing.

Our 767-300 IFE systems run from CD and DVD technology anyway, and passengers on the 767-300 aircraft without seatback TVs in the premium seats are given portable DVD players to watch movies on.

I have listened to my personal CD player on the flightdeck (sometimes on the jumpseat and sometimes in the right seat) on the long overnight Atlantic crossings.

To my knowledge there is no evidence to suggest that CD/DVD players cause any interference with aircraft systems. Similarly the chance of cellular interference from mobile phones is extremely unlikely, I have (accidentally) left my phone on a few times for the entire flight after using it on the turnaround and forgetting to switch it off again.

In my opinion it's all a bit over-rated but rules are rules and you have to enforce what your airline regulates. I feel though that as time goes on a ban on CD players (which exists in a few airlines) will become very unpopular with passengers. I mean, who uses tape cassette walkmans these days? It is not surprising if people complain.



I used to love the smell of Jet-A in the morning...
User currently offlineKLAX From , joined Dec 1969, posts, RR:
Reply 2, posted (11 years 6 months 2 weeks 2 days 10 hours ago) and read 1967 times:

Very interesting Rick, what about Scanners? I had mine confiscated and put in the cargo hold at CDG, even though I tried it prior to that and got only a vary weak signal from inside the aircraft.

-Clovis


User currently offlineIllini_152 From United States of America, joined Jan 2001, 1000 posts, RR: 2
Reply 3, posted (11 years 6 months 2 weeks 2 days 10 hours ago) and read 1968 times:

Well, I used my CD player all the time last summer without a problem. Of course, my plane didn't have an electrical system, so it was a moot point!

From what I understand, while the likelyhood of these devices causing any interference is remote, they DO put out some electrical noise. A very small ammount, but some none the less. As you may remember from your high school physics classes, RF passing wires at right angles will induce a voltage across them, creating interference. None of these devices have been CERTIFIED to not adversely affect systems in the aircraft, IE there has been no testing or empirical evidence that they DON'T cause a problem.

So it becomes an "I don't know" and when it comes to "I don't know's" do you really want to take a gamble during the critical phases of flight?

BTW- I've also used cd players and cell phones in light GA airplanes without any detrimental effects, BUT this is purely anecdotal evidence, and doesn't even come close to testing all the differant positions, devices, and equipment configurations possible. And that's just one, I wonder what 300 cell phones all being used at once in close quarters would do?



Happy contrails - I support B747Skipper and Jetguy
User currently offlineNight_Flight From United States of America, joined May 1999, 156 posts, RR: 0
Reply 4, posted (11 years 6 months 2 weeks 2 days 9 hours ago) and read 1954 times:


We had a few ALPA / Safety representatives come and speak to UND Aerospace about airlines safety. One of their examples was amazing.

I don’t remember the exact details, but in early 1990’s, an airliner was flying somewhere over the United States. The flight crew noticed that every once in awhile, the aircraft would make turns to the right for no apparent reason. After the turns caught the attention of ATC, the captain advised the flight attendants to look for electronic equipment including portable televisions, radios and scanners.

The flight attendants did not see anything unusual. In fact, the only electronic device being used was a child’s electronic learning computer. The captain went back to investigate the computer. The captain turned it on and nothing happened. Then while the captain was pushing various buttons, the aircraft started a bank the right. After explaining what was going on, the captain borrowed the computer and took it up to the flight deck where the flight crew continued to investigate. After awhile, they had discovered that when they were in a certain mode, the aircraft reacted with a bank. Somehow, this child’s electronic learning computer was interfering with the flight computers. The captain then bought the computer from the family so technicians could see for themselves and develop a solution.

This story was amazing how a little child was able to indirectly “Fly” the airplane. There are reasons why the FAA and airlines have certain rules pertaining the use of electronic equipment. Please just follow them.

Even though these rules may seem annoying, there is a reason they are there--- SAFETY.

-Night_Flight-



Remember when sex was safe and flying was dangerous?
User currently offlineAvioniker From United States of America, joined Dec 2001, 1109 posts, RR: 11
Reply 5, posted (11 years 6 months 2 weeks 2 days 9 hours ago) and read 1952 times:

The possibility of causing interference is indeed remote, but...
All audio devices have amplifiers which boost the IF and audio portions of the electromagnetic spectrum. Unless they are specifically shielded to prevent emission they give off harmonics which in certain scenerios can interfere with aircraft systems. Computers use busses to transmit data internally. Until very recently these were in the 100MHz range. Like audio devices they are not specifically shielded to prevent emission.
The Navaids work on AM in the 108 to 117 MHz range. That's close enough to be suceptable to spurious signals inside the fuselage if there are any imperfections in the coax shielding.
There have been quite a few tests in the US and overseas where computers and "walkman" type devices were used in test conditions during various phases of flight.
The worst result I'm personally aware of involved a laptop with an 850Mhz processor being used to do simple math calculations that caused a 4deg. track error in a 727 ILS approach. The test was repeated numerous times doing various functions with the computer located in different seats. The problems occured when the computer was in the last two rows (closest to the 1183 disconnect rack).
My own favorite personal experience was with a 757 that had a long distinguished history of fuel quantity problems. It turned out that the shields on the overwing seats' PES seat-to-seat cables had been interrupted by mishandling. Every time someone in the involved seats changed channels the fuel quantity fluxuated. We were able to duplicate it on the ground.
I, personally, don't want to be on a plane in bad weather on final in those circumstances. When I'm riding and see the FA's having trouble with some drunk, I'm happy to say I've finally overcome my knee-jerk reaction to rip their head off (but I'd still like to).
Happy flying...



One may educate the ignorance from the unknowing but stupid is forever. Boswell; ca: 1533
User currently offlineSilverfox From United Kingdom, joined Mar 2001, 1058 posts, RR: 0
Reply 6, posted (11 years 6 months 2 weeks 2 days 7 hours ago) and read 1906 times:

Am i correct in saying that radio waves etc do not pass through lead?

If so what effect would a Video have if encased in one of those leadlined film cassette bags?

I did bring this up on another forum, by querying, if the use of video etc does cause problems, WHY then does Discovery wings have programmes filmed from the flightdeck during t/o and landing.
Oh thats it. their VCR are trained not to emit signals... How cute

And Night Flight. i have filed that under urban myths (airborne)


User currently offlinePPGMD From United States of America, joined Sep 2001, 2453 posts, RR: 0
Reply 7, posted (11 years 6 months 2 weeks 2 days 6 hours ago) and read 1884 times:

So Night Flight since the child was able to control the aircraft what does he log? Child in Command maybe?


At worst, you screw up and die.
User currently offlineShamrock1Heavy From Ireland, joined Nov 2002, 250 posts, RR: 0
Reply 8, posted (11 years 6 months 2 weeks 2 days 5 hours ago) and read 1876 times:

I know that Aer Lingus does not allow any personal electronics to be used during flight. I had my own headphones on plugged into the plug in the armrest and a flight attendant said quite sternly "I hope that isnt plugged into a cd player" It wasnt, and she gave me a angry look...anyway.

This is due to Irish FAR's from long ago when it was thought electronics did interfere with flight computers...

-D



when in hell, we'll do shots at the bar
User currently offlineAA61hvy From United States of America, joined Nov 1999, 13977 posts, RR: 57
Reply 9, posted (11 years 6 months 2 weeks 2 days 3 hours ago) and read 1845 times:

I have not had any problems, but my dad was told to put his cd player away on a LH from BOM-FRA


Go big or go home
User currently offlineNight_Flight From United States of America, joined May 1999, 156 posts, RR: 0
Reply 10, posted (11 years 6 months 2 weeks 2 days 3 hours ago) and read 1837 times:

"So Night Flight since the child was able to control the aircraft what does he log? Child in Command maybe? "

I often wondered if military pilot who control UAV's are able to log that time as flight time?

-Night_Flight-



Remember when sex was safe and flying was dangerous?
User currently offlineAirplay From , joined Dec 1969, posts, RR:
Reply 11, posted (11 years 6 months 2 weeks 1 day 23 hours ago) and read 1822 times:

To my knowledge there is no evidence to suggest that CD/DVD players cause any interference with aircraft systems. Similarly the chance of cellular interference from mobile phones is extremely unlikely, I have (accidentally) left my phone on a few times for the entire flight after using it on the turnaround and forgetting to switch it off again.

I get a kick out of arm-chair engineers that not only experiment on their own and jeopardize everyone's safety on the flight, but then go on public forums and make ignorant remarks like this one.

These are the same people who jump off cliffs just to see if "mom" was right.

As someone who is directly involved in design and certification of aircraft, I have personally witnessed interference from these devices and can say without hesitation that the potential is there.

Whether or not it can occur every time is irrelevent. Disruption of data busses, communications or navigation on modern aircraft at critical times can lead to catastophie.

Don't treat airplanes like science experiments.


User currently offlineDelta-flyer From United States of America, joined Jul 2001, 2676 posts, RR: 6
Reply 12, posted (11 years 6 months 2 weeks 1 day 22 hours ago) and read 1823 times:

Airplay ... well said!

Taking what you said one step further, any electrical or electronic equipment that is installed in an aircraft is tested for electromagnetic emissions, both radiated and conducted (the latter if it is physically wired to the aircraft system). This is done to assure that the equipment cannot possibly interfere with other equipment. Just because a component is not specifically treated for EMI does not mean that it will interfere with the aircraft systems, but it may. That's why it must be tested.

Why, then, should passengers be allowed to operate all kinds of untested equipment onboard? Those "trained" VCR's that Silverfox so derisively mocks have probably been tested for EMI to the same standards as other airborne electrical/electronic equipment.

Incidentally, the standards most commonly used today are contained in RTCA document DO-160, which covers all airborne environmental test requirements. One chapter deals with EMI (ElectroMagnetic Interference).

When airlines make rules about the use of untested equipment onboard their aircraft, they are essentially taking a calculated risk, with some airlines accepting more or less risk than others.

Cheers,
Pete


User currently offlineSilverfox From United Kingdom, joined Mar 2001, 1058 posts, RR: 0
Reply 13, posted (11 years 6 months 2 weeks 1 day 12 hours ago) and read 1798 times:

Not so much mocking, but rather tongue in cheek.
I have yet to see anything that says one Video recorder is different from the rest in operating on a plane.
Thats the one i want to but.
Until then.... all this conclusive proof.. well Bliar and Powell spring to mind

Jumping off a cliff has proven results that i can see.So i dont.
But.... for years.. before there was all this dont video etc i did and have plenty of take offs and landing to prove it, and nobody said a thing.
Now we get the nanny state all over us.
As i have asked on previous occasions show me conclusive proof, not couch BS.
Someone once said, it isn't the electrics, because if portable equipment can effect a plane to that extent, then the plane is not safe, but rather if there was an incident, a videocam floating around the cabin bouncing off peoples heads would create a problem. Having said that, my camera would have my arm attached to it, as i keep it strapped to my hand, and if my arm was going walkabout on its own, neither me nor the rest of the pax would be in any fit state of mind to worry about it.


User currently offlineIl75 From Argentina, joined May 2001, 263 posts, RR: 0
Reply 14, posted (11 years 6 months 2 weeks 1 day 4 hours ago) and read 1737 times:

Once I was flying on a Finnair MD11 to the US when the captain asked for our cooperation with the cabin crew in telling what kind of electronic equipment each of us was using. He told us they were experiencing some kind of instrument malfunction and he wanted to rule out interference. It was perfectly clear that it was a minor problem and nobody got nervous.

I was asked to switch off the laptop I was using.

I am sorry I can not recall if we were allowed to turn our machines on later on the flight. And I don't think we got to know the findings of that test.

I tell this episode just to show that a captain flying an airliner was giving the possibility of interference onboard a serious thought. At least for six, seven years ago.

best regards
erico


User currently offlineTadex From Vatican City, joined Sep 2002, 91 posts, RR: 0
Reply 15, posted (11 years 6 months 2 weeks 1 day ago) and read 1707 times:

Hi folks!

We observed some interference on several light aircraft when leaving our mobile phones on. We tested it out on several flights and in different aircraft and, for example, in some cases (not all) we experinced up to half scale deflection !!! on the VOR.
Now, i wouldn´t like to be in that situation during T/O and landing in hard IMC.

Happy landings!!!


User currently offlineDelta-flyer From United States of America, joined Jul 2001, 2676 posts, RR: 6
Reply 16, posted (11 years 6 months 2 weeks 23 hours ago) and read 1688 times:

Silverfox,

I'll say this once more, if video player or other electrical or electronic equipment is not tested to validate conformace to the aircraft's EMI standards, then no one can say whether it meets those standards or not. There have been many reports of interference of electronic equipment with aircraft systems. Obviously, the offending systems did not meet the standards. That's why we have standards by which equipment can be measured objectively.

Typically, consumer electronic designers only test to the less stringent FCC standards to assure that equipment do not interfere with communication equipment. But they do not test to airborne standards as required by DO-160, because the cost of compliance is high. And, just because a device fails to meet the standard still does not mean that it will pose a problem on the aircraft, or it may only pose a problem in a certain location, or possibly on one type of aircraft but not on another. But engineers and regulators do not play by chance, that's why every piece of equipment installed on an aircraft must comply with the standards. Since consumer electronic products are not tested to these standards, we do not know whether they comply or not.

I hope you can understand that this is not a question of "prove that my video player is not safe" but rather a question of complying with standards which have been developed over the years by technically competent people for maintaining the aircraft's EMI integrity.

Pete


User currently offlineAirplay From , joined Dec 1969, posts, RR:
Reply 17, posted (11 years 6 months 2 weeks 22 hours ago) and read 1681 times:

Silverfox,

Again, you imply that you experiment based on the lack of evidence that electronic devices have the potential to affect operation of the aircraft.

VCRs are other devices for installation on aircraft need to be certified. There are various processes for this but they all include EMI/RFI testing to determine if the particular unit emits unacceptable levels of interference.

For "Off the Shelf" consumer type devices, the FAA publishes guidance:

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/1ab39b4ed563b08985256a35006d56af/29dfc7721e609573862569ce00751c05/$FILE/ac25-10.pdf

Read that, then tell me if you "have yet to see anything that says one Video recorder is different from the rest in operating on a plane." If you don't know then ask. Don't make uninformed assumptions and spread ignorance.


User currently offlineDelta-flyer From United States of America, joined Jul 2001, 2676 posts, RR: 6
Reply 18, posted (11 years 6 months 2 weeks 9 hours ago) and read 1662 times:

Airplay ... excellent post! Kudos to you for finding that AC.

Of particular interest are paragraphs 5-f and 5-n of the requirements, and paragraph 3-e of Appendix I.

From the information in the AC, the party responsible for installing such equipment on board the aircraft must first select the appropriate EMI parameters based on the airframe design standards, then prove to the FAA that their equipment meets these standards when installed in the aircraft.

For battery operated equipment that passengers would bring onboard, obviously the electrical load analysis, crashworthiness issues and conducted emissions would not apply, only radiated emissions. Airlines obviously base their policies on examining various common consumer products that passengers might use onboard, then determine what level of risk is reasonable given that all of these equipments cannot possibly be tested.

I suspect the reason they do not allow equipment to be used below 10,000 feet is that there is too little margin to regain control of the aircraft in case a serious interference should occur.

Back to the subject of video equipment, I recall when Delta was transitioning to BusinessElite, they gave out portable video players on aircraft that did not have the new in-seat systems. These players were not like the ones you buy in a store -- they looked rather "institutional" in design. I am sure they were specially designed for airborne use, and tested by DL's engineering department to assure compliance to EMI requirements.

Cheers,
Pete


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