Using RF signals while flying.

We are all told to turn off our cell phone and electronic devices during takeoffs (and climbs) and landings (and descents) on commercial flights. But is using a cell phone really dangerous or is the FAA just being overly cautious?

I ask, because it I think the iPad has great potential for being an all in one flight computer. A large number of the iPad apps work better when they have a connection to the internet thru 3G or wifi. Would it be dangerous to fly around with your iPad with the 3G turned on?

I sat thru a presentation on this once, specifically someone studied how often people use cell phones on commercial flights. They found that on just about every flight someones cell phone was trying to connect to cell towers on the ground. Their conclusion was that cell phone were going to eventually cause a plane to crash. But so far there is only circumstantial evidence that any cell phone has ever affected a planes flight systems...

I think you'll find that having cell phones (or iPad) on in a personal aircraft is an FCC issue more than an FAA issue. The FAA wants it off when flying airlines so you can pay attention and the FCC wants it's off so you don't overload rural towers. I think there is a old thread here that goes in to more detail.

It is legal to use a cellphone in private aircraft in Canada. I have not seen any interference using mine. Nav Canada even says to use your cell phone to call them(their tower) if your radio craps out. They operate in a different frequency band than of the avionics. I haven't checked the harmonics from the cell phone but I doubt they would be strong enough to bother anything. I think the airlines and the phone companies may have had some input to having them outlawed. They want you to use their phone system that cost them millions to install and billions for the infrastructure.

You will find that they have taken steps to prevent your device from working at much altitude. Years gone by you could get away with it with the older phones and technologies but the newer stuff stops working once you start hitting multiple towers.

I 've been told, it is illigale to use any electronic device that is not part of the installed devices of the aircraft (i.e. cell phone, etc)
but I have often carried my cell phone with me during VFR flight and never experinced any issues as a result.

Texting A/C to A/C works pretty good as long as the flight is fairly low (below 3K) and over a town...
Or so I'm told... <BG>

Bavafa said:

I 've been told, it is illigale to use any electronic device that is not part of the installed devices of the aircraft (i.e. cell phone, etc)
but I have often carried my cell phone with me during VFR flight and never experinced any issues as a result.

Click to expand...

This is not true, otherwise portable GPS units and handheld radios would be illegal. I believe this *is* true for air carrier ops. I'm sure one of our esteemed captains will speak up to confirm/deny.

The Mythbusters tested this...

They came to the conclusion that the FAA is just being very conservative and it is highly unlikely that a cell phone or ipad would bring down an aircraft due to RF interference. Found a reference here and here with some interesting comments.

GSM Cellphones...

You know how you can hear a funny "beedip-beedip-beedip" buzzing noise thru any nearby audio amplifier/speaker gear (e.g. computer speakers) right before, and during a GSM phone ringing for an incoming call? When that's happening in the cockpit, the GSM phone will also swing a whiskey compass around quite a bit too. I've seen this happen firsthand (cellphone in left shirt pocket, directly in line with panel-mounted compass on left side of panel in front of me).

GSM phones (and the older, now-defunct TDMA phones) spew out some pretty obnoxious RF signals and harmonics when they are receiving an an incoming call during the ringing setup cycle. CDMA phones do not do this. You can also hear the pre-ring GSM interference thru most typical aircraft intercom systems and active ANR headsets too.

But if the whiskey compass swinging around during an incoming GSM phone call is disrupting your flying enough to be an issue, you've got much worse problems on your hand than that.

I am very glad they do not allow cell phone use on commercial airlines. Even if it is proven 100% that there is no danger, they should still be banned.

Reason: Who wants to spend hours stuck in a tube a 35K feet will 150 people talking on the phone! That would be the loudest cabin in history. A B-29 taking flak over Europe would sound like a church by comparison.

I have noticed my Iphone will not work above 3500 feet.
Drop below and I can stream music etc.

FAR 91.21 Portable Electronic Devices

(a) Except as provided in paragraph (b) of this section, no person may operate, nor may any operator or pilot in command of an aircraft allow the operation of, any portable electronic device on any of the following U.S.-registered civil aircraft:

(1) Aircraft operated by a holder of an air carrier operating certificate or an operating certificate; or

(2) Any other aircraft while it is operated under IFR.

(b) Paragraph (a) of this section does not apply to?

<snipped out non-applicable stuff>

(5) Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used.

(c) In the case of an aircraft operated by a holder of an air carrier operating certificate or an operating certificate, the determination required by paragraph (b)(5) of this section shall be made by that operator of the aircraft on which the particular device is to be used. In the case of other aircraft, the determination may be made by the pilot in command or other operator of the aircraft.

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Bottom line...for us, it's up to the PIC.

Interference

WingsOnWheels said:

I am very glad they do not allow cell phone use on commercial airlines. Even if it is proven 100% that there is no danger, they should still be banned.

Reason: Who wants to spend hours stuck in a tube a 35K feet will 150 people talking on the phone! That would be the loudest cabin in history. A B-29 taking flak over Europe would sound like a church by comparison.

Click to expand...

A new study shows that the link between cell phones and aircraft RF interference is unclear, but the link between cell phones and inconsiderate idiots remains strong.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

I have seen use of a cellphone within the cabin of an Arrow would screw up the VOR indicator, causing it to go to full deflection while a call was in progress and returning to normal once the call was ended. I don't allow pax to use their cell phones once the wheels leave the ground, and have asked a couple of folks to put them away.

Mobile Phone in Aircraft

One of the reasons cell phones do not work well in aircraft over ~ 3000' AGL. is it does not make sense to provide coverage where there are less than 1% of the customers. (FCC regs. disregarded)

Modern ground based cell antennas mounted on water towers, high buildings and the like, are extremely directional providing very high gain. The antenna design concentrates the energy on the horizon to get the maximum customer coverage at the expense of vertical coverage where the aircraft operates.
The ideal ground based cell antenna system would blanket the surface of the earth and have all its coverage below 200' AGL. The benefits to the customer would be extended battery life, smaller devices, and extended reliable range.
The mobile device designers are looking for the same benefits, directional antennas in the mobile device compressing out the vertical component, forcing the signal to the horizon would be ideal but not an easy challenge.

Flat antenna patterns...

I have been in the television industry for 39 years. I learned very early that television transmission antennas compress the pattern vertically to get maximum coverage to the horizon. Cell towers are built the same way for the same reasons.

In Canada, Navcan encourages you to leave your cellphone on in flight. I confirmed this yesterday with a coordinator from the RCC (Rescue Coordination Center).

The purpose of this is to be able to track your position should you dissappear. There are several examples of recoveries facilitated by using cell networks to determine the position of a cell phone during flight or on the ground. The phone does not need to be in an active call for this to be effective.

In fact, we have examples where ELTs were destroyed or did not trigger, but recovery was made by using the cell phone locator service. Of course, there are also examples where phone calls or texts from the ground have assisted survivors as well.

So, we have an effective emergency beacon called the cell phone. In relatively populated areas, it is useful for rescues, *even though it is not used for active calling*.

Food for thought.

Vern

FCC Regulation 22.925

Thermos said:

(

Bottom line...for us, it's up to the PIC.

Click to expand...

Not really, from a regulatory standpoint the FCC gets the last word on this. I'm not going to argue the real merits of the issue, but here is what the FCC has to say:

FCC 22.925
Revised as of October 1, 2007

Sec. 22.925 Prohibition on airborne operation of cellular telephones.

Cellular telephones installed in or carried aboard airplanes, balloons or
any other type of aircraft must not be operated while such aircraft are
airborne (not touching the ground). When any aircraft leaves the ground, all
cellular telephones on board that aircraft must be turned off. The following
notice must be posted on or near each cellular telephone installed in any
aircraft:

"The use of cellular telephones while this aircraft is airborne is
prohibited by FCC rules, and the violation of this rule could result in
suspension of service and/or a fine. The use of cellular telephones while
this aircraft is on the ground is subject to FAA regulations."



John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

Absolutely right, John...I was thinking only of cell phone impacts on avionics/airplane systems.

Dave

Inteferrence

Rules say turn 'em off. Although we would most likely not get caught on, doesn't a person of integrety do what is right? Very similiar to a game of golf in which you can tell the metal of the person your playing with by their honesty.

As others have done before, I've left mine on by accident. It was in my pocket and the dang thing interferred with my headset. I use Bose so it wasn't a cheap headset and the radio/intercom were Garmins. Every time it tried to connect to a tower and I was talking to ATC, there was a lot of noise over the headset. Reached in my pocket and turned it off. Presto, crystal clear again.

Secondly, I've heard the buzz over the radio from other planes and even when a controller was talking to me which indicates there was a phone on in the location of the person on the other end. The way I look at it, if a controller heard that, YOU could be cited for a violation.

Lastly, it drains the battery unbelievable fast when it cannot "see" a tower. I work in a hospital and there are areas in which there is no coverage due to tons of concrete and radiation shielding and the battery drains quickly. Not much fun when you need the phone after landing and it's dead.

Hmmm, it's unlawful, doesn't work, drains the battery, and does interfer with electronics.........why is this even a post? Oh I know, it's an I-Phone and you have it in airplane mode so you can listen to the music or use it as a flashlight......how could I be so stupid.

Without even touching on any technical evidence I have to think that if a cell phone presented even the slightest hint of danger to the operation of an airliner (even a slight twitch on a needle or display in the cockpit) it would not even be allowed on board. They DO confiscate those deadly nail clippers right?

If a passenger in the back of the airplane had a device that had a one in a million chance of influencing something in the cockpit, do you think the feds would trust mere personal integrity to "not" do it? Not a chance. Therefore I am drawn to only one reasonable conclusion - Cell phones on airplanes = zero danger to the aircraft.

BTW, I have "heard" that if you are on a flight without one of those on board GPS displays, you can use your personal "car" GPS to let you know where you are. "Driving West on Main street... 500MPH"

Webb said:

As others have done before, I've left mine on by accident. It was in my pocket and the dang thing interferred with my headset. I use Bose so it wasn't a cheap headset and the radio/intercom were Garmins. Every time it tried to connect to a tower and I was talking to ATC, there was a lot of noise over the headset. Reached in my pocket and turned it off. Presto, crystal clear again.

Hmmm, it's unlawful, doesn't work, drains the battery, and does interfer with electronics.........why is this even a post? Oh I know, it's an I-Phone and you have it in airplane mode so you can listen to the music or use it as a flashlight......how could I be so stupid.

Click to expand...

I have left my iPhone on and will ocasionally get interference on my David Clark noise cancelling headset. I now make sure I turn it off as the radio interernce is annoying.

I agree with the "it's unlawful, doesn't work, drains the battery, and does interfer with electronics" and will add one more. When I am flying I do not care what anyone else is doing and I am to busy have fun to call anyone. I see no reason to use the cell in the air. I have enough electronics in the plane to not need an iPhone app that either approximates what I already have in the plane or does not work becuase I have no 3G coverage (phone in airplane mode)