Electronic Devices on Aircraft

[scoolbubba]

Those are built specifically for aviation purposes.

I'm not certain of the hoops a product has to go through to be certified for use in a plane, but I'd assume they've been tested to be free of any electronic emissions that could interfere with the rest of the avionics. Probably a little different than taking your tomtom up in your cessna and hoping for a "turn right here...descend to 300 AGL...you're at your MDA"

 

[Gatordev]

Not sure why you think a receive-only GPS unit would be bad? I didn't see any Bluetooth capability on it (though I may have missed it). It's no different than an AM/FM radio. A cell phone is a two-way radio, so the alleged problem is that it's output is what would cause the interference.

 

[Alpha_Echo_606]

If your cell phone ringing is giving you a buzz in your headset you have problems with your ICS and radios and associated wiring. Just think that if the HF can make a man sterile what power it's putting out. I don't know of any cell phone with that type of power.

<Sarcasm> Oh look, my INS is all screwy because my wing man is transmitting again. </sarcasm>

 

[ThreeGreen]

Not sure why you think a receive-only GPS unit would be bad? I didn't see any Bluetooth capability on it (though I may have missed it). It's no different than an AM/FM radio. A cell phone is a two-way radio, so the alleged problem is that it's output is what would cause the interference.

I was comparing the one-way GPS to the one-way mouse, but I see your point, and obviously yoke mounted GPS is very acceptable.

I thought it was illegal to use a cell phone in flight? The cell phone headset device seems to encourage it, and I thought it was interesting given the discussion about the "alleged" interference.

 

[nittany03]

I was comparing the one-way GPS to the one-way mouse, but I see your point, and obviously yoke mounted GPS is very acceptable.

I thought it was illegal to use a cell phone in flight? The cell phone headset device seems to encourage it, and I thought it was interesting given the discussion about the "alleged" interference.

Cell phones operate on many freqs depending on if they are GSM/CDMA/UMTS etc. They also, when first connecting, go max blast in order to ensure they find the best tower to connect to. So if you are at altitude and further away from any tower, your cell is going like mad to connect because it wasn't designed to be at 30,000ft.

I know Mythbusters found interference with at least one cell phone on a light civil's NAVAIDs. I'm sure it would cost inordinate taxpayer dollars to certify each new cell technology to ensure that its frequency and any applicable harmonics do not interfere with aircraft systems.

That said, this whole Qantas thing puzzles me. Granted, I got a B- in E&M in college. But I wonder what kind of voltages or magnetic fields it would take to induce a current in a wire bad enough to screw with the AFCS.

 

[TheBubba]

But I wonder what kind of voltages or magnetic fields it would take to induce a current in a wire bad enough to screw with the AFCS.

NATOPS id your friend on this one.



If electronics and magnetic fields were enough to make a plane go crazy, then common sense says that the Prowler, SparkVark (when it was in service) Rivet Joint and all other EA pllatforms should have a much higher mishap rate... but they don't. Only interference I've EVER seen with that kind of thing is comms or GOS.

 

[HAL Pilot]

Bubba - probably a BIG difference in the amount of electronic shielding on those aircraft and the typical civilian plane.

 

[TheBubba]

Bubba - probably a BIG difference in the amount of electronic shielding on those aircraft and the typical civilian plane.

Good point, but not entirely sure about that. Even buzzing around the FL Panhandle in a 172 with three cell phones in the plane, all I ever headr was the buxzzing over the ICS.

That and I've actually used a cell phone in an airplane... no interference at all. Not even with the ICS & radios.

 

[Catmando]

My physicist cousin, who has long worked at Bell Labs once told me, while the likelihood is somewhat remote, there still is a real possibility of some breakdown in shielding due to wear or whatever, and that a cell phone in close proximity to the breakdown could easily cause some severe disruptions, especially due to harmonics. (But I was an Econ. Major, so WTFDIK.)

What I do know is that I once had a flight attendant come forward and tell me a passenger was again trying to use his cell phone in-flight after being told not to earlier.

I informed her if she caught him again, 'ding' me on the intercom, and I would change speed/heading/alt. noticeably, so she could tell the guy he was screwing up the flight. She did, and it definitely got the guy's attention. That, and an in-range call for security/the law to meet him at the gate upon arrival.

 

[A4sForever]

....I informed her if she caught him again, 'ding' me on the intercom, and I would change speed/heading/alt. noticeably, so she could tell the guy he was screwing up the flight. She did, and it definitely got the guy's attention. That, and an in-range call for security/the law to meet him at the gate upon arrival.

Ahhhh ... I love it. When you grab 'em by the balls (or by their cellular) their hearts and minds will follow ... inflight justice, airline style.

 

[Flash]

If electronics and magnetic fields were enough to make a plane go crazy, then common sense says that the Prowler, SparkVark (when it was in service) Rivet Joint and all other EA pllatforms should have a much higher mishap rate... but they don't. Only interference I've EVER seen with that kind of thing is comms or GOS.

Firstly, the RJ isn't an EA platform.

Secondly, when you are dealing with EA you are dealing with a much wider frequency spectrum than civilians do. So many of the things that EA does would have no impact on civilian freqs, and vice versa. There is certainly some overlap, but the spectrum is pretty split up. It is a gross oversimplification of the subject, but it will do for the internets.

HAL already notes the shielding associated with some platforms. And simply put, the Prowler is not the most high tech of aircraft. Its age and older systems provide an 'unintended' protection for the aircraft, much like A4s older 747-100/200 models. Less electronics make them less susceptible to electronic interference. And I would pretty certain that pretty high on the test and eval list for the E/A-18 is how the jamming systems interact with the aircraft systems. That is why we have NAVAIR, VX squadrons and all those TPS grads, in addition to others.

 

[Bjammin]

Anyone that has flown the Prowler knows that transmitting on the HF can mess with the autopilot. Happened to me.

More interesting a buddy of mine that flys for American on the MD-80 said they tried an experiment with cell phones in the cockpit. They made a phone call from a cell phone and at the exact moment they pressed "send" the autopilot shut off.

Being a "Master of the Electromagnetic Spectrum" myself, I believe in this crap.

 

[BACONATOR]

I'm curious to see how much, if at all, cell phones and computers (wireless components) REALLY affect avionics. I remember that Mythbusters episode and it seemed like there was absolutely NOTHING readable in terms of interference, but perhaps their test setup was just not close enough to real conditions.

As for any other personal electronic device, that seems like nonsense. It clearly states on any MP3 player or whatever other device that it will accept any and ALL interference, so it should be a non-issue. I always thought that it was so that you could listen up to the silly safety briefs or whatever they wanted you to hear.

I always hate when I forget to turn my cell phone off, leave it in my leg pocket, have to listen to the damn thing clicking/buzzing over ICS, and then the battery is dead because it was searching for towers the whole time...

That being said, I think the wireless mouse thing is a stretch by a company trying to avoid another lawsuit...

You should have picked helos. You could have saved some serious battery life. My cell phone does fine at <1000 AGL.

 

[xj220]

Anyone that has flown the Prowler knows that transmitting on the HF can mess with the autopilot. Happened to me.

More interesting a buddy of mine that flys for American on the MD-80 said they tried an experiment with cell phones in the cockpit. They made a phone call from a cell phone and at the exact moment they pressed "send" the autopilot shut off.

Being a "Master of the Electromagnetic Spectrum" myself, I believe in this crap.

Or you could fly the T-44A and have the autopilot shut itself off for no reason.

 

[Flash]

I'm curious to see how much, if at all, cell phones and computers (wireless components) REALLY affect avionics. I remember that Mythbusters episode and it seemed like there was absolutely NOTHING readable in terms of interference, but perhaps their test setup was just not close enough to real conditions.

As for any other personal electronic device, that seems like nonsense. It clearly states on any MP3 player or whatever other device that it will accept any and ALL interference, so it should be a non-issue. I always thought that it was so that you could listen up to the silly safety briefs or whatever they wanted you to hear.

I believe it was noted earlier in the thread that when you consider the hundreds, if not thousands, of devices that are on the market today with more coming out every week, it would be virtually impossible to test them all and their effect on avionics. And I am sorry, but Mythbusters, while good entertainment, is not something I would rely on for scientific accuracy, especially when it comes to stuff like this. Also, there can be variances in manufacturing that make certain production runs different for the same piece of equipment, it might meet tolerances for a civilian cell phone but might not meet it for avionics equipment. When you through in harmonic frequencies, it starts getting really hairy.

As for non-wireless devices, how can the cabin crew know that they are wireless? Many previously 'non-wireless' devices actually have wireless capability now, like some newer iPods. So instead of inspecting every piece of electronic gear to make sure it is not wireless, the easy thing is to prohibit their use.

So all in all, better to be safe than sorry.