So let me see if I got this right, I am practically cavity searched in security line. I cant take my water bottle or bring back a bottle of wine .... because I might have packed enough James Bond liquid explosive to punch a big hole in the plane. So like it or not that's the risk assessment and security measures. But your telling me the same guys let a plane fill up with literally HUNDREDS of devices that could bring the plane down, but as long as we "scouts honor" promise not to cut them on ....... lets take to the skies!!!

Sorry, I am not a pilot, electrical engineer, or a belt and suspenders type ----- still aint buying it baby. If anybody REALLY thought these could bring a plane down -- you would be locking all your techno-goodies in a lead lined bin at the front of the plane, probably before boarding.

There are lots of reasons, some good/some bad for limiting all kinds of techno-devices on a plane. but aint no, GPS/iPhone/Blackberry/PSP/LAPTOP/Handheld game ------ gonna bring the plane down.

you would be better off worrying about tripping on the way to the lav and cracking your head on the arm rest :D

This FAR does not specifically prohibit GPS receivers.

This thread has been merged with the other (similar) thread in this forum, so if things seem a little out of place, you'll know why.

the question arose many years ago when the instruments in the cockpit went wild....the co-pilot went thru the cabin..and sure enough there was another PRIVATE pilot with his gps on.....trying to follow the flight....now if this happens in IFR on an approach.....well..... there could be a lot of bent aluminum.

with every device...there is always a certain amount of uncertainy about the interaction with cock pit electronics......electrons are strange creatures. if you really want to know exactly where you are in time and space......i suggest you get some therapy, you are just way to much into control.

sit back and do the sudoku....

Cell phones are prohibited because their signal interferes with the logic of the ground towers - not because of inflight signal interference.

The latent radio activity you cite could be traced to watches as well - should we confiscate the timepieces of passengers as well? Can't be too prudent.

Now, I agree a higher powered radio transmitter *could* bleed interference into a poorly insulated line, but it would take a combination of a bad line and a rather high powered transmitter to have any effect, let alone one which could result in a dangerous outcome.

Not sure where the TWA 800 cite fits in - there is no evidence that incident was caused by a portable electronic device.

Many years ago? And note correlation does not equal causation. I'm a private pilot and no longer find GPS interesting in flight, however, on my last commercial flight, I was embarrassed to discover that my cellphone had been on the entire time. :o

I'm a fan of following the instructions of the flight crew, go out of my way to catch the attention of the crewmember doing the safety dance so they know that at least have an audience of one. @:-)

On any flight today there are going to be many PEDs active below 10,000 ft. They are just that ubiquitous and people too forgetful for it to be otherwise.

Aircraft and flight crews are just going to have to deal with it. The only other solution is to send someone up and down the aisles with an RF meter before every flight.

The very pen I use to take notes during meetings radiates RF. :eek:

During my GPS career I've tested several military GPS receivers with GPS Satellite RF Simulators and test scenarios involving crossing or standing on the International Date Line (IDL), the Greenwich Meridian, the equator and the North and South poles. GPS evaluators do these kinds of tests to make sure that the GPS systems and software engineers have used appropriate algorithms to insulate the user from the "math problems" that exist at 0, 90 and 180 degree values of some of the trig functions.

It was therefore with great anticipation that I clipped my first civilian GPS unit (a Magellan) onto my Palm III organizer on a 2002 UA trip LAX-SFO-HKG and had the opportunity to do a date line crossover with actual GPS satellite signals and a commercial unit. As we approached the IDL with a good GPS solution (right side window seat in E+, window shade up) I was so focused on anticipating the longitude crossover that I almost missed the fact that we were going to go right over N45 W180. That was an extra "thrill" because I've used that waypoint for some of my military GPS simulator based testing and here I was now doing a live test. The Magellan worked fine.

I've also walked my Palm III/Magellan unit across the GPS zero meridian at Greenwich, UK with no unusual behavior. The GPS zero meridian is actually about 100 meters to the east of the brass line in the ground at the Observatory. See http://www.nmm.ac.uk/server/show/conWebDoc.416 for the explanation.

Perhaps I'll have the chance someday to do a North pole test for real. All I need is a good MR opportunity for something like ORD-SIN or JFK-HKG.

Is it true, or an urban legend, that an early military GPS guided flight tried to go inverted as it crossed the equator? ;)

http://www.delta.com/traveling_check...ices/index.jsp
This past Feb/March, I was flying DL from ATL to DXB. I had great signal on my Garmin GPS 60CSX in the ATL parking lot but imediately lost signal when I got closer to the door. I am assuming they have some type of jammer or more powerful/higher frequency radio waves in the air. Anyways, once up in the air, I tried to turn my gps back on and could never get a signal whether we were over North America, the Atlantic, or Europe. I basically gave up because the inflight entertainment on our Boeing 777 had a map of our location with airspeed, head/tail wind speed, altitude, ATL time, DXB time, and a few other things. We could never look out the windows because the FA had them shut to preserve darkness so people could sleep. I did manage to slip to the back and look out over Iraq and see the Euphrates and Tigris river. Pretty cool from 55,000ft.

On the way back, we flew over Iran. Thank God they didn't decide to launch a SAM and shoot down an American plane full of passengers down.

Most of the unsupported items in the FAR's are from 1963
 

FAR 91.21 hasn't changed since 1963!

TV's, Radios and Shavers are less interference prone than in the 60's

Digital or solid state tuners limit interference. Any newer Shaver from Braun, Norelco/Philips, Remington, etc that is battery powered will generally NOT cause interference.

I use my GPS all the time, but have a GPS bluetooth dongle that I shove in the window shade then I use Google Earth Pro with cached data on my Mac or the built in Nokia nav app on my Nokia E61i (you can set the destination Coordinates before departure and get a fairly accurate estimation of arrival time :)

I've been involved with GPS since 1972 (called Project 621B at that time) and worked in the GPS Joint Program Office from 1974 to 1985. Saw a lot of the early flight test reports but never anything about going inverted across the equator.

I would hazard that it's an urban legend about GPS but wonder if something similar to this happened during early INS testing. Perhaps some FTer is an inertial navigation system (INS) expert and could inform us whether gimbal lock in an INS flying across the equator could produce such a situation.

Yes I am aware of that thread. But on UA - where our thread was originally - GPS are not tolerated. The FAs consistently complain if you use GPS inflight and once I was even once read a policy that they are not to operated aboard.

The generalization was inappropriate though, I concede.

On a sidenote - do FAs generally give in to your FOM reference or do they simply use their 'powers of the sky' to overrule you?

Only twice have I had an FA ask me to turn it off.

In both cases, I sent a card via the FA with a note and the F.O.M. reference to the pilot and in both cases the FA came back and said it was fine.

Wow - well done!

My last GPS logger I bought in Taiwan is specifically camouflaged as a Teddy mascot so flight crews would not 'interfere with it'. It's a bit sneaky but what isn't within the scope of air travel :o?
Which is only true in a very academic sense for many antenna types - especially narrow-band ones - and it would not matter as these devices must operate in a band which is different from the communication and guidance systems used aboard.
Which are no longer in use in consumer electronics - all done with phased locked loops these days.

And still you are right - the problem comes in during malfunction or error operation. Say when then initial transistor (or operations amplifier to be more to the point) which amplifies the aerial's weak signal burns and then couples the oscillation frequency into the antenna. That device would then radiate quite a bit. But still in a relatively safe band. But if the oscillator's frequency is not a proper sine wave then you get a jammer out of it.
Still generating interference to very different wavelengths is very difficult when not explicitly aiming at it.

FYI, I turend on my Garmin Forerunner 301 on LAX-HKG (UA). I sat in F, and had placed my GPS on top of the top of the side bin.

It took a while for the GPS to sync after takeoff. I turned it off after two hours.

Two hours before arriving into HKG, I turned it back on, but it could not sync the rest of the flight.