Paul, I think the airlines do conduct research on the effects of interference from devices. The main issue is the effect of radio interference on the reception of navigation signals - GPS, ILS, etc.. But, you are not going to turn the cockpit screens black just because someone left their I-stuff turned on. The reality is that there are many lines of code and many bits toggling inside those glass panels that could easily cause something to break without the help of a passenger's device. Now, about the cabin detector - Not that the flight attendant actually has to do this, but he/she _could_ tell if you left your device on by looking for Bluetooth and Wi-fi signals.

I don't know about turning stuff off, but I can tell from the flight deck of the E190 when someone's phone is on.... I can hear the "dah dit dah dit dah dit dit dit" of a phone looking for a tower in my headphones. Thought I forgot to turn mine off but both mine and the F/O's were solidly non-transmitting. Maybe the F/A, but someone was doing a good job draining their battery.

I work for Oshkosh Truck Corporation (we technically dropped "Truck", but whatever), and we do a fair amount of EMI (electromagnetic interference) testing on equipment for our defense trucks. Specifically in regards to radios (nav and comm), military stuff can be made pretty immune to interference, but it's not at all hard to get a messed up cell or Wi-Fi device either broadcasting or creating noise in the aviation or GPS bands. The risk is small and very controllable from an engineering perspective, but unless the device is from an aerospace or defense manufacturer, the engineers and production people don't necessarily have the incentive to drive those failure modes of their devices toward zero. I second the statements by Peter Buckley and Steve Bowling above. They won't kill your deck, but they'll take out a nav, annoy you on the comm, or interfere with your GPS. I've seen the first two, and done all three intentionally while testing.

As a comm/electronics type I've followed the back & forth EMI discussions for years. I’ve read dozens of these anecdotal tales of berserk cockpits suddenly correcting themselves when a passenger in coach turned off his cellphone or CD player, and I invariably assign a mental “yeah, right, and lemmie see you duplicate that”.

As Peter Buckley notes, the digital crap generated by the RF bursts of a cellphone can (and does) get into audio gear. Digital devices are inherently noisy; my Garmin portable GPS noticeably raises the background noise floor on my Bonanza’s comm radios, and as another example we found the RF hash radiating from the multiplexed frequency readouts of a friend’s Narco 12D nav-com was so bad he had to turn off the radio to get reliable GPS on his portable using its attached antenna. (He finally gave up and installed an external GPS antenna for the portable).

In spite of all this, I hold the potential for actually corrupting nav or communication, much less the inner workings of digital systems specifically designed to be EMI-tolerant, is vanishingly small. Hey, among the couple of hundred passengers on any given flight there are probably at least a half-dozen forgotten or ignored cell phones turned on and squawking merrily away, so I hold it’s been more than adequately demonstrated that the stuff shrugs it all off. I vote with Steve Bowling….look for internal system faults, not an iPad back in the cattle section.

Last year my Garmin GNS530 failed in-flight and my COMPLETELY INDEPENDENT Garmin Aera as well. Resetting the units never resolved the problem (I'm a recovering Windows user) and I navigated to my destination via VORs.

A brief conversation with my avionics shop revealed the problem: my iPhone was causing the GNS 530's amplified antenna to go into oscillation, which then wiped out the signal to the Aera's antenna right beside it.

I turned my iPhone off the next several flights and had no further problems. Replacing the 530's antenna resolved the issue, apparently permanently. The avionic technician told me this is a known issue with that antenna.

When the flight attendent tells me to turn off my stuff, I turn it OFF.

Most pilots will have heard the chirping from a cell phone in their headsets or sometimes in RT, but switching into flight mode will stop radio transmissions and receiving. Unless the user or phone fails, I can't see any technical reason to turn it off completely. Personally I do to save battery and comply with legal instructions.

Has anyone out there ever dared asking the Flight Attendant to turn his/her watch off when they make turn off 'all electronic equipment' announcement (I'm assuming not many of them still have clockwork ones)? I suspect a very unfriendly welcoming party would be in attendance at destination. I know of no better illustration of the stupidity of these rules.

I have tried to use one of the radios expressly designed NOT to interfere with airline electronics. I still get ordered to turn it off. Even if taken to court I would probably get nailed (guiltified)just because I did not obey "the rules". Some cabin crew have told me how proud they are in being able to "lay charges" on people who do not comply with their instructions. Typical shotgun solution for those who neither think nor care - and find personal security in a framework of rules.

In my Cessna T210 I have a GNS530W and in several occasions I got this intermittent incredibly loud chirping on my headphones, I blamed it on the head phone plugs and had them verified, nothing wrong was found. One day I had my son with me, he is a systems engineer and when the noise started I mentioned that this had been going on for a while and I did not know what was wrong, he asked me if my iPhone was on, which it was, I turned it off and the noise went away. It has happened a couple of times since, if I forget to turn the phone off, sometimes I get the noise, not always, but it always goes away when I turn the phone off. Never had the problem with earlier phones.

Not so many years ago, one would relax and enjoy the flights. We would sleep or read or EVEN CONVERSE with the pax next to us ( what a concept). Now we whine because we aren't allowed to withdraw into our little entitled spheres to play with our toys. We've adopted the attitude that: "unless you ( authorities, technicians ) can prove,100%, that my toy might kill me and the other pax, I want my toys" Am becoming less impressed with the "ME" species. A significant problem is the number of RF generating toys turned on at the same time and there is NO WAY to allow only a select few to play !

One need only read through the NASA Aviation Safety Reporting System (ASRS) Passenger Electronic Device (PED) report, available in '.pdf' format at http://asrs.arc.nasa.gov/docs/rpsts/ped.pdf, to understand why the cockpit requests devices be turned off.

Previous comment should have included URL: asrs.arc.nasa.gov/docs/rpsts/ped.pdf

I suppose it is a reflection of my lack of importance but I have no problem with turning off my cell phone. Being cooped up on an airliner with seatmates yacking away on their phones would be a horrible form of torture. On the other hand it would be a welcome form of escape when the guy next to you smiles and asks,"Have you been saved?"

I think the unknown here is when consumer electronics don't work as designed, or that they have in some way malfunctioned. With the poor design validation, production manufacturing and testing that is endemic in Chinese made junk, it is not beyond reasonable doubt that on a 300 seat airplane there could be a rogue piece of consumer electronics that could cause a problem.

Paul...whle the premise SEEMS simple enough, from the above discussion you can see that numerous pilots have had 'issues' with portable electronics. I keep a handheld near my laptop because I live near my airport. When I move the HT near the laptop, the squelch function goes haywire ... somehow bothered by the laptop. SO ... as many above have indicated, I have no problemo with the requirement to turn off all portable electronics in flight. Beyond that, it's bad enough to occasionally be seated near a crying baby or a kid who's parents don't control them ... I don't want to be sitting next to someone yacking incessantly over their cell phone, as well.

As a retired B-2 avionics type, I likewise wonder if all the cockpit devices proliferating with WiFi and bluetooth connectivity have been fully tested for EMI since they are commercial, not military, products. The EMI shielding of hardwiring in airplanes is done for a reason as well as proper grounding techniques. Then we want to have perhaps hundreds of RF devices "alive" in a commercial airplane ... I don't THINK so !!!

The two examples you cite had their normal avionics suites either failed or off. Under THAT situation, I'd use whatever I had to properly nav and communicate, too. Imagine, however, if everyone in the back had airband HT's available ... what would THAT do.

As others here have said, get in, sit down, turn your electronics off, shut up and enjoy the ride best you can, I say.

My GNS 530 seems fine when I put the iphone in "airplane" mode. Normal mode, I noticed the interference the first time I flew with the iPhone; my older cell phone didn't cause a problem. However, I noticed the iPhone interfered with my office's two-line phone system before I ever flew with the thing, so I knew what I was listening to. It's bad enough (in both the plane and phone system) that I turn the phone to airplane mode, and keep my phone as far from the phone as I can--the noise drops off dramatically with four feet of clearance.

There was an episode of Myth Busters where they proved that portable electronic devices disturbed some aircraft instruments.

So how come you get to turn most of that stuff back on (with exception of cell phones,gps, etc.) when the aircraft reaches 10,000 feet?

It's not the airlines' corporate kneejerk. They are following the law. FAR 91.21 requires portable electronic devices to be turned off. This also includes Part 91 IFR GA flights. "Airplane mode" was never authorized.

Read 91.21 carefully, Matthew. It doesn't require these devices to be turned off. Otherwise, you wouldn't be allowed to operate them at all. It allows the operator discretion in permitting their use. Read the last paragraph. The airlines do indeed set their own acceptable standard.

Simple answer, other than the standard FAA rules: If flying as a passenger, you're on that plane for one purpose; to get from point A to point B. Get over yourself. Let the experts resolve the issue, and be guaranteed a calm flight, (not necessarily a nice one.) With the cramming in of people, like sardines in a can, it might be hard to enjoy the flight.

We have a full Garmin GTN and 800 traffic system installed and have never had problems, if passengers/crew left cell phones and/or tablets on in flight. Maybe the guys in the radio shop had THEIR cell phones and iPads ON during the install.

I too have noted interference in my own cockpit from various devices - including a CD player my son was listening to in the rear seat of a C182 (which interfered with the VOR reception). I also get squealing on occasion in my ANC headsets when I have forgotten to turn off my iPhone. It is now on my checklist to turn it off prior to flight. I do not get interference from my iPad2, as long as I have the cellular function turned off. The cellular band is too close to the GPS band to expect that the cellular function will not interfere with GPS. In any given situation it may or may not interfere with aircraft systems, but since it is against FCC regs to use a cellular telephone while airborne, the cellular function must be turned off anyway.

Part 91.21 says the operator of an aircraft can use portable electronic devices if it has been determined that the device will not cause interference with the navigation or communication system of the aircraft on which it is to be used. I have determined (by testing in VFR conditions) that my iPad2 with charts does not, as long as the cellular function is turned off. WiFi and Bluetooth functions do not interfere with my aircraft systems.

Each device must be checked with each aircraft on which it is to be used. It would clearly be impossible for air carriers to check every device brought aboard for every aircraft on which they would be used, hence the better safe than sorry approach.

Sigh. So much strength of convictions, and so little fact.

Yeah, I know, Mythbusters fabricated a scenario where they could make a plausible case for interference, if the worst case combinations of brands, locations, and antennas aligned. Let’s get hysterical why not?

You could also be hit by an asteroid, even if your cell phone and portable GPS and watch are turned off. It’s about as likely. Let’s get hysterical about that also!

Referencing an article at aneclecticmind dot com/tag/fars/ , “But let’s face it: airlines want to boss you around. They want to make sure you follow their rules. So they play the “safety” card. They tell you their policies are for your safety. And they they throw around phrases like “FAA Regulations” to make it all seem like they’re just following someone else’s rules. But as we’ve seen, they have the authority to make the rule, so it all comes back to them. And that’s the way they like it.”

With what was at the time written into FAR part 121 ( I thought it was under 121.306 but it’s not there now) a TWA PIC gave me an exemption to use an ICOM R1 triple conversion superheterodyne receiver to monitor COM, and nobody died, nobody was frightened, and his CDIs behaved all the way to the ground.

I’m not wholly insensitive to the plight of airlines, who can’t possibly pay FAs more than $6/hr, and for $6/hr you aren’t going to get people with enough electronic knowledge and judgment to be able to make a distinction between a harmless Kestrel wind meter with barometric altimeter and a very potentially threatening Rockwell Collins' FlexNet-One Compact Vehicular Wideband transceiver.

More to the point, nobody in America with any love of freedom an appreciation for our bill of rights should embark on any commercial flight (or now even a train ride) anywhere, until the unconstitutional abuses of the TSA are a thing of the past. The TSA is turning America into a Fascist homeland while most media giants pretend this is for our protection. Who’s protecting me from Asteroids that are about as likely?

As an airline captain, I can agree there are some (many) stupidities in the rules and how they are enforced, but we put up with them as we all know regulatory change in any country makes glacial movement look like the Reno Air Races. Case in point of the right hand not knowing (regulating) what the left foot is doing: All electronic toy must be off for take off and landing. Partly the interference issue and (I'm assuming) partly large, hard objects flying through the cabin like missiles in an overrun, etc. However, no one seems to care about the guy in the next seat reading a first edition, hard cover copy of War and Peace and what it would do in the same incident. My Kobo in its padded case looks a lot less likely to cause injury, but where do you draw the line? Personally, during take-off and landing I'd like to see any large, hard objects stowed. A blanket rule is just easier (and fairer) to enforce.

Having read 91.21 and FAA policy, if I owned an airline I would keep existing policy for legal reasons even if I didn't know anything about avionic safety. The FAA makes it clear that the airlines are responsible for approving "safe" devices. Therefore they are legally responsible if they approve a device which then contributes to an accident. If an airline approves iPads etc, then an aircraft suffers avionics failure resulting in injuries/fatalities, there is no doubt that the lawyers will try to blame the airline's PED policy for contributing to the accident. Banning such devices simply removes one path to litigation; it's the safe and conservative path for a CEO.

Well Richard Have you been saved?

I had a iPhone and it gave me endless grief with my radio equipment. Changed to an Android and what a difference no noise unless I'm using 3G.

A question did anyone notice about two weeks ago the SatNav (GPS) giving false information? My Garmin 496 suddenly told me that the position accuracy was 3400M (3 and a half kilometers)and kept warning me I was about to crash. I believe it was caused by the intense sunspots activity at the time.

Glass (either complete panel or as a component) is certainly fallible. Just last week I was flying a steam gauge airplane with a Garmin 430W onboard when we lost GPS position. We grabbed an iPad and fired that up, also no position. Finally we found that turning the 430W off would allow the iPad to work (and verified that turning the 430W back on caused the iPad to fail again). A couple lessons learned here:

- If flying IFR, 1 certified GPS is not enough.

- Supposedly "receive only" electronic devices *can* and *do* interfere with each other (so keep those phones/iPads off during flight unless necessary for safety of flight).

- Do carry a handheld/standalone GPS of some kind and don't be shy about turning OFF the primary if you encounter weird problems!

Seems this thread was hijacked by the Cel phone woes.

I fly a Cirrus with Garmin G1000 Perspective system. My concerns is what if the whole system died (lightning strike) I would loose all my nav and com capability. Yes the Ipad with a Garmin GLD 39 (on battery) would allow me to navigate and see weather plus my handheld radio would allow me to communicate. Certainly would need to find VFR weather or a GCA. approach.

Steam gauges have some degree of redunancy; all the eggs are not in one basket. This has bothered me about glass panels since they started appearing in GA planes. I used to see some backup AH, DG, and airspeeds installed but even some of these are now going away. Gauges work just fine if you learn how to use them; may heaven help you if you're in IMC and that "TV screen" goes blank...

Keep in mind that the airlines don't simply tell their pilots to go ahead and use their iPads in the cockpit. They are required to go through an approval process that includes a technical evaluation of interference and other aspects of both the hardware and the software for use as an "Electronic Flight Bag". Check the FAA's "Information for Operators" number 11011 dated 13-May-2011 and FAA AC120-76A for details. (In Canada, AC 700-020). Carrying extra (unapproved) electronic devices for use in an emergency such as a complete failure of all navigation systems is different from allowing the use of such devices so that they may cause the nav systems to behave in a way that is unknown and possibly difficult to detect.

As a former radio shop owner and amateur radio operator I can state that any modern receiver can and does transmit radio waves that may or may not be at a frequency that could interfere with ANY other receiver. Do you want to bet your life that your device does not interfere with the aircraft systems???

Take an AM portable receiver and place it close to your computer, you'll be surprised at the amount of radio frequency (RF) noise that little gem is putting out.

I retired from the airlines in 2007. At that time, jumpseating crewmembers in the upper deck used cellphones, DVD players, handheld GPS's and any other PED's that existed at the time. I personally never noticed any issues.

Flying a post retirement, survey Twin Otter, we had to turn off cellphones, strobes, beacon, position lights and the electric hydraulic pump in order to not corrupt the mag data we were gathering. That was a different animal, though.

I'm now back to flying an airliner for a particular scientific agency who's primary product is airborne science. We have no restrictions on PED's. There might be 40 laptops, cellphones and a half dozen iPads on during all phases of flight (to include the iPad EFB's in the cockpit) with no issues noted. Given that personal experience, my feeling on this is that the airlines are erring on the side of safety from the standpoint of their legal departments.

Personally, it isn't a big issue for me to wait until 10,000' to use a PED on an airliner, but I'm not convinced that we're significantly contributing to safety, as a result.

So the real question is... If electronics cause havoc; then why have the terrorists not figured this out?

Brady, Havoc may be to strong a term, however just the chance scares me.

In the 1950s a midair collision involving two airliners was given a probable case as a passenger listening to an FM radio which interfered with one airliners navigation receiver. Today there is little chance of a repeat due to radar but we are moving to a system that uses GPS and other frequencies to track aircraft, do we want to take the chance of interfering?

Ray... ATC Retired.

Wow, this isn't really that complex.

Having had a blackberry in the backseat interrupt my coms, I figured this out. Before that, I was perfectly willing to believe the airlines were being nazis. Alas, it's not an evil conspiracy. Try imagining you had to make the rules.

1. The airline can't have a policy that says quality stuff can stay on. That won't work. 2. The airline can check what they approve for their cockpits. 3. You are not the standard they use when developing policies, it's that jerk in the next seat that you simply can't believe figured out how to both buy a ticket and find an airport. 4. While you might buy tickets based on the quality of airline, your neighbors and aforementioned jerk have managed to make air travel a cheap commodity which is hindering the hiring and retention of quality people. Those wonderful airline people who have made your day in the past are getting harder and harder to find and it's not because they are moving into management.

MedTech software has to meet very strict no-interference requirements with much of the software now used to track tumors and the like having to sit next to scanners able to fly metal chairs across a room. It is guaranteed for life and death information -- the doctors now operate if the software shows the tumor is growing -- do not if the software says it is not. In spite of this, prices are tumbling -- should not the same standards be required for glass cockpit software?

“yeah, right, and lemmie see you duplicate that”.

As a comm/electronics type, you should know that duplicating that would almost be impossible. The multitude of variables, both inside and outside the aircraft,precludes quantitative testing. Maybe in an anechoic chamber, with all the possible permutations of every piece of consumer electronics gear produced, you might get close.

I can have my RT next to my iPhone and it works fine. Until I use the touch screen or actively charge the iPhone; the squelch goes full open on the RT. If the RT is in dual watch mode, the open squelch prevents the use of any other buttons. If the charging cable is plugged up, the phone is at 100% charge, and I do not touch the screen, my RT works fine. Now, work out all the different permutations of that simple scenario with all the phones in production, all the cockpit systems, and all possible combinations in switchology.

Regardless of whether or not the issue is real, (and I doubt it is), telling people to turn off their devices is an example of bureaucratic ineptitude. If there is any meaningful risk associated with these electronic devices, simply telling people to turn them off is no solution. If there is a meaningful risk, I for one, do not want to be forced to accept the risk of someone not turning of their device, (I am sure this happens on almost every commercial flight). If there is a meaningful risk, either passengers should not be able to carry these devices through security, or aircraft systems should be modified to eliminate the risk, (this should have been decided twenty plus years ago). If there is no meaningful risk, then turning them off is obviously unnecessary.

"If there is a meaningful risk, I for one, do not want to be forced to accept the risk of someone not turning of their device....If there is no meaningful risk, then turning them off is obviously unnecessary."

Oh, Richard, you're entirely too logical. You fail bureaucracy 101.

In this month's Avionics Magazine there is an article by Walter Shawlee. According to him NTSB has listed 58 cases of either definite or probable personal electronics devices causing interference or damage since 2002. Not a significant number but it shows there is some substance to the issue. Affected instruments have been localizers, TCAS, comm interference, compass errors, VAV/DME interference, fuel guage errors, and panel instrument failure or error. Part of his research indicates the problem may not be from just a single device but the combination of any number of devices operating on an aircraft. By the way there are handheld instruments that can detect RF emissions if the airlines do decide to get really picky

I have serious doubts about "incident one" above. I'm a United guy, and I know that our company-issued iPads do not even have GPS capability. Yes, I know it is possible to purchase a "Dual" brand GPS which is able to work with it, but as cheap as we pilots are, I know that only a small number have done so. In addition, we do not even have a moving map app on the iPad at this time, and as inadvisable as it is, the company has made it impossible to install your own. It is designed as an inflight library only. (I'll reserve my personal opinion of the suitability of the device for that use until a later discussion.) My problem has to do with the fact that I'm one of the safety people at our company who would almost certainly have heard about this incident if it had happened, and though I have checked with several others in similar positions, as far as anyone I can find knows, THIS NEVER HAPPENED. (cont'd.)

Now, maybe it's a matter of someone embellishing a real story, or changing the company, etc., but can you seriously tell me you beleive that a major air carrier could have a flight "lose all navigation capability", do a return to land, with a full load of passengers, and it would NOT make the news? Really? When an overheat light on a transcon flight makes the news for no reason? I seriously doubt that. But in any case, this particular incident, in all likelihood, was made up by someone to justify their self-important need to make their own decisions which affect the welfare of an entire airplane full of people, disregarding the authority, responsibility and much greater capability of the crew and airline to do that. The comments above by others who are similarly overly impressed with their own "knowledge" of the subject indicate that the feeling is widespread. Not a surprise, pilots are notoriously hard to direct, but in this case, the rules say you have to deal with it. If you don't like the rules, buy your own airline, your own airplane, or stay the heck home. (cont'd.)

If you get on the airplane, you have given up your right to argue about it. But either way, you'd best not make an issue of it onboard. At least not on my airplane... (Oh yeah, and I absolutely do have an app on MY android phone which will tell me exactly how many WiFi and/or devices are in use. It's available to anyone else, as well. Most folks, it seems, either use the default name or create their own descriptive names for their wireless devices, so the flight attendant disparaged above is likely smarter than you think. And quite possibly smarter than you.)

If you get on the airplane, you have given up your right to argue about it. But either way, you'd best not make an issue of it onboard. At least not on my airplane... (Oh yeah, and I absolutely do have an app on MY android phone which will tell me exactly how many WiFi and/or devices are in use. It's available to anyone else, as well. Most folks, it seems, either use the default name or create their own descriptive names for their wireless devices, so the flight attendant disparaged above is likely smarter than you think. And quite possibly smarter than you.)

What app is that that tells you whether it's a Droid or an iPhone not in wireless mode?

I am the person who was on the Boeing 767. I am a pilot. I do not own an iPad myself, nor any Apple phone, nor any other Android or other tablet device. I could care less whether or not people have to turn off their iPads. When I board an airliner, I sit at the window if possible, and look out the window, and read a magazine, and I am very happy. I always turn my phone off when requested. Even if we were allowed to keep our phones on and talk during the entire flight, I would consider it rude. I sure don't want to hear other passengers' conversations. I hope it never becomes allowed, talking on cell phones in airliners, though it probably will be eventually.

The incident happened exactly as Paul Bertorelli described. However, I do not have absolute confirmation that they used the iPad for navigation (see below). I, and over one hundred other passengers, sat in that 767 and went back to SFO. And yes, I was quite surprised it wasn't on the news. However, the jet didn't have a stuck landing gear or anything like this. Once in radar contact, (a flight attendant relayed to me, when I asked, that the pilots said they'd be in radar contact when they were within about 30 minutes of the shoreline) I assume ATC gave them vectors to the airport and there's nothing unusual about that. I suppose the news missed it. The "equipment" was lined up all along the runway and followed us in with lights on. But "the equipment" (firetrucks etc) gets called out at busy airports all the time.

After landing, as all passengers were exiting the plane, I stepped into that little space at the cockpit door. The cockpit was open and both pilots were standing there, the Captain standing right where the cockpit door would be, and the FO behind him. I congratulated them both, so they wouldn't be defensive and think I was going to complain about something. Besides, I truly felt they did a great job. I said I was a pilot, and that I was curious how they navigated back, since the FO had announced to the passengers that the entire nav system was broken (I believe his words over the intercom were that they had lost the entire navigation system). The Captain perked right up with a big smile and said, "Whiskey Compass!". The FO behind him said he had an iPad but did not say specifically that they relied on the iPad. I said, "so you mean you just turned the plane and pointed it to the right compass heading?" and the Captain said Yep. I was just going to ask specifically which instruments/systems went down but right then the FAA guys in suits stepped up and I was whisked away.

I called several departments at the airline. One major manager in the maintenance dept. in San Francisco hung up on me as soon as I said I was a journalist, after I had explained I was on the flight. I left an extended message on the customer assistance line, or whatever they call it, can't remember. I also called several other numbers and got nowhere. A couple weeks after leaving the message I got a call from a woman at the airline, do not know her position, and she said all they would say was No Comment. I tried telling her I thought the pilots did exactly the right thing, that I had no complaints about anything related to the flight or the airline (all true) bla bla bla but that did no good. So I don't really have confirmation they used the iPad, only the compass. Obviously when the jet got within about 30 min of the shoreline, ATC would have picked them up on radar and fine-tuned their heading to SFO, if necessary, though I do not remember any major heading changes toward the end of the flight, until we were actually approaching the airport. However, once we turned around over the Pacific, the jet made very slight corrections, left and right, the entire way home, obviously being hand-flown, and this makes sense if you assume they were steering via compass. And SFO was completely VFR when we landed.

My guess is they probably didn't have a whole lot of fuel left, but I don't know. Fuel had been my biggest concern. If I remember correctly, by the time we turned around we'd been in the air over 3 hrs. I asked, and a flight attendant asked the pilots, and then told me they had 7 hrs of fuel onboard when they took off. The flight attendant told me the pilots had told her they had plenty of fuel.

I spoke to a couple of 767 Captains who said the FMCs receive their data from the IRUs, VORs, and DME but over the ocean only IRU data is avail. You could have a "complete nav failure" if the IRUs or FMCs failed, and the Captains said that would be a very rare thing, but certainly within the realm of possibility, and they also said it sounded like the pilots did exactly the right thing. (declare emergency with ATC, climb to 34,500 to get away from other IFR traffic until ATC could clear a wide path, then descended to 33,000, hand-fly, pull back on power to save fuel, and get back to the west coast).

So to reiterate, I cannot say definitively that they relied on the iPad for navigation; the Captain only said compass.

I will say the FO was almost giddy, like a big kid, standing there behind the Captain, kind of on his toes, when he exclaimed, "I had an iPad!". Who knows? Maybe they had been scared and were just glad to be down. When the FO made the initial announcement as we were turning, his voice sounded a bit shaky to me, but that's just speculation.

When we arrived back at SFO we, and most of the other passengers, were able to book another non-stop flight and so arrived around 11 p.m., roughly 12 hours behind our originally scheduled arrival time, but at least we got there. I personally have no complaints. Things break. The pilots did a great job and according to the Captain they used ded reckoning to get back.

Since the whole point of this thread is whether or not you should be forced to turn off your iPad etc., I will throw in my two cents and say: bring a magazine, take a nap, or read a good book, and find something else to worry about. And, as a pilot, make sure you still remember how to use pilotage, ded reckoning, VORs, ADFs, and whatever other equipment your airplane may have, but glass does break.

FWIW, when at the airline I always carried a GPS (when they became available), as my Boy Scout background demanded it. Triple mix INS, and later with GPS update, the odds of losing everything was pretty remote, although I did lose two of the three INS systems one dark and rainy night from Tokyo to Anchorage.

Nowadays, the trusty iPad with Foreflight and a Jepp CR-3 "E6B" is with me on every trip, whether in the jet or in the spam can. Not a bad idea to know the whiskey compass acel/decel and turning errors, either.

Paul, You can use any WiFi scanner program. I use one called "WiFi Analyzer". It will show you any station within range and it's SSID unless it's hidden, and then it shows just a generic entry. There are others that will show Bluetooth, as well. It would take more equipment (or a non-public app I've seen used on a regular phone) to detect just the cellular signal, probably, but we've had such equipment on board for testing before, and it generally shows between 6 and 20 phones turned on. Amazingly, when we make an announcement, no one fesses up, but they miraculously go off... Hmmm.... Magic? Keep in mind that such detection equipment can read the MEID of the offending phone, which can identify the user with an easily accessible database. You may not even know you've been busted. Until the FCC and FAA come a calling. U

Ron, I was talking about the cellular signal, not WiFi. I don't know about most users, but my WiFi is off unless I know I've got a signal. It seems to conserve the battery.

With no app at all, my phone sees other WiFi networks.

I am not sure if the Original Poster is aware, but ATC records are in the public record and easily accessed. And ... in August, EVERY UAL B767 that left SFO for HNL, arrived at HNL!

Not one diverted, and certainly none retuned after having passed the Equal Time Point!

For those of you who believe I made up the story of the 767 having to turn back to SFO due to a nav failure, I invite you to check http://flightaware.com/live/flight/UAL989/history/20120827/1610Z/KSFO/PHKO

It clearly shows our return. It is also interesting to note the slight alteration in course on the outbound before turning. This MAY correspond to the initial problem, because the FO said over the intercom that they continued flying for a while before making the decision to turn back. Once they turned back, they held course until within about 30 min of the shoreline, which is when ATC could pick them up on radar. At that point you see a slight alteration to the right, to SFO.

For some reason when I posted the Flight Aware link above, it did not show up. Here it is: flightaware.com/live/flight/UAL989/history/20120827/1610Z/KSFO/PHKO