Thursday, April 30, 2009

iPhone EFB

Shortly after recently reviewing iPhone aviation apps, I learned of another cool app called SkyCharts that lets you view VFR sectionals, Airport/Facility Directory information, and Terminal Procedures (STARs, SIDs, and approaches) on your iPhone. If that sounds boring or similar to other apps, bear with me because at US$9.99, SkyCharts offers some surprisingly useful and powerful features.

The iPhone's screen is admittedly small and any images it displays are going to be of limited use - especially if your eyes are over 50 years of age! You wouldn't want to do something crazy like not carry paper versions of your charts and rely on your iPhone, would you? Still, the iPhone could be considered an Off-The-Shelf device that, on the surface at least, would meet the requirements of a class 1 Electronic Flight Bag per Advisory Circular 91-78. But there's the problem of the iPhone also being a cellphone ...

When you first launch SkyCharts, you'll see a splash screen for a few seconds, then the app asks permission to use your current location. Many iPhone apps do this, so I just said yes. The app also asks permission to do an initial update and warns you it could take awhile. For me, the update process took less than a couple of minutes, but I was connected to my WiFi network at home. I've not tried doing the update with 3G or Edge connectivity.

Please ensure all electronic devices ...

You'll also see a disclaimer message that you must acknowledge and this bears some in-depth consideration.

Some people may be routinely using their cellphones while airborne in GA aircraft, but it's not legal. The FAA may not care, as long as you are VFR or have determined that the phone will not interfere with your IFR 14 CFR 91 operation, but the FCC does care. The regulation, 47 CFR 22.295, is pretty clear: It doesn't just say that you can't make any calls, it says that cellphones have to be turned off.

While it is possible to put an iPhone into airplane mode, which turns off the cellphone component, airplane mode also turns off the GPS receiver. It would be nice if Apple would provide a way to turn the phone and Bluetooth off, but leave the GPS alive. We can but hope ...

Assuming the iPhone could allow the phone component to be switched off and the GPS receiver to remain active, this brings up the question of whether or not an iPhone's GPS receiver can be used while airborne. My research (and personal experience) indicates that using a non-aviation handheld GPS receiver on board an airliner is not a problem. Every time I have asked, I've been told it's fine once the cabin crew announces it is permissible to use approved electronic devices. Some people claim the TSA doesn't allow handheld GPS units on airliners, but I've never seen this substantiated by any regulation or rule.

Here's a video of SkyCharts in action (not posted by me). Apparently this iPhone is not in airplane mode as it shows the aircraft's approximate position, georeferenced on the moving map. I'm told that jail-breaking an iPhone may allow you to have airplane mode with the GPS still active.

Where you at?

With the iPhone in airplane mode, SkyCharts still allows you to drag and zoom the chart using the usual iPhone gestures. And by double-tapping on an airport, you can access the A/FD entry or the terminal procedures for that airport. Assuming you initially launch SkyCharts with the iPhone's airplane mode turned off (GPS active), the app will cache the appropriate VFR sectional for your current location along with the related A/FD entires and terminal procedures.

Here's a portion of the San Francisco VFR Sectional showing the greater Sacramento Metropolitan area in landscape view. Sectional charts can be viewed in portrait or landscape view, but the A/FD and terminal procedures can currently only be viewed in portrait mode. I tried double-tapping on KSAC while in landscape view and I just got a pop-up telling me the latitude and longitude. In portrait view, double-tapping showed all the A/FD and TPP data available for KSAC.

The D-> button on the lower left side of the chart view allows you to switch your view to a particular airport. Given the ambiguity in the US between VOR and airport IDs, I'd like to see SkyCharts support 4-character ICAO-style airport identifiers, but that's nitpicking. After entering the 3-character identifier for Telluride, Colorado, I got my choice of displaying the sectional chart, the A/FD (this option includes terminal procedures) or simply calling the airport's ASOS.

Cache Me if You Can

If you want to cache more charts, press the Information icon on the lower right side of the chart view. You can select any of the VFR sectionals for the continental US (support for Hawaii and Alaska are slated for a future release). Given the amount of data for each sectional, caching is best done while connected to a WiFi network rather than over a 3G or Edge connection.

Once you have cached the data you want, SkyCharts is still quite useful in the air with airplane mode turned on. Sure, you lose the georeferenced position on the chart, but you have easy, fingertip access to a lot of data.

Airport data has been available in Avidyne and Garmin panel mount units for some time, but that data has some serious limits. I've always been amazed that simple, important stuff just isn't there, like the traffic pattern altitude, whether the runways are left or right pattern, and details on noise abatement procedures. This is where SkyCharts provides a big advantage: You have the A/FD entry for any airport in your area (or in the continental US) at your fingertips.

The developer of SkyCharts has a lot of updates planned and support seems to be very responsive. I'd like to see support for displaying A/FD entries in landscape mode, which would make them much more readable and useful. I'd also like to see support for low-altitude en route IFR charts, but I hope that future releases remain true to the app's name. It's really about charts and adding too many extraneous features could actually make this cool app a little less appealing, to me at least.

I found SkyCharts to be useful and certainly worth the price. Heck, it's fun to just sit in a comfy chair with your iPhone on a rainy day, scroll around the US, daydream about future trips, or just call up approach charts for far-flung airports. Check it out!


Colin said...

You cannot operate personal electronic devices in the airplane if it is being operated under IFR. Or if it is being operated for hire. That's the FAA, not the FCC.

I think it is boneheaded and severely out-dated regulation. The sort of regulation that if it is not changed runs the risk of casting a lot of good regulations in a bad light.

John Ewing said...


Dismissing this regulation out-of-hand seems a bit presumptuous. Ever heard the loud, distracting noise a phone makes over a communications radio as the phone tries to connect to a cell? I've even seen interference with VOR reception caused by a cell phone and the iPhone generates a lot of RF: Try placing an iPhone near a CRT monitor if you need some evidence.

While the FCC prohibits cellphone use in aircraft you most certainly can operate other personal electronic devices under IFR according to the FAA. Here are the relevant parts of IFR. 14 CFR 91.21 (emphasis mine):

"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:


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

(1) Portable voice recorders;

(2) Hearing aids;

(3) Heart pacemakers;

(4) Electric shavers; or

(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.

Paul said...

A guy I know used to let his kids play with their Gameboys in the back of his Bonanza.

He was working with my avionics shop to find out what was causing his VORs to go crazy until he correlated it to the Gameboy use.

I would assume that his LOC performance was affected as well. Something to think about when you are on an ILS in the soup.

He still lets the kids play with the GBs, but now only during VFR.


Maria said...

I have to admit that I was unaware of an FCC regulation about cellphone use in aircraft. In my agricultural work (cherry drying) I routinely depend on my cell phone to communicate with my clients on the ground. I even have a device that connects the cell phone directly to my intercom system so I can talk and hear through my helmet or headset. I only use this device when I MUST have cell phone contact with the ground -- usually just cherry drying work.

I have never noticed any interference between my telephone (formerly a Treo; currently a BB Storm) and my communication or navigation systems. Admittedly, they're very limited on my helicopter: GPS, two comms. I have, however, heard feedback in my comm from folks using AT&T or Cingular phone systems; in all cases, their phones were turned on but not in use. 91.21(b)(5) quoted in John Ewing's comment is what I use to guide my advice to my for-hire clients. They normally don't try talking on their cell phones because they simply cannot hear. But they'll occasionally take and send cell phone photos. I'm always VFR, so the minor interference I've noticed never seemed to be a big deal.

I know the FCC frowns on airborne cell phone use because of the confusion it supposedly creates among cell towers. But I fly very close to the ground when drying cherries -- usually within 5 to 10 feet of tree tops -- and almost always below 700 feet AGL at less than 120 knots in transit for my part 91 and 135 work. I can't imagine low-level flight, especially in a mountainous area, causing cell phone tower problems. But then again, I'm no expert.

I'll certainly look into this some more. I believe that the FCC regulation is outdated, likely written in a time when systems were less sophisticated. But I agree that if an airline or charter operator believes a cell phone interferes with nav or comm equipment, they should ask for such devices to be turned off.

Anonymous said...


You can use the iPhone with GPS by turning it off completely, and then turning it on again. When you turn it on just don't unlock the sim card. The phone then works but without connecting to a cell phone provider. The other option it to take out the SIM card when you are flying.

John Ewing said...


Removing the sim card before flight and then reinstalling it seems like a recipe for disaster, especially for night flights when it seems that everything is harder to do and small objects are easy to lose. For those who want to know how to remove their iPhone SIM card, go here.

As for not unlocking the sim card, I'm assuming you mean not activating the iPhone with a provider. If that's what you're getting at, again that would seem to be a less-than-elegant solution. If you meant something else, feel free to explain.

I guess one could have two iPhones, one that you actually made calls on and the other just for GPS use. Then you could get a phone holster for each hip ...

It seems this could all be solved so easily with software.

Jean-Claude said...

Don't remove the SIM card. Just put the phone in airplane mode.

That way, the transmitter section of the phone is turned off.

John Ewing said...


What's at issue here is the fact that airplane mode also disables the GPS ...