Jeppesen wasn't the first to offer an iPad app to the aviation market, but its Mobile TC app was worth the wait. Released at the end of last July, heavy downloading of the app caused overload of Jeppesen servers, which the company quickly corrected. 

Mobile TC is a free download from Apple's iTunes store, but the app is useless without a JeppView subscription. The good news is that if you already subscribe to JeppView (version 3.0 or later) or NavSuite, either for a charts database for your cockpit avionics or flight planning software or the new online JeppView system, you don't have to pay extra to get the same charts on your iPad. Subscriptions come with four product serial numbers, and as long as those numbers aren't already being used, the rest are good for populating your iPad and Mobile TC with whatever charts you're already paying for.

The version of JeppView for Mobile TC that I tried includes worldwide charts, and this offers an excellent example of not only how the app works but also the incredible amount of information that Jeppesen disseminates.

Anyone interested in Mobile TC should first understand that the app is not a do-all flight-planning, weather-gathering, moving-map program. All that Mobile TC does is display terminal charts, and nothing more. There is no moving-map nor own-ship position display on charts.

It turns out that the iPad's 9.7-inch screen is almost perfectly sized for displaying approach charts. And the iPad's high brightness level shines in even the sunniest cockpit. I tried the iPad in a Hawker 4000 cockpit at 45,000 feet recently, and the screen was perfectly readable and far more legible than the screen of a netbook PC that the captain was using for performance calculations. In fact, the netbook screen was nearly impossible to see, even at its maximum brightness setting.

There was one drawback to using the iPad in the cockpit. I had left it sitting in the sun inside its Apple protective case and when I turned it on, it immediately shut down due to overheating. Placing it in the shade near the floor quickly restored the iPad to normal operation.

Jeppesen Mobile TC starts with whatever chart was last displayed or a blank screen. There is just one button–“Airports”–and a settings button. Clicking the settings button reveals a screen showing the update status and a button for updating charts, as well as a blank field for the JeppView serial number. Updates can be done via WiFi or 3G, depending if the iPad is the WiFI-only version or the WiFi plus 3G version. 

Pushing the airports button reveals a search box, and any airport ID or city name entered here brings up either the specific airport or a list of choices for that city. When airports are listed, a blank star is shown next to each airport. Touching this star fills it in with a gold color, indicating that is now a favorite airport. When looking for airports, at the bottom left are two choices, airports or favorites, and this is where favorite airports are easily and quickly accessed.

Selecting any airport brings up a list of available charts. En route charts are not yet available, but Jeppesen executives promise these are coming soon. To select a chart, simply touch the desired chart for that airport and up it comes. Now with the chart filling the display, look at the bottom of the screen for a unique Jeppesen design touch. A menu bar shows all the available charts, with the displayed chart's number highlighted with a red monocle-like slider symbol. You can slide the monocle left and right to pull up any other chart for that airport. This saves you the trouble (not that much really) of having to push the airport's name and pick from the list of approaches. The slider is a clever and intuitive interface that works well without intruding on the user experience.

Charts open to fill the screen in either portrait or landscape mode. You can view the entire chart by using the standard iPhone/iPad pinch-zoom, and even though the chart details shrink when fitting the whole chart, letters and numbers are clear and sharp and perfectly legible. Need to see more detail? Just pinch and zoom. Jeppesen's charts are all vector-based graphics, which retain their sharpness at any size.

While Jeppesen's Mobile TC for the iPad doesn't do everything, it is a capable and efficient chart viewer that resides on a tablet computer that can be used for many other tasks. The iPad's long battery life means you won't run out of juice, although you do need to keep the unit from overheating at an inopportune moment.

Part 91 pilots can use Mobile TC; the FAA doesn't specify whether charts be printed or electronic, but many iPad users carry paper as a backup.

For Part 135 operators, things get a little sticky because FAA inspectors get to make up their own rules (otherwise known as operations specifications) and have been reluctant to approve iPads for charter operations.