American Airlines delayed “dozens” of flights over two days because of an application software bug that caused pilots’ flight deck iPads to malfunction. The airline resolved the problem with a temporary fix on April 29; a permanent solution will follow when application provider Jeppesen supplies new data on May 8.

Fort Worth-based American Airlines is a pioneer among U.S. commercial carriers in adapting iPads to serve as electronic flight bags (EFB) in the cockpit, replacing weighty paper manuals and charts. The airline received FAA approval in December 2011 to use the tablet computer as an EFB during all phases of flight on its Boeing 777 fleet. In June 2013, American said that it had secured FAA approval to use iPads across all of its fleet types, and had distributed more than 8,000 of the devices to its pilots.

Jeppesen spokesman Mike Pound said the software problem arose during a 24-hour period when both an old and a new ILS approach chart were available to view using the company’s Mobile TC Pro app, which runs on the Apple iPad.

“The issue is there’s a duplicate chart in the database that American Airlines is using. That duplicate chart is for Washington National Airport,” Pound explained. “Last night, when we got to the point 24 hours before (the new chart) became effective, it became viewable in the Mobile TC Pro app. When it became viewable in the app, those pilots who had favorited Washington National had their iPads become unresponsive.”

Within the application, pilots can save airport charts to a “favorites” file for quick retrieval. In the case of the Washington Reagan National Airport chart at issue, the old and new charts carried the same name and index number, which the application couldn’t reconcile and so shut down.

In a statement emailed to AIN, American Airlines said the software bug caused it to delay “a couple dozen” flights. “We have experienced  technical difficulties with a third-party application installed on some of our electronic flight bag for our pilots. It is not all electronic flight bags,” the carrier said. “Pilots have been given instructions to rectify the situation.”

The airline did not specify the aircraft type or locations involved. The website Quartz reported that the problem affected American’s Boeing 737 fleet and flights from Dallas, Chicago and New York.

Responding to an AIN query, the Allied Pilots Association, the union that represents American Airlines pilots, said the problem was resolved as of the afternoon of April 29. “Our relevant subject-matter experts consider the issue contained and addressed to our satisfaction, with the company providing crews with guidance,” the union said.

Pound said Jeppesen troubleshot the problem and found a quick fix that involved “uninstalling” and reinstalling the app. The chart duplication will be corrected when Jeppesen sends a new data set containing the chart on May 8. In the meantime, the airline can “push” PDF versions of charts to pilots wirelessly.

As an “early adopter” of pilot iPads, American Airlines has used an earlier version of Jeppesen’s mobile application software, Pound said. “The issue stems from the fact that the version that American Airlines is using isn’t capable of having two charts with the same title as the newer versions of the app are,” he elaborated. “American was an early adopter of the mobile application. There have been versions that have been released since they implemented it. I’m hesitant to say it’s anybody’s fault; it’s just the nature of the situation.”