A software fault on Apple Inc. iPads used by American Airlines pilots for navigation charts delayed some flights Wednesday after affecting operations overnight.

About 40 flights ran late Tuesday night and into early Wednesday, according to American and data compiled by tracking service FlightAware.com. Pilots have been given instructions to fix the issue involving an application from a third-party vendor, said Andrea Huguely, an airline spokeswoman.

The fault isn’t affecting iPads used by all pilots, Huguely said. In some cases Tuesday night, planes had to return to terminal gates so pilots could access Wi-Fi to fix the issue, Huguely said.

Pilots use iPads as part of their “electronic flight bag,” which was adopted by American in 2013. It replaces more than 35 pounds of paper-based reference materials and manuals that flight crews carried onboard in the past.

Electronic navigation devices became available in recent years to private pilots before regulators approved the units for use in commercial operations, starting with charter operations. The first such authorization came in December 2010.

To contact the reporter on this story: Mary Schlangenstein in Dallas at maryc.s@bloomberg.net To contact the editors responsible for this story: Edward Dufner at edufner@bloomberg.net Bruce Rule

This article was written by MARY SCHLANGENSTEIN from Bloomberg and was legally licensed through the NewsCred publisher network.

Photo Credit: Pilots Nick Duke, left, and Bill Arabak look at an iPad being used in place of a heavy bag full of flight data in the cockpit of a jet operated by Flight Options in Teterboro, New Jersey, on March 27, 2012. Michael Karas / The Record/MCT