"Some flights are experiencing an issue with a software application on pilot iPads," American Airlines said in a statement. "In some cases, the flight has had to return to the gate to access a WiFi connection to fix the issue."
Airline spokeswoman Andrea Huguely said "more than a couple dozen flights" were affected.
"We apologize for the inconvenience to our customers," American Airlines said. "We are working to have them on the way to their destination as soon as possible."
It's still unclear which iPad app was faulty -- or whether the fault lies with American Airlines or Apple.
In 2013, American Airlines became the first airline to have its pilots rely entirely on iPads for flight plans and navigation. Plans get updated all the time, so the company cut down on lots of excess paper.
The airline has estimated the paperless program saves the company at least 400,000 gallons of fuel every year. In all, 8,000 iPads replaced 24 million pages of documents.
But, as is always the story with neat technology, software isn't always reliable.