AA 1238 BOS-DFW was delayed for about 4 hours today. It finally got up in the air, but I decided to make alternate arrangements.

We sat at the gate for awhile, and there was a mechanic in the cockpit. The mechanic finally left, and we taxied out and sat for about 30 minutes. The pilot finally came on the PA and indicated that there was a navigational issue and that they were trying to resolve it remotely. We waited some more, and then there was another announcement that we'd be returning to the gate.

The mechanics came on board, and after another 30 minutes the pilot came on the PA and said that the GPS was broken and that they would be filing a new flight plan to use ground-based navigation. 30 minutes later we were refueled, doors closed, and rolled back out to the taxiway and proceeded to sit for another 30 minutes. The captain then made another announcement that we weren't being cleared for the new flight plan and that they were working to resolve the issue. At this point people started crowding the forward lav, and a number were requesting to disembark due to the 3-hour rule.

I was checking a combination of ExpertFlyer and FlightAware, and it doesn't look good for those who missed connections. Almost everything seemed to be zeroed out.