Delayed flight and confusing data


I’m looking at UAL1540 this morning. It was delayed about 4.5 hours due to thunderstorms in Houston. Due to the delay there are now two UAL1540 flights in the air which are obviously different aircraft. Is it normal for airlines to use different aircraft for a given flight number? It just caught me off guard.

This is the flight I’m tracking from DCA to IAH.

While tracking the flight from DCA to IAH the enroute status seems reversed though the duration amounts seem to be in the correct proportions. The scheduled arrival time seems wrong… should be closer to 7:30 AM CDT.



It’s rare but known to happen for airlines to have two flights in the air at the same time with the same flight number.

It looks like the scheduled arrival time was modified, I’ve asked the flight tracking team to take a look at it.