United Airlines flights were grounded briefly Tuesday morning due to unspecified “automation issues.” United attributed the delay to faulty flight information in the airline’s dispatch system.
We began delaying flights at approx. 8 a.m. CT to ensure aircraft departed with proper dispatch information. Flights are now departing.
— United Airlines (@united) June 2, 2015
The Federal Aviation Administration issued a temporary advisory notice early Tuesday morning stating that the ground stop applied to all United Airline flights on Tuesday morning. The advisory was lifted just a few minutes later.
Stranded passengers took to Twitter, describing extended wait times on the tarmac.
Hey everyone who is also grounded on #UnitedAirlines flights. 👋🏼
— Mary (@mary__b__) June 2, 2015
Sitting on runway. Pilot inferring #UnitedAirlines has grounded all flights due to possible hack: fake flight plans found in system.
— Ted Benson (@edwardbenson) June 2, 2015
TIME has reached out to United for additional comment. We will update this post if we hear back with more information.