United has grounded its entire fleet of 7578 aircraft for "unscheduled maintenance", a move likely to lead to delays for domestic services over the next few days.
There is no official statement on the carrier's website, but US media including The Wall Street Journal and CNN report that all of United's fleet of 96 Boeing 757 aircraft have been voluntarily grounded for checks on the air data computers as part of a modification process to the system.
According to CNN (in a post updated at 0144 GMT on February 16) the checks take about 60 to 90 minutes per aircraft, and the carrier should be ready to return to full service within the next 12 to 24 hours.
United's 757 fleet operates on its domestic network, so transatlantic routes to the UK should not be affected by the move. Merger partner Continental's 757 fleet has not been grounded.
For more information visit united.com.
Report by Mark Caswell
