Air Canada briefly grounded its planes Thursday due to a problem with its computer system. The airline said a technical issue with the system it uses to transmit messages to aircraft and monitor their performance, prompted a halt to operations.

Airline spokesman Peter Fitzpatrick said the temporary order was precautionary, and that there were some flight delays as a result, but the effects were limited and service was returning to normal.

As of Thursday night, 241 Air Canada flights – 46% of its trips that day – were delayed, according to tracking service FlightAware. That compares with about 35% on Wednesday and 30% on Tuesday.

Another 19 flights were also cancelled Thursday.

Air Canada said it advised Nav Canada and the US Federal Aviation Administration of the temporary freeze, which lasted about an hour.

The FAA posted an advisory stating all Air Canada and Air Canada Rouge flights were put on hold “due to internal computer issues.”

British Airways

Meanwhile, British Airways cancelled dozens of flights on Friday due to computer problems, disrupting the plans of thousands of travellers at the start of a busy holiday weekend.

Most of the 42 affected flights were on short-haul routes to and from Heathrow, Europe’s busiest airport. Computer issues on Thursday caused planes and crew to be out of position Friday, which was expected to be the busiest day for UK air travel since before the coronavirus pandemic.

Other flights were delayed, as some passengers were unable to check in online.

“We’re aware of a technical issue, which we have been working hard to fix,” the airline said on its website.

Travel is expected to be especially busy over the next few days as a three-day weekend coincides with the start of a weeklong holiday for most schools in Britain.