BA CityFlyer (CJ, London City) has been warned that it could incur penalties for failing to adhere to its allocated slot times at London City, cabin crew blog Paddle Your Own Kanoo has written.

"We are seeing a trend of aircraft arriving early into London City, which has led to a number of letters to CityFlyer and potential fines from the Slot Coordinators," the carrier told its staff in a leaked internal memo.

To address the problem, BA CityFlyer is now enforcing a more rigorous policy of on-time departures from outstations. It has also reminded its ground staff at other airports not to begin boarding more than 20 minutes before scheduled departure times. The problem is said to be particularly acute on the airline's shortest domestic and Irish routes and, paradoxically, has been partially caused by improving efficiency at air traffic control.

The ch-aviation schedules module shows that BA CityFlyer is by far the largest airline at London City, operating 296 weekly scheduled departures and having a 61.8% market share by scheduled weekly capacity. All twenty-two E190s operated by BA CityFlyer, which is a wholly-owned subsidiary of British Airways (BA, London Heathrow) and operates exclusively under its parent's code, are based out of London City. The mainline does not serve the airport, which is not equipped for narrowbody operations.

BA CityFlyer operates 20 scheduled routes out of London City, including three UK services to Edinburgh and Glasgow International in Scotland, and Belfast City in Northern Ireland.

British Airways did not respond to ch-aviation's request for comment.