LONDON (Bloomberg) — London Heathrow airport will switch to a new air-traffic control tower tomorrow, raising the possibility of flight delays at Europe’s busiest airline hub.The switch to the new tower, introduced as part of Heathrow’s Terminal 5 expansion, will take place at 2 a.m. tomorrow London time, NATS En Route Plc, the UK’s air-traffic agency, said yesterday in a Regulatory News Service statement.

Heathrow airport is running at 99 percent of its government-permitted capacity and handles 67 million passengers every year. Expansion at the airport, owned by Grupo Ferrovial SA’s BAA Plc unit, includes the new tower and the fifth terminal, which is scheduled to open at the end of March 2008.