British Airways cabin crews began a five-day strike Monday that threatens to disrupt service in Philadelphia through June 9. Starting Tuesday, the airline will suspend one of its two daily flights from Philadelphia to London's Heathrow Airport.

British Airways P.L.C. will continue to operate a 6:10 p.m. nonstop flight from Philadelphia International Airport to London during the strike, but will cancel a 9:15 p.m. daily flight from here starting Tuesday.

Both flights will operate normally Monday because flight crews arrived Sunday.

Passengers whose flight has been canceled can transfer to a competitor airline such as US Airways Group Inc., which operates a daily Philadelphia flight to London Heathrow; rebook at a later time, or get a refund, said airline spokesman John Lampl. "We are slated to carry some passengers from the British Airways cancellations," US Airways spokesman Morgan Durrant said.

The union representing cabin crew staff has announced plans for two additional five-day walkouts: May 30-June 3 and June 5-9. In March, cabin crews walked out twice for a total of seven days.

British Airways plans to suspend its 9:15 p.m. Philadelphia flight through June 9, unless an agreement is reached, Lampl said. Striking workers are protesting cost-cutting changes in work practices, including fewer staff on long-haul flights and a yearlong pay freeze. The airline, which suffered in the economic downturn because of reliance on business- and first-class fare passengers on trans-Atlantic routes, said the cuts are necessary to survive.

British Airways hopes to accommodate 70 percent of booked passengers during the strike, and said flights at London Gatwick and London City airports will not be affected.

British Airways is operating as many flights as possible, using non-striking cabin crews, and staff from elsewhere in the company who have volunteered and had training. The airline intends to operate 60 percent of long-haul flights and 50 percent of short-haul flights from Heathrow.