Thousands of British Airways passengers have been stranded by canceled flights and lengthy delays at Heathrow Airport because of staff shortages and technical problems at the airline. British Airways canceled 21 flights to and from short-haul destinations in Britain and Europe on Tuesday _ a day after the airline scrapped 25 flights to the United States and other European destinations. The airline, which usually carries around 100,000 passengers throughout the day, said there would also be delays to short-haul flights that have not been canceled. It urged all passengers to consult its web site before traveling to Heathrow. The airline's problems began Monday afternoon when it canceled flights to Philadelphia, Chicago and New York because of technical problems with its aircraft. Those cancellations, combined with existing staff shortages at the airline, had a domino effect, leading to the cancellation of another 22 flights and several more delays. The airline estimated around 5,000 passengers have been affected so far and at least another 2,500 would be affected Tuesday.
