This airline's pilots are planning to strike for the first time ever in September

Here’s some bad news for anyone with a British Airways flight booked for Sept. 9, 10 or 27.

BALPA, the British Airline Pilots Association, set those dates Friday for strikes as negotiations between the airline and the pilots' union have failed to reach an agreement in a pay dispute.

It would mark the first time British Airways pilots have ever gone on strike, according to BALPA.

The pilots said British Airways has not accepted any of the pay packages they’ve proposed, while the airline’s most recent offer “will not gain the support of anywhere near a majority” of the pilots. The union said 93 percent of its members voted in favor of the strike.

“British Airways is an extremely profitable and successful company, and pilots have been proud to play their part in that,” BALPA said in a statement.

The airline said its offer to the pilots “is very fair” and above the UK’s current inflation rate. It said unions for other British Airways workers like engineers and cabin crew had accepted similar deals.

“It is completely unacceptable that BALPA is destroying the travel plans of tens of thousands of our customers with this unjustifiable strike action,” British Airways said in a statement.

The company said it is making changes to its schedule to accommodate the strike. It is looking into the possibility of supplementing its fleet with aircraft and crew from other airlines, but it may have to re-book or offer refunds to passengers on some flights that will be canceled.

“We will do everything we can to get as many people away on their journeys as possible,” the airline said.

The airline had sought an injunction to prevent strikes based at London's Heathrow and Gatwick airports. A court sided against the company last month.

The pilots said they expect one day of striking will cost British Airways 40 million British pounds — about $49 million — so three days will cost 120 million pounds. Meanwhile, the difference between what the airline offered and what they want adds up to just 5 million pounds, they said.

“Over recent years BA pilots have made sacrifice after sacrifice to assist the company such as taking a pay cut, productivity increases, closing the final salary pension scheme, giving up annual leave days, a new rostering system and reducing flight pay,” the pilots said.

They said the pro-strike ballot is valid until January and more dates may be announced in the future.