There were American Airlines pilots protesting at Philadelphia International Airport and other airports Monday after the pilots voted to authorize a strike, reports 6abc.

Philadelphia International Airport is a hub for American Airlines.

There’s not much chance the authorization will generate an immediate walkout by the pilots, however.

Federal law prohibits airline unions from striking without approval from a U.S. mediation board. Congress and the president can also take steps if a strike appears imminent.

The authorization, though, was approved by 99 percent of the Allied Pilots Association membership, of which 96 percent participated in the vote.

An American Airlines spokeswoman said the airline is confident it can reach a quick agreement with the union.

“We understand that a strike-authorization vote is one of the important ways pilots express their desire to get a deal done, and we respect the message of voting results,” said the spokeswoman, Sarah Jantz.

Delta Airline pilots won a 34 percent raise over a four-year contract earlier this year and now American and United Airlines are being asked to match or beat those terms.

The American Pilots’ Union also wants scheduling changes to improve efficiency and prevent widespread delays and cancellations.  

Read more about the American Airlines pilot strike authorization at 6abc.