WASHINGTON — Sen. Chuck Schumer apologized today after word got out that he called a flight attendant a “bitch” for ordering him to follow the rules and turn off his cellphone before takeoff.

And his political protégé, Sen. Kirsten Gillibrand, initially provided him with public cover.

Schumer’s outburst was overheard aboard a US Airways flight from LaGuardia Airport to Washington on Sunday.

Schumer and his seatmate, Gillibrand, were chatting on their cellphones when the plane’s captain told passengers to turn them off.

But the two Democratic senators ignored the order and kept talking — prompting a flight attendant to ask them to follow Federal Aviation Administration rules, according to a House Republican aide who was seated nearby.

Schumer asked if he could finish his call. The attendant said “no” because the plane was waiting for him to finish so it could take off. The state’s senior senator ended his call, but then launched into an argument with her, claiming he was entitled to continue his chat until the cabin door was closed.

“She said she doesn’t make the rules, she just followed them,” the aide said, according to Politco.com.

“Bitch!” Schumer remarked to Gillibrand after the attendant walked away.