NEW YORK — U.S. Sen. Charles Schumer wants to require the Federal Aviation Administration to establish seat size standards for commercial airlines, which he says now force passengers to sit on planes “like sardines.”

The New York Democrat said the airlines have been slowly cutting down legroom and seat width.

He said he will add an amendment to the FAA Reauthorization Bill that is pending before Congress that would require the agency to set the seat size guidelines.

Schumer said seat pitch, the distance between a point on an airline seat and the same spot on the seat in front of it, has dropped from 35 inches in the 1970s to a current average of closer to 31 inches, and seat width has gone from 18.5 inches to about 16.5 inches.

He argues that the requirement is needed to stop airlines from shrinking those numbers even further.

“They’re like sardines,” Schumer said of airplane passengers. “It’s no secret that airlines are looking for more ways to cut costs, but they shouldn’t be cutting inches of legroom and seat width in the process ... It’s time for the FAA to step up and stop this deep-seated problem from continuing.”

Schumer pointed to a practice used by some airlines in which passengers are charged more money for seats with extra legroom. He says that exemplifies the problem.

“It’s just plain unfair that a person gets charged for extra inches that were once standard,” he said.