A court has ordered the US aviation regulator to reconsider whether shrinking seat pitches on aircraft are a safety matter.

The decision by an appeals court panel came after a challenge to the Federal Aviation Administration brought by Flyers Rights, a passenger group.

The group had requested that the FAA agrees regulations governing seat size and the distance between rows of seat, a plea the regulator had rejected.

Dubbed by one of the US federal appeal court judges in Washington as ‘the case of the incredible shrinking airline seat’, the case could open the way to regulation stipulating larger seats.

The court decreed that the FAA had relied on outdated or irrelevant tests and studies before deciding that seat spacing was a matter of comfort, not safety.

Sending the issue back to the FAA, the court said the agency must come up with a better response to the Flyers Right’s health and safety concerns.

Kendall Creighton, a spokeswoman for Flyers Rights, said: “We applaud the court’s decision, and the path to larger seats has suddenly become a bit wider.”

The FAA is considering the ruling and said it considers the spacing between seat rows when testing to make sure that airliners can be evacuated safely.

Flyers Rights point out that the average seat has been getting steadily narrow as US passengers have been getting bigger.

It says the issue is not just one of safety when having to evacuate an aircraft but the wellbeing of passengers.

Judge Patricia Millett of the appeals court wrote in her ruling: “This is the case of the incredible shrinking airline seat.

“As many have no doubt noticed, aircraft seats and the spacing between them have been getting smaller and smaller, while American passengers have been growing in size.”

The issue could wind up in the US Congress amid proposals for legislation to regulate seat size, something the airline industry opposed.