A U.S. appeals court has ordered the Federal Aviation Administration (FAA) to formally respond to a consumer petition aimed at limiting airlines’ ability to reduce seat sizes on aircraft, the New York Times reported July 31.

The consumer advocacy group Flyers Rights filed a petition with the FAA in 2015 raising concerns that the combination of heftier passengers and smaller seats could pose a safety hazard in the event of an emergency evacuation. The U.S. Court of Appeals for the District of Columbia agreed and said the FDA needs to “adequately address” the petition.

The petition noted that between 1960 and 2002 the weight of the average American male increased 25 pounds, to 191 pounds, while the average American female’s weight rose 24 pounds, to 164 pounds. Meanwhile, average airline seat pitch has decreased from 35 inches to 31 inches.

The FAA initially rejected the petition, which called on the agency to issue a moratorium on further seat-pitch reductions and to establish standards for street sizes, but the appeals court ruled that the federal agency provided insufficient grounds for doing so. In response, the FAA said it was “studying the ruling carefully and any potential actions we may take to address the court’s findings.”

The court ruling doesn’t necessarily mean the FAA will move to require greater seat pitch; the agency could reject the petition again and simply provide better justification to support its ruling. Nonetheless, the decision was described as “groundbreaking” by aviation attorney Arthur Alan Wolk.

“This is the first case I have seen where an organization has successfully challenged the FAA’s basically being asleep at the switch and not fulfilling its safety responsibilities adequately,” he said.