The Federal Aviation Administration will not seek to regulate airline seating size because the current dimensions do not pose an immediate safety threat to passengers, the agency said on Tuesday in a letter to a nonprofit passenger rights organization.

FlyersRights.org previously argued in the D.C. appeals court that larger passengers are unable to swiftly evacuate in an emergency because of the smaller seat sizes. The FAA in its letter said it has no evidence that the existing dimensions “hamper the speed of passenger evacuation, or that increasing passenger size creates an evacuation issue.”