Let the armrest elbow wars continue. This week, in response to a federal appeals court case, the Federal Aviation Administration announced it will not regulate the size of seats on airplanes, despite consumer complaints about comfort and questions about safety.

The nonprofit advocacy group FlyersRights.org had filed a petition with the United States Court of Appeals in the District of Columbia requesting the F.A.A. establish guidelines for seat dimensions; it noted the discomfort of shrinking seats and the potential danger for plane evacuations caused by narrow rows.

Though the agency requires that all planes must be evacuated in case of emergency in 90 seconds, it claimed, in its July 2 letter to FlyersRights.org announcing its decision, “that seat width and pitch, even in combination with increasing passenger size, do not hamper the speed of an evacuation.”

The agency relies on passenger evacuation simulations that are run and filmed by airplane manufacturers when forming its conclusions. But Paul Hudson, a lawyer and the president of FlyersRights.org, said the drills did not include children, the elderly, infirm or obese — passengers likely to slow down an evacuation.