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 U.S. Court of Appeals in the District of Columbia requesting the FAA 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 Monday 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.

“Seats have gotten smaller and people have gotten bigger,” Hudson said, noting that seat pitch — the distance from one seat back to the next — was 31 to 35 inches in the 1970s. Now it’s down to as low as 28 on low-cost carriers like Spirit Airlines. Seat width, he added, was about 18½ inches, and is now 17 to 17½ inches.

Concurrently, Americans have gained weight. According to the Centers for Disease Control and Prevention, the rate of obesity in the U.S. is nearly 38 percent, up from 15 percent in 1980. Seventy percent of adults are currently overweight, versus about 45 percent in 1960.

Newer, slimmer aircraft seats mean that passengers haven’t entirely lost a commensurate amount of legroom. But travelers aren’t hallucinating when they say conditions are cramped. American Airlines, for one, retreated on its plans last year to reduce pitch in some economy sections from 31 to 29 inches on its newer jets.

As documentation supporting its conclusion, the FAA added several video clips from airline manufacturers showing their successful evacuation tests to the case docket.

“The FAA also has no evidence that current seat sizes are a factor in evacuation speed, nor that current seat sizes create a safety issue necessitating rule-making, because the time to stand up from one’s seat is less than the time it will take for the exit door to be opened and, for most passengers, for the aisle to clear,” wrote Dorenda Baker, the executive director for aviation security at the FAA, in the letter.

Critics say the tests do not reflect real-world scenarios on planes filled with diverse ages, sizes and states of dress, nor do they capture the panic inevitable in an emergency situation.

“In real life, people are in heels or barefoot or in flip-flops, and grabbing their own stuff from the bins or under the seats,” said Erin Bowen, a professor and the chair of the behavior and social sciences department at Embry-Riddle Aeronautical University in Prescott, Arizona. “In a real accident, people will panic and they will freeze and that is very different than the experiments they are running.”