Airplane passengers loathe being crammed together in coach and seethe when seat backs are reclined onto their laps. But are these crowded conditions actually unsafe? Americans soon should find out.

A 2018 bill gave the Federal Aviation Administration the authority to set minimum seat sizes as cabins shrink and body sizes grow. Federal regulations require an evacuation time of 90 seconds in an emergency, seemingly leaving little time to disentangle cramped limbs or squeeze through tight rows.

Over 12 days of testing in November, 720 volunteers will go through simulated emergency evacuations, the Washington Post reported. Authorities will prepare 3,000 data points from the results to decide how small-airplane seats can get and how close rows of seats can be to one another, a figure known as "pitch."

Pitch is a key figure for evacuations. It represents the space to stand up, maneuver and take those awkward steps toward the aisle that may impact how quickly rows can be emptied. We don't believe government should dictate seat size to airlines on the basis of comfort. Consumers can decide which airlines to patronize and which type of seat to buy — or whether to fly at all. But if airlines compress plane configurations to pack in passengers and maximize revenue at the risk of safety, the FAA must act.

We've raised concerns about seat size and safety in the past, noting that seat pitch had shrunk from 35 inches before airline deregulation in the 1970s to about 31 inches. Now, it's a mere 28 inches on some planes, though airlines argue that streamlined seats take up less of that space than older designs. In 2017, the U.S. Court of Appeals for the District of Columbia Circuit ordered the FAA to address safety concerns associated with dwindling space.

The upcoming simulated emergencies will take place at the FAA's Civil Aerospace Medical Institute in Oklahoma City and will attempt to re-create real conditions of darkness and panic. Experts urged that these tests use volunteers of varying sizes to reflect the flying public, the Post reported, and include people who are disabled or have other reasons to move a bit more slowly.

A bad knee or tricky back could be enough to prevent a passenger from springing instantly from their seat per the demands of the stopwatch. Some passengers may be accompanied by babies or pets. For extra verisimilitude, we hope the tests include volunteers who try to take their belongings, because that could really gum up evacuations.

Planes now typically fly very close to full. The public deserves to know whether the safety rules that protect passengers bear any resemblance to the current reality in the sky. If packed planes can't be evacuated quickly during a fire or other emergency, there will be reason beyond discomfort to demand changes.

FROM AN EDITORIAL IN THE CHICAGO TRIBUNE