Everyone who flies, but who doesn’t have deep enough pockets to travel exclusively in first class, knows it: Airplanes are increasingly crowded and unpleasant. But is that frustrating lack of legroom actually endangering your life when you fly?

The Daily Beast reports today that based on more than 900 pages of Department of Transportation and FAA documents it reviewed, that coach may simply be so crowded that it’s no longer safe in the event of an emergency.

Smaller and Smaller

It’s no secret that coach has steadily been getting more crowded for years.

Seat pitch in particular — the distance between your seat and the seat in front of you — has been putting the squeeze on consumers for decades.

In 1985, that depth measured between 31 and 36 inches on the major airlines; by 2014, it was down to the 30-33 inch range. Budget carrier Spirit crams their seats in even more shallowly, with a seat pitch of 28 inches, while American recently abandoned a plan to drop their economy seat pitch to 29 inches.

Seats are also significantly narrower. Thirty years ago, they measured an average of 19 to 20 inches across; these days, they’re as low as 16.5 inches and average 17-18 inches wide.

In Aug. 2015, an organization called Flyers Rights called on the Federal Aviation Administration to start making rules about seat pitch. Flyers Rights claimed that it wasn’t just a matter of convenience and comfort, but literally one of health and safety: Decreased space could make evacuations more difficult, they argued, as well as increase the risk of blood clots forming in the legs of passengers trapped in tiny seats for long-duration flights.

After a lengthy legal back-and-forth, the D.C. Circuit Court of Appeals ruled earlier this year that the FAA needs to at least give serious consideration to the Flyers’ Rights petition, even if ultimately declines to make a rule about minimum allowable seat pitch.

The dangers of squeezing in

The Daily Beast reports that one of the reasons the FAA may have tried to dismiss Flyers Rights’ claims out of hand is because none of the safety testing actually lines up with the current configuration of planes and passengers.

“All of the tests designed to achieve the fastest possible evacuations were devised decades before” density began to skyrocket and seat size began to shrink, the Daily Beast writes.

As a result, it’s impossible to know if everyone really can evacuate a fully-packed jet under current seating conditions based on the tests that are currently done — especially as many tests are kept proprietary and internal by the airlines and manufacturers that conduct them.

Of particular concern are the individual seat-back TV screens that airlines increasingly use. Sure, they’re convenient for catching an in-flight film or ordering a snack, but the combination of “TV” and “head” is not a healthy one.

Department of Transportation documents the Daily Beast examined revealed that testing seat-back screens for blunt trauma impact destroyed so many screens that the FAA started allowing manufacturers to test with cheaper replicas, instead. Why? Because dummies’ heads were whamming into them with alarming frequency.

For your safety, in a crash or otherwise problematic landing, you’re supposed to put yourself in the brace position to protect your head. But DOT diagrams show that simple geometry means that with low seat pitch, you literally don’t have enough space to do so.

Does it matter?

The FAA has until Dec. 28 to respond to the Flyers Rights’ petition with “a properly reasoned disposition of the petition’s safety concerns about the adverse impact of decreased seat dimensions and increased passenger size on aircraft emergency egress.”

In English, that means the agency has to explain why it’s fine for them not to make rules about seat size or pitch, and ignore how densely packed airplanes are getting to be.

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