(Alamy Stock Photo)

Somewhere in the mountain of regulations that govern commercial airline safety, the U.S. Department of Transportation has a graphic that unwittingly offers evidence that jamming more and more airline passengers into smaller seats and rows could be dangerous to their health.

The illustration — which was shown in a report by the Daily Beast last week on the possible safety risks of the ever-shrinking airline seat — suggests that by shortening the distance between passenger seat rows, the airlines may have increased the likelihood that a passenger could suffer head trauma from the seat in front.

The DOT graphic — which shows the “head strike zone” for a seated flight attendant — is intended to offer guidance on seat design to reduce the risk of injury to flight attendants in a crash, the Daily Beast reported. But the illustration might as well be Exhibit A for the proposition that while the Federal Aviation Administration has given some thought to seat design for protecting flight attendants from possible head injury, it’s done no such thing for everybody crammed into coach these days.

FlyersRights.Org has been arguing for some time that stuffing more and more bodies onto a plane is not only uncomfortable but potentially risky. The organization — which filed a lawsuit to force the FAA to set rules on minimum seat and aisle sizes — argues that the seating is so jam-packed now that passengers may not be able to evacuate quickly in a crash. The organization also says the cramped seating raises some passengers’ risk of developing potentially dangerous blood clots in their legs.

Earlier this summer, the  U.S. Court of Appeals for the District of Columbia partially sided with the group and, in a stinging opinion, ordered the FAA to reexamine its response to the argument that shrinking seats have safety consequences.

The Daily Beast article, which the news site said was based on a review of more than 900 pages of DOT documents, said that no seat in coach meets the agency’s own standards for the space required for flight attendant seat safety. The article also included the following DOT illustration:

Inside the potential dangers of cramped aircraft.

DEPARTMENT OF TRANSPORTATION

“[The illustration] shows the requirements for the seats used by flight attendants during takeoff and landing and it specifically delineates what it calls the head strike zone — the space that must be kept clear so that, in the event of an impact, the occupant’s head avoids contact with an adjacent seat,” the Daily Beast reported. “The zone must extend for at least 35 inches from the axis of the seatback and seat cushion—not from seatback to seatback.”

Yet, as FlyersRights.org has documented in its rulemaking petition for the FAA, economy class seat pitch — which is the distance between a point on one seat and the same point on the seat in front of it — has shrunk from an average of 35 inches to 31 inches. On some aircraft, it’s as narrow as 28 inches. At the same time, the average American passenger has grown taller and larger.

So far, the FAA has declined to draw up regulations on seat size, arguing that the agency’s regulatory authority doesn’t include questions of comfort and that existing safety tests suggest the shrinking seats pose no danger.

But U.S. Appeals Court Judge Patricia A. Millett’s opinion says that, at the very least, the FAA needs to come up with more scientific evidence as to why the narrower aisles and tighter seats are not also safety issues.

Since the Appeals Court’s ruling on July 28, the FAA has declined requests by FlyersRights.org to discuss the matter, the group’s president, Paul Hudson, said Monday in an interview. Here’s what the FAA had to say:

“Flight attendants and passengers have the same occupant injury protection regulations,” an FAA spokesman said in an email. “Flight attendants are required to have both a lap belt and shoulder harness, because they are expected to assist other occupants and carry out evacuation procedures in the event of an accident. But in terms of the injury criteria, there is no difference between the passengers and the crew.”

This is also something that lawmakers must address. Congress has made some noise about this but not nearly enough. And that’s enough to make you want to smack your head.

–This posting has been updated.

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