

Uh-oh: airlines ordering new Dreamliner 787s and Airbus A330s are asking to have them fitted with 16.7"-wide coach seats, a new low for long-haul travel. These are planes intended for intercontinental flights — six to 14 hours! — and they're shaving the armrests, squeezing the seats, and otherwise cramming in ways that beggar the imagination. The airlines say it'll all be OK — they'll just distract you from your terrible circumstances with big meals and TV.

Of the airlines that have bought Boeing Co.'s new 787 Dreamliner—a model touted as improving passenger comfort—90% have selected nine-abreast seating in coach over roomy eight-abreast. And 10 airlines around the world now fly narrower Airbus A330 jetliners with nine 16.7-inch seats in each row—among the tightest flying—rather than the eight it was designed for, according to the unit of European Aeronautic Defence & Space Co. EADSY +2.04%

The new trend in economy seating reverses a half century of seat growth in economy class. Early jet planes like Boeing's 707 had 17-inch seats, a dimension based on the width of a U.S. Air Force pilot's hips, says Airbus marketing chief Chris Emerson.

That standard for long-haul flying increased to 18-inches in the 1970s and 1980s with the 747 jumbo and the first Airbus jets. It widened to 18.5 inches with the Boeing 777 in the 1990s and A380 superjumbo in the 2000s. Now, cost-conscious airlines are moving to lighter 17-inch-wide seats on their Boeing 777 and 787 Dreamliners and 18-inch seats for A350s.