Gadget Aims to Protect Knees of Coach Passengers

W A S H I N G T O N, D.C., Oct. 25 -- Every cramped air traveler may have the right to lean his seat back, but Ira Goldman sees airplane justice from another perspective — that of the person behind — and he's found a way to even the score.

Goldman invented the Knee Defender, a beeper-sized block of plastic that lets passengers prevent the seat in front of them from reclining.

The gadget, which went on sale about a month ago on the Internet for $10, has sparked heated debate in online chat rooms, and aviation officials worry about the disagreements that will be generated at 30,000 feet.

Alison Duquette, a spokeswoman for the Federal Aviation Administration, said the product violates no FAA regulations, so it would be up to individual airlines to prohibit it. Although the FAA has not tested the Knee Defender, it sought to discourage people from using anything that would "alter the performance of any part of an airplane."

Northwest Airlines said it will ban the Knee Defender from all flights. Other carriers, such as American Airlines and Delta Air Lines, acknowledged concerns about safety — not to mention the comfort of passengers who want to recline — but are still figuring out what to do.

The safety concerns stem from the design, because the Knee Defender works only when the tray table is down. The hard plastic block, which has an inch-wide groove down the middle, fits around the arm of a tray table and acts as a barrier to the seat's backward movement.

"We have tested this product on several seat types and find that when installed, should someone try to force the seat to recline, the tray table assembly can break," said Mary Stanik, a Northwest spokeswoman. "If the seat is damaged, including the tray table, in flight, it may adversely affect passenger evacuation in the event of an emergency."