THIN AIR: Flight attendants, pilots, federal air marshals and even insurance companies are part of a growing backlash to the Transportation Security Administration's new policy allowing passengers to carry small knives and sports equipment like souvenir baseball bats and golf clubs onto planes.

CARRY-ON: The new policy permits folding knives with blades that are 2.36 inches or less in length and are less than 1/2-inch wide. Passengers also will be allowed to board with novelty-sized baseball bats less than 24 inches long, toy plastic bats, billiard cues, ski poles, hockey sticks, lacrosse sticks and two golf clubs. Items like box cutters and razor blades are still prohibited.

TSA O.K.: The policy change was based on a recommendation from an internal TSA working group, which decided the items represented no real danger. A TSA spokesman said the presence on flights of gun-carrying pilots traveling as passengers, federal air marshals and airline crew members trained in self-defense provide additional layers of security to protect against misuse of the newly allowed items.