Delta Air Lines, the world’s second-largest air carrier, has joined in opposition to new federal regulations that will allow passengers to bring small knives on planes.

Delta chief executive Richard Anderson said Friday he shares the “legitimate concerns” of flight attendants and others about the changes. He said the changes will do little to improve checkpoint delays and other customer-service issues, compared to the “additional risk” for cabin staff and passengers.

Anderson made his case in a letter to Transportation Security Administration chief John Pistole, who announced the changes Tuesday.

“There are much more effective steps we can take together to streamline the security checkpoints with risk-based screening mechanisms,” Anderson said in the letter, obtained by the Associated Press.

The changes — which also allow passengers to carry on miniature baseball bats, lacrosse and hockey sticks, ski poles, plastic bats and two golf clubs — were immediately denounced by a chapter of the Southwest Airlines’ Flight Attendants Union.