American Airlines has joined the growing opposition to the U.S. Transportation Security Administration's new policy that allows passengers to carry small knives on planes.
In a letter to TSA Administrator John Pistole, American's Senior Vice President Will Ris wrote that the Fort Worth, Texas-based carrier agreed that it was "important" for the TSA to "regularly revisit its rules and regulations" and said American would "adhere fully" to TSA's policies, but added that he wanted to "voice American's concern" over the new change, which is scheduled to take effect on April 25.
"We encourage the TSA to reassess its proposed revisions to the prohibited items list," Ris wrote.
American is the third major U.S. airline to oppose the new policy since Pistole announced it last week, following in the footsteps of Delta Airlines and US Airways.
Delta, which is the world's second-largest airline, was the first to speak out against the policy.
In his letter last week, Delta's CEO Richard Anderson said although the Atlanta-based carrier had a strong relationship with the TSA, he disagreed with the agency's recent decision and shared the "legitimate concerns" of flight attendants. Anderson also pointed out that small knives have been banned from commercial planes for the past 11 years.
US Airways CEO Doug Parker also urged Pistole to "reconsider" the policy, writing in a March 11 letter, "US Airways fully supports the continuous review and amendment of TSA policies. We also understand and support the risk-based assessment employed by the TSA. However, this review and policy amendment process is most effective when it is conducted in a collaborative way with airlines and their flight crews."
"In particular, seeking input before implementing a change in policy that might place out flight attendants' safety at risk would have provided a more thoughtful path to the desired outcome of secure and safe air travel."
The new TSA policy will permit folding knives that do not lock and have blades that are 2.36 inches or less in length and are less than 1/2-inch wide inside the cabin. Novelty-sized and toy bats less than 24 inches long, billiard cues, ski poles, hockey sticks, lacrosse sticks and two golf clubs will also now be allowed in carry-on luggage.
The change, which was announced March 5, came after a TSA working group recommended that such items were not a security threat. The new policy will allow TSA security officers "to better focus their efforts on finding higher threat items such as explosives," the agency said in a statement.
The move will conform to international rules that allow small knives and sporting goods. Razor blades, ice picks, scissors and box-cutters -- like those used by the 9/11 terrorists -- will still be banned. Full-sized baseball bats will also remain on the prohibited carry-on list.
World's Largest Pilot Union Supports TSA Policy Change
Aside from the airlines, the change has sparked mass opposition from some pilots, flight attendants, federal air marshals and insurance companies. Politicians have also voiced concerns.
Flanked by flight attendants and pilots, Rep. Ed Markey, D-Mass., held a press conference at Boston's Logan Airport today, in which he urged the TSA to abandon its new policy. If the TSA does not, Markey said he would introduce legislation to prevent knives from being allowed on planes, the Associated Press reported.
The Flight Attendants Union Coalition, which represents nearly 90,000 flight attendants, launched a wide campaign to kill the TSA policy change two days after it was announced. Flight attendants posted a petition on the White House's "We the People" website, asking the Obama administration to "tell the TSA to keep knives out of the cabin." The petition now has more than 26,200 signatures.
"Our nation's aviation system is the safest in the world thanks to multilayered security measures that include prohibition on many items that could pose a threat to the integrity of the aircraft cabin," the coalition, which is made up of five unions, said in a statement last week. "The continued ban on dangerous objects is an integral layer in aviation security and must remain in place."
Mike Karn, the president of the Coalition of Airline Pilots Association, which represents over 22,000 professional airline pilots at carriers including American Airlines and US Airways, also said in a statement that the organization will "categorically reject a proposal to allow knives of any kind in the cabin."
However, the Air Line Pilots Association, the largest airline pilots union in the world, representing nearly 51,000 pilots, supports the TSA's new carry-on policy change.
"ALPA supports TSA efforts to streamline security and shift focus to individuals who intend to do harm. This will standardize TSA policy with the international community," the organization said in a statement. "Common sense risk-based security screening initiatives, like Known Crewmember and Pre-check, are the answer to protecting our nation's air transportation system. These TSA initiatives increase resources for screening so that they focus on the real security threats instead of objects."
ABC News' Genevieve Brown contributed to this report