WASHINGTON - Lockheed Martin Corp.'s F-22 jets began corroding soon after being introduced into the Air Force in 2005, and the Defense Department plans to spend $228 million through 2016 to fix the deteriorating aluminum-skin panels, the Government Accountability Office said in a report.

The newer F-35 aircraft, also built by Lockheed, have an improved design and use updated materials and paint to prevent such corrosion, the report sent Thursday to the Senate and House Armed Services Committees said.

Corrosion of the panels was first observed less than six months after the F-22 jets were first deployed, the report said. By October 2007, 534 cases of damage to the panels were documented, it said, and "corrosion in the substructure was becoming prevalent."

Air Force spokesman Chris Isleib said the service was reviewing the report and had no immediate comment.

Lockheed spokesman Christopher McGee said by e-mail that the F-22s experienced corrosion because of "interaction" with stealth materials used to hide them from enemy radar. Lockheed has developed alternative material that "eliminated that interaction" and began changing the fleet in early 2010, he said.

Defense Secretary Robert M. Gates in 2009 curtailed production of F-22s to the 187 planes on order. The F-35 is in the early stages of production.