Congress continues to wrangle over the number of F-22 Raptor fighters it will approve for the Air Force.

The fortunes of the world's most expensive fighter jet have yo-yoed from an Air Force call for more than 700 of the stealth aircraft, to a request for 381, to a cap at 187, and now consideration for seven more.

The program has cost $65 billion, according to Defense Secretary Robert Gates, who has questioned the need for any more of the Cold War-type planes.

Each Raptor costs $143 million, and more than twice that factoring in research and development, but the aircraft has yet to see combat.

All of this is important to Hawai'i, which is supposed to get 20 of the Raptors. The Hawai'i Air National Guard will be the only Guard unit to "own" the aircraft, with a minority of pilots and mechanics coming from active-duty units.

"Everything right now, today, is on track," Hawai'i National Guard spokesman Lt. Col. Chuck Anthony said of the basing plan.

Two maintenance training F-22s are expected next June, followed by two more of the advanced fighters in the fall. The phase-out of the existing 19 F-15 Eagles before that, however, will create a gap.

The Air Force decided to accelerate the retirement of its aging F-15s as a cost-saving measure.

A "B" model F-15 will leave Hawai'i in August, and a couple of the oldest "A" models will be gone by September, Anthony said. "C" models will be sent elsewhere starting next year, and will be gone by August 2010.

Because only two F-22s will be at Hickam by then, Mainland fighter units will "cover down" for the air defense of Hawai'i, a primary job of the fighters here.

"They have been identified, we're working the issues," Anthony said. "It looks as though it's a done deal for them coming here on or about August of 2010."

Anthony said it's premature to say what unit that will be. But there are likely to be a succession of Mainland units covering the skies over Hawai'i. That could mean F-15s or F-16s doing the job until the F-22 Raptors arrive in sufficient numbers.

Reach William Cole at wcole@honoluluadvertiser.com or 525-5459.