WASHINGTON - An audit agency's recommendation that the Air Force reopen bidding on a contract to build a new generation of aerial refueling planes almost certainly means the Air Force will fail to put the planes into service starting in 2013, as planned, the service's departing civilian chief said Friday.

"Of course, the Air Force will try desperately to hold onto" that target date "because of the age of our (current) fleet," Air Force Secretary Michael Wynne told a small group of reporters.

"I will also say there's almost no way to do that in the face of this straightforward delay in the start date," he added. He noted that Northrop has put off groundbreaking for two facilities that would build the aircraft.

Timing is an important issue because the current fleet of aerial refuelers is growing decrepit. The fleet of refuelers is a critical link in the global reach of the Air Force, enabling fighters and bombers to operate over great distances and to remain on station for long periods over Iraq, Afghanistan and elsewhere.

Grand Forks Air Force Base in North Dakota is changing from a refueling tanker base to a new mission involving unmanned aerial vehicles. However, officials are hoping for a new line of tankers to also be based there.

On his final day in office, a relaxed-looking Wynne told reporters that he was disappointed by the review conducted by the Government Accountability Office. The GAO found "a number of significant errors" in the Air Force's February decision to award the $35 billion contract to Northrop Grumman and its European partner. Boeing, the loser in the bidding, protested to the GAO.

Wynne was ousted two weeks ago by Defense Secretary Robert Gates, along with the top uniformed Air Force officer, Gen. Michael Moseley. Wynne is to be replaced starting Saturday by Michael Donley, who will be the acting secretary pending his confirmation by the Senate to be the permanent successor.

Wynne said he saw no possibility that the GAO could be made to alter its findings. And although its recommendation that the bidding be reopened is not binding on the Air Force, Wynne indicated that after studying the decision further, the Air Force likely would issue a new request for contract bids.

"We were very disappointed," by the decision, Wynne said in the Air Force's most extensive comments thus far on a GAO ruling that gives ammunition to Boeing supporters in Congress who have been seeking to block funding for the tanker deal or to force a new competition.

"The reason we are very disappointed, I think, is the intensity of effort that went into having a very open and a very transparent" competition between Boeing and Northrop, Wynne said. He spoke of "reshaping and revising" the competition, but he did not indicate that any final decisions had been made.

He described the ruling as "an opportunity perhaps to take a whole other look at the way that we offered, in other words the way we offered to buy" from the manufacturers who submitted contract bids.

Wynne said the Air Force is "somewhat confused by some of the wording" of the GAO ruling, and he said the service would seek clarifications before it proceeds with a new competition.