WASHINGTON — Two weeks after being ousted, Air Force Secretary Michael Wynne said Friday he had a "difference in philosophy" with his boss, Defense Secretary Robert Gates, on numerous issues — not just on the nuclear slip-up that Gates said was his reason for removing Wynne.

On his final day in office, a relaxed-looking Wynne told a group of reporters that he is not angry about being forced out as the top civilian official of the Air Force. He defended his record, saying he had "pushed the system pretty hard" to ensure that the Air Force is at the leading edge of war fighting.

He indicated no animosity toward Gates, with whom he said he was "not aligned" on some key issues.

"When you have a difference of philosophy with your boss, he owns the philosophy and you own the difference," he said.

Wynne, who took office Nov. 3, 2005, after serving as the Pentagon's top weapons buyer, is being replaced by Michael Donley, who will hold the job as the acting secretary pending Senate confirmation as the permanent replacement.

Beyond matters of philosophy, Wynne said he and Gates differed on future investment in the new-generation F-22 stealth fighter, on the extent of Air Force personnel cuts and other substantive issues.

"There were differences that accrued," Wynne said.

By coincidence, Wynne's exit came on the same week that the Air Force suffered yet another major setback — a ruling by the Government Accounting Office that the service had made significant errors in awarding a $35 billion aircraft contract to Northrop Grumman and its European partner. The audit agency recommended that the Air Force reopen the bidding process on the tanker aircraft.

Wynne indicated that the GAO ruling had rocked the Air Force and raised some tough questions internally. He also said it almost certainly means the Air Force will fail to put the planes into service starting in 2013, as planned.

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.

When Gates announced on June 5 that he was removing Wynne as well as Gen. Michael Moseley, the Air Force chief of staff, Gates said his decision was based mainly on the findings of a review of the Air Force's nuclear weapons mission by Navy Adm. Kirkland Donald, following two nuclear-related slip-ups.

The Donald report detailed the mistaken shipment to Taiwan of four Air Force electrical fuses for nuclear missile warheads. It also linked the underlying causes of that error to another startling incident: the flight last August of a B-52 bomber that was mistakenly armed with six nuclear-tipped cruise missiles. Donald concluded that the Air Force had let its nuclear focus deteriorate.