Air Force Secretary James G. Roche and the service's senior weapons acquisition manager plan to resign before the start of the second Bush administration, senior Defense Department officials said yesterday.

Roche and Air Force assistant secretary for acquisitions Marvin R. Sambur were involved in the past three years in a scandal-ridden proposal to lease new fuel tanker aircraft for the Air Force from the Boeing Co. The lease program has been blocked by Congress, and two top officials from Boeing and the Air Force have pleaded guilty in federal court to ethics violations; related investigations are underway.

Defense Department spokesman Bryan Whitman said neither Roche nor Sambur was pushed and that both were leaving "on their own volition. . . . Both have served well." In a statement, Defense Secretary Donald H. Rumsfeld said Roche "led the Air Force during an important period in history. . . . I thank him for his service and wish him all the best."

Rumsfeld sought last year to shift Roche from the Air Force to the Army's top civilian post but ran into stiff opposition from lawmakers, including Sen. John McCain (R-Ariz.), causing Roche to withdraw his nomination. Yesterday, the Senate voted 85 to 12 to confirm Francis J. Harvey, a Maryland businessman, as the new Army secretary.

McCain, a member of the Armed Services Committee, has fiercely opposed the tanker leasing deal, calling it a costly government gift to Boeing; he has criticized Roche and Sambur for promoting the deal.

Internal Air Force e-mails reviewed by McCain have shown that Roche opposed conducting a mandated review of alternatives to the leasing deal. Sambur promoted a procurement strategy that the Pentagon's inspector general called "inappropriate" and unnecessarily risky.

In a statement Monday, following the guilty plea of former Boeing executive Michael M. Sears, McCain said "the conduct of the Air Force leadership in touting the 'merits' of this $30 billion deal requires further scrutiny. The chapter on the tanker lease proposal cannot be closed until all the stewards of taxpayer funds who committed wrongdoing are held accountable."

Roche, a 23-year Navy veteran and former Northrop Grumman Corp. executive, yesterday issued a statement highlighting his efforts to reform the Air Force Academy, which was beset by accusations of sexual harassment, and to supervise the development and production of a new generation of fighter planes -- the F/A-22 and F-35, which are to replace the F-15 and F-16.

Officials said the Pentagon's inspector general is reviewing a May 2003 e-mail exchange about the Boeing lease plan between Roche and Robin Cleveland, the Office of Management and Budget's national security chief, in which Roche offered to recommend Cleveland's brother for a position at Northrop Grumman. Northrop has said Cleveland's brother interviewed for a position but was not hired.

"Doctor Roche is confident that the IG will find nothing criminal or unethical in the course of their investigation," said William Nichols, an Air Force spokesman.

Sambur, an electrical engineer who was president and chief executive of defense work for ITT Industries Inc. of McLean, said in an interview last week, "I will tell you that I said at the beginning that one term would probably be it for me. This job takes a lot out of you."