The general nominated to become the next Air Force chief of staff  favors preserving the production line for F-22 Raptor fighter jets  — a top priority for Lockheed Martin but  slated for closure.

During his nomination hearing on Tuesday, Gen. Norton Schwartz signaled he could support building more than 183 F-22s. He said 183 Raptors “is not the ceiling on the low end.”

The F-22 Raptor has been part of a rift over acquisition priorities between the Air Force and the Office of the Secretary of Defense, which has criticized the service for aggressively pursuing funds not requested in the president’s budget. The differences over funding contributed to the forced resignations of former chief of staff Michael Moseley and former Air Force Secretary Michael Wynne, although the two officials were mainly held accountable for a series of mishaps involving nuclear weapons and parts.

Defense Secretary Robert Gates wants the Pentagon to focus on weapons that serve ground forces, and does not believe more than 183 F-22s are needed. He argues they were designed to fight more of a conventional enemy instead of the insurgents the U.S. is fighting in Iraq and Afghanistan.

Contractor Lockheed Martin and its high-profile partners, including Boeing , however, want to keep the production line open beyond 2011, when the last of 183 F-22s are scheduled for delivery.

They and the Georgia and Texas delegations are pressing the Pentagon to green-light more F-22s, which are manufactured in the two states.

In its 2009 budget submission, the Pentagon did not request funding for more F-22s, but also did not ask for money to shut down the line. The Pentagon decision on the fate of the F-22 has been punted to the Congress and the next administration.

Moseley and Wynne were the F-22’s strongest champions within the Pentagon.

Sen. Carl Levin (D-Mich.) pressed Schwartz for his opinion on the future of the F-22, which has received increased attention from Congress after the intense lobbying by Lockheed and pressure from the Georgia and Texas delegations.

Schwartz, a Special Operations pilot and the first chief of staff nominee who has not been a fighter jet or bomber pilot, said the F-22 production line should be preserved “at least for the near term.” He also said he would carefully delve into previous studies that recommend the U.S. retain a range of 183 to 381 F-22s.

“I will be happy in being able to come back to the committee with my best recommendation on the total procurement for F-22,” Schwartz told the committee.

Schwartz stressed the F-22 is “an essential part of the force mix.”

“There are many who think that the F-22 was only an air-to-air platform,” he added. In fact, it has important capability for destruction of enemy air defenses in an era when surface-to-air missile threats are available from the commercial market and are increasingly lethal.”

Defense authorizers in both chambers proposed some additional funds for the F-22 to purchase advance items in case production goes beyond 2011.

Gates believes that buying more F-22s would come at the expense of the multi-service, multinational fighter known as the F-35 Lightning II Joint Strike Fighter, which is expected to be much cheaper than the F-22.

Schwartz told senators that the Air Force is planning to increase the production rate of the F-35 from 48 per year to as high as 110.

“It is the major strategy for addressing the inventory shortfalls as we go out toward 2025,” he said. The Air Force is expected to receive an additional $5 billion over a five-year period starting in 2010 to boost its aircraft recapitalization efforts.

Schwartz and Michael Donley, nominated to replace Wynne, both told lawmakers that they would work to restore confidence and trust in the troubled service.

Levin told the nominees that they have their “work cut out” for themselves, and pointed out that their jobs will be to fix “the underlying problems and not just the symptoms.”

Facing questions over the Air Force’s process in awarding a $35 billion mid-air refueling tanker contract to Northrop Grumman and EADS North America, Donley said that the Air Force acquisition system is “not fatally flawed.”

The Government Accountability Office (GAO) upheld rival Boeing’s protest of the contract, and now the Pentagon leadership is involved in the next effort to select a tanker — the Air Force’s No.1 priority.

The tanker protest is one of several major Air Force programs to be protested with the GAO within the last year. Donley said that there are “opportunities for improvement” in the Air Force’s acquisition system. He is planning two 90-day reviews, one internal and one external, of the Air Force’s acquisition process “to recommend opportunities for longer-term improvement,” Donley said in his prepared answers to the committee.