Federal prosecutors, in a stinging attack on the Air Force, have argued for debarment of Northrop Corp. from doing business with the government, and strongly recommended vigorous new Air Force tests to ensure that no faulty Northrop parts are installed in nuclear missiles, according to documents released on Capitol Hill yesterday.

The sharp rebuke followed a review of the service's proposed guidelines for an administrative settlement with Northrop, after the defense contractor pleaded guilty last spring to 34 counts of falsifying tests on key components of the nuclear-armed, air-launched cruise missile and the Marine Corps Harrier AV-8B jet and other charges.

"This is the first time we are aware of in which a major defense contractor has been convicted of failing to conduct critical tests on a nuclear weapon system," wrote three U.S. attorneys who prosecuted the criminal cases against Northrop in a Los Angeles court last spring. "If any case cries out for debarment, this is the case. If ever the American people deserve to be protected from the type of reckless and potentially life-threatening conduct, this is it."

The Air Force proposal, which listed recommendations for retesting the components of the air-launched cruise missile (ALCM) and other guidelines for dealing with Northrop "appears in many ways to allow Northrop to occupy the driver's seat in what should be the continuation . . . of an adverse action against it," the prosecutors wrote.

An Air Force public affairs official said yesterday that Northrop's Precision Products Division, which was responsible for the faulty testing, remains under suspension.

A Northrop Corp. spokesman said, "We as a corporation did what any responsible company would do when we found out about this {the testing fraud}. We fired the plant manager and three other employees and closed the plant down and moved the work."

The Justice Department letter was released by the House Committee on Energy and Commerce panel on oversight and investigations which is holding hearings on a series of issues involving Northrop Corp.

The Justice officials suggested that Air Force guidelines for retesting the questionable cruise missile parts were too lenient and said the service should demand that the parts be tested in a "worst case scenario." The authorities said the rationale for subjecting the weapon parts to tougher requirements "is to assure the Air Force that each {unit} will perform as required."

The authorities also recommended that the Air Force subject the entire corporation, not only its Precision Products Division, to stringent ethics and reporting standards.

Other Justice Department officials, in testimony prepared for today's congressional hearing on Northrop, said the Navy lowered test requirements twice so that Northrop-built components of the Harrier warplane could pass the tests.

"These successful attempts by Northrop to modify contract requirements . . . which Northrop knew were the subject of our investigation were highly damaging to our ability to prosecute," said Deputy Assistant Attorney General Mark M. Richard in prepared testimony. "Northrop's efforts continued after it was indicted."