The Federal Aviation Administration has found some "fairly serious slips" in quality-control procedures at McDonnell Douglas Corp.'s Long Beach, Calif., aircraft production plant, the FAA said yesterday.

Anthony J. Broderick, the FAA's associate administrator for regulation and certification, said the problems were found early in the manufacturing process and did not involve any of the company's existing jetliners. He said the company was "very responsive" and top management moved "very promptly" to correct the problems.

"We thought the problems we found are serious," Broderick said. "We were pleased with the response."

The Los Angeles Times disclosed the audit in a report based on an internal McDonnell Douglas memo. The memo, according to the Times, warned workers that the FAA audit is "no joke," and unless the company improves, the FAA will revoke the company's certification to build jetliners or impose a heavy fine.

According to the memo, the FAA found the company was using out-of-date blueprints, had performed unauthorized repairs on aircraft, was using unapproved tools, and the condition of parts on the factory floor was poor.

A company spokesman emphasized that the audit did not involve product quality. "It did uncover some areas where we need to make some system improvements, and that's good," the spokesman said, adding that many of the problems involved employee efforts to perform a task better while failing to obtain proper certification of a new tool or procedure.

The spokesman said the memo -- actually a copy of slides used by a manager to motivate his employees -- was overstated, and "we have every belief we're going to settle this on the administrative level."

The audit, called a quality assurance system review, was performed Jan. 22 to Feb. 8, and the FAA is scheduled to return later for a reinspection. "We must pass," the company memo said. "It's our future."

Broderick, while not enumerating the problems found by inspectors, said, "We did find some fairly serious slips in McDonnell Douglas quality control. There are a number of areas where we found a breakdown in the system."

Broderick said the problems did not have an effect on safety, and that, to be fair, the FAA holds "world class" manufacturers like McDonnell Douglas to high standards. "When you do inspections like McDonell Douglas, Boeing, Pratt & Whitney -- that class of operation -- we go in expecting we are going to find near perfection," he said.

McDonnell Douglas has been a company in turmoil since a 1989 decision to require all managers to resign and reapply for their old jobs. The ill will created by that decision, coupled with manufacturing problems in the new MD-11 jetliner, has affected morale throughout the company.