The Federal Aviation Administration yesterday ordered a special inspection of Boeing Co. after a series of quality-control problems, including improperly tightened bolts and use of material that failed to meet flammability standards.

Beth Erickson, the FAA's director of aircraft certification, said the FAA has determined that the problems do not represent a safety hazard and "these issues appear to be isolated." But she said a special eight-member FAA team will determine whether the problems go deeper and will recommend corrective action.

Erickson said she could not say whether the three-month inspection will result in production slowdowns at three Boeing plants in Everett, Renton and Auburn, Wash., because "their ability to deliver aircraft is a secondary issue for us."

The federal inspection is an embarrassment for Boeing, which is locked in a worldwide battle with the European consortium Airbus Industrie to be the top manufacturer of commercial airliners, a position held for decades by Boeing but which Airbus appears to be slowly winning. Boeing, the only major airliner manufacturer in the United States, is responsible for a huge chunk of the United States' balance of trade.

Erickson said major manufacturers such as Boeing undergo full comprehensive inspections every two years. Unscheduled special inspections may be called at any time if accidents or other unusual problems raise FAA concerns, she said.

In this case, four incidents prompted the special inspection, all of them reported to the FAA by Boeing:

* American Airlines mechanics discovered 16 improperly tightened bolts in a Boeing 767 tail section. Erickson said Boeing had determined that an incorrect torque wrench had been used because of a difference between Boeing requirements and the work instructions given to workers.

* Drip shields, which form a condensation barrier to keep water out of cockpit electronics, did not pass flammability tests in a number of planes and were improperly applied with adhesive. Delivery of 34 new 747, 757, 767 and 777 model jets were delayed to ensure that the drip shields were assembled correctly.

* Fiber glass ducts that carry heating and air conditioning through the passenger cabins were applied with too much adhesive, leaving them unable to pass flammability tests.

* Fuel-cell doors, which provide access to fuel tanks, were cleaned with a new type cleaning fluid after the Environmental Protection Agency banned use of the former cleaning fluid. But a corrosion inhibitor did not bond well to the doors after use of the new fluid, and it began flaking off and showing up in fuel filters.

Sue Bradley, a Boeing spokeswoman, acknowledged the inspection was a public relations problem. "Certainly the visibility of all these unrelated issues surfacing at once has not been the easiest of situations," she said. "But . . . we accept the responsibility. We can't afford to lose the confidence of the customer and the flying public."

The FAA last year ordered a narrowly focused inspection of Boeing after the 1997 crash of a Silkair Boeing 737 jet, when some bolts were discovered missing in the wreckage; later it was determined they popped off because of the crash, not before it.

Erickson said this time a team of inspectors, drawn from the FAA's Northwest Mountain Region and the New England Region, would examine the company more broadly, paying close attention to whether Boeing's procedures comply with FAA rules and FAA-approved Boeing procedures. She said they will also delve into engineering and manufacturing processes, parts-receiving procedures, how the company handles engineering changes and how they are implemented.

Erickson emphasized that all the problems were reported to the FAA by Boeing. "These issues appear to be isolated slips at this point," she said. "But we need to understand the root causes," including whether Boeing is suffering from some systemic problem.

She said that none of the problems had resulted in an incident or an accident, and "there's no immediate safety concern."