FAA administrator J. Randolph Babbitt revoked the licenses Tuesday of the two Northwest Airlines pilots who said they were distracted by laptops when they flew 150 miles past the Minneapolis International Airport before circling back to land.

Air traffic controllers lost radio contact with Northwest Flight 188, carrying 147 passengers, for 90 minutes Oct. 21. Controllers and airline dispatchers repeatedly tried to reach them through radio and data contact, without success. The agency cited the pilots for ignoring air traffic control instructions and "operating in a reckless manner that endangered the lives and property of others."

"The confidence in the aviation system in our country demanded FAA take the action they did," said Jim Hall, a former chairman of the National Safety Transportation Board. "What the pilots did obviously breached aviation safety and aviation security and reflects badly on the professionalism of fellow pilots."

In interviews Sunday, the pilots told NTSB investigators that they lost track of time because they were involved in a "concentrated period of discussion" about the company's pilot scheduling system. Co-pilot Richard Cole of Salem, Ore., told NTSB investigators that he was explaining the system to the plane's captain, Timothy Cheney of Gig Harbor, Wash.

In congressional testimony and speeches before pilots' groups, Babbitt repeatedly has spoken about the need to restore pilot professionalism. Babbitt is a former president of the Air Line Pilots Association, the world's largest pilot union.

Babbitt's comments about professionalism generally have come in response to questions about the February crash of a commuter plane in Buffalo that killed 50 people. NTSB investigators so far have exposed evidence that the plane's captain had concealed past flight test failures. They also found that the co-pilot hadn't made arrangements to get proper sleep before the flight despite undertaking a cross-country, red-eye commute to work. The flight was contracted out by Continental Airlines to Colgan Air, a regional airline.

In separate letters to the two Northwest pilots, the agency stated the FAA administrator "finds that you lack the qualifications necessary to hold an Airline Transport Pilot certificate."

Even with the FAA license revocations, the Northwest pilots remain under intense scrutiny, and the incident is still under investigation by the NTSB. Agency investigators interviewed the pilots for five hours Sunday. Delta, which merged with Northwest last year, has suspended the pilots until the investigations are completed.

The pilots have 10 days during which they can appeal the revocation, issued under an emergency order.

In a statement Monday, Delta said using laptops in the cockpit is against the airline's policies and vowed to terminate pilots for the infraction.

"The flying public right now is dealing with fewer flights, higher costs, having to pay for baggage," Hall said. "I think they certainly should expect a better performance out of the airline and the pilots than we see here."