The Federal Aviation Administration announced yesterday that it is seeking to revoke the licenses of a People Express flight crew and has collected a $30,000 civil penalty from Pan American World Airways in air safety enforcement cases.

Spokesman Ed Pinto said the FAA charges that the People Express crew members flew "an unairworthy aircraft from Newark to Buffalo" last July 26. Pinto said the crew ignored vibrations that "severely shook" a Boeing 727 jet shortly after it left Newark. The vibrations occurred again before the plane landed at Buffalo, but the crew allowed passengers to board for the next flight.

The plane was taxiing out for a takeoff at Buffalo when two portions of the flaps on the left wing were discovered missing, Pinto said. Flaps extend from the rear of the wing to give a plane added lift at low speeds. They are customarily deployed for takeoffs and landings, and a loose or missing flap would cause vibration.

Pinto identified the crew members as Capt. Dale Morris Andrew, First Officer Thomas W. Dupree and Flight Engineer William D. Bella. They have until Feb. 14 to answer the complaint.

People Express spokesman Russell Marchetta said "the allegations by the FAA are not proven at this point. People Express and the crew members individually will contest them."

On Jan. 1, 1984, Pinto said, a Pan Am charter flight from Guadeloupe to New York carried 10 more passengers than seats. As a result, 20 passengers had to share seats and seatbelts and there were too few oxygen masks and life rafts available in case of emergency, he said.

The FAA has collected the $30,000 civil penalty from Pan Am and issued an order suspending for 60 days the license of pilot Frank C. Rice, who has appealed to the National Transportation Safety Board, Pinto said.

James Arey, a spokesman for Pan Am, acknowledged the penalty and said the matter "will be dealt with in due course."