SAN FRANCISCO (AP) _ A Boeing 747 with author James Michener, actor John Travolta and other notables aboard took off Friday on a flight to the Philippines to commemorate the China Clipper's pioneering trans-Pacific journey half a century ago.

The Pan Am jumbo jet dubbed ''China Clipper II'' circled over San Francisco Bay, then headed westward ''smack over the Golden Gate Bridge,'' said airline spokesman Al Guthertz.

The 747, carrying 250 passengers, was to fly to Manila in 40 hours and 55 minutes, including an overnight stop in Honolulu. The old flying boats took more than six days, including stops, when Clipper service began in 1935.

The anniversary flight was to cover the same route the old Clippers used: California to Hawaii, then on to Midway Island, Wake Island, Guam and Manila.

The passenger list also included original Pan Am board Chairman C.V. Whitney, Charles Trippe, the son of Pan Am founder and President Juan Trippe; and four grandsons of aviation pioneer Charles Lindbergh.

Pan Am captured world attention when it began Clipper service on Nov. 22, 1935. Before then, the only way across the Pacific was by ship.

The anniversary brings Pan Am service to the Pacific full circle. The airline has sold its routes, except for Hawaii-mainland service, to United Airlines.

Although they would be dwarfed by the 747, the Martin M-130s like the China Clipper were the giants of their day. They had a wingspan of 130 feet and a length of 90 feet, and could carry 32 passengers and nine crew members. The sleek-hulled Clipper was the first plane with enough power to carry the equivalent of its weight in payload.

The planes could fly 3,200 miles non-stop at 130 mph. The first flight, piloted by Ed Musick, covered 8,210 miles in a flying time of 59 hours and 48 minutes. But overnight stops along the way made for a total travel time of 6 days, 7 hours and 46 minutes.

The trip cost $720, more than the price of a car at the time.

In 1935, more than 25,000 people turned out to watch the inaugural flight. Juan Trippe gave Musick his ''sailing orders'' and spoke by radio to operators at the Clipper's stops. Each operator barked an answering ''Ready 3/8''

The radio roll call was re-enacted Friday before the China Clipper II left for Honolulu.

The original Clippers exist only on film and in photos. By 1945, all had been lost to crashes and fires, including a 1938 fire that claimed Musick's life.