Pan Am confirmed the order for this aircraft, the airline's seventh, on July 09, 1977. This was the nineteenth Boeing 747SP to be constructed. Rolled out at the Boeing plant at Everett on April 20, 1978 it was powered by Pratt & Whitney JT9D-7A engines. Entered onto the United States Aircraft Register as N537PA it flew for the first time on May 05, 1978.

Accepted by Pan Am at Paine Field on June 09, 1978 the aircraft was named 'Clipper High Flyer' and was configured to seat 18 First Class, 62 Business Class and 164 Economy Class passengers. It was immediately deployed on Pan Am's routes around the world. On November 01, 1980 the aircraft was renamed 'Clipper Washington'.

In April 1985 Pan Am sold its entire Pacific Division (routes and aircraft) for $US 750,000,000 to United Airlines in an attempt to deal with its dire financial problems. Ownership of 'Clipper Washington' was transferred to United on February 13, 1986.

It was reregistered as N146UA on March 01, 1986 and by April 01, 1986 it had been repainted into the airline's 'rainbow' livery with small fuselage titles. It was observed at London's Heathrow Airport on October 22, 1993 wearing the revised larger titles. By February 01, 1994 N146UA had been withdrawn from service and stored at Oakland Airport, California.

On May 01, 1994 it was observed stored at Las Vegas in the basic United livery but with an all-white tail. It was then ferried San Francisco - Marana on January 01, 1996 where it was officially withdrawn from use. Sold to Air Liance Materials on July 30, 2001 it was prepared for scrapping. This had taken place by October 2003. 'Clipper High Flyer' had flown 70,184 hours with 9,220 cycles.