Construction number 19651 was the 16th 747 built at Boeings Everett Washington Plant. This 747 was fitted with four Pratt & Whitney JT90-7A engines and made its first flight on March 3, 1970.

On March 21,1970 Boeing delivered its 25th 747 to Pan American Airways. Pan Am registered the 25th 747 as N744PA, it named the new 747-121 the "Clipper Star of the Union" and later re-named it "Clipper Ocean Spray". In June 1981, because of the high inflation of the late 1970's Pan Am hit hard times and sold the Boeing 747 to the Wilmington Trust Company. Pan Am leased the aircraft back from Wilmington Trust. In 1991 Pan American airlines went bankrupt and Wilmington Trust company re-possessed the Boeing 747 aircraft from Pan Am.

On March 9,1992 the former Pan Am Boeing 747-121 was registered to General Electric Aircraft Engines (GEAE) at the Mojave Airport in Mojave, California. At the Mojave Airport General Electric removed all passenger coach seating from the former Pan Am 747 and installed three engine data-gathering systems. General Electric strengthened the 747-100 airframe to allow it to be capable of flying 747-300 type maneuvers, needed for high - inlet - angle, fan - stress and inlet - stability testing. GEAE would attach the test engine to the number two engine pylon located on the aircrafts left wing. Some of the engines that GEAE wanted to test on the test bed were bigger and heavier then the Pratt & Whitney JT9D-7A engines originally installed on the 747. So to test bigger and heavier engines with a higher thrust level, GEAE reinforced the center fuselage and the left wing of the aircraft. GEAE also rebuilt section 41 on the forward fuselage of the aircraft because it was a common weak spot on all Boeing 747-100 airframes. The new customized 747 test bed, unlike other older and smaller GEAE test beds can process all of the test information aboard the aircraft during flight.

The GE90 made its first flight on the test bed in December 1993. The GE90 is used on such airframes as the Boeing 777-200, 777-200ER, 777-200LR 777-300ER, 777-Freighter and some Boeing 767's.

In 2002 General Electric Aircraft Engines Purchased the Boeing 747-121 it was leasing from Wilmington Trust, GEAE now owned the test bed.

GEAE's next new ground braking engine would be the GEnx engine, which was based off the GE90 with its composite technology. Before the GEnx engine could be used on the GEAE test bed, the test bed had to be upgraded. GEAE moved the home of the GEAE test bed from the Mojave Airport in Mojave, CA to Southern California Logistics Airport in Victorville, CA. GEAE built a new $15 million dollar 161,700sq.ft hangar facility to store the 747 test bed and the site is also used for engine research. The facility opened in 2004 and began upgrading the flying test bed to handle the GEnx engine. Electrical work was needed to supply the GEnx engine with sufficient power for starting, the electrical work was completed in January 2007. On February 22,2007 the GEAE GEnx engine made its maiden flight on the Boeing 747 test bed. Two GEnx flight test programs were conducted using the 747 flying test bed, the GEnx-1B program and the GEnx-2B program. The GEnx-1B will be used on the new Boeing 787 Dreamliner and the GEnx-2B will be used on the new Boeing 747-8 Intercontinental and Freighter aircrafts. The GEnx engine has also been ordered for the Airbus A350. Nine GEnx test engines were used on the flying test bed for flight testing. GEAE used the flying test bed to test fly the GEnx engine three times a week for three months to test and evaluate the engine GE tested air re-starting, combustor operations margins, throttle, response's, nacelle and undercowl cooling.

Hot day testing was tested at Yuma, Arizona, General flights were flown out of Victorville, California and high - altitude take off flights were flown out of Colorado Springs, Colorado.

Flight testing on the GEnx-1B was completed after four months and 187 test flight hours, in June 2007. The GEnx-2B engine was tested on the GEAE test bed during 2008, the program was made up of five engines and will concluded in early 2009.

GEAE also tested an oddball engine on the 747 test bed in 2003-2004 it was the GEAE CF34-10 engine, it made total of 23 flights on the test bed. this was a small engine, compared to other engines tested on the test bed and is employed on the ARJ21 regional jets.

The GEAE 747 flying test bed is one of the most high tech test beds for engine testing in the industry and will continue test GEAE and other engines out of GEAE's Victorville facility for years to come.