Boeing 747-400

Quad Jet

The Boeing 747-400, introduced in 1989, revolutionized long-haul aviation as the first widebody to feature winglets and a two-crew glass cockpit, eliminating the flight engineer position that defined earlier 747 variants. With a range exceeding 7,200 nautical miles and seating for up to 416 passengers in typical three-class configurations, the 747-400 became the backbone of intercontinental travel for three decades and remains the most successful 747 variant ever built, with 694 delivered before production shifted to the 747-8. The "Queen of the Skies" cruises at Mach 0.85 and can reach altitudes of 45,100 feet, capabilities that allowed airlines to operate nonstop routes previously requiring fuel stops. Its distinctive hump houses the flight deck and a small upper cabin, though the B74S designation specifically denotes the shortened upper deck configuration. The type's four-engine redundancy and proven reliability made it the preferred choice for ultra-long routes like Los Angeles to Melbourne and New York to Hong Kong throughout the 1990s and 2000s. Pratt & Whitney Canada operates specially modified 747-400s as flying testbeds, mounting experimental engines on the aircraft to conduct high-altitude certification testing in real-world conditions. These testbed aircraft retain the 747-400's robust airframe and systems while serving as airborne laboratories, allowing engineers to validate new turbofan and turboprop designs at cruise altitudes and speeds that ground facilities cannot replicate. The testbed role represents one of the 747's many post-passenger-service careers, alongside cargo conversion and VIP transport. SkyMeter has tracked flights across airframes and operators, with the largest observed operator.