After two decades of groundbreaking contributions to aviation, Rolls-Royce has retired its Boeing 747-200 Flying Test Bed (FTB), registered as N787RR.
This uniquely modified aircraft, capable of operating with five engines, has been a cornerstone in developing advanced engines like the Trent 1000 and Pearl 10X since 2005.
Its retirement marks the end of an era but highlights the company’s ongoing commitment to sustainable aviation.
Boeing 747-200 FTB Final Flight
The FTB’s final mission in July 2025 supported the Advanced Low Emissions Combustion System (ALECSys) demonstrator, advancing Rolls-Royce’s efforts to create more efficient, eco-friendly engines.
Over its 20-year service, the aircraft logged more than 2,000 hours of testing, playing a pivotal role in pushing engine development boundaries.
John Knight, Director of Test & Experimental Engineering at Rolls-Royce, praised its legacy.
“The Flying Test Bed has been a workhorse for us, helping us innovate in engine development. While we bid farewell to this Queen of the Skies, we continue to advance testing through flying test beds, ground facilities, and digital modeling.”
Previous Test Highlights
Trent 1000 SAF testing
A standout moment came in 2021 when the FTB tested a Trent 1000 engine powered by 100% sustainable aviation fuel (SAF) during a nearly four-hour flight from Tucson, Arizona, over Texas and New Mexico.
The other three RB211 engines ran on standard jet fuel, and the test confirmed no engineering issues with SAF.
This flight was part of a broader program that certified all Rolls-Royce in-production engines for long-haul aircraft and business jets as compatible with 100% SAF.
This milestone made Rolls-Royce the first jet engine manufacturer to achieve this, supporting the aviation industry’s push toward sustainability.
The 2021 SAF test also paved the way for Virgin Atlantic’s historic 2023 transatlantic flight. This became the world’s first flight using 100% SAF on a Trent 1000-powered Boeing 787 Dreamliner.
This achievement underscored Rolls-Royce’s commitment to becoming a net-zero company by 2050 and helping customers reach similar goals.
The FTB’s work on the Trent 1000 also validated a durability enhancement package, significantly extending the engine’s time on wing.
Pearl 10X Engine Tests
Another notable chapter involved testing the Pearl 10X, the most powerful engine in Rolls-Royce’s leading Pearl family for business aviation.
Designed exclusively for Dassault’s Falcon 10X, the Pearl 10X required a custom pylon to mount on the FTB’s starboard wing alongside two RB211 engines.
The port wing carried a third RB211 and a Trent 1000, creating the aircraft’s distinctive five-engine configuration.
During tests, pilots controlled the RB211s and Trent 1000 from the cockpit. Meanwhile, a dedicated Pearl 10X operator on the engineering deck managed that engine, maintaining constant communication with the flight crew.
This setup showcased the aircraft’s flexibility and the ingenuity of Rolls-Royce’s teams and partners.
Conclusion
As Rolls-Royce retires the iconic Boeing 747 FTB, it continues to innovate through a combination of advanced testing methods.
The company’s focus remains on developing sustainable, high-performance engines to meet the aviation industry’s evolving needs.
The FTB’s legacy as a pioneer in engine testing will inspire future advancements, ensuring Rolls-Royce remains at the forefront of aviation technology.
