With a 99.97-percent dispatch reliability rate, Honeywell’s HTF7000 engine–which entered service in 2004–recently passed its 500,000-hour use mark. The Phoenix, Arizona-based engine and avionics maker, having since built nearly 500 of the engines, removed two of the highest hour units from service for detailed examination, as part of its Continued Airworthiness Program plan, to validate its on-condition maintenance philosophy and improve future engine designs.

The two engines, each with more than 5,000 hours, were given extensive performance checks and borescope inspections prior to removal. The pair were subjected to incoming test cell evaluations to determine what, if any, changes in baseline performance they had experienced. The engines were then disassembled and the components reviewed by Honeywell. It’s a process that will be repeated again and again over the next several years as the HTF7000 fleet reaches time-specific milestones. “With more than 30,000 hours of testing prior to entry into service, this propulsion system is delivering the level of reliability our customers told us they expected,” said Rob Wilson, Honeywell’s president of business aviation.
“While this achievement is rewarding, we continue development of new technologies making derivative HTF7000 engines even better values for future aircraft applications.”

The company continues to further its engine development with its Tech7000 new technology demonstrator, which it believes will help improve the standard set by the HTF7000 in terms of dependability and low maintenance. “From a quiet high-speed fan that is more efficient and reduces engine noise signature, to improved combustors, new engine coatings that improve durability and new alloy materials that will save weight and improve engine durability, are all technologies being tested,” said Ron Rich, Honeywell’s director of advanced technologies.

As part of its flight testing process, Honeywell purchased a Boeing 757 for use as an airborne testbed. “The knowledge gained during these flight tests leads to improvements in materials, processes and techniques, improving our HTF7000 family of engines, and stages us for successful future engine programs,” said Wilson.