Aviation Partners
| Company type | Private |
|---|---|
| Industry | Aerospace |
| Founded | 1991 |
| Founder | Dennis Washington, Joe Clark |
| Headquarters | Seattle , United States |
| Products | Winglet systems for aircraft |
| Owner | The Washington Companies |
Aviation Partners Inc. (API) is a privately held company located in Seattle, specializing in innovative winglet systems designed to boost aircraft performance. Established in 1991, the firm is under the ownership of The Washington Companies.
History
The inception of API traces back to entrepreneur Dennis Washington and aviation specialist Joe Clark, who assembled a group largely composed of former engineers from Boeing and Lockheed. Leading the aerodynamic design efforts was Dr. Louis "Bernie" Gratzer, a seasoned Boeing engineer, serving as senior vice president.
In pursuit of extending his private jet’s operational range without acquiring a new plane, Washington collaborated with Clark—co-founder of Horizon Air—to develop winglets that enhanced fuel efficiency and increased range by 4–5%. With endorsement from Gulfstream Aerospace, they conducted successful testing and validation, initiating a campaign that established several performance milestones.
By 1997, API’s winglets had become standard equipment on all Boeing Business Jet models and were available as options for conventional 737 aircraft, securing approximately 95% of the 737 market share. That same year, API launched Aviation Partners Boeing (APB), a joint venture created to license Blended Winglet Technology for Boeing airframes. APB’s winglets have been installed as original equipment on the Boeing 737 Next Generation series and retrofitted onto 737 'Classic' (-300 and -500), 757, and 767-300ER aircraft.
API also achieved certification for winglets on the Hawker 800 series jets, with over 100 units outfitted by 2008. At EBACE 2007, API collaborated with Dassault Aviation to introduce High Mach winglets on the Falcon 2000 LX—the first production aircraft to feature this new API design. Subsequent FAA certifications extended to Falcon models through 2011.
Between 2006 and 2011, API worked alongside Airbus on modernizing the A320 family; however, Airbus ultimately developed its own "sharklets" design and initiated legal action in Texas in 2011 contesting API’s patent rights. The dispute concluded in 2018 with Airbus making a significant financial settlement to API.
By 2009, API’s winglet technology had expanded to include Boeing 757s, 767s, and various business jet platforms. The company is further developing Spiroid winglets—a closed-loop wingtip design tested on a Gulfstream II—that offers potential fuel savings exceeding 10% during cruise phases.
APB’s Split Scimitar Winglet retrofit program upgrades existing 737NG winglets by adding aerodynamically refined tip caps and ventral strakes, achieving around a 2% reduction in drag. FAA supplemental type certifications for these modifications were awarded between 2014 and 2015 across multiple 737 variants including the BBJ2.
The Split Scimitar Winglet system is estimated to enable airlines operating a 737-800 to conserve over 45,000 gallons of jet fuel annually per aircraft while reducing carbon dioxide emissions by roughly 476 tons. These improvements also allow for an increased payload capacity up to 2,500 pounds or an extended flight range of approximately 75 nautical miles. Additional enhancements in low-speed handling benefit operations from airports with high elevations or obstacle constraints. The first European installations took place in 2014 on TUI aircraft at Stansted Airport through Chevron Technical Services Ltd.