An F-35A Lightning II conventional takeoff and landing aircraft, known as AF-1, completed its final test mission for clean wing flutter recently.

Flutter testing was conducted to ensure the jet's structure could withstand various aerodynamic loads verifying the F-35A's design.

The mission, flown by Major Ryan “Gunner” Reinhardt, marks the conclusion of three years of testing that now allows the F-35A to proceed with tests continuing to expand its flight envelope and validate predictions in real-world scenarios.

The testing demonstrated the F-35 is clear of flutter, at speeds up to 1.6 Mach and 700 knots with weapon bay doors open or closed, critical to performing its combat mission.  

Data collected proves the F-35A flight dynamics maintains a large margin between its designed airspeed and airspeeds where possible flutter could occur.

The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, fifth generation multirole fighters under development to perform ground attack, reconnaissance, and air defense missions with stealth capability.

The F-35 has three main models; the F-35A is a conventional takeoff and landing variant, the F-35B is a short take off and vertical-landing variant, and the F-35C is a carrier-based variant.

The F-35 is descended from the X-35, the product of the Joint Strike Fighter (JSF) program. JSF development is being principally funded by the United States, with the United Kingdom and other partner governments providing additional funding. The partner nations are either NATO members or close U.S. allies. It is being designed and built by an aerospace industry team led by Lockheed Martin. The F-35 carried out its first flight on 15 December 2006.

The United States plans to buy a total of 2,443 aircraft to provide the bulk of its tactical airpower for the U.S. Air Force, Marine Corps and Navy over the coming decades.

The United Kingdom, Italy, Netherlands, Australia, Canada, Norway, Denmark, Turkey, Israel and Japan are part of the development program and may equip their air services with the F-35.