Source: United States Navy
An F-35B Lightning II fifth generation strike fighter conducted compatibility and envelope expansion testing with the U.S. Air Force’s newest tanker aircraft, the KC-46A Pegasus, in October 2021. The test not only proved that the systems worked together, but that they worked at the limits of each aircraft’s flight envelopes.
The F-35 Integrated Test Force (ITF) team used data from previous tests on similar tankers to streamline their approach. This allowed them to start testing further into the envelope limits of both the F-35 and the KC-46A. Typically, testing is done incrementally starting with a clean aircraft, one that has no extra weight in its configuration, and then moving step-by-step to the maximum load the aircraft will carry. Since data was available for many of those configurations, the ITF immediately went to the highest weight and furthest edge of the respective aircraft’s aerial refueling envelope to begin testing. Leveraging the near identical flying qualities in the aerial refueling envelopes of the F-35B short takeoff vertical landing (STOVL) and F-35C carrier variants allowed the team to clear both for KC-46 operations without requiring a repeat of every single point. This approach drastically cut the time and money required to complete the evaluation and push clearance to both the F-35B and F-35C fleets. In total, only five flights were required, with the last occurring in early November 2021. The team released the full flight clearance in January 2022.
This type of streamlined approach to flight test is one of the many benefits of joint programs like the F-35. Although demonstrated on what is typically considered a simple mission set in modern aerial warfare, the attitude and professionalism exhibited by both the KC-46 and F-35 test teams demonstrated that despite the challenges and often long timelines inherent to the acquisition process, a properly motivated team can clear those hurdles and deliver a solid product and capability to the warfighter in a timely manner.