On its 20th flight, the first F-35 Lightning II successfully
tested engine performance and aircraft handling qualities at up to
20,000 feet as pilots and crew prepare for air refueling in the
coming weeks. Shortly afterward, a dedicated test-bed aircraft
began final check-out flights for airborne testing of the Lightning
II's Communication-Navigation-Identification system, initiating a
test program that will ultimately integrate and fly the complete
F-35 avionics package.