Piper Aircraft today said that the PiperJet proof of concept’s Williams FJ44-3AP engine was started and tested on June 19, describing the first on-ship run and subsequent operational tests as “flawless.” After the initial engine starts and operational checks were completed, the single-engine PiperJet moved forward under its own power for the first time. Piper test pilots have already begun low-speed taxi tests to verify controllability and authority of the nosewheel, which employs a direct-linkage steering system. Piper test pilots reported “light rudder pedal forces and excellent response” as the PiperJet prototype was maneuvered within the Vero Beach factory test ramp for the first time. The next major milestone in the countdown to first flight is high-speed taxi testing. During these tests, test pilots will accelerate to speeds just below liftoff to check for basic runway handling characteristics and elevator control authority. “After that, it’s on to the excitement of the first flight with performance verifications and handling characteristics testing to follow in an extensive flight-test program,” Piper said.