Piper Aircraft reports that its PiperJet prototype is making progress, with the first engine start and run to “occur shortly.” Earlier this month, the Vero Beach, Fla.-based aircraft manufacturer finished all static load testing on the single-engine jet proof-of-concept airframe. These tests consisted of applying normal loads (+3.8g to -1.5g) to the airframe. The prototype has since been removed from the test fixture and is now standing on its own landing gear. However, the landing gear configuration used on this test aircraft is a conventional oleo design instead of the trailing-link gear planned for follow-on test and production aircraft. Meanwhile, the airplane’s Williams FJ44-3AP turbofan was installed in the vertical tail location, which Piper said results in better engine efficiency because air entering the intake is undisturbed and not subject to airframe interference. Workers are now finishing installation of the PiperJet prototype’s electrical and avionics systems, with first power-on tests expected to take place in the next week or so. Following this, Piper will start engine runs and then ground runs before first flight, which is expected to occur this summer.