Flight Testing of a New Ultralight Airplane for LTF-UL Certification

The present paper discusses the flight testing activities carried out in support of the development and type certification of a new Italian high-wing ultralight airplane. A structured approach to flight testing, employing a simple, complete and reliable instrumentation and involving accurate planning, execution and post-flight analysis led to significant results for design optimization and demonstration of compliance. In particular, the effect of static probe configuration, vortex generators on the fuselage above the cockpit, flap slot configuration, and elevator circuit arrangement have been investigated, leading to improvements in the aircraft behaviour in significant characteristics such as trimmability in level flight, stall behavior, take-off distance, and high-speed longitudinal static stability. Based on the flight test results, compliance has been demonstrated on a number of certification items, paving the way for the future request of the type certificate, to be issued upon completion of some limited modifications of the airframe and possible repetitions of some of the test already accomplished to date.