FAA Certifcation of The Liberty Xl2

Leo G. Janssens, Liberty Aircraft Company, Melbourne, FL, USA
Jason Russell, PhD. Chief Engineer, Liberty Aircraft Company, Melbourne, FL, USA

Abstract

Both ground tests and flight tests of the Liberty XL2 have been completed for FAA certification under FAR Part 23 for small (under 12,500 pounds) aircraft. The Liberty XL2 design is based on a derivative the very successful experimental “kit airplane” called the Europa. Aircraft builders worldwide bought over 900 glass fiber Europa kits since they were first introduced in 1994. The derivative Liberty XL2 is a light two place, fixed tricycle gear, 125 HP, aircraft with a maximum design gross weight of 1653 pounds and a full flaps stall speed of 43 knots calibrated airspeed.

The Liberty XL2 is designed for construction under the “modular concept” whereby the Liberty Aircraft Company, Melbourne, FL, will essentially assemble the aircraft components shipped in by their suppliers. The “specially designed” high lift wing is of all aluminum construction. The fuselage and vertical fin components are made of molded carbon fiber. The four-cylinder engine, equipped with FADEC (Full Authority Digital Engine Control) is supplied by Teledyne Continental Motors. The wooden, fixed pitch, propeller is supplied by Sensenich. The aircraft is equipped with “finger brakes” instead of the conventional “toe brakes” normally located on the rudder pedals. The flight test aircraft was also equipped with a mechanical spin chute, specially designed by the Strong Parachute Company, Orlando, FL.

This paper will describe portions of the Liberty XL2 ground and flight test programs that began in February 2003 which led to certification in February 2004. For FAA certification, over 250 hours of performance and handling qualities flight tests have been completed. This amount includes 213 one-turn spins. The flight test program was completed under the guidelines of FAA Advisory Circular 23-15 which is intended to be less “burdensome” for certification by manufactures of light, non-complex aircraft.