The FAA has issued a notice of proposed rulemaking (NPRM) that would revise the requirement for function and reliability (F&R) flight testing to include turbine-powered airplanes with an mtow of less than 6,000 pounds. The requirement adds significant costs to certification of new airplanes and is a threshold that the Eclipse 500 VLJ was able to remain under when it was certified. New single-engine jets under development also would fall under the 6,000-pound threshold. While these jets currently are not required to undergo F&R flight testing, “The FAA has determined that most, if not all, of these airplane designs would benefit from the F&R flight testing requirement.” In explaining the need to change the rule, the FAA citied the Eclipse 500 certification program. A requirement for 150 to 300 hours of F&R flight testing, the FAA noted, “might have preventatively identified problems encountered by the EA-500 when it entered into service.” These included pitch and rudder trim problems, pitot system moisture trapping, engine surges and brake and tire problems. The new rule would exempt gliders and piston-powered airplanes. Comments are due by July 8.