The FAA has issued a Notice of Proposed Rulemaking (PDF) that could significantly complicate the certification process for several small jets currently in development and future aircraft weighing less than 6,000 pounds with turbine engines. The FAA is proposing that all turbine-powered aircraft be put through function and reliability tests. Function and reliability testing is real-world testing of airframes and engines in the full spectrum of weather, missions and flight envelopes the planes are expected to encounter in service and is designed to catch snags that tend to show up soon after the aircraft are put into service. It can add as much as 300 hours to the certification flight testing. In 1950, the FAA exempted aircraft weighing less than 6,000 pounds from that type of testing since the small aircraft of the day were aimed at the private market and were exclusively powered by piston engines. New piston designs weighing less than 6,000 pounds and gliders will continue to be exempt. In the NPRM, the FAA cites problems with freshly certified Eclipse 500 aircraft as part of the foundation for the proposed rule. “This reconsideration was driven in part by difficulties encountered with the voluntary application of the requirement during the FAA type certification of the [Eclipse 500] and the subsequent problems experienced during that airplane’s entry into service,” the NPRM states.
The FAA says it likely would have spotted five problems that developed with the Eclipse if they’d done the function and reliability tests, including pitch and rudder trim issues, pitot system moisture trap, engine surges caused by carbon buildup on the static vanes, brake problems and tire problems. The comment period for the rule ends July 8. The rule, if made final, would affect Piper, Cirrus and Stratos jet programs. Diamond’s D-Jet is being certified in Canada so the effect is less clear. Calls placed to Piper and Diamond were not immediately returned.
