Aero-Cert LLC

To require a function and reliability test purely on the basis of the type of powerplant is flawed. Hopefully, the day is not far away when there will be a small turbine suitable for a typical single-engine, general aviation aircraft. This rule would force this aircraft to have to comply with the new requirements, despite the fact that in all likelihood, the turbine would be far more reliable and simpler to operate than a piston engine of similar power. The issues that should drive the need for function and reliability tests are performance and the kinds of operations in which the aircraft will be used. The Eclipse 500 was intended for use at higher flight levels, into known icing and at relatively high Mach numbers. Therefore, the Eclipse required sophisticated systems. Add onto that the fact that this manufacturer elected to design its own avionics and the justification for function and reliability testing becomes justifiable. To use this example as a reason for a blanket ruling for all turbine aircraft would be a mistake. I suggest that if an aircraft has an MMO higher than Mach 0.6, a maximum operating altitude above 25,000 ft, is pressurized and is approved for flight into known icing, then function and reliability should be required, regardless of the type of powerplant.