In an effort to bring propeller and engine control systems certification up to date and harmonize U.S. and European standards, the Federal Aviation Administration is revising the airworthiness standards for the issuance of original and amended type certificates. In twin proposed rulemakings, the FAA is calling for comments on the propeller standards by June 11 and the engine control rule by July 10.
“The existing propeller requirements do not adequately address the technological advances of the past 20 years,” said the preamble to the proposed prop rule. “The proposed standards address the current advances in technology and would harmonize FAA and European Aviation Safety Agency (EASA) prop certification requirements and simplify airworthiness approvals for imports and exports.”
The proposed changes result from an effort that began in 1994, said the FAA, adding advances in technology have meant that many propeller certification programs over the past decade have required repeated application of special conditions or special tests. In addition, the need to demonstrate compliance with both FAA and EASA requirements has placed additional burdens on propeller manufacturers who require foreign certification.
Only one part of current FAA propeller certification rules is more stringent than its EASA counterpart and that is the bird strike capability. Consequently, the FAA proposes to extend the current special condition four-pound bird strike test for composite propeller blades rather than adopt the 2.8-pound bird strike for equivalent part 23 commuter airplanes and lack of requirement for a bird strike test for other equivalent part 23. The cost would be minimal said FAA, which estimated the cost at $458,000or $213,000 in present value (seven percent discount rate) for 635 future propellers.
As for the engine control systems the proposed changes “reflect current practices and harmonize FAA standards with those recently adopted by EASA.” They would establish uniform standards for all engine control system for aircraft engines certificated by both U.S. and European countries.
Propellers: Docket No. FAA 2007–27310; Notice No. 07–04
Engine Control Systems: Docket No. FAA–2007–27311; Notice No. 07–03