Federal Aviation Administration October 18, 2005 – Federal Register Recent Federal Regulation Documents

These special conditions are issued for the Gulfstream Aerospace Limited Partnership (GALP) Model G150 airplane. This airplane will have a novel or unusual design feature associated with use of a hydrophobic coating, rather than windshield wipers, as the means to maintain a clear portion of the windshield during precipitation conditions, as required by the airworthiness standards for transport category airplanes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This notice announces the availability of and requests comments on a proposed advisory circular (AC) that sets forth acceptable methods of compliance with 14 CFR part 25, Appendix H, section H25.5(a)(1). This proposed AC complements revisions to the airworthiness standards that are being proposed by a separate notice. This notice is necessary to give all interested persons an opportunity to present their views on the proposed AC.

The FAA proposes to supersede an existing airworthiness directive (AD) for certain RRC 250-B and 250-C series turboshaft and turboprop engines. That AD currently requires a onetime inspection of the fuel nozzle screen for contamination, and if contamination is found, inspection and cleaning of the entire aircraft fuel system before further flight. That AD also requires replacing the fuel nozzle with a new design fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first. This proposed AD would require the same actions, but would add additional part numbers (P/Ns) to the list of affected fuel nozzles. This proposed AD would also explain that the existing AD, as worded, allows certain part number (P/N) fuel nozzles back into service. Those fuel nozzles must not be allowed back into service. This proposed AD results from the discovery that several P/Ns of fuel nozzles were inadvertently left out of AD 2004-24-09. We are proposing this AD to minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.