Federal Aviation Administration March 30, 2006 – Federal Register Recent Federal Regulation Documents

The FAA is revising an earlier proposed airworthiness directive (AD) for all Gulfstream Model GV and certain Model GV-SP series airplanes. The original NPRM would have required a one-time inspection of the left and right aileron and elevator actuators to determine the part and serial numbers of each actuator, repetitive inspections of suspect actuators to detect broken damper shafts, and replacement of any actuator having a broken damper shaft. The original NPRM would also have required that operators report any broken damper shaft they find to the FAA. The original NPRM would also have provided an optional terminating action for the repetitive inspection requirements of the proposed AD. The original NPRM resulted from reports of broken or cracked damper shafts within the aileron and elevator actuator assemblies. This action revises the original NPRM by proposing to mandate the previously optional terminating action. We are proposing this supplemental NPRM to prevent broken damper shafts, which could result in locking of an aileron or elevator actuator (hard-over condition), which would activate the hard-over protection system (HOPS), resulting in increased pilot workload and consequent reduced controllability of the airplane.

The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 777 airplanes. This proposed AD would require, for the drive mechanism of the horizontal stabilizer, repetitive detailed inspections for discrepancies; repetitive lubrication of the ballnut and ballscrew; repetitive measurements of the freeplay between the ballnut and the ballscrew; and corrective action if necessary. This proposed AD results from a report of extensive corrosion of a ballscrew in the drive mechanism of the horizontal stabilizer on a Boeing Model 757 airplane, which is similar in design to the ballscrew on certain Model 777 airplanes. We are proposing this AD to prevent an undetected failure of the primary load path for the ballscrew in the horizontal stabilizer and subsequent wear and failure of the secondary load path, which could lead to loss of control of the horizontal stabilizer and consequent loss of control of the airplane.

The FAA adopts a new airworthiness directive (AD) for certain Cirrus Design Corporation (CDC) Models SR20 and SR22 airplanes. This AD requires you to inspect the fuel line and wire bundles for any chafing damage; replace any damaged fuel line and repair any damaged wires or sheathing of the wire harness if any chafing damage is found; and install (to prevent any chafing damage to the fuel line and wire bundles) the forward loop clamp, fuel line shield, aft loop clamp, and anti-chafe tubing. This AD results from reports of fuel line leaks resulting from wire chafing on the fuel lines. We are issuing this AD to detect, correct, and prevent damage to the fuel line and wire bundles, which could result in fuel leaks. This failure could lead to unsafe fuel vapor within the cockpit and possible fire.

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-301, -311, and -315 airplanes. This AD requires replacing the pressure control valve of the Type 1 emergency door. This AD results from reports that the pressure control valve of the Type 1 emergency door is susceptible to freezing. We are issuing this AD to ensure that the pressure control valve does not freeze and prevent the door seal from deflating, which could result in the inability to open the door in an emergency.

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires repetitive general visual inspections for dirt, debris, and drain blockage and cleaning of the aft fairing cavities of the engine struts; and modification of the aft fairings, which terminates the repetitive general visual inspections. This AD results from a report indicating that water had accumulated in the cavities of the engine strut aft fairings. We are issuing this AD to prevent drain blockage by debris that, when combined with leaking, flammable fluid lines passing through the engine strut aft fairing, could allow flammable fluids to build up in the cavity of the aft fairing, and consequently could be ignited by the engine exhaust nozzle located below the engine strut, resulting in an explosion or uncontrolled fire.