Federal Aviation Administration November 2011 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for PW4000 series turbofan engines. This proposed AD would require replacing the fuel metering unit (FMU), part number (P/N) 50U150, at the next shop visit after the effective date of this proposed AD. This proposed AD was prompted by an engine overspeed event that occurred during taxi and resulted in a high-pressure compressor (HPC) surge and tailpipe fire. We are proposing this AD to prevent engine overspeed on these engines, which could result in an uncontained engine failure and damage to the airplane.

We are superseding an existing airworthiness directive (AD) for the engines identified above. That AD currently requires initial and repetitive visual inspections of the forward engine mount assembly side links for cracks, stripping and reapplying the Sermetel W coating on the side links at every exposure of the side link. This new AD requires those same inspections, stripping and reapplying the Sermetel W coating, and adds two part numbers to the applicability. This AD was prompted by a review of the inspection program, which revealed that GE had omitted two affected side link part numbers from the applicability. We are issuing this AD to prevent failure of the side links and possible engine separation from the airplane.

We propose to adopt a new airworthiness directive (AD) for all DASSAULT AVIATION Model MYSTERE-FALCON 900 airplanes. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

We are adopting a new airworthiness directive (AD) for Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series 900) airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

This amendment supersedes an existing airworthiness directive (AD) for Bell Model 205B and 212 helicopters with certain main rotor blade (blade) assemblies installed. That AD currently requires washing the upper and lower surfaces of each blade and visually inspecting the grip plates, doublers, and the remaining upper and lower surfaces of the blades in the area between blade stations 24.5 to 40 for an edge void, corrosion, or a crack. This amendment retains the requirements of that AD for the affected part-numbered blades but increases the scope and frequency of the inspections and expands the applicability to include the Model 205A-1 and 210 helicopters, additional blade part numbers, and all helicopter serial numbers for the affected helicopter models. This amendment also requires applying a light coat of preservative oil (C-125) to all surfaces of the blade in addition to the inspection areas as required in the existing AD. This amendment is prompted by an additional report of a fatigue crack on a blade installed on a Model 212 helicopter. The actions specified by this AD are intended to detect an edge void, corrosion, or a crack on a blade, and to prevent loss of a blade and subsequent loss of control of the helicopter.

This amendment adopts a new airworthiness directive (AD) for the specified Agusta model helicopters. This action requires inspecting certain modules and related connectors for corrosion. If there is corrosion on the connectors, this AD requires cleaning the connectors before further flight. If there is corrosion on a module, before further flight, this AD requires replacing the module with an airworthy module. This AD also requires modifying the Number 2 Modular Avionic Unit (MAU) ventilation duct. This amendment is prompted by some in- flight emergencies due to internal corrosion of the MAU circuit card assemblies. The actions specified in this AD are intended to detect corrosion of certain modules to prevent the display of misleading data to the flight crew, disengagement of the flight director modes of the autopilot or other alert system, increased workload of the flight crew, and subsequent loss of control of the helicopter.

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

This document proposes superseding four existing airworthiness directives (ADs) for the specified Bell model helicopters. Two of the existing ADs require an initial and repetitive inspection of certain part-numbered main rotor yokes installed on Bell Model 204B, 205A-1, and 212 helicopters. Two other existing ADs also establish a retirement life of 3,600 hours time-in-service (TIS) for certain part-numbered main rotor yokes installed on the Bell Model 204, 205 series, and 212 series helicopters. Those ADs were prompted by reports of cracks in the main rotor yoke (yoke). This action would retain the requirements of the existing ADs and would apply these inspections and retirement lives to additional part-numbered yokes. This action would also increase the inspection frequency for certain yokes installed on a Bell Model 205B or 212 helicopter and would require replacing any unairworthy yoke. This proposal is prompted by the need to expand the applicability to include yokes produced under a Parts Manufacturing Approval (PMA) whose design approval was based on identicality with the affected Bell yoke parts and a recent discovery of a cracked yoke. The actions specified by the proposed AD are intended to prevent cracking of a yoke, failure of the yoke, and subsequent loss of control of the helicopter.

We are adopting a new airworthiness directive (AD) for Rolls- Royce Corporation (RRC) AE 3007A, AE 3007A1/1, AE 3007A1, AE 3007A1/3, AE 3007A1E, AE 3007A1P, and AE 3007A3 turbofan engines. This AD requires initial and repetitive eddy current inspections (ECI) of certain 6th-through-13th stage compressor wheel knife edge seals, and initial and repetitive ECIs of the compressor wheel outer circumference, for cracks. This AD was prompted by reports of low-cycle fatigue cracks found during shop visits, in the 6th-through-13th stage compressor wheels having chrome-carbide coated or uncoated knife edge seals. We are issuing this AD to prevent uncontained failure of the 6th-through-13th stage compressor wheel, leading to damage to the airplane.

We are superseding an existing airworthiness directive (AD) for certain Model 737-300, -400, and -500 series airplanes. That AD currently requires repetitive inspections for cracking of the 1.04-inch nominal diameter wire penetration hole, and applicable related investigative and corrective actions. This AD reduces the compliance times for those actions. This AD was prompted by reports of cracking in the frame, or in the frame and frame reinforcement, common to the 1.04- inch nominal diameter wire penetration hole intended for wire routing; and recent reports of multiple adjacent frame cracking found before the compliance time required by the existing AD. Such cracking could reduce the structural capability of the frames to sustain limit loads, and result in cracking in the fuselage skin and subsequent rapid depressurization of the airplane. We are issuing this AD to correct the unsafe condition on these products.

We are adopting a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Model 525C airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires replacing certain lithium-ion batteries installed as the main aircraft battery with either a Ni-Cad or a lead acid battery. This AD was prompted by a report of a battery fire that resulted after an energized ground power unit was connected to one of the affected airplanes equipped with a lithium-ion battery as the main aircraft battery. We are issuing this AD to correct the unsafe condition on these products.