Department of Transportation May 23, 2006 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for certain Raytheon Aircraft Company Model 390 airplanes. This proposed AD would require you to inspect the spigot bearing, part number (P/N) MS14104-16, for the proper position in the spigot fitting assembly and to install the wing spigot bearing retainer kit, P/N 390-4304-0001. This proposed AD results from two reports of the spigot bearing not being positioned flush with the fitting assembly, but protruding outside of the fitting assembly. We are proposing this AD to detect spigot bearings that are not positioned flush with the fitting assembly. This condition could result in the spigot bearing becoming disengaged from the fitting assembly, which could cause motion between the wing and the fuselage and degrade the structural integrity of the wing attachment to the fuselage. This could lead to wing separation and loss of control of the airplane.

These special conditions are issued to Avidyne Corporation, 55 Old Bedford Road, Lincoln, MA 01773, for a Supplemental Type Certificate for the models listed under the heading ``Type Certification Basis.'' This special condition includes various airplane models to streamline the certification process needed to improve the safety of the airplane fleet by fostering the incorporation of new technologies that can be certificated affordably under 14 CFR part 23. The airplanes listed under this multi-model approval will have novel and unusual design features when compared to the state of technology envisaged in the applicable airworthiness standards. These novel and unusual design features include the installation of the Entegra II Avionics System, consisting of: (2) Model 700-0003-( ) Integrated Flight Displays (IFD), (2) Model 700-00011-( ) Magnetometer/ OAT sensors, and (1) Model 700-00085-000 Keyboard/Controller. These components are all manufactured by Avidyne Corporation, Inc. The applicable regulations do not contain adequate or appropriate airworthiness standards for the protection of these systems from the effects of high intensity radiated fields (HIRF). These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to the airworthiness standards applicable to these airplanes.

The FAA is superseding an existing airworthiness directive (AD) for Rolls-Royce plc (RR) RB211-22B series, RB211-524B, -524C2, - 524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with high pressure compressor (HPC) stage 3 disc assemblies, part numbers (P/Ns) LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. This AD requires removing from service certain disc assemblies before they reach their full published life if not modified with anticorrosion protection. This AD results from the manufacturer's reassessment of the corrosion risk on HPC stage 3 disc assemblies that have not yet been modified with sufficient application of anticorrosion protection. We are issuing this AD to prevent corrosion-induced uncontained disc failure, resulting in damage to the airplane.

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited Model DHC-7 airplanes. This AD requires implementing a corrosion prevention and control program (CPCP) either by accomplishing specific tasks or by revising the maintenance inspection program to include a CPCP. This AD results from a determination that, as airplanes age, they are more likely to exhibit indications of corrosion. We are issuing this AD to prevent structural failure of the airplane due to corrosion.