Airworthiness Directives; The Boeing Company Airplanes
We are superseding an existing airworthiness directive (AD) for The Boeing Company Model 787-8 airplanes. That AD currently requires modification of the battery system, or other actions. This AD requires installing main and auxiliary power unit (APU) battery enclosures and environmental control system (ECS) ducts; and replacing the main battery, APU battery, and their respective battery chargers. This AD also requires revising the maintenance program to include an airworthiness limitation. This AD also revises the applicability by removing airplanes on which these changes have been incorporated in production prior to delivery. This AD was prompted by recent incidents involving lithium ion battery failures that resulted in release of flammable electrolytes, heat damage, and smoke on two Model 787-8 airplanes. We are issuing this AD to minimize the occurrence of battery cell failures and propagation of such failures to other cells and to contain any flammable electrolytes, heat, and smoke released during a battery thermal event in order to prevent damage to critical systems and structures and the potential for fire in the electronics equipment bays.
Airworthiness Directives; PILATUS Aircraft Ltd. Airplanes
We propose to adopt a new airworthiness directive (AD) for all PILATUS Aircraft Ltd. Model PC-7 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 a need to incorporate new revisions into the Limitations section of the FAA-approved maintenance program (e.g., maintenance manual). The limitations were revised to include an emergency fuel control system adjustment test. We are issuing this proposed AD to require actions to address the unsafe condition on these products.
Airworthiness Directives; General Electric Company Turbofan Engines
We are superseding an existing airworthiness directive (AD) for certain General Electric Company (GE) CF6-80C2 series turbofan engines. That AD currently requires replacement of the fuel tube connecting the flowmeter to the integrated drive generator (IDG) fuel- oil cooler and the fuel tube(s) connecting the main engine control (MEC) or hydromechanical (HMU) to the flowmeter, with improved fuel tubes. This new AD requires the same actions, requires installation of a new simplified one-piece supporting bracket, adds an engine model, alters the list of affected part numbers (P/Ns), changes the replacement schedule, and revises our estimated cost of compliance. This AD was prompted by several additional reports of fuel leaks and two reports of engine fire due to improper assembly of supporting brackets on the fuel tube connecting the flowmeter to the IDG fuel-oil cooler. We are issuing this AD to prevent high-pressure fuel leaks caused by improper seating of fuel tube flanges, which could result in an engine fire and damage to the airplane.