Federal Aviation Administration July 8, 2016 – Federal Register Recent Federal Regulation Documents

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This AD was prompted by reports of water leakage from the potable water system due to improperly installed waterline couplings, and water leaking into the electronics equipment (EE) bays from above the floor in the main cabin, resulting in water on the equipment in the EE bays. This AD requires replacing the potable waterline couplings above the forward and aft EE bays with new, improved couplings. This AD also requires sealing the main cabin floor areas above the aft EE bay, installing drip shields and foam blocks, and rerouting the wire bundles near the drip shields above the equipment in the aft EE bay. We are issuing this AD to prevent a water leak from an improperly installed potable water system coupling, or main cabin water source, which could cause the equipment in the EE bays to become wet, resulting in an electrical short and potential loss of system functions essential for safe flight.

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by reports of a manufacturing oversight, in which a supplier omitted the required protective finish on certain bushings installed in the rear spar upper chord on horizontal stabilizers, which could lead to galvanic corrosion and consequent cracking of the rear spar upper chord. This AD requires an inspection or records check to determine if affected horizontal stabilizers are installed, related investigative actions, and for affected horizontal stabilizers, repetitive inspections for any crack of the horizontal stabilizer rear spar upper chord, and corrective action if necessary. We are issuing this AD to detect and correct cracking of the rear spar upper chord, which can result in the failure of the upper chord and consequent departure of the horizontal stabilizer from the airplane, which can lead to loss of control of the airplane.

We are superseding Airworthiness Directive (AD) 2006-13-05 for certain Pacific Aerospace Limited Model 750XL (type certificate previously held by Pacific Aerospace Corporation Ltd.) airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued 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 some critical rivets on the wing not being fully age-hardened and being installed in specific locations where reduction in rivet strength reduces wing strength. We are issuing this AD to require actions to address the unsafe condition on these products.