AD NUMBER: 2019-25-12

PRODUCT: Boeing Model 777-200 and -300ER series airplanes.

ACTION: Final rule; request for comments.

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2016-18-02, which applied to certain The Boeing Company Model 777-200 and -300ER series airplanes.

AD 2016-18-02 required replacing the low-pressure oxygen flex hoses with new non-conductive low-pressure oxygen flex hoses in the gaseous passenger oxygen system in airplanes equipped with therapeutic oxygen. This AD retains those actions and adds actions for certain airplanes.

AD 2016-18-02 was prompted by the determination that the low-pressure oxygen flex hoses in the gaseous passenger oxygen system can potentially be conductive. This AD was further prompted by the determination that the associated service information is inadequate for certain airplanes.

DATES: This AD is effective January 21, 2020. The FAA must receive any comments on this AD by February 20, 2020.

COST: The FAA estimates that this AD affects 0 airplanes of U.S. registry. If an affected airplane is imported and
placed on the U.S. Register in the future, the following are the cost estimates to comply with this AD:

Replacement (actions retained from AD 2016-18-02)

• Labor: Up to 33 work-hours × $85 per hour = Up to $2,805 per aircraft.
• Parts: Up to $15,173.
• Total cost per aircraft: Up to $17,978.

New actions for Group 4, Configuration 2 airplanes

• Labor: 6 work-hours × $85 per hour =$510 per aircraft.

FMI: AD