Airworthiness Directive · Amendment 39-17426 · Oxygen
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes; certificated in any category; as identified in Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by a report that during a test of the oxygen system, an operator found that the passenger oxygen masks did not properly flow oxygen, and that a loud noise occurred in the overhead area, which was caused by the flex line separating from the hard line due to a missing clamshell coupler. This AD requires, for certain airplanes, performing a detailed inspection of certain areas of the airplane oxygen system to ensure clamshell couplers are installed and fully latched, and corrective actions if necessary. For all airplanes, this AD requires performing and meeting the requirements of the low pressure leak test. We are issuing this AD to prevent the oxygen system flex line from separating from the hard line, which could cause an oxygen leak and a drop in the oxygen system pressure, resulting in improper flow of oxygen through the passenger masks and injury to passengers if emergency oxygen is needed.
Within 36 months after the effective date of this AD, do the applicable actions in paragraph (g)(1) or (g)(2) of this AD.
(1) For Groups 1-6, 8, and 9 airplanes, as identified in Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011: Do a detailed inspection of certain areas of the airplane oxygen system to ensure clamshell couplers are installed and fully latched, and perform and meet the requirements of the low pressure leak test, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011.
(2) For Group 7 airplanes, as identified in Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011: Perform and meet requirements of the low pressure leak test, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011.
If, during any inspection required by paragraph (g) of this AD, any clamshell coupler is not fully latched: Before further flight, latch the clamshell coupler, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-35-0024, dated September 1, 2011.
If, during any inspection required by paragraph (g) of this AD, any clamshell coupler is not installed: Before further flight, install a clamshell coupler.
Note 1 to paragraph (i) of this AD: Guidance on installation of the clamshell coupler may be found in Subject 35-00-00, Oxygen, of Chapter 35, Oxygen, of Part II, Practices and Procedures, of the Boeing 777 Aircraft Maintenance Manual, Revision 67, dated January 5, 2013.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
