Airworthiness Directive · Amendment 39-15476 · Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes
Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes
This AD applies to Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-30-1056, Revision 1, dated October 25, 2007.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires a one-time inspection to determine the material of the forward and aft gray water drain masts. For airplanes having composite gray water drain masts, this AD requires installation of a bonding jumper between a ground and the clamp on the tube of the forward and aft gray water composite drain masts. This AD results from a report of charred insulation blankets and burned wires around the forward gray water composite drain mast found during an inspection of the forward cargo compartment on a Model 767-300F airplane. We are issuing this AD to prevent a fire near a composite drain mast and possible disruption of the electrical power system caused by a lightning strike on a composite drain mast, which could result in the loss of several functions essential for safe flight.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 60 months after the effective date of this AD, inspect the forward and aft gray water drain masts to determine whether the drain masts are made of aluminum or composite. A review of airplane maintenance records is acceptable in lieu of this inspection if the material of the forward and aft gray water drain masts can be conclusively determined from that review.
(1) For any aluminum gray water drain mast identified during the inspection or records check required by paragraph (f) of this AD, no further action is required by this paragraph for that drain mast only.
(2) For any composite gray water drain mast identified during the inspection or records check required by paragraph (f) of this AD, do the actions specified in paragraph (g) of this AD.
For any composite gray water drain mast identified during the inspection or records check required by paragraph (f) of this AD: Within 60 months after the effective date of this AD, install a bonding jumper between a ground and the clamp on the tube of the gray water composite drain mast, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-30-1056, Revision 1, dated October 25, 2007.
Actions done before the effective date of this AD according to Boeing Special Attention Service Bulletin 737-30-1056, dated February 28, 2007, are considered acceptable for compliance with the corresponding actions specified in this AD provided the results of the resistance measurements meet the acceptable values specified in Boeing Special Attention Service Bulletin 737-30-1056, Revision 1, dated October 25, 2007.
(i) As of the effective date of this AD, no person may install, on any airplane, a composite gray water drain mast, unless a bonding jumper is also installed, as specified in paragraph (g) of this AD.
