Airworthiness Directive · Amendment 39-18355 · Fuselage
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 767-200, -300, -300F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014.
(2) Installation of Supplemental Type Certificate (STC) ST01920SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/59027F43B9A7486E86257B1D006591EE) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01920SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/59027F43B9A7486E86257B1D006591EE) is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 767-200, -300, and -300F series airplanes. This AD was prompted by a finding that certain barrel nuts installed at the vertical fin may be subject to stress corrosion and cracking. This AD requires either repetitive inspections of vertical fin barrel nuts for corrosion or a magnetic check to identify certain barrel nuts, and corrective actions if necessary. We are issuing this AD to detect and correct corroded and loose barrel nuts that attach the vertical fin to body section 48; this condition could result in reduced structural integrity of the vertical fin attachment joint, loss of the vertical fin, and consequent loss of controllability of the airplane.
For airplanes identified in Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014: Do the actions specified in paragraph (g)(1) or (g)(2) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014. Signs of corrosion include, but are not limited to, sealant cracks, sealant bulging, powder residue, and cracked barrel nuts.
(1) At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014, except as provided by paragraph (i) of this AD: Do internal and external detailed inspections of the barrel nuts and sealant for signs of corrosion, and do a torque check of the vertical stabilizer attachment bolts for loose barrel nuts.
(i) If corrosion or any loose barrel nut is found at any attachment point location, before further flight, replace the barrel nut with a new Inconel barrel nut.
(ii) If no corrosion or loose barrel nut is found at any attachment point location, do the actions specified in paragraphs (g)(1)(ii)(A) and (g)(1)(ii)(B) of this AD.
(A) Repeat the inspections and torque check thereafter at intervals not to exceed 18 months until the replacement specified in paragraph (g)(1)(ii)(B) of this AD is done at that attachment point location.
(B) Within 36 months after the effective date of this AD, replace all barrel nuts with new Inconel barrel nuts.
(2) At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014, except as provided by paragraph (i) of this AD: Do a magnetic check to identify H-11 steel barrel nuts.
(i) If any H-11 steel barrel nut is found at any attachment point location, before further flight, do an internal and external detailed inspection of the barrel nut holes and sealant for signs of corrosion, and do a torque check of the vertical stabilizer attachment bolts for loose barrel nuts.
(A) If corrosion or any loose barrel nut is found, before further flight, replace the barrel nut with a new Inconel barrel nut.
(B) If no corrosion or loose barrel nut is found, do the actions specified in paragraphs (g)(2)(i)(B)(1) and (g)(2)(i)(B)(2) of this AD.
(1) Repeat the inspections and torque check thereafter at intervals not to exceed 18 months until the replacement specified in paragraph (g)(2)(i)(B)(2) of this AD is done at that attachment point location.
(2) Within 36 months after the effective date of this AD, replace all H-11 steel barrel nuts with new Inconel barrel nuts.
(ii) If no H-11 steel barrel nut is found at all attachment point locations, no further work is required by this paragraph.
(1) Replacing a barrel nut at an attachment point location with a new Inconel barrel nut, in accordance with Part 5 of Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014, terminates the inspections and replacement required by paragraph (g) of this AD for that attachment point location only.
(2) If no H-11 steel barrel nut is found installed at an attachment point location, the repetitive inspections and replacement required by paragraph (g) of this AD are terminated for that attachment location only.
(1) Where Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014, specifies a compliance time “after the Original Issue date of this Service Bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 767-53A0261, dated August 12, 2014, specifies a compliance time after the “last Torque Check Inspection” in accordance with Task 53-734-00, “Internal, Special Detailed, Vertical Stabilizer Attach Bolt, of Section 2, Structural Maintenance Requirements,” of the Boeing Model 767 Maintenance Planning Document, that compliance time only applies if the most recent accomplishment of Task 53-734-00 occurred on or before the effective date of this AD.
