Airworthiness Directive · Amendment 39-17914 · Stabilizers
The Boeing Company Airplanes
(1) This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category.
(2) Installation of Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/408E012E008616A7862578880060456C?OpenDocument&Highlight=st00830se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST00830SE 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 737-600, -700, -700C, -800, -900 and -900ER series airplanes. This AD was prompted by reports of incorrectly installed bolts common to the rear spar termination fitting on the horizontal stabilizer. This AD requires inspecting for a serial number that starts with the letters "SAIC" on the left- and right-side horizontal stabilizer identification plate; inspecting for correct bolt protrusion and chamfer of the bolts of the rear spar termination fitting of the horizontal stabilizer, if necessary; inspecting to determine if certain bolts are installed, if necessary; and doing related investigative and corrective actions if necessary. We are issuing this AD to prevent loss of structural integrity of the horizontal stabilizer attachment and loss of control of the airplane.
For Group 1 and Group 2 airplanes identified in Boeing Service Bulletin 737-55-1090, dated March 30, 2011, except as provided by paragraphs (j)(4) and (j)(5) of this AD: Except as provided by paragraphs (i) and (j) of this AD, at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-55-1090, dated March 30, 2011, do an inspection for a serial number that starts with the letters “SAIC” on the identification plates of the left- and right-side horizontal stabilizers, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-55-1090, dated March 30, 2011. A review of manufacturer delivery and operator maintenance records is acceptable to make the determination specified in this paragraph if the serial number can be conclusively identified from that review.
(1) If no “SAIC” serial number is found, no further action is required by paragraph (g) of this AD.
(2) If a serial number starting with the letters “SAIC” is found on a horizontal stabilizer identification plate on an airplane after line number (L/N) 1556, and the serial number of the horizontal stabilizer is the same as stated in the delivery documentation of the airplane, no further action is required by paragraph (g) of this AD for that horizontal stabilizer only.
(3) If a serial number starting with the letters “SAIC” is found on a horizontal stabilizer identification plate on any airplane, and the serial number of the horizontal stabilizer is the same as stated in the delivery documentation of an airplane having a line number after L/N 1556, no further action is required by paragraph (g) of this AD for that horizontal stabilizer only.
(4) If a serial number starting with the letters “SAIC” is found on a horizontal stabilizer identification plate, except as specified in paragraphs (g)(2) and (g)(3) of this AD: Except as provided by paragraphs (i) and (j) of this AD, at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-55-1090, dated March 30, 2011, do a detailed inspection for correct bolt protrusion and correct chamfer of the termination fitting bolts of the horizontal stabilizer rear spar, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-55-1090, dated March 30, 2011. Concurrently with the detailed inspection, inspect to determine if any bolt other than part number (P/N) BACB30US14K() or BACB30US16K(), as applicable, is installed. Before further flight, do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-55-1090, dated March 30, 2011.
For airplanes identified in paragraph (g)(4) of this AD at any location where a new bolt having a P/N BACB30US14K() is installed as corrective action for damage found during any inspection required by paragraph (g) of this AD: Except as provided by paragraphs (i) and (j) of this AD, at the times specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-55-1090, dated March 30, 2011, do HFEC and ultrasonic inspections for cracking of the forward and aft sides of the termination fitting, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-55-1090, dated March 30, 2011. If any crack is found in any termination fitting: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD. Repeat the HFEC and ultrasonic inspections thereafter at intervals not to exceed 3,500 flight cycles on the horizontal stabilizer.
Where the compliance times stated in Boeing Service Bulletin 737-55-1090, dated March 30, 2011, are “total flight cycles,” the compliance time in this AD is total flight cycles accumulated on the horizontal stabilizer since new.
(1) Where Boeing Service Bulletin 737-55-1090, dated March 30, 2011, specifies a compliance time “after the original issue date on the service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Figure 1 of Boeing Service Bulletin 737-55-1090, dated March 30, 2011, points to the location of a part number rather than the serial number, this AD requires an inspection for an identification plate with a serial number that starts with the letters “SAIC.”
(3) If, during any inspection required by paragraphs (g) and (h) of this AD, any bolt other than P/N BACB30US14K() or BACB30US16K(), as applicable, is found: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
(4) Where Boeing Service Bulletin 737-55-1090, dated March 30, 2011, identifies Group 1 airplanes as 737-600, -700, -800, and -900 airplanes having line numbers 379 through 1556 inclusive, this AD specifies Group 1 airplanes as 737-600, -700, -800, -900, and -900ER airplanes “with original airworthiness certificate or original export certificate of airworthiness dated before the effective date of this AD.”
(5) Where Boeing Service Bulletin 737-55-1090, dated March 30, 2011, identifies Group 2 airplanes as 737-700C airplanes having line number 496 through 1548 inclusive, this AD specifies Group 2 airplanes as 737-700C airplanes “with original airworthiness certificate or original export certificate of airworthiness dated before the effective date of this AD.”
(6) Any instructions specified in Boeing Service Bulletin 737-55-1090, dated March 30, 2011, regarding the removal and re-installation of gap covers, trailing edge panels, and access doors are not required by this AD.
As of the effective date of this AD, no person may install a horizontal stabilizer on any airplane included in the applicability of this AD, unless the horizontal stabilizer has been inspected and any applicable corrective actions have been done in accordance with paragraphs (g) and (h) of this AD.
