Airworthiness Directive · Amendment 39-18900 · Stabilizers
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 737-100, -200, and -200C series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, -200, and -200C series airplanes. This AD is intended to complete certain mandated programs to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. This AD requires various repetitive inspections for cracking of certain lugs on the rear spar and horizontal stabilizer, related investigative and corrective actions if necessary, and replacement of the center section rear spar upper chord as applicable. We are issuing this AD to address the unsafe condition on these products.
At the applicable time specified in table 1 or table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD: Do detailed, high frequency eddy current (HFEC), and ultrasonic inspections of the center section rear spar upper clevis lugs for any cracking, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 1 or table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
For airplanes identified as Group 1, Configuration 1, in Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015: At the applicable time specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD, replace the center section rear upper chord with a new part or replace the center section with a serviceable center section assembly, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
For airplanes identified as Group 1, Configuration 1, in Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, with a new or serviceable 0.932-inch-thick center section rear spar upper chord: At the applicable time specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD, do detailed, HFEC, and ultrasonic inspections of the center section rear spar upper chord clevis lugs for any cracking, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
For airplanes on which the center section rear spar upper chord was last replaced with a new part or serviceable part: Within the applicable times specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD, do detailed, HFEC, and ultrasonic inspections of the center section rear spar upper chord clevis lugs for any cracking, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 4 of 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
Within the applicable time specified in table 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD, do detailed, HFEC, and ultrasonic inspections of the rear spar upper lugs of the horizontal stabilizer for any cracking, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 5 of 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
For airplanes with a replaced horizontal stabilizer with a new part or serviceable assembly, within the applicable times specified in table 6 of 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD: Do a detailed, HFEC, and ultrasonic inspection of the rear spar upper lugs of the horizontal stabilizer for any cracking, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 6 of 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
Within the applicable times specified in table 7 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD: Do HFEC and fluorescent dye penetrant inspections for cracking in the front and rear spar upper clevis lugs of the center section and front and rear spar upper lugs of the horizontal stabilizer, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 7 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
For airplanes on which the center section rear spar upper chord or horizontal stabilizer rear spar upper chord has been replaced: Within the applicable time specified in table 8 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, except as specified in paragraph (o) of this AD; do HFEC and fluorescent dye penetrant inspections for cracking in the front and rear spar upper clevis lugs of the center section or front and rear spar upper lugs of the horizontal stabilizer, as applicable, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015; except as specified in paragraph (p) of this AD. Do all related investigative and corrective actions before further flight. Repeat the inspections thereafter at the applicable times specified in table 8 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015.
Where Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, specifies a compliance time “after the Revision 2 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
If any cracking of the lug is found during any inspection required by this AD, and Boeing Alert Service Bulletin 737-55A1033, Revision 2, dated August 7, 2015, specifies to contact Boeing for appropriate action: Before further flight, repair the lug using a method approved in accordance with the procedures specified in paragraph (r) of this AD.
(1) For Model 737-100, -200, and -200C series airplanes: Accomplishment of the initial inspections specified in paragraph (g) of this AD terminates all requirements of AD 84-23-05, Amendment 39-4949 (Docket No. 84-NM-37-AD; 49 FR 45744, November 20, 1984).
(2) For Model 737-200 and -200C series airplanes: Accomplishment of the initial inspections specified in paragraph (m) and (n) of this AD terminates all requirements of AD 86-12-05, Amendment 39-5321 (Docket No. 85-NM-162-AD; 51 FR 18771, May 22, 1986).
