Airworthiness Directive · Amendment 39-17785 · Wings
The Boeing Company Airplanes
(1) This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.
(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/BE866B732F6CF31086257B9700692796?OpenDocument&Highlight=st01219se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE 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 superseding Airworthiness Directive (AD) 2010-15-08 for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. AD 2010-15-08 required repetitive inspections for discrepancies of each carriage spindle of the outboard mid-flaps; repetitive gap checks of the inboard and outboard carriages of the outboard mid-flaps to detect fractured carriage spindles; measuring to ensure that any new or serviceable carriage spindle meets minimum allowable diameter measurements taken at three locations; repetitive inspections, measurements, and overhaul of the carriage spindles; replacement of any carriage spindle when it has reached its maximum life limit; and corrective actions if necessary. This new AD requires reducing the life limit of the carriages, reducing the repetitive interval for certain inspections and gap checks for certain carriages. This new AD also adds an option, for certain replacements, of doing an inspection, and related investigative and corrective actions if necessary. This AD was prompted by a report of failure of both flap carriages. We are issuing this AD to detect and correct cracked, corroded, or fractured carriage spindles, which could lead to severe flap asymmetry, and could result in reduced control or loss of controllability of the airplane.
This paragraph restates the requirements of paragraph (g) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information that shortens the compliance times for certain inspections. The tables in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; and Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012; specify the compliance times for paragraphs (g) through (k) of this AD. For carriage spindles that have accumulated the number of flight cycles or years in service specified in the “Threshold” column of the tables in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003, accomplish the gap check, nondestructive test (NDT) inspection, and general visual inspection specified in paragraphs (h) and (j) of this AD within the corresponding interval after December 4, 2003 (the effective date AD 2003-24-08, Amendment 39-13337 (68 FR 67027, December 1, 2003)), as specified in the “Interval” column of the tables in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003, except as specified in paragraph (g)(1) or (g)(2) of this AD. Repeat the gap check, NDT, and general visual inspections at the intervals specified in the “Interval” column of the tables in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003, except as specified in paragraph (g)(1) and (g)(2) of this AD. As of the effective date of this AD, accomplish the gap check, NDT inspection, and general visual inspections specified in paragraphs (h) and (j) of this AD within the corresponding interval as specified in the “Interval” column of the tables in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003, and thereafter at the intervals specified in Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, except as specified in paragraphs (g)(1) and (g)(2) of this AD. Repeat the gap check, NDT, and general visual inspections thereafter at the intervals specified in the “Interval” column of the tables in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, except as specified in paragraphs (g)(1) and (g)(2) of this AD.
(1) The gap check does not have to be done at the same time as an NDT inspection; after doing an NDT inspection, the interval for doing the next gap check may be measured from the NDT inspection.
(2) As carriage spindles gain flight cycles or years in service and move from one category in the “Threshold” column to another, they are subject to the repetitive inspection intervals corresponding to the new threshold category.
This paragraph restates the requirements of paragraph (h) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information. Perform a gap check of the inboard and outboard carriage of the left and right outboard mid-flaps to determine if there is a positive indication of a severed carriage spindle, in accordance with Work Package 2 of paragraph 3.B., “Work Instructions,” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
This paragraph restates the requirements of paragraph (i) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information and new optional actions and exception. If there is a positive indication of a severed carriage spindle during the gap check required by paragraph (h) of this AD, before further flight, do the actions specified in paragraph (i)(1) or (i)(2) of this AD, except for carriage spindles on which an ultrasonic inspection has been done in accordance with the “Work Instructions” of Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012; and the spindle has been confirmed not to be severed, no further actions are required by this paragraph for that carriage spindle.
(1) Remove the carriage spindle and install a new or serviceable carriage spindle, in accordance with the “Work Instructions” of any service bulletin specified in paragraph (i)(1)(i), (i)(1)(ii), (i)(1)(iii), or (i)(1)(iv) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
(i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003.
(ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012.
(iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009.
(iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011.
(2) Do a detailed inspection of the spindle to determine if there is corrosion, cracking, or a severed spindle, and, before further flight, do all related investigative and corrective actions, in accordance with the “Work Instructions” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012. If, during the detailed inspection described in paragraph 4.b. of Work Package 2 of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing Alert Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012; a carriage spindle is found not to be severed, and no corrosion and no cracking is present, it can be reinstalled on the outboard mid-flap, in accordance with any service bulletin specified in paragraph (i)(2)(i), (i)(2)(ii), (i)(2)(iii), or (i)(2)(iv) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
(i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003.
(ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012.
(iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009.
(iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011.
This paragraph restates the requirements of paragraph (j) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information. Perform an NDT (ultrasonic) inspection and general visual inspection for each carriage spindle of the left and right outboard mid-flaps to detect cracks, corrosion, or severed carriage spindles, in accordance with “Work Package 1” of the “Work Instructions” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
This paragraph restates the requirements of paragraph (k) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information and new optional action. If any corroded, cracked, or severed carriage spindle is found during any inspection required by paragraph (j) of this AD: Before further flight, do the actions specified in paragraph (k)(1) or (k)(2) of this AD.
(1) Remove the carriage spindle and install a new or serviceable carriage spindle, in accordance with any service bulletin identified in paragraph (k)(1)(i), (k)(1)(ii), (k)(1)(iii), or (k)(1)(iv) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
(i) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003.
(ii) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012.
(iii) Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009.
(iv) Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011.
(2) Do a detailed inspection of the spindle to determine if there is corrosion, cracking, or a severed spindle, in accordance with the “Work Instructions” of Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; or Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012. If any corrosion, cracking, or a severed spindle is found, before further flight, install a new or serviceable carriage spindle, in accordance with any service bulletin identified in paragraph (k)(1)(i), (k)(1)(ii), (k)(1)(iii), or (k)(1)(iv) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, may be used to perform the actions specified in this paragraph.
This paragraph restates the requirements of paragraph (l) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010). Except as provided by paragraph (i) of this AD: As of December 4, 2003 (the effective date AD 2003-24-08, Amendment 39-13337 (68 FR 67027, December 1, 2003)), no person may install on any airplane a carriage spindle that has been removed as required by paragraph (i) or (k) of this AD, unless it has been overhauled in accordance with the “Work Instructions” of the applicable service bulletin identified in paragraph (l)(1), (l)(2), (l)(3), or (l)(4) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012; or Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011; may be used to perform the actions specified in this paragraph. To be eligible for installation under this paragraph, the carriage spindle must have been overhauled in accordance with the requirements of paragraph (m) of this AD.
(1) Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003.
(2) Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012.
(3) Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009.
(4) Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011.
This paragraph restates the requirements of paragraph (m) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010) with revised plating application procedures. As of the effective date of this AD, during accomplishment of any overhaul specified in paragraph (l) or (o) of this AD, follow the requirements specified in paragraphs (m)(1), (m)(2), and (m)(3) of this AD during application of the plating to the carriage spindle, in accordance with a method approved by the Manager, Seattle, Aircraft Certification Office (ACO), FAA. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.
(1) The maximum deposition rate of the nickel plating in any one plating/baking cycle must not exceed 0.002-inch-per-hour.
(2) Begin the hydrogen embrittlement relief bake within 10 hours after application of the nickel plating, or less than 24 hours after the current was first applied to the part, whichever is first.
(3) The carriage must not be plated using any high velocity oxygen fuel (HVOF) thermal spray process.
Note 1 to paragraph (m) of this AD: Guidance on the application of nickel plating can be found in Chapter 20-42-09, Electrodeposited Nickel Plating, of the Boeing (737) Standard Overhaul Practices Manual, Revision 25, dated July 1, 2009.
This paragraph restates the provisions of paragraph (n) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information. Although Boeing Alert Service Bulletin 737-57A1277, Revision 1, dated November 25, 2003; and Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012; recommend that operators report inspection findings to the manufacturer, this AD does not require reporting.
This paragraph restates the requirements of paragraph (o) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010) with clarification of overhaul restrictions. At the applicable times specified in paragraphs (o)(1) and (o)(2) of this AD: Do the detailed inspection for corrosion, pitting, and cracking of the carriage spindle; magnetic particle inspection for cracking of the carriage spindle; measurements of the spindle to determine if it meets the allowable minimum diameter; overhauls of the carriage spindle; and applicable corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009; or Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011. As of the effective date of this AD, only Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011, may be used to perform the actions specified in this paragraph. The applicable corrective actions must be done before further flight. Repeat these actions thereafter at intervals not to exceed every 12,000 flight cycles on the carriage spindle or every 8 years since first installation of the carriage spindle on the airplane, whichever comes first. As of the effective date of this AD: For any overhaul required by this paragraph, the carriage spindle must be overhauled in accordance with the requirements of paragraph (m) of this AD.
(1) For Model 737-100, -200, -200C series airplanes: At the later of the times specified in paragraphs (o)(1)(i) and (o)(1)(ii) of this AD.
(i) Before the accumulation of 12,000 total flight cycles on the carriage spindle since new or overhauled, or within 8 years after the installation of the new or overhauled part, whichever comes first.
(ii) Within 1 year after August 31, 2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)).
(2) For Model -300, -400, and -500 series airplanes: At the later of the times specified in paragraphs (o)(2)(i) and (o)(2)(ii) of this AD.
(i) Before the accumulation of 12,000 total flight cycles on the carriage spindle since new or overhauled, or within 8 years after the installation of the new or overhauled part, whichever comes first.
(ii) Within 2 years after August 31, 2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)).
This paragraph restates the requirements of paragraph (p) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information and a shortened compliance time. For Model 737-100, -200, -200C series airplanes: Replace the carriage spindle with a new or documented (for which the service life, in total flight cycles, is known) carriage spindle, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009; or Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011; at the earlier of the times specified in paragraphs (p)(1) and (p)(2) of this AD, except as required by paragraph (r) of this AD. As of the effective date of this AD, only Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011, may be used to perform the replacement. Overhauling the carriage spindles does not zero-out the flight cycles. Total flight cycles accumulate since new.
(1) At the later of the times specified in paragraphs (p)(1)(i) and (p)(1)(ii) of this AD.
(i) Before the accumulation of 48,000 total flight cycles on the new or overhauled carriage.
(ii) Within 3 years or 7,500 flight cycles after August 31, 2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)), whichever occurs first.
(2) Before the accumulation of 40,000 total flight cycles on the new or overhauled carriage or 6 months after the effective date of this AD, whichever occurs later.
This paragraph restates the requirements of paragraph (q) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised service information and a shortened compliance time. For Model 737-300, -400, and -500 series airplanes: Replace the carriage spindle with a new or documented (for which the service life, in flight cycles, is known) carriage spindle, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1218, Revision 5, dated February 9, 2009; or Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011; at the later of the times specified in paragraphs (q)(1) and (q)(2) of this AD, except as required by paragraph (r) of this AD. As of the effective date of this AD, only Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011, may be used to perform the replacement required by this paragraph. Overhauling the carriage spindles does not zero-out the flight cycles. Total flight cycles accumulate since new.
(1) Before the accumulation of 40,000 total flight cycles on the new or overhauled carriage.
(2) Within 6 years or 15,000 flight cycles after August 31, 2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)), whichever occurs first.
This paragraph restates the requirements of paragraph (r) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010). For airplanes with an undocumented carriage: Do the applicable actions specified in paragraph (p) or (q) of this AD at the applicable time specified in paragraph (r)(1) or (r)(2) of this AD.
(1) For Model 737-100, -200, -200C series airplanes: Do the actions specified in paragraph (p) of this AD at the time specified in paragraph (p)(1)(ii) of this AD.
(2) For Model -300, -400, and -500 series airplanes: Do the actions specified in paragraph (q) of this AD at the time specified in paragraph (q)(2) of this AD.
This paragraph restates the requirements of paragraph (s) of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010), with revised compliance times.
(1) For airplanes on which the actions required by paragraph (p) or (q) of this AD, as applicable, have been done as of the effective date of this AD: Repeat the replacement of the carriage spindle specified by paragraph (p) or (q) of this AD, as applicable, one time at the later of the times specified in paragraphs (s)(1)(i) and (s)(1)(ii) of this AD, and thereafter at intervals not to exceed 40,000 total flight cycles on the new or overhauled carriage spindle.
(i) Before the accumulation of 40,000 total flight cycles on the new or overhauled carriage.
(ii) Within 6 years or 15,000 flight cycles after August 31, 2010 (the effective date of AD 2010-15-08, Amendment 39-16374 (75 FR 43803, July 27, 2010)), whichever occurs first.
(2) For airplanes on which the actions required by paragraph (p) or (q) of this AD, as applicable, have not been done as of the effective date of this AD: Repeat the replacement of the carriage spindle specified by paragraph (p) or (q) of this AD, as applicable, thereafter at intervals not to exceed 40,000 total flight cycles on the new or overhauled carriage spindle.
Where Boeing Service Bulletin 737-57A1277, Revision 3, dated May 16, 2012, and Boeing Alert Service Bulletin 737-57A1218, Revision 6, dated June 9, 2011, specify a compliance time after the dates of those service bulletins, this AD requires compliance within the specified compliance time after the effective date of this AD.
