Airworthiness Directive · Amendment 39-15462 · Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes
Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes
This AD applies to all Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. For certain airplanes, this AD requires replacing the outboard stabilizing fitting and certain adjacent components of the main landing gear (MLG) support beam. This AD also requires repetitive inspections for discrepancies of the outboard stabilizing fitting, walking beam hanger, and rear spar attachment, and corrective actions if necessary. For certain airplanes, this AD provides an alternative one-time inspection of the outboard stabilizing fitting for discrepancies, and corrective actions if necessary, which would extend the compliance time for the replacement of the outboard stabilizing fitting. For certain other airplanes, this AD also requires performing a torque check of the aft pin of the outboard stabilizing fitting, and corrective actions if necessary. This AD results from reports of findings of fatigue cracking of the outboard stabilizing fitting and stress corrosion cracking of the bolts attaching the fitting to the wing rear spar. We are issuing this AD to detect and correct that cracking, which could result in disconnection of the MLG actuator from the rear spar and support beam, consequent damage to the hydraulic system, and possible loss of the "A" and "B" hydraulic systems and damage or jamming of the flight control cables. Damage or jamming of the flight control cables could result in loss of control of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
The term “alert service bulletin” as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1266, Revision 1, dated January 3, 2007.
For airplanes identified as Groups 1 through 8, as specified in the alert service bulletin, except as provided by paragraphs (h) and (k) of this AD: Within 36 months after the effective date of this AD, replace the outboard stabilizing fitting, H-11 bolts, forward pin, and aft pin, as applicable, with new components by doing all the applicable actions in accordance with Part II of the alert service bulletin, except as provided by paragraph (j) of this AD. Within 120 months after accomplishing the replacement, do a general visual inspection for discrepancies of the outboard stabilizing fitting, walking beam hanger, and rear spar attachment fitting, and do all applicable corrective actions, by doing all the actions, except as provided by paragraph (j) of this AD, in accordance with Part V of the alert service bulletin. Do all corrective actions before further flight. Repeat the inspection at intervals not to exceed 120 months.
For airplanes identified as Groups 1 through 8, as specified in the alert service bulletin, on which the existing H-11 bolts were replaced before the effective date of this AD with Inconel 718 bolts, in lieu of doing the actions required by paragraph (g) of this AD: Within 4,500 flight cycles or 36 months after the effective date of this AD, whichever is later, do a magnetic test of the attach bolts in accordance with the alert service bulletin. If any bolt is magnetic, discontinue the alternative inspection specified in the alert service bulletin and accomplish the actions required by paragraph (g) before further flight. If none of the bolts are magnetic, do all the applicable actions in accordance with Part I of the alert service bulletin before further flight.
(1) If any crack is found: Stop the inspection and before further flight do the actions required by paragraph (g) of this AD. Repetitive inspections must be done after replacing the fitting at the interval specified in paragraph (g) of this AD.
(2) If no crack is found: Before further flight, replace the forward pin and aft pin, as applicable, in accordance with the alert service bulletin, and within 60 months after the effective date of this AD, do the remaining replacement required by paragraph (g) of this AD. Repetitive inspections must be done after replacing the fitting at the interval specified in paragraph (g) of this AD.
(3) If damage other than cracking is found, or if the fitting lug hole is beyond hole size limits, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
(i) For airplanes identified as Group 9, as specified in the alert service bulletin: Within 36 months or 4,500 flight cycles after the effective date of this AD, whichever occurs later, do a general visual inspection of the outboard stabilizing fitting and fasteners for discrepancies, and do all applicable corrective actions in accordance with Part IV of the alert service bulletin, except as provided by paragraphs (j) and (k) of this AD. Within 120 months after the inspection specified in Part IV has been done, do a general visual inspection for discrepancies of the outboard stabilizing fitting, walking beam hanger and rear spar attachment fitting in accordance with Part V of the alert service bulletin, and do all applicable corrective actions in accordance with Part V of the alert service bulletin, except as provided by paragraphs (j) and (k). Do all applicable corrective actions before further flight. Repeat the Part V inspection at intervals not to exceed 120 months.
During any inspection required by this AD, if any corrosion damage is found that cannot be removed, or if any damage is found that is outside the limits specified in the alert service bulletin, or if any discrepancy is found and the alert service bulletin specifies contacting the manufacturer for disposition of certain repair conditions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
(k) Certain sections in Parts I, II, and V of the alert service bulletin specify “For 737-100 and -200 airplanes” and “For 737-300 and -500 airplanes.” However, those sections are applicable to Model 737-100, -200, and -200C airplanes, and Model 737-300, -400, and -500 airplanes, respectively.
For airplanes identified as Groups 1 through 5, as specified in the alert service bulletin, on which the aft pin of the aft outboard stabilizing fitting was replaced before the effective date of this AD, in accordance with Boeing Alert Service Bulletin 737-57A1266, dated May 8, 2003: Within 36 months after the effective date of this AD, do a torque check to determine whether the aft pin is correctly installed. Do all applicable corrective actions before further flight. Do the actions in accordance with Part III of the alert service bulletin.
For airplanes identified as Groups 1 and 3, as specified in the alert service bulletin: Prior to or concurrently with accomplishment of paragraph (g) of this AD, do the replacement of the existing tube assembly of the outboard stabilizing fitting as specified in Part IV of Boeing Service Bulletin 737-57-1052, Revision 4, dated October 24, 1980.
Replacement of the tube assembly before the effective date of this AD in accordance with Boeing Service Bulletin 737-57-1073, Revision 4, dated April 12, 1985, is acceptable for compliance with the replacement specified in paragraph (m) of this AD.
(o) For Groups 1 through 4, as specified in the alert service bulletin: Replacement of the H-11 bolts for the inboard stabilizing fitting before the effective date of this AD, in accordance with Boeing Service Bulletin 737-57-1231, dated December 1, 1994, is acceptable for compliance with the replacement of the H-11 bolts specified in paragraph (g) of this AD.
