Airworthiness Directive · Amendment 39-11968 · McDonnell Douglas Model DC-9-10, -9-20, -9-30, -9-40, and -9-50 Series Airplanes and C-9 (Military) Airplanes
McDonnell Douglas Model DC-9-10, -9-20, -9-30, -9-40, and -9-50 Series Airplanes and C-9 (Military) Airplanes
Model DC-9-10, -9-20, -9-30, -9-40, and -9-50 series airplanes and C-9 (military) airplanes, as listed in Boeing Alert Service Bulletin DC9-57A218, dated September 20, 2000; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-10, -9-20, -9-30, -9-40, and -9-50 series airplanes and C-9 (military) airplanes. This action requires, among other actions, measuring the diameter of the hole counterbore of the outboard idler hinge fitting of the left and right wing flap; performing repetitive high frequency eddy current inspections (HFEC) to detect cracks at the flap idler hinge fitting, if necessary; and replacing the flap idler hinge fitting with a new like part, if any crack is detected. This action is necessary to prevent failure of the outboard flap idler hinge fitting due to fatigue cracking, which could result in a deflected flap that may cause an asymmetric lift and consequent reduced controllability and structural integrity of the airplane. This action is intended to address the identified unsafe condition.
To prevent failure of the outboard flap idler hinge fitting due to fatigue cracking, which could result in a deflected flap that may cause an asymmetric lift and consequent reduced controllability and structural integrity of the airplane, accomplish the following:
(a) Before the accumulation of 24,000 total landings, or within 90 days after the effective date of this AD, whichever occurs later, measure the diameter of the hole counterbore of the outboard idler hinge fitting of the left and right wing flap, per Boeing Alert Service Bulletin DC9-57A218, including Appendix, dated September 20, 2000.
(1) If the diameter of any hole counterbore is 0.875 (\7/8\) inch, before further flight, install a new nut, plain washer, and PLI washer, per the service bulletin.
(2) If the diameter of any hole counterbore is 1.125 (1\1/8\) inches, before further flight, do a high frequency eddy current inspection (HFEC) to detect cracks at the flap idler hinge fitting, per the service bulletin.
(i) Condition 1. If no crack is detected, before further flight, install a new nut, plain washer, and PLI washer, per the service bulletin. Repeat the HFEC inspection every 1,000 landings until the replacement specified in paragraph (a)(2)(ii) has been done.
(ii) Condition 2. If any crack is detected, before further flight, replace the flap idler hinge fitting with a new like part, per the service bulletin. Within 24,000 landings after accomplishment of the replacement, do the HFEC inspection required by paragraph (a)(2) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
