Airworthiness Directive · Amendment 39-14273 · McDonnell Douglas Model DC-9-14, DC-9-15, and DC-9-15F Airplanes; and McDonnell Douglas Model DC-9-20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes
McDonnell Douglas Model DC-9-14, DC-9-15, and DC-9-15F Airplanes; and McDonnell Douglas Model DC-9-20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes
Superseded. A later AD replaced this one: AD 2009-24-21. Comply with the one in force.
This AD applies to all McDonnell Douglas Model DC-9-14, DC-9-15, and DC-9-15F airplanes; Model DC-9-21 airplanes; Model DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, and DC-9-32F (C-9A, C-9B) airplanes; Model DC-9-41 airplanes; and Model DC-9-51 airplanes; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all transport category airplanes listed above. This AD requires repetitive inspections for cracks of the main landing gear (MLG) shock strut cylinder, and related investigative and corrective actions if necessary. This AD results from two reports of a collapsed MLG and a report of cracks in two MLG cylinders. We are issuing this AD to detect and correct fatigue cracks in the shock strut cylinder of the MLG, which could result in a collapsed MLG during takeoff or landing, and possible reduced structural integrity 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 “service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin DC9-32A350, Revision 1, dated August 3, 2005.
Before the applicable compliance time specified in paragraph (h) or Table 1 of this AD, as applicable, do the applicable actions in paragraphs (g)(1) and (g)(2) of this AD.
(1) For all airplane groups: Review the airplane maintenance records of the MLG to determine its service history and the number of landings on the MLG shock strut cylinder.
(2) For Group 3 airplanes identified in the service bulletin: Review the maintenance records to determine if the MLG cylinder on each Group 3 airplane has always been on a Group 3 airplane, and do the actions in paragraph (k) of this AD.
Inspect the MLG shock strut cylinders for cracks using the Option 1 or Option 2 non-destructive testing inspection described in the service bulletin. Inspect in accordance with the Accomplishment Instructions of the service bulletin. Do the detailed inspection before the accumulation of 60,000 total landings on the MLG, or at the applicable grace period specified in Table 1 of this AD, whichever occurs later, except as provided by paragraph (k) of this AD. If the review of maintenance records is not sufficient to conclusively determine the service history and number of landings on the MLG shock strut cylinder, perform the initial inspection at the applicable grace period specified in Table 1 of this AD.
| Airplanes identified in the service bulletin as group | Grace period | Repetitive interval |
|---|---|---|
| 1 | Within 18 months or 650 landings after the effective date of this AD, whichever occurs first | Intervals not to exceed 650 landings. |
| 2 | Within 18 months or 500 landings after the effective date of this AD, whichever occurs first | Intervals not to exceed 500 landings. |
| 3, except as provided by paragraph (k) of this AD | Within 18 months or 2,500 landings after the effective date of this AD, whichever occurs first | Intervals not to exceed 2,500 landings. |
| 4 | Within 18 months or 2,100 landings after the effective date of this AD, whichever occurs first | Intervals not exceed 2,100 landings. |
(i) If no crack indication is found during the inspection required by paragraph (h) of this AD, repeat the inspection at the applicable interval specified in Table 1 of this AD.
If any crack indication is found during any inspection required by paragraph (h) or (i) of this AD, before further flight: Confirm the crack indication by doing all applicable related investigative actions and doing the applicable corrective actions in accordance with the service bulletin. Repeat the inspection at the applicable threshold and interval specified in paragraph (h) of this AD.
For MLG cylinders on Group 3 airplanes as identified in the service bulletin: If the MLG cylinder was previously installed on a Group 4 airplane, as identified in the service bulletin, or if the service history and number of landings cannot be determined, the MLG cylinder must be inspected at the grace period and repetitive interval that applies to Group 4 airplanes, as specified in Table 1 of this AD.
Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin DC9-32A350, dated December 3, 2004, are acceptable for compliance with the corresponding actions required by 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.
