AD 95-12-23

Final rule

95-12-23 TWIN COMMANDER AIRCRAFT CORPORATION: Amendment 39-9275; Docket No. 94-CE-29-AD.

Applicability: The following airplane models and serial numbers, certificated in any category:

Model Serial Numbers
690C 11600 through 11735
695 95000 through 95084

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 use the authority provided in paragraph (g) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required upon the accumulation of 6,000 hours time-in-service (TIS) or within the next 50 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished, and thereafter as indicated in the body of this AD.

To prevent wing damage caused by fatigue cracking, which, if not detected and corrected, could progress to the point of structural failure, accomplish the following:

(a) For all affected serial number Model 695 airplanes, and any Model 690C airplane incorporating a serial number in the 11600 through 11730 range, inspect the wing structure for cracks in accordance with the PART I ACCOMPLISHMENT INSTRUCTIONS (INSPECTIONS) section of Twin Commander Service Bulletin (SB) No. 213, dated July 29, 1994.

(b) For any Model 690C airplane incorporating aserial number in the 11731 through 11735 range, inspect the wing structure for cracks in accordance with Item 10 of the PART I ACCOMPLISHMENT INSTRUCTIONS (INSPECTIONS) section of Twin Commander SB No. 213, dated July 29, 1994.

(c) If, during the inspections required in paragraphs (a) and (b) of this AD, cracks are found in the areas referenced in Figures 1 through 5 and the instructions of the service information referenced above, prior to further flight, replace the damaged structure and modify the wing structure in accordance with the PART II ACCOMPLISHMENT INSTRUCTIONS (MODIFICATIONS) section of Twin Commander SB No. 213, dated July 29, 1994.

(d) If no cracks are found, accomplish one of the following:

(1) For all airplanes, upon the accumulation of 7,500 hours TIS or within 1,000 hours TIS after the initial inspection, whichever occurs later, reinspect the structure in accordance with either paragraph (a) or (b) of this AD, as applicable, and reinspect thereafter atintervals not to exceed 1,000 hours TIS, and, if applicable, replace any damaged part or modify the wing structure as specified in paragraph (c) of this AD; or

(2) For Model 695 airplanes and any Model 690C airplane incorporating a serial number in the 11600 through 11730 range, prior to further flight, modify the wing structure in accordance with the PART II ACCOMPLISHMENT INSTRUCTIONS (MODIFICATIONS) section of Twin Commander SB No. 213, dated July 29, 1994.

(e) For all affected Model 695 airplanes and any Model 690C airplane incorporating a serial number in the 11600 through 11730 range, the modification referenced in paragraphs (c) and (d)(2) of this AD may be accomplished any time after the initial inspection as terminating action for the repetitive inspection requirement of this AD, except for the inspection of the doublers at the wing attach fittings located in the Fuselage Station 144 frame (Item 10 of PART I ACCOMPLISHMENT INSTRUCTIONS section of the Twin Commander SBNo. 213, dated July 29, 1994). All affected model and serial number airplanes must inspect in this area at every 1,000 hours TIS.

NOTE 2: For those airplanes that have not accumulated 6,000 hours TIS, the initial and first repetitive inspection required by this AD were established to coincide with the 6,000-hour Major Inspection Guide I and 7,500-hour Major Inspection Guide II inspections, respectively, so that the operator may schedule the required action in accordance with these major inspections.

(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(g) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Northwest Mountain Region, 1601 Lind Avenue S.W., Renton, Washington 98055-4056. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(h) The inspections and modification required by this AD shall be done in accordance with Twin Commander Service Bulletin No. 213, dated July 29, 1994. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Twin Commander Aircraft Corporation, 19003 59th Drive, NE., Arlington, Washington 98223. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(i) This amendment becomes effective on July 30, 1995.