91-25-08 R1 CESSNA AIRCRAFT COMPANY: Amendment 39-9024; Docket No. 91-CE-83-AD; Revises AD 91-25-08, Amendment 39-8109.
Applicability: The following model and serial number airplanes, certificated in any category:
Model
Serial Numbers
421C
421C0801 through 421C1807
425
425-0002 through 425-0236
Compliance: Required initially upon the accumulation of 3,000 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 within the last 300 hours TIS, and thereafter as indicated in the body of this AD.
NOTE 1: The compliance times specified in this AD take precedence over those referenced in the applicable service information.
To prevent wing failure caused by excessive wing spar cracking, accomplish the following:
(a) Fluorescent penetrant inspect both the left and right wing front spar upper caps for cracks between the main landing gear actuating cylinderattachment and the front spar wing attach fittings in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of ATTACHMENT TO SERVICE BULLETIN (SB) to Cessna SB CQB91-8R1, or the ACCOMPLISHMENT INSTRUCTIONS attachment to Cessna SB MEB91-7R1, as applicable.
(b) If any crack is found that is parallel (inboard - outboard) to the top of the spar cap, install the applicable SK421-142 or SK425-44 service kit (-1 for left spar cap and -2 for right spar cap) in accordance with instructions to the applicable service kit (included with the service bulletins referenced in paragraph (a) of this AD) at the times that correspond with the following crack lengths, and reinspect (as applicable) as specified in paragraph (d) of this AD:
(1) If equal to or less than 2.0 inches in length, within the next 200 hours TIS;
(2) If more than 2.0 inches and less than 2.5 inches in length, within the next 50 hours TIS; or
(3) If 2.5 or more inches in length, prior to further flight.(c) If any crack (regardless of length) is found that is not parallel (inboard - outboard) to the top of the spar cap, prior to further flight, obtain a repair scheme from the manufacturer through the Wichita Aircraft Certification Office (ACO), incorporate this repair scheme, and reinspect as specified in paragraph (d) of this AD.
(d) Reinspect (fluorescent penetrant) the left and right wing front spar upper caps for cracks in accordance with those procedures specified in paragraph (a) of this AD at intervals presented within the applicable criteria below:
(1) With cracks less than or equal to 2.0 inches in length that are parallel (inboard - outboard) to the top of the spar cap, at 50-hour TIS intervals until the applicable service kit is installed in accordance with paragraph (b) of this AD, and then reinspect thereafter at intervals not to exceed 600 hours TIS.
(2) With cracks found and the applicable SK421-142 or SK425-44 service kit (-1 for left spar cap and -2for right spar cap) incorporated, at 600-hour TIS intervals.
(3) With no cracks found and the applicable SK421-142 or SK425-44 service kit (-1 for left spar cap and -2 for right spar cap) not incorporated, at 300-hour TIS intervals; or
(4) With no cracks found and the applicable SK421-142 or SK425-44 service kit (-1 for left spar cap and -2 for right spar cap) incorporated, no repetitive inspections required.
(e) 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.
(f) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita ACO, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209. The request shall be forwarded through an appropriate FAA Maintenance Inspector,who may add comments and then send it to the Manager, Wichita ACO.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.
(g) The inspections and modifications required by this AD shall be done in accordance with ATTACHMENT TO SERVICE BULLETIN to Cessna Service Bulletin CQB91-8R1, or the ACCOMPLISHMENT INSTRUCTIONS attachment to Cessna Service Bulletin MEB91-7R1, as applicable. The modification required by this AD shall be accomplished in accordance with Cessna SERVICE KIT SK421-142, dated July 3, 1993, or Cessna SERVICE KIT SK425-44, dated November 6, 1992, as applicable. 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 Cessna Aircraft Company, P.O. Box 7704, Wichita, Kansas 67277. 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.
(h) This amendment (39-9024) revises AD 91-25-08, Amendment 39-8109.
(i) This amendment becomes effective on November 4, 1994.