AD 98-08-19 Airworthiness Directives; Twin Commander Aircraft Corporation 500, 600, and 700 Series Airplanes

Makes named: commander, twin commander. Read the applicability below — it usually turns on serial or part numbers too.

Models 500, 500A, 500B, 500S, 500U, 520, 560, 560A, 560E, 560F, 680, 680E, 680F, 680FL, 680FLP, 680FP, 680T, 680V, 680W, 681, 685, 690, 690A, 690B, 690C, 690D, 695, 695A, 695B and 720 airplanes, all serial numbers, 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 (f) 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.

Required as indicated in the body of this AD after the effective date of this AD, unless already accomplished. To prevent cracks at the wing to fuselage attach points, which, if not detected and corrected, could cause structural failure and loss of control of the airplane, accomplish the following: (a) For all models except Models 520, 560, 690C and 695, accomplish the actions in the following table in accordance with the Compliance section and Part I, I, and III of the ACCOMPLISHMENT INSTRUCTIONS sections of Twin Commander Service Bulletin No. 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997: [[Page 19174]] ------------------------------------------------------------------------ A B C ------------------------------------------------------------------------ Part I......... Upon the If cracked, prior If no cracks are accumulation of to further found, repeat 6,000 hours flight, replace inspection at total time-in- the brackets and 1,000 hour (hr.) service (TIS) or straps or repair intervals until within the next the part by an cracks are 100 hours TIS, approved repair found, replace whichever occurs scheme (see the cracked part later, install paragraph (b) of or repair by an access holes in this AD). Then, approved repair left and right accomplish PART scheme (see wing leading II of this AD.. paragraph (b) of edges and (Accomplish in this AD), then inspect the accordance with accomplish PART forward attach PART I of II. brackets and Compliance (Accomplish in straps for Section in Twin accordance with cracks. Commander SB PART I of For any airplanes 223, dated Oct. Compliance that have wings 24, 1996 as Section in Twin modified with amended by Commander SB titanium leading Revision Notice 223, dated Oct. edges through an No. 1, dated May 24, 1996 as STC, remove the 8, 1997 and amended by wing root Revision Notice Revision Notice farings to No. 2, dated No. 1, dated May accomplish the August 18, 8, 1997 and required 1997.) Revision Notice inspections, in No. 2, dated lieu of August 18, installing the 1997.) access holes. (Accomplish in accordance with PART I of Compliance Section in Twin Commander SB 223, dated Oct. 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997.) Part II........ Inspect for If cracked, prior After repair or cracks at the to further replacement is wing leading flight, replace accomplished, edge close-outs, any cracked part continue to upper & lower or repair the inspect at 6,000 return flange part with an hr. intervals. radius, fuselage approved repair (Accomplish in frame where tee scheme (see accordance with bracket paragraph (b) of PART II of attaches, this AD). If no Compliance inboard side of cracks are Section in Twin attach bracket found, continue Commander SB and frame tee to repetitively 223, dated Oct. bracket. inspect at 1,000 24, 1996 as (Accomplish in hour TIS amended by accordance with intervals. Revision Notice PART II of (Accomplish in No. 1, dated May Compliance accordance with 8, 1997 and Section in Twin PART II of Revision Notice Commander SB Compliance No. 2, dated 223, dated Oct. Section in Twin August 18, 24, 1996 as Commander SB 1997.) amended by 223, dated Oct. Revision Notice 24, 1996 as No. 1, dated May amended by 8, 1997, and Revision Notice Revision Notice No. 1, dated May No. 2, dated 8, 1997 and August 18, Revision Notice 1997.) No. 2, dated August 18, 1997.) Part III....... For pressurized If cracked, prior If no cracks, airplanes, at to further repeat 6,000 hr. total flight, repair inspection at TIS or within with an approved 1,000 hr. the next 100 repair scheme intervals until hours TIS (see paragraph cracks are whichever occurs (b) of this AD), found, then later, inspect and continue to accomplish PART fuselage station inspect at 1,000 III B of this (F.S.) 100 for hr. intervals. AD. cracks. (Accomplish in (Accomplish in For non- accordance with accordance with pressurized PART III of PART III of airplanes, at Compliance Compliance 12,000 hr. total Section in Twin Section in Twin TIS or within Commander SB Commander SB the next 100 223, dated Oct. 223, dated Oct. hours TIS 24, 1996 as 24, 1996 as whichever occurs amended by amended by later, inspect Revision Notice Revision Notice F.S. 100 for No. 1, dated May No. 1, dated May cracks. 8, 1997 and 8, 1997 and (Accomplish in Revision Notice Revison Notice accordance with No. 2, dated No. 2, dated PART III of August 18, August 18, Compliance 1997.) 1997.) Section in Twin Commander SB 223, dated Oct. 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997.) ------------------------------------------------------------------------ (b) Obtain a FAA-approved repair scheme from the manufacturer through the Manager of the Seattle Aircraft Certification Office at the address specified in paragraph (f) of this AD. (c) For Twin Commander Models 520 and 560 airplanes, upon the accumulation of 6,000 hours total TIS or within the next 100 hours TIS, whichever occurs later, accomplish PART II of the table in paragraph (a) of this AD. Accomplish PART III in accordance with the compliance times in the above table of paragraph (a). These models are excluded from the wing leading edge access hole installation in PART I of the table in paragraph (a) of this AD. (d) For Twin Commander Models 690C and 695 airplanes, accomplish PARTS I and II in accordance with the compliance times in the above table of paragraph (a). These Models are excluded from PART III of the table in paragraph (a) of this AD. (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 initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Seattle Aircraft Certification Office, 1601 Lind Ave. 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 Aircraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle Aircraft Certification Office. (g) The inspections and installations required by this AD shall be done in accordance with the Twin Commander Service Bulletin No. 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997. 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, P.O. Box 3369, Arlington, Washington, 98223. Copies may be inspected at the FAA, Central Region, Office of the Regional 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 becomes effective on May 18, 1998. Issued in Kansas City, Missouri, on April 3, 1998. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certificate Service. [FR Doc. 98-9874 Filed 4-16-98; 8:45 am] BILLING CODE 4910-13-U