AD 98-08-25

This amendment supersedes Airworthiness Directive (AD) 96-12-08 on certain Twin Commander Aircraft Corporation (Twin Commander) 500, 680, 690, and 695 series airplanes, which currently requires replacing the nose landing gear (NLG) drag link bolt with one that has been manufactured with the proper heat-treatment. This action will retain the requirements of AD 96-12-08, add an additional model and additional serial numbers to the applicability section of the AD, and require replacing bolt part number (P/N) ED10055 with bolt P/N 750076-1 on certain Models 690D and 695A airplanes. This action is prompted by a defective manufacture of a certain lot of drag link bolts used in the NLG. The actions specified by this AD are intended to prevent the NLG from collapsing caused by a failed drag link bolt, which could result in loss of control of the airplane during landing operations.

Final rule.

98-08-25 Twin Commander Aircraft Corporation: Amendment No. 39-10474; Docket No. 96-CE-54-AD; Supersedes AD 96-12-08, Amendment No. 39-9650.

Applicability: The following model and serial number airplanes, certificated in any category:

Models
Serial Nos.
500S
3185, 3228, 3230, 3262, and 3291
500U
1765
680F
1195
681
6027
680V
1677
690
11035, 11053, 11068, and 11074
690A
11111, 11134, 11146, 11153, 11173, 11177, 11205, 11215, 11237, 11249, 11271, 11273, and 11282
690B
11360, 11382, 11409, 11424, 11451, 11455, 11463, 11491, 11513, 11521, 11535, 11536, 11539, and 11566
690C
11638, 11643, 11676, 11689, and
11719
690D
15041
695
95010, 95033, 95044, and 95066
695A
69010, 69041, 69056, and 69061

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 (g) 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.

Compliance: Required within the next 75 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished.

To prevent the nose landing gear (NLG) from collapsing, which could result in loss of control of the airplane during landing operations, accomplish the following:

(a) For all airplane models, except for Models 690D and 695A, replace the NLG drag link bolt, part number (P/N) ED 10055, with a new bolt in accordance with the INSTRUCTIONS section of Twin Commander Service Bulletin(SB) 224, Revision C, dated July 25, 1996.

(b) For airplane Models 690D and 695A, replace the NLG drag link bolt (P/N ED 10055), with a new bolt (P/N 750076-1) in accordance with Twin Commander SB 224, Revision C, dated July 25, 1996.

(c) The new replacement bolt must be marked with the manufacturer's serial number, the date of manufacture, and the last three digits of the drawing number, 055, on the bolt head for all but Models 690D and 695A. Models 690D and 695A bolts must be marked with the manufacturer's serial number, the date of manufacture, and the last three digits of the drawing number, 76-1, on the bolt head.

Note 2: Although not required by this AD, FAA highly recommends that the removed bolt (P/N ED 10055) be returned to Twin Commander for Rockwell Hardness testing.

(d) For all affected models except for Models 690D and 695A, compliance with Twin Commander Service Bulletin (SB) 224, Revision A, dated April 24, 1996, or Revision C, dated July 25, 1996, fulfills the applicable requirements of this AD, and is considered "unless already accomplished."

(e) As of the effective date of this AD, no person shall install an NLG drag link bolt that does not have the manufacturer's serial number, manufacture date, and the last three digits of the drawing number as specified in paragraph (c) of this AD.

(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 compliance times that provides an equivalent level of safety may be approved by the Manager, Seattle Aircraft Certification Office, 1601 Lind Ave. SW, 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained at the Seattle Aircraft Certification Office.

(h) The inspection and replacement required by this AD shall be done in accordance with Twin Commander Service Bulletin No. 224, Revision C, dated July 25, 996. 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, 19010 59th Dr. NE, Arlington, Washington, 98223-7832. 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.

(i) This amendment supersedes AD 96-12-08, mendment 39-9650.

(j) This amendment becomes effective on May 18, 1998.

Events Leading to the Issuance of This AD

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Twin Commander 500, 680, 690, and 695 series airplanes that do not have a nose landing gear drag link bolt with the manufacturer's serial number, manufacture date, and the last three digits of the drawing number 055 on the bolt head, was published in the Federal Register on May 9, 1997 (62 FR 25563). The action proposed to require:

replacing the NLG drag link bolt with an approved heat-treated bolt that has the manufacturer's serial number, manufacture date, and the last three digits of the drawing number (055) on the bolt head,

including Model 680V in the applicability of the AD;

including additional serial numbers of the already affected models; and

changing the bolt part number (P/N) to be installed on Models 690D and 695A from P/N ED10055 to P/N 750076-1.

Accomplishment of the proposed action would be in accordance with Twin Commander Service Bulletin (SB) No. 224, Revision C, dated July 25, 1996.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination

After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Cost Impact

The FAA estimates that 54 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per airplane to accomplish this action, and that the averagelabor rate is approximately $60 an hour. The manufacturer is providing parts and one hour labor free of charge. With this in mind, this AD imposes no cost impact upon the U.S. operators of the affected airplanes.

Regulatory Impact

The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39-AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Airworthiness Directive (AD) 96-12-08, Amendment No. 39-9650 and by adding a new AD to read as follows: