[Federal Register Volume 60, Number 114 (Wednesday, June 14, 1995)]
[Rules and Regulations]
[Pages 31241-31243]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14404]



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[[Page 31242]]



DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-CE-29-AD; Amendment 39-9275; AD 95-12-23]


Airworthiness Directives; Twin Commander Aircraft Corporation 
Models 690C and 695 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Twin Commander Aircraft Corporation (Twin Commander) 
Models 690C and 695 airplanes. This action requires initially 
inspecting the wing structure for cracks, modifying any cracked wing 
structure, and, if not cracked, either repetitively inspecting or 
modifying the wing structure. Results of full-scale fatigue testing 
that indicated areas in the wing that are subject to fatigue cracks 
prompted this action. The actions specified by this AD are intended to 
prevent wing damage caused by fatigue cracking, which, if not detected 
and corrected, could progress to the point of structural failure.

DATES: Effective July 30, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 30, 1995.

ADDRESSES: Service information that applies to this AD may be obtained 
from the Twin Commander Aircraft Corporation, 19010 59th Drive, NE., 
Arlington, Washington 98223. This information may also be examined at 
the Federal Aviation Administration (FAA), Central Region, Office of 
the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. David D. Swartz, Aerospace 
Engineer, FAA, Northwest Mountain Region, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (206) 227-2624; facsimile (206) 227-
1181.

SUPPLEMENTARY INFORMATION: 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 Models 690C and 695 airplanes was published 
in the Federal Register on February 10, 1995 (60 FR 6459). The action 
proposed to require initially inspecting the wing structure for cracks, 
modifying any cracked wing structure, and, if not cracked, either 
repetitively inspecting or modifying the wing structure. Accomplishment 
of the proposed action would be in accordance with Twin Commander 
Service Bulletin No. 213, dated July 29, 1994.
    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.
    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.
    The FAA established the compliance time of the initial and first 
repetitive inspection to coincide with the 6,000-hour Major Inspection 
Guide I and 7,500-hour Major Inspection Guide II inspections, 
respectively.
    The FAA estimates that 86 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 66 workhours per 
airplane to accomplish the required inspection, and that the average 
labor rate is approximately $60 an hour. Based on these figures, the 
total cost impact of this AD on U.S. operators is estimated to be 
$340,560. This figure does not take into account the cost of repetitive 
inspections or the cost of any modifications that may be needed based 
on the inspection results. The FAA has no way of determining how many 
wing structures may be cracked and need modification, or how many 
repetitive inspections each owner/operator may incur over the life of 
the airplane.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new AD to read as follows:

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 Nos.            
------------------------------------------------------------------------
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, 

[[Page 31243]]
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 a serial 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 at intervals 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 SB No. 
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 (39-9275) becomes effective on July 30, 1995.

    Issued in Kansas City, Missouri, on June 7, 1995.
Gerald W. Pierce,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-14404 Filed 6-13-95; 8:45 am]
BILLING CODE 4910-13-U