[Federal Register Volume 62, Number 90 (Friday, May 9, 1997)]
[Proposed Rules]
[Pages 25563-25565]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-11878]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-54-AD]
RIN 2120-AA64


Airworthiness Directives; Twin Commander Aircraft Corporation 
500, 680, 690, and 695 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 96-12-08 on Twin Commander Aircraft Corporation (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, which currently requires replacing the nose landing gear (NLG) 
drag link bolt with one that has been manufactured with the proper 
heat-treatment. The proposed action would retain these requirements, 
would require additional models and serial numbers be added to the 
applicability section, and would require certain Models 690D and 695A 
airplanes to replace bolt part number (P/N) ED10055 with bolt P/N 
750076-1. The addition of airplane models and serial numbers, as well 
as changing the part number of the bolt to be replaced on some models 
prompted the proposed action. The actions specified by the proposed AD 
are intended to prevent the NLG from collapsing which could result in 
loss of control of the airplane during landing operations.

DATES: Comments must be received on or before July 17, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 96-CE-54-AD, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106. Comments may be inspected at 
this location between 8 a.m. and 4 p.m., Monday through Friday, 
holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Twin Commander Aircraft Corporation, 19010 59th Dr. NE., 
Arlington, Washington, 98223-7832; telephone (360) 435-9797; facsimile 
(360) 435-1112. This information also may be examined at the Rules 
Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Jeffrey Morfitt, Aerospace Engineer, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Ave. SW., Renton, 
Washington, 98055-4056; telephone (206) 227-2595; facsimile (206) 227-
1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report that summarizes each FAA-public contact concerned 
with the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 96-CE-54-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 96-CE-54-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    Airworthiness Directive (AD) 96-12-08, Amendment 39-9650, (61 FR 
28738, dated June 6, 1996), currently requires replacing the NLG drag 
link bolt with an approved heat-treated bolt on Twin Commander 500, 
680, 690, and 695 series airplanes. This bolt has the manufacturer's 
serial number, manufacture date, and the last three digits of the 
drawing number, 055, on the bolt head.

[[Page 25564]]

Actions Since Issuance of Previous Rule

    Since the issuance of AD 96-12-08, the manufacturer has notified 
the FAA that Twin Commander Model 680V was inadvertently left out of 
the applicability section, several serial numbers on the other 
applicable airplane models were not listed, and the part number of the 
bolt to be used on Models 690D and 695A was not correct. The AD should 
have required installing Twin Commander bolt part number
(P/N) 750076-1, instead of P/N ED10055 on these two airplane Models.

Relevant Service Information

    Twin Commander has revised their original Service Bulletin No. 224, 
Revision A, dated April 24, 1996 to reflect the changes in 
applicability and part numbers with a new revised Twin Commander 
Service Bulletin (SB) No. 224, Revision C, dated July 25, 1996. Twin 
Commander SB No. 224, Revision B also added serial numbers that were 
not included in the first revision. All three revisions retain the same 
action which specifies procedures for inspecting the nose landing gear 
drag link bolt for a specific part number, and replacing any bolt that 
does not have the correct part number stamped on the top of the bolt 
head.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that AD action should be taken to prevent the NLG from 
collapsing which could result in loss of control of the airplane during 
landing operations.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Twin Commander 500, 680, 690, and 695 series 
airplanes of the same type design, the proposed AD would supersede AD 
96-12-08 with a new AD that would 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 on the bolt head,
     including Model 680V in the applicability of the affected 
airplanes,
     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.

Cost Impact

    The FAA estimates that 54 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately one 
workhour per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. The manufacturer is 
providing parts and one hour labor free of charge. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be zero.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would 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) if promulgated, 
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 draft regulatory evaluation 
prepared for this action has been placed 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, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 14 
CFR part 39 of the Federal Aviation Regulations 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 39-9650, and by adding a new AD to read as 
follows:

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

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

------------------------------------------------------------------------
              Models                           Serial numbers           
------------------------------------------------------------------------
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 (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.

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

[[Page 25565]]

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) 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 
numbers as specified in paragraph (c) of this AD.
    (e) Special flight permits may be issued in accordance with 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, 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. Alternative methods of compliance approved in 
accordance with AD 96-12-08 are not considered approved as 
alternative methods of compliance for this AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from Seattle Aircraft Certification Office.

    (g) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Twin Commander 
Aircraft Corporation, 19010 59th Dr. NE., Arlington, Washington, 
98223-7832; telephone (360) 435-9797; facsimile (360) 435-1112; or 
may examine this document at the FAA, Central Region, Office of the 
Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, 
Missouri 64106.
    (h) This amendment supersedes AD 96-12-08, Amendment 39-9650.

    Issued in Kansas City, Missouri, on April 30, 1997.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-11878 Filed 5-8-97; 8:45 am]
BILLING CODE 4910-13-U