[Federal Register Volume 61, Number 110 (Thursday, June 6, 1996)]
[Rules and Regulations]
[Pages 28738-28740]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14032]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-22-AD; Amendment 39-9650; AD 96-12-08]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to Twin Commander Aircraft Corporation (Twin Commander) 500, 
680, and 690 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. 
This action requires replacing the nose landing gear (NLG) drag link 
bolt with one that has been manufactured with the proper heat 
treatment. This action was prompted by the failure of an improperly 
heat treated NLG drag link bolt causing collapse of the nose landing 
gear on a certain Twin Commander Model 690B airplane while taxiing. The 
actions specified by this AD are intended to prevent the NLG from 
collapsing, which if not corrected, could result in loss of the 
airplane.

DATES: Effective June 27, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 27, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before July 29, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket 96-CE-22-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106.
    Service information that applies to this 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 may also be examined at the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket 96-CE-22-AD, 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: David D. Swartz, Aerospace Engineer, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Ave. S.W., 
Renton, Washington, 98055-4056; telephone (206) 227-2624; facsimile 
(206) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has recently received an accident 
report on a certain Twin Commander Model 690B airplane. The accident 
was caused by the failure of the nose landing gear (NLG) after the NLG 
drag link bolt, part number (P/N) ED 10055, broke. Further 
investigation revealed that the bolt had not been heat treated properly 
during manufacture, thus making it weak and the NLG susceptible to 
collapse during landing or taxiing operations. Additional bolts in two 
other manufactured lots also failed the Rockwell Hardness test, 
resulting in the need to replace all of these NLG drag link bolts.
    Twin Commander has issued service bulletin (SB) 224, Revision A, 
dated April 24, 1996 which specifies replacing the NLG drag link bolt 
with an approved heat treated bolt.

    Note: Although it is not required by this AD, the FAA recommends 
that the owner/operator return the removed bolt to the factory for 
testing.

    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 
failing, which if not corrected, could result in loss of the airplane.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Twin Commander 500, 680, and 690 series 
airplanes of the same type design, this AD requires replacing the NLG 
drag link bolt with an approved heat treated bolt which has the 
manufacturer's serial number, manufacture date, and the last three 
digits of the drawing number, 055, on the bolt head. The actions are to 
be done in accordance with the instructions in

[[Page 28739]]

Twin Commander SB 224, Revision A, dated April 24, 1996.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for public 
prior comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting immediate flight safety and, thus, was not 
preceded by notice and opportunity to comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 will be considered, 
and this rule may be amended in light of the comments received. Factual 
information that supports the commenter's ideas and suggestions is 
extremely helpful in evaluating the effectiveness of the AD action and 
determining whether additional rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 
AD 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-22-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation and that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a significant regulatory action under 
Executive Order 12866. It has been determined further that this action 
involves an emergency regulation under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979). If it is determined that 
this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket (otherwise, an evaluation is 
not required). A copy of it, if filed, may be obtained from the Rules 
Docket.

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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

96-12-08.  Twin Commander Aircraft Corporation: Amendment 39-9650; 
Docket No. 96-CE-22-AD.

    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.                               
690...............................  11035, 11053, 11068, and 11074.     
690A..............................  11111, 11134, 11146, 11173, 11177,  
                                     11205, 11215, 11237, 11271, 11273, 
                                     and 11282.                         
690B..............................  11360, 11382, 11409, 11424, 11451,  
                                     11455, 11463, 11491, 11513, 11535, 
                                     11536, and 11539.                  
690C..............................  11638, 11676, 11689, and 11719.     
690D..............................  15041.                              
695...............................  95010, 95033, and 96066.            
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 (e) 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 10 hours time-in-service 
(TIS), unless already accomplished.
    To prevent the nose landing gear (NLG) from collapsing, which if 
not corrected, could result in loss of the airplane, accomplish the 
following:
    (a) 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 224, Revision A, dated April 24, 1996.
    (b) 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.

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

    (c) 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, 055, on the bolt head.
    (d) 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.
    (e) An alternative method of compliance (which would include 
Rockwell Hardness test) 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. 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle Aircraft Certification Office.

    (f) The replacement required by this AD shall be done in 
accordance with Twin Commander Aircraft Corporation Service Bulletin 
224, Revision A, dated April 24, 1996. 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

[[Page 28740]]

from Twin Commander Aircraft Corporation, 19010 59th Dr. NE, 
Arlington, Washington, 98223-7832; telephone (360) 435-9797; 
facsimile (360) 435-1112. 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.
    (g) This amendment (39-9650) becomes effective on June 27, 1996.

    Issued in Kansas City, Missouri, on May 30, 1996.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-14032 Filed 6-5-96; 8:45 am]
BILLING CODE 4910-13-P