[Federal Register Volume 61, Number 110 (Thursday, June 6, 1996)]
[Rules and Regulations]
[Pages 28730-28732]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-14051]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-23-AD; Amendment 39-9645; AD 96-12-03]
RIN 2120-AA64


Airworthiness Directives; Aviat Aircraft, Inc. Models S-1S, S-1T, 
S-2, S-2A, S-2S, and S-2B Airplanes (Formerly Known as Pitts Models S-
1S, S-1T, S-2, S-2A, S-2S, and S-2B 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 certain Aviat Aircraft, Inc. (Aviat) Models S-1S, S-1T, S-2, 
S-2A, S-2S, and S-2B airplanes that are equipped with aft lower 
fuselage wing attach fittings incorporating either part number (P/N) 
76090, 2-2107-1, or 1-210-102. This action requires repetitively 
inspecting the aft lower fuselage wing attach fitting on both wings for 
cracks and modifying any cracked aft lower fuselage wing attach 
fitting. Modifying the aft lower fuselage wing attach fitting on both 
wings eliminates the repetitive inspection requirement of the AD. 
Several reports of cracked fuselage wing attach fittings on the 
affected airplanes prompted this action. The actions specified by this 
AD are intended to prevent possible in-flight separation of the wing 
from the airplane caused by a cracked fuselage wing attach fitting.

DATES: Effective June 24, 1996.

    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 24, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before August 9, 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-23-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106.

[[Page 28731]]

    Service information that applies to this AD may be obtained from 
Aviat Aircraft, Inc., P.O. Box 1240 (postal service delivery), 672 
South Washington Street (express mail), Afton, Wyoming 83110. This 
information may also be examined at the FAA, Central Region, Office of 
the Assistant Chief Counsel, Attention: Rules Docket 96-CE-23-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: Mr. Roger Caldwell, Aerospace 
Engineer, FAA, Denver Aircraft Certification Office, 5440 Roslyn 
Street, suite 133, Denver, Colorado 80216; telephone (303) 286-5683; 
facsimile (303) 286-5689.

SUPPLEMENTARY INFORMATION:

Events Leading to the AD

    The FAA has received 11 reports of the aft lower fuselage wing 
attach fittings cracking on Aviat Models S-1S, S-1T, S-2, S-2A, S-2S, 
and S-2B airplanes. Five of these incidents were reported on in-service 
airplanes and six were found defective during Aviat's in-house 
manufacturing process. Each of the cracked aft lower fuselage wing 
attach fittings incorporate either part number (P/N) 76090, P/N 2-2107-
1, or P/N 1-210-102. If not detected and corrected, a cracked aft lower 
fuselage wing attach fitting could lead to in- flight separation of the 
wing from the airplane.
    Further analysis of the design of the P/N 76090, 2-2107-1, and 1-
210-102 aft lower fuselage wing attach fittings reveals a bend radius 
that could reduce the fatigue life and subsequently make the parts more 
susceptible to cracking. Aviat started manufacturing airplanes in 1990 
with aft lower fuselage wing attach fittings with a larger bend radius. 
The FAA has received no reports of cracking on airplanes incorporating 
attach fittings that incorporate this larger bend radius design.
    Aviat has issued Service Bulletin (SB) No. 25, dated April 3, 1996, 
which specifies procedures for inspecting and modifying the aft lower 
fuselage wing attach fittings incorporating either P/N 76090, 2-2107-1, 
and 1-210-102.
    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 possible in-flight 
separation of the wing from the airplane caused by a cracked fuselage 
wing fitting.

Explanation of the Provisions of the AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Aviat Models S-1S, S-1T, S-2, S-2A, S-2S, and 
S-2B airplanes of the same type design that are equipped with aft lower 
fuselage wing attach fittings incorporating either P/N 76090, 2-2107-1, 
or 1-210-102, this AD requires repetitively inspecting the aft lower 
fuselage wing attach fitting on both wings for cracks, and modifying 
any cracked aft lower fuselage wing attach fitting. Modifying the aft 
lower fuselage wing fitting on both wings eliminates the repetitive 
inspection requirement of this AD. Accomplishment of the required 
actions is in accordance with Aviat SB No. 25, dated April 3, 1996.
    Since a situation exists (possible in-flight separation of the wing 
from the airplane) 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-23-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation 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 U.S.C. 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:

    96-12-03 Aviat Aircraft, Inc.: Amendment 39-9645; Docket No. 96-
CE-23-AD.

    Applicability: Models S-1S, S-1T, S-2, S-2A, S-2S, and S-2B 
airplanes (formerly

[[Page 28732]]

known as Pitts Models S-1S, S-1T, S-2, S-2A, S-2S, and S-2B 
airplanes), all serial numbers, certificated in any category, that 
are equipped with aft lower fuselage wing attach fittings 
incorporating part number (P/N) 76090, 2-2107-1, or 1-210-102, and 
where these aft lower fuselage wing attach fittings on both wings 
have not been modified in accordance with the ACCOMPLISHMENT 
INSTRUCTIONS section of Aviat Service Bulletin (SB) No. 25, dated 
April 3, 1996.

    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 initially within the next 50 hours 
time-in-service (TIS) after the effective date of this AD, unless 
already accomplished, and thereafter at intervals not to exceed 50 
hours TIS.

    To prevent possible in-flight separation of the wing from the 
airplane caused by a cracked aft lower fuselage wing attach fitting, 
accomplish the following:
    (a) Inspect the aft lower fuselage wing attach fitting on both 
wings for cracks in accordance with the ACCOMPLISHMENT INSTRUCTIONS 
section of Aviat Service Bulletin (SB) No. 25, dated April 3, 1996.
    (b) If any cracked aft lower fuselage wing attach fitting is 
found during any inspection required by this AD, prior to further 
flight, modify the cracked aft lower fuselage wing attach fitting in 
accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Aviat SB 
No. 25, dated April 3, 1996. Repetitive inspections are no longer 
necessary on a cracked aft lower fuselage wing attachment fitting 
that has the referenced modification incorporated.
    (c) Modifying the aft lower fuselage wing attach fitting on both 
wings in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of 
Aviat SB No. 25, dated April 3, 1996, is considered terminating 
action for the repetitive inspection requirement of this AD.
    (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 or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Denver Aircraft 
Certification Office, 5440 Roslyn Street, suite 133, Denver, 
Colorado 80216. The request shall be forwarded through an 
appropriate FAA Maintenance Inspector, who may add comments and then 
send it to the Manager, Denver ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Denver ACO.

    (f) The inspection and modification (if necessary) required by 
this AD shall be done in accordance with Aviat Service Bulletin No. 
25, dated April 3, 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 from Aviat 
Aircraft, Inc., P.O. Box 1240 (postal service delivery), 672 South 
Washington Street (express mail), Afton, Wyoming 83110. 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 (39-9645) becomes effective on June 24, 1996.

    Issued in Kansas City, Missouri, on May 29, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-14051 Filed 6-5-96; 8:45 am]
BILLING CODE 4910-13-U