[Federal Register Volume 63, Number 108 (Friday, June 5, 1998)]
[Proposed Rules]
[Pages 30658-30660]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14906]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-23-AD]
RIN 2120-AA64


Airworthiness Directives; Aviat Aircraft, Inc. Models S-1S, S-1T, 
S-2, S-2A, S-2S, and S-2B Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise Airworthiness Directive (AD) 
96-12-03 R1, which applies to 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 part number (P/N) 
76090, P/N 2-2107-1, or P/N 1-210-102. That AD currently 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 both aft lower fuselage wing attach 
fittings eliminates the repetitive inspection requirement of AD 96-12-
03. Aviat started incorporating modified aft lower fuselage wing attach 
fittings on newly manufactured airplanes beginning with serial number 
5337, instead of 5349 as referenced in the existing AD. This proposed 
AD would retain the repetitive inspection and possible modification 
requirements of AD 96-12-03 R1, and would change the applicability 
accordingly. The actions specified by the proposed AD are intended to 
prevent possible in-flight separation of the wing from the airplane 
caused by a cracked fuselage wing attach fitting.


[[Page 30659]]


DATES: Comments must be received on or before July 30, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 96-CE-23-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 Aviat Aircraft, Inc., P.O. Box 1240, Afton, Wyoming 83110; 
telephone: (307) 886-3151; facsimile: (307) 886-9674. This information 
also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Roger Caldwell, Aerospace 
Engineer, FAA, Denver Aircraft Certification Office, 26805 E. 68th 
Avenue, Room 214, Denver, Colorado 80249; telephone: (303) 342-1086; 
facsimile: (303) 342-1088.

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-23-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 Regional Counsel, Attention: 
Rules Docket No. 96-CE-23-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    AD 96-12-03 R1, Amendment 39-10109 (62 FR 44535, ugust 22, 1997), 
currently requires the following on 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 P/N 76090, P/N 2-2107-1, or P/N 1-210-
102:

--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 both aft lower fuselage wing attach fittings eliminates the 
repetitive inspection requirement of AD 96-12-03.

    Accomplishment of the actions required by AD 96-12-03 R1 is in 
accordance with Aviat Service Bulletin (SB) No. 25, dated April 3, 
1996, Revised November 12, 1996.
    AD 96-12-03 R1 replaced AD 96-12-03, Amendment 39-9645 (61 FR 
28730, June 6, 1996), and incorporated an ending serial number of 5348 
on the Aviat Model S-2B airplanes. AD 96-12-03 required the current 
actions on all serial numbers of the affected airplanes.

Actions Since Issuance of Previous Rule

    Since issuance of AD 96-12-03 R1, Aviat has reported to the FAA 
that the ending serial number for the Model S-2B airplanes is 
incorrect. The correct serial number should be 5336 instead of 5348.
    Aviat has revised Service Bulletin No. 25 (dated April 3, 1996; 
Revised November 12, 1996; Revised November 11, 1997) to reflect this 
serial number change.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that (1) the applicability in AD 96-12-03 R1 of the Aviat 
Model S-2B airplanes should be changed from an ending serial number of 
5348 to 5336; and (2) AD action should be taken to continue to prevent 
possible in-flight separation of the wing from the airplane caused by a 
cracked fuselage wing attach fitting.

Explanation of the Provisions of the Proposed 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 P/N 76090, P/N 2-2107-1, or 
P/N1-210-102, the FAA is proposing AD action to revise AD 96-12-03 R1. 
The proposed AD would retain the repetitive inspection and possible 
modification requirements of AD 96-12-03 R1, and would change the 
applicability of the Model S-2B airplanes from an ending serial number 
of 5348 to an ending serial number of 5336.

Cost Impact

    The FAA estimates that 500 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 2 
workhours per airplane to accomplish the initial inspection, and that 
the average labor rate is approximately $60 an hour. Parts to 
accomplish the inspections cost approximately $100 per airplane. Based 
on these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $110,000. These figures do not take into 
account the cost of repetitive inspections. The FAA has no way of 
determining how many repetitive inspections each owner/operator may 
incur over the life of each airplane.
    AD 96-12-03 R1 currently requires the same actions on the affected 
airplanes as is proposed in this NPRM. The only difference between the 
proposed AD and AD 96-12-03 R1 is a change in the ending serial number 
of the Model S-2B airplanes. Therefore, the proposed AD has no 
additional cost impact over that already required by AD 96-12-03 R1.

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

[[Page 30660]]

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 
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) 96-12-03 R1, Amendment 39-10109 (62 FR 44535, August 22, 1997), 
and by adding a new AD to read as follows:

Aviat Aircraft, Inc.: Docket No. 96-CE-23-AD; Revises AD 96-12-03 
R1, Amendment 39-10109.

    Applicability: The following airplane models and serial numbers, 
certificated in any category, that are equipped with aft lower 
fuselage wing attach fittings incorporating part number (P/N) 76090, 
P/N 2-2107-1, or P/N 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 one of 
the following service bulletins (SB):

Service Bulletins

--Aviat SB No. 25, dated April 3, 1996, Revised November 12, 1996, 
Revised November 11, 1997;
--Aviat SB No. 25, dated April 3, 1996, Revised November 12, 1996; 
or
--Aviat SB No. 25, dated April 3, 1996.

Airplanes Affected

--Models S-1S, S-1T, S-2, S-2A, and S-2S airplanes, all serial 
numbers.
--Model S-2B airplanes, serial numbers 5000 through 5336.

    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 as indicated in the body of this AD.
    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) Within 50 hours time-in-service (TIS) after October 3, 1997 
(the effective date of AD 96-12-03 R1), unless already accomplished 
(compliance with either AD 96-12-03 R1 or AD 96-12-03), and 
thereafter at intervals not to exceed 50 hours TIS, inspect the aft 
lower fuselage wing attach fitting on both wings for cracks. 
Accomplish these inspections in accordance with the ACCOMPLISHMENT 
INSTRUCTIONS section of one of the following SB's:
    (1) Aviat SB No. 25, dated April 3, 1996, Revised November 12, 
1996, Revised November 11, 1997;
    (2) Aviat SB No. 25, dated April 3, 1996, Revised November 12, 
1996; or
    (3) Aviat 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 one of 
the SB's referenced in paragraphs (a)(1), (a)(2), and (a)(3) of this 
AD. Repetitive inspections are no longer necessary on an aft lower 
fuselage wing attachment fitting that was found cracked and 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 
one of the SB's referenced in paragraphs (a)(1), (a)(2), and (a)(3) 
of this AD 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, 26805 E. 68th Avenue, Room 214, Denver, 
Colorado 80249.
    (1) The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Denver ACO.
    (2) Alternative methods of compliance approved in accordance 
with AD 96-12-03 R1 or AD 96-12-03 are considered approved for this 
AD.

    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) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Aviat Aircraft, 
Inc., P.O. Box 1240, Afton, Wyoming 83110; or may examine this 
document at the FAA, Central Region, Office of the Regional Counsel, 
Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (g) This amendment revises AD 96-12-03 R1, Amendment 39-10109.

    Issued in Kansas City, Missouri, on May 29, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-14906 Filed 6-4-98; 8:45 am]
BILLING CODE 4910-13-U