[Federal Register Volume 61, Number 96 (Thursday, May 16, 1996)]
[Rules and Regulations]
[Pages 24684-24686]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12137]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-20-AD; Amendment 39-9619; AD 96-10-12]
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 Aviat Aircraft, Inc. (Aviat) Models S-1S, S-1T, S-2, S-2A, 
S-2S, and S-2B airplanes that are equipped with a flight control stick 
with a wall thickness of .035 inch. This action requires repetitively 
inspecting the flight control stick for cracks, and replacing any 
cracked flight control stick with one with a wall thickness of .058 
inch. An incident on an Aviat Model S-2A airplane where the flight 
control stick fractured in flight prompted this action. The actions 
specified by this AD are intended to prevent the inability to maneuver 
the airplane because of a cracked flight control stick, which, if not 
detected and corrected, could result in loss of control of the 
airplane.

DATES: Effective June 7, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 7, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before July 19, 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-20-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106.
    Service information that applies to this AD may be obtained from 
Aviat Aircraft, Inc., The Airport-Box 1240, South Washington Street, 
Afton, Wyoming 83110. 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-20-AD, Room 
1558, 601 E. 12th Street, Kansas City, Missouri 64106; or

[[Page 24685]]

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 This Action

    The FAA has received a report of the flight control stick 
fracturing in flight on an Aviat Model S-2A airplane. Analysis of the 
fractured flight control stick revealed fatigue cracking at the upper 
weld above the pivot bearing. The flight control stick in the 
referenced incident had a wall thickness of .035-inch. If not detected 
and corrected, a cracked flight control stick could result in the 
inability to maneuver the airplane with subsequent loss of control of 
the airplane.
    Aviat has issued Service Bulletin (SB) No. 23, dated March 29, 
1996, which specifies procedures for (1) Inspecting, using dye 
penetrant methods, the .035-inch wall thickness flight control stick; 
and (2) installing a flight control stick with a wall thickness of .058 
inch.
    The affected airplane had accumulated 2,015 hours time-in-service 
(TIS) when the incident occurred. The FAA has determined that cracking 
in this area can develop after 1,000 hours TIS accumulated on a .035-
inch wall thickness flight control stick. All Model S-2A airplanes and 
some Model S-2S airplanes were equipped with a .035-inch wall thickness 
flight control stick at manufacture. Models S-1S, S-1T, S-2, S-2B and 
certain Model S-2S airplanes were manufactured with control sticks with 
a wall thickness greater than .035 inch, but could have .035-inch 
flight control sticks installed through FAA-approved field 
modification.
    After examining the circumstances and reviewing all available 
information related to the incident described above, the FAA has 
determined that (1) flight control sticks with a wall thickness of .035 
inch should be repetitively inspected for cracking after 1,000 hours 
TIS; and (2) AD action should be taken to prevent the inability to 
maneuver the airplane because of a cracked flight control stick, which, 
if not detected and corrected, could result in loss of control of the 
airplane.

Explanation of the Provisions of the AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Aviat S-1S, S-1T, S-2, S-2A, S-2S, and S-2B 
airplanes of the same type design that are equipped with a .035-inch 
wall thickness flight control stick, this AD requires repetitively 
inspecting the affected flight control stick for cracks, and replacing 
any cracked flight control stick with one with a wall thickness of .058 
inch. This action also allows the option of installing a .058-inch wall 
thickness flight control stick as terminating action for the repetitive 
inspection requirement if cracks were not found. Accomplishment of the 
required actions are in accordance with Aviat SB No. 23, dated March 
29, 1996.
    Since a situation exists (possible inability to maneuver the 
airplane with subsequent loss of control of 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-20-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:

96-10-12  Aviat Aircraft, Inc.: Amendment 39-9619; Docket No. 96-CE-
20-AD.

    Applicability: 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), all serial numbers, certificated in any 
category, that are

[[Page 24686]]

equipped with a flight control stick with a wall thickness of .035 
inch.

    Note 1: All Model S-2A airplanes and some Model S-2S airplanes 
were equipped with a .035-inch wall thickness flight control stick 
at manufacture. Models S-1S, S-1T, S-2, S-2B and certain Model S-2S 
airplanes were manufactured with control sticks with a wall 
thickness greater than .035 inch, but could have .035-inch flight 
control sticks installed through FAA-approved field modification.
    Note 2: 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 (d) 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 upon accumulating 1,000 hours 
time-in-service (TIS) or within the next 25 hours TIS after the 
effective date of this AD, whichever occurs later, unless already 
accomplished, and thereafter as indicated in the body of this AD.
    To prevent the inability to maneuver the airplane because of a 
cracked control stick, which, if not detected and corrected, could 
result in loss of control of the airplane, accomplish the following:
    (a) Inspect, using dye penetrant methods, the .035-inch wall 
thickness flight control stick for cracking in accordance with the 
ACCOMPLISHMENT INSTRUCTIONS section of Aviat Service Bulletin (SB) 
No. 23, dated March 29, 1996.

    Note 3: Aviat SB No. 23, dated March 29, 1996, only references 
the Model S-2A airplanes. The procedures included in this service 
bulletin should be utilized for all of the airplanes affected by 
this AD.

    (1) If cracking is found, prior to further flight, replace the 
.035-inch wall thickness flight control stick with one with a .058 
inch wall thickness in accordance with the ACCOMPLISHMENT 
INSTRUCTIONS section of Aviat SB No. 23, dated March 29, 1996.
    (2) If no cracks are found, reinspect at intervals not to exceed 
50 hours TIS. If cracking is found during any repetitive inspection, 
prior to further flight, accomplish the replacement specified in 
paragraph (a)(1) of this AD.
    (b) Replacing the .035-inch wall thickness flight control stick 
with one with a .058-inch wall thickness in accordance with the 
ACCOMPLISHMENT INSTRUCTIONS section of Aviat SB No. 23, dated March 
29, 1996, is considered terminating action for the repetitive 
inspection requirement of this AD. This replacement may be 
accomplished at any time, and must be accomplished prior to further 
flight if cracking is found as required by paragraph (a)(1) of this 
AD.
    (c) 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.
    (d) 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 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Denver ACO.

    (e) The inspection and replacement (if necessary) required by 
this AD shall be done in accordance with Aviat Service Bulletin No. 
23, dated March 29, 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., The Airport-Box 1240, South Washington Street, 
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.
    (f) This amendment (39-9619) becomes effective on June 7, 1996.

    Issued in Kansas City, Missouri, on May 8, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12137 Filed 5-15-96; 8:45 am]
BILLING CODE 4910-13-U