[Federal Register Volume 64, Number 226 (Wednesday, November 24, 1999)]
[Proposed Rules]
[Pages 66116-66118]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30588]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-57-AD]
RIN 2120-AA64


Airworthiness Directives; Ayres Corporation S2R Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to all Ayres Corporation (Ayres) S2R series 
airplanes that are equipped with at least one main landing gear 
fuselage attach bolt with a grease fitting installed through the shank. 
The proposed AD would require replacing the main landing gear fuselage 
attach bolts that are drilled with a grease fitting with undrilled (no 
grease access) attach bolts. This AD is the result of a report of 
cracks found in all four main landing gear fuselage attach bolts on one 
of the affected airplanes. The actions specified by the proposed AD are 
intended to prevent collapse of the main landing gear caused by cracked 
main landing gear fuselage attach bolts, which could result in main 
landing gear collapse with possible wing fuel tank rupture and 
consequent fire.

DATES: Comments must be received on or before January 21, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-CE-57-AD, Room 506, 901 Locust, 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 Ayres Corporation, P.O. Box 3090, One Ayres Way, Albany, Georgia 
31706-3090; telephone: (912) 883-1440; facsimile: (912) 439-9790. This 
information also may be examined at the Rules Docket at the address 
above.

FOR FURTHER INFORMATION CONTACT: Satish Lall, Aerospace Engineer, FAA, 
Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix 
Boulevard, suite 450, Atlanta, Georgia 30349; telephone: (770) 703-
6082; facsimile: (770) 703-6097.

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. 99-CE-57-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. 99-CE-57-AD, Room 506,

[[Page 66117]]

901 Locust, Kansas City, Missouri 64106.

Discussion

    The FAA has received a report of cracks found in all four main 
landing gear fuselage attach bolts on an Ayres S2R series airplane. 
Further analysis reveals that the main landing gear fuselage attach 
bolts are cracking at the \1/16\-inch (.0625-inch) grease access hole, 
which is located approximately 1\7/8\ inches (1.875 inches) deep and 
then drilled from the side to intersect the center hole. The side 
drilled hole is causing the fatigue cracking that results in the attach 
bolt failure.
    These main landing gear fuselage attach bolts that are drilled with 
a grease fitting incorporate part number 21418T001 or 21418T005.
    This condition, if not corrected in a timely manner, could result 
in main landing gear collapse with possible wing fuel tank rupture and 
consequent fire.

Relevant Service Information

    Ayres has issued Service Bulletin No. SB-AG-42, dated June 16, 
1999, which specifies replacing the main landing gear fuselage attach 
bolts that are drilled with a grease fitting with undrilled (no grease 
access) attach bolts, part number AN10-33 or NAS6610-42D.
    The procedures to accomplish this replacement are included in both 
the service bulletin and the applicable maintenance manual.

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 collapse of the 
main landing gear caused by cracked main landing gear fuselage attach 
bolts.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Ayres S2R series airplanes of the same type 
design, the FAA is proposing AD action. The proposed AD would require 
replacing the main landing gear fuselage attach bolts that are drilled 
with a grease fitting with undrilled (no grease access) attach bolts.
    Accomplishment of the proposed action would be required in 
accordance with both Ayres Service Bulletin No. SB-AG-42, dated June 
16, 1999, and the applicable maintenance manual.

Differences Between the Service Bulletin and the Proposed AD

    Ayres Service Bulletin No. SB-AG-42, dated June 16, 1999, specifies 
repetitive inspections and repetitive replacements of the main landing 
gear fuselage attach bolts. The FAA does not have justification to 
mandate the repetitive inspections and repetitive replacements. Based 
on all available information, the FAA has determined that initially 
replacing the main landing gear fuselage attach bolts with attach bolts 
of improved design will correct the unsafe condition on the affected 
airplanes.

Cost Impact

    The FAA estimates that 1,000 airplanes in the U.S. registry would 
be affected by the proposed AD, that it would take approximately 4 
workhours per airplane to accomplish the proposed replacement, and that 
the average labor rate is approximately $60 an hour. Parts cost 
approximately $88 per airplane (4 bolts per airplane at $22 each). 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $328,000, or $328 per airplane.

Regulatory Impact

    The proposed rule does not have Federalism implications as defined 
in Executive Order No. 13132. This means it 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. The FAA has 
not consulted with state authorities prior to publication of this 
proposed rule.
    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 
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:

Ayres Corporation: Docket No. 99-CE-57-AD.

    Applicability: The following airplane models; all serial 
numbers; certificated in any category, that have at least one main 
landing gear fuselage attach bolt (that is drilled with a grease 
fitting), part number 21418T001 or 21418T005 (or FAA-approved 
equivalent part number): S-2R, S2R-G1, S2R-G5, S2R-G6, S2R-G10, S2R-
R3S, S2R-T11, S2R-T15, S2R-T34, S2R-T45, S2R-T65, S2R-R1340, S2R-
R1820, S2RHG-T34, and S2RHG-T65.

    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 (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 as indicated in the body of this AD, unless 
already accomplished.
    To prevent collapse of the main landing gear caused by cracked 
main landing gear fuselage attach bolts, which could result in main 
landing gear collapse with possible wing fuel tank rupture and 
consequent fire, accomplish the following:
    (a) Within the next 100 hours time-in-service (TIS) after the 
effective date of this AD, replace each main landing gear fuselage 
attach bolt that is drilled with a grease fitting with an undrilled 
(no grease access) attach bolt, part number AN10-33 or NAS6610-42D 
(or FAA-approved equivalent part number). Accomplish this 
replacement in accordance with both Ayres Service Bulletin No. SB-
AG-42, dated June 16, 1999, and the applicable maintenance manual.
    (b) As of the effective date of this AD, no person may install, 
on any affected airplane, a main landing gear fuselage attach bolt 
(that is drilled with a grease fitting), part number 21418T001 or 
21418T005 (or FAA-approved equivalent part number).

[[Page 66118]]

    (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 
compliance times that provides an equivalent level of safety may be 
approved by the Manager, Atlanta Aircraft Certification Office 
(ACO), One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, 
Georgia 30349. The request shall be forwarded through an appropriate 
FAA Maintenance Inspector, who may add comments and then send it to 
the Manager, Atlanta ACO.

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

    (e) All persons affected by this directive may obtain copies of 
the service information referred to herein upon request to the Ayres 
Corporation, P.O. Box 3090, One Ayres Way, Albany, Georgia 31706-
3090; or may examine this service information at the FAA, Central 
Region, Office of the Regional Counsel, Room 506, 901 Locust, Kansas 
City, Missouri 64106.

    Issued in Kansas City, Missouri, on November 18, 1999.
Marvin R. Nuss,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-30588 Filed 11-23-99; 8:45 am]
BILLING CODE 4910-13-U