[Federal Register Volume 68, Number 181 (Thursday, September 18, 2003)]
[Proposed Rules]
[Pages 54686-54688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-23835]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-SW-45-AD]
RIN 2120-AA64


Airworthiness Directives; Eurocopter France Model AS332C, L, and 
L1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD) for the specified Eurocopter France (Eurocopter) model 
helicopters that would have required, for bevel gears with more than 
6,600 hours time-in-service (TIS), inspecting the bevel gear for a 
crack using a borescope within 50 hours TIS, and thereafter at 
intervals not to exceed 150 hours TIS. That proposal was prompted by a 
crack that was detected on a bevel gear during a main gearbox teardown 
inspection. This action revises the proposed rule by requiring the 
borescope inspection at intervals not to exceed 150 hours TIS or 1,000 
torque variation cycles (cycles) for helicopter operations involving 
frequent torque variations, whichever occurs first. This action is 
prompted by an analysis of the crack growth rate, which indicates that 
the growth rate is higher in helicopters with operations involving a 
torque variation frequency of 4 or more cycles per hour. The actions 
specified by this proposed AD are intended to detect a bevel gear crack 
and prevent failure of the bevel gear,

[[Page 54687]]

loss of torque to the main rotor system, and subsequent loss of control 
of the helicopter.

DATES: Comments must be received on or before November 17, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2002-SW-45-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected]. 
Comments may be inspected at the Office of the Regional Counsel between 
9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Uday Garadi, Aviation Safety Engineer, 
FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 
76193-0110, telephone (817) 222-5123, fax (817) 222-5961.

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 document 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 summarizing 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 mailed 
comments submitted in response to this proposal must submit a self-
addressed, stamped postcard on which the following statement is made: 
``Comments to Docket No. 2002-SW-45-AD.'' The postcard will be date 
stamped and returned to the commenter.

Discussion

    A proposal to amend 14 CFR part 39 to add an AD for the specified 
Eurocopter model helicopters was published in the Federal Register on 
December 31, 2002 (67 FR 79893). That NPRM would have required for 
bevel gears with more than 6,600 hours TIS, inspecting the bevel gear 
for cracks using a borescope within 50 hours TIS, and thereafter at 
intervals not to exceed 150 hours TIS. If a crack were found in the 
bevel gear, replacing the bevel gear would be required. That NPRM was 
prompted by a crack that was detected on a bevel gear during a main 
gearbox teardown inspection. That condition, if not corrected, could 
result in failure of the bevel gear, loss of torque to the main rotor 
system, and subsequent loss of control of the helicopter.
    Since issuing that NPRM, the FAA discovered that certain part 
numbered bevel gears were omitted from the applicability and one was 
incorrectly stated in that NPRM. Also, the manufacturer has revised the 
service information to introduce the new inspection interval of 1,000 
cycles for helicopter operations involving a torque application 
frequency of more than 4 cycles per hour for helicopters that conduct 
external load operations involving more frequent torque applications. 
Additionally, we inadvertently included Model AS332C1 helicopters in 
the ``Applicability'' section of the NPRM--those model helicopters are 
not on the U.S. Registry. Finally, the DGAC has issued a revised AD for 
helicopters operated in France.
    This SNPRM revises the NPRM to:
    [sbull] Correct the basic bevel gear part number (P/N) stated in 
the ``Applicability'' of the NPRM to state ``332A32-2181-00'';
    [sbull] Add bevel gear P/Ns 332A32-2181-01 and -08 to the 
``Applicability'';
    [sbull] Delete the Model AS332C1 helicopters from the 
``Applicability'';
    [sbull] Incorporate the latest Eurocopter Alert Telex and 
references the latest DGAC AD;
    [sbull] Require the repetitive inspection at intervals not to 
exceed 150 hours TIS or 1,000 torque cycles, whichever occurs first; 
and
    [sbull] Exclude from the ``Applicability'' any main gearbox 
(regardless of the P/N of the main reduction gear module or bevel gear) 
overhauled after December 31, 2002, and any part number inspected in 
accordance with AS332 letter to Repair Stations No. 183 or repaired in 
accordance with Repair Sheet (F.R.) 332A32-2181-ZA or 331A32-3110-ZA.
    Since this change expands the scope of the originally proposed 
rule, we have determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.
    The Direction Generale De L'Aviation Civile (DGAC), the 
airworthiness authority for France, notified the FAA that an unsafe 
condition may exist on Eurocopter Model AS332C, C1, L, and L1 
helicopters, equipped with main gearbox main reduction gear modules, 
part numbers (P/N) 332A32-2027-00 or 332A32-2026-00, containing bevel 
gears, P/N 332A32-2181-00, -01, -02, -03, or -04, or 331A32-3110-07, -
09, or -19. The DGAC advises that borescope inspections of the bevel 
gear are necessary to detect cracks.
    Eurocopter has issued Alert Telex No. 05.00.58 R2, dated February 
3, 2003, which indicates that as a result of metal particles found on 
the chip detector of the main gearbox sump on a helicopter, further 
investigation has revealed a longitudinal crack that grows lengthwise 
in the shaft, up to the combiner gear, in the bevel gear where the ring 
retains the pinion toe bearing. The alert telex specifies inspecting 
the bevel gear for cracks using a borescope, pending the result of the 
investigation into the cause of the fatigue crack initiation currently 
being conducted in France. The DGAC classified this alert telex as 
mandatory and issued AD 2002-424-081(A) R2, dated March 19, 2003, to 
ensure the continued airworthiness of these helicopters in France.
    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's AD system. The 
regulation now includes material that relates to altered products, 
special flight permits, and alternative methods of compliance. Because 
we have now included this material in part 39, we no longer need to 
include it in each individual AD. Therefore, Note 1 of the original 
NPRM has been removed and paragraph (c) has been modified in this 
SNPRM.
    The FAA estimates that 4 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 4 work 
hours per helicopter to accomplish the inspections and 16 work hours 
per helicopter to replace the bevel gear. The average labor rate is $65 
per work hour. Required parts would cost approximately $31,372. Based 
on these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $130,688, assuming that upon the first 
inspection a crack is detected and the bevel gear will be replaced.
    The regulations proposed herein would not have a substantial direct

[[Page 54688]]

effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the 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 is contained 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 
to read as follows:

Eurocopter France: Docket No. 2002-SW-45-AD.

    Applicability: Model AS332C, L, and L1 helicopters, with main 
gearbox bevel gear (bevel gear), part numbers (P/N) 332A32-2027-00 
or 332A32-2026-00, containing bevel gears, P/N 332A32-2181-00, -01, 
-02, -03, or -04, or 331A32-3110-07, -08, -09, or -19, installed, 
certificated in any category. This AD does not apply to:
    [sbull] Main gearboxes that were overhauled after December 31, 
2002;
    [sbull] Parts inspected in accordance with AS332 letter to 
Repair Stations No. 183; or
    [sbull] Parts repaired in accordance with Repair Sheet (F.R.) 
332A32-2181-ZA or 331A32-3110-ZA.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect a bevel gear crack and prevent failure of the bevel 
gear, loss of torque to the main rotor system, and subsequent loss 
of control of the helicopter, accomplish the following:
    (a) For bevel gears that have more than 6,600 hours time-in-
service (TIS), within 50 hours TIS and thereafter at intervals not 
to exceed 150 hours TIS, or at intervals not to exceed 1,000 
frequent torque variation cycles, whichever occurs first, inspect 
for a crack using a boroscope in accordance with the Operational 
Procedure, paragraph 2.B.1. and 2.B.2. of Eurocopter Telex No. 
05.00.58 R2, dated February 3, 2003. A frequent torque variation 
cycle is each landing or external load operation beginning at the 
point when there are 4 or more landings, or 4 or more external load 
operations, or any combination of 4 or more landings and external 
load operations in any 60 minute time period, and ending when any 
combination of landings and external load operations is less than 4 
in any 60 minute time period.
    (b) If a crack is found in the bevel gear, before further 
flight, replace the bevel gear with an airworthy bevel gear.
    (c) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Safety Management Group, Rotorcraft Directorate, FAA, 
for information about previously approved alternative methods of 
compliance.

    Note: The subject of this AD is addressed in Direction Generale 
De L'Aviation Civile (France) AD 2002-424-081(A) R2, dated March 19, 
2003.


    Issued in Fort Worth, Texas, on September 8, 2003.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 03-23835 Filed 9-17-03; 8:45 am]
BILLING CODE 4910-13-P