[Federal Register Volume 63, Number 123 (Friday, June 26, 1998)]
[Rules and Regulations]
[Pages 34790-34796]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-17043]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-11-AD; Amendment 39-10633; AD 98-06-04]
RIN 2120-AA64


Airworthiness Directives; Eurocopter France Model AS332C, L, and 
L1 and Model SA330F, G, and J Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 98-06-04 which was sent 
previously to all known U.S. owners and operators of Eurocopter France 
Model AS332C, L, and L1 and Model SA330F, G, and J helicopters by 
individual letters. This AD requires performing a procedure to 
determine the angular play of the tail rotor gearbox, and repeating the 
procedure at certain intervals. This amendment is prompted by an 
accident involving a Model SA330 helicopter which resulted from the 
loss of the tail rotor drive. An investigation determined that the loss 
of the tail rotor drive was caused by excessive play between the tail 
rotor gearbox bevel gear and the bevel wheel. This condition, if not 
corrected, could result in failure of the tail rotor gearbox, loss of 
tail rotor drive, and subsequent loss of control of the helicopter.

DATES: Effective July 13, 1998, to all persons except those persons to 
whom it was made immediately effective by priority letter AD 98-06-04, 
issued on March 4, 1998, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before August 25, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-11-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr. Scott Horn, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham 
Blvd., Fort Worth, Texas 76137, telephone (817) 222-5125, fax (817) 
222-5961.

SUPPLEMENTARY INFORMATION: On March 4, 1998, the FAA issued priority 
letter AD 98-06-04, applicable to Eurocopter France Model AS332C, L, 
and L1 and Model SA330F, G, and J helicopters, which requires 
performing a procedure to determine the play of the tail rotor gearbox 
within 25 hours time-in-service (TIS), and repeating the procedure at 
intervals of 100 hours TIS or 520 hours TIS depending on the amount of 
play that is detected. That action was prompted by an accident 
involving a Model SA330 helicopter that occurred on October 21, 1997, 
which resulted from the loss of the tail rotor drive. An investigation 
determined that the loss of tail rotor drive was caused by excessive 
play between the tail rotor gearbox bevel gear and the bevel wheel. 
This condition, if not corrected, could result in failure of the tail 
rotor gearbox, loss

[[Page 34791]]

of tail rotor drive and subsequent loss of control of the helicopter.
    Since the unsafe condition described is likely to exist or develop 
on other Eurocopter France Model AS332C, L, and L1 and Model SA330F, G, 
and J helicopters of the same type design, the FAA issued priority 
letter AD 98-06-04 to prevent failure of the tail rotor gearbox, loss 
of tail rotor drive and subsequent loss of control of the helicopter. 
The AD requires, within 25 hours TIS after the effective date of this 
AD, and thereafter at specified intervals, performing a procedure to 
determine the angular play of the tail rotor gearbox and replacing the 
tail rotor gearbox with an airworthy gearbox if the specified angular 
play limit is exceeded. The short compliance time involved is required 
because the previously described critical unsafe condition can 
adversely affect the controllability of the helicopter. Therefore, 
inspections of the tail rotor gearbox for excessive play is required 
within 25 hours TIS or upon or before attaining 520 hours TIS and this 
AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on March 4, 1998 to all known U.S. owners and operators of 
Eurocopter France Model AS332C, L, and L1 and Model SA330F, G, and J 
helicopters. These conditions still exist, and the AD is hereby 
published in the Federal Register as an amendment to section 39.13 of 
the Federal Aviation Regulations (14 CFR 39.13) to make it effective to 
all persons. However, the FAA has made several nonsubstantive editorial 
changes since the issuance of Priority Letter AD 98-06-04; the word 
``excess'' was changed to ``excessive,'' the incorrect placement of the 
number ``12'' in Figure 1 has been corrected, and a new paragraph was 
added to clarify that brackets and mounts installed during the required 
inspection are to be removed between inspections. The FAA has 
determined that these changes will neither increase the economic burden 
on an operator nor increase the scope of the AD.
    The FAA estimates that 4 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 3 work hours per 
helicopter to accomplish the required actions, and that the average 
labor rate is $60 per work hour. Required parts will cost approximately 
$100 per helicopter to create the necessary tools and $45,000 to 
replace the gearbox, if necessary. Based on these figures, the total 
cost impact of the AD on U.S. operators is estimated to be $45,280 per 
helicopter.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public 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 under the caption ADDRESSES. 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 rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-SW-11-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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 that it 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. 
A copy of it, if filed, may be obtained from 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.

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 
to read as follows:

98-06-04  Eurocopter France: Amendment 39-10633. Docket No. 98-SW-
11-AD.

    Applicability: Model AS332C, L, and L1 and Model SA330F, G, and 
J helicopters, certificated in any category.

    Note 1: This AD applies to each helicopter 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 helicopters that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (e) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition, or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any helicopter from the applicability of this AD.

    Compliance: Required within the next 25 hours time-in-service 
(TIS) for tail rotor gearboxes (TGB) with 495 or more hours TIS 
since manufacture or overhaul; or, for TGB with less than 495 hours 
TIS since manufacture or overhaul, required upon or before attaining 
520 hours TIS, unless accomplished previously.

[[Page 34792]]

    To detect excessive play between the splines of the TGB bevel 
gear and the bevel wheel and to prevent failure of the TGB, which 
could result in loss of tail rotor drive and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) For TGB that are not equipped with a tail rotor blade 
deicing system as shown in Figure 1, fabricate a steel angle bracket 
(angle bracket) (No. 1 of Figure 1) and an aluminum mount (No. 2 of 
Figure 1).
    (1) Place a tail rotor blade in the horizontal position with the 
blade's tip facing forward.
    (2) Immobilize the TGB input flange by placing a wooden block 
between the TGB input flange and the deck.
    (3) Secure the angle bracket on the TGB output casing with a nut 
(No. 3 of Figure 1) and a washer (No. 5 of Figure 1).
    (4) Secure the mount on the rotor shaft.
    (5) Secure the dial indicator gage (No. 4 of Figure 1) on the 
angle bracket.
    (6) Install the feeler of the dial indicator on the mount at the 
index mark which is 120 mm from the rotor shaft center line.
    (7) Using a dynamometer, apply a 1 daN (2.25 lbs.) load in both 
directions (indicated by letter ``F'' in Figure 1), 30 mm from the 
blade tip, to measure the total play.

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[[Page 34793]]

[GRAPHIC] [TIFF OMITTED] TR26JN98.002



[[Page 34794]]

    (b) For TGB that are equipped with a tail rotor blade deicing 
system as shown in Figure 2, fabricate a steel angle bracket (angle 
bracket) (No. 6 of Figure 2) from a 90 deg. formed steel sheet.
    (1) Place a tail rotor blade in the horizontal position with the 
blade's tip facing forward.
    (2) Immobilize the TGB input flange by placing a wooden block 
between the TGB input flange and the deck.
    (3) Secure the angle bracket on the TGB output casing with a nut 
(No. 7 of Figure 2) and a washer (No. 8 of Figure 2).
    (4) Secure the dial indicator gage (No. 9 of Figure 2) on the 
angle bracket.
    (5) Install the feeler of the dial indicator on the tail rotor 
hub, 5 mm from the spindle attachment bolt (Item A of Figure 2).
    (6) Using a dynamometer, apply a 1 daN (2.25 lbs.) load in both 
directions (indicated by letter ``F'' in Figure 1), 30 mm from the 
blade tip, to measure the total play.


[[Page 34795]]

[GRAPHIC] [TIFF OMITTED] TR26JN98.003



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[[Page 34796]]

    (c) Record the play measurement on the equipment log card or 
equivalent record.
    (1) If the play is 0.37 mm or less, comply with paragraphs (a) 
or (b) of this AD, as applicable, at intervals not to exceed 520 
hours TIS.
    (2) If the play is greater than 0.37 mm and less than 0.52 mm, 
comply with paragraphs (a) or (b) of this AD, as applicable, at 
intervals not to exceed 100 hours TIS.
    (3) If the play is equal to or greater than 0.52 mm, remove the 
TGB and replace it with an airworthy TGB.
    (d) Brackets and mounts installed to perform the requirements of 
this AD, as applicable, are to be removed prior to flight.
    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Rotorcraft Standards Staff, FAA. 
Operators shall submit their requests through an FAA Principal 
Maintenance Inspector, who may concur or comment and then send it to 
the Manager, Rotorcraft Standards Staff.

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

    (f) Special flight permits will not be issued.
    (g) This amendment becomes effective on July 13, 1998, to all 
persons except those persons to whom it was made immediately 
effective by Priority Letter AD 98-06-04, issued March 4, 1998, 
which contained the requirements of this amendment.

    Note 3: The subject of this AD is addressed in Direction 
Generale De L'Aviation Civile (France) AD 97-322-067(AB) and AD 97-
323-079(AB), both dated November 19, 1997.

    Issued in Fort Worth, Texas, on June 18, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-17043 Filed 6-25-98; 8:45 am]
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