[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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