Airworthiness Directives; Eurocopter France Model AS 332C, AS 332L, AS 332L1, and AS 332L2 Helicopters

[Federal Register Volume 63, Number 226 (Tuesday, November 24, 1998)]
[Rules and Regulations]
[Pages 64854-64856]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-31329]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-19-AD; Amendment 39-10906; AD 98-24-21]
RIN 2120-AA64


Airworthiness Directives; Eurocopter France Model AS 332C, AS 
332L, AS 332L1, and AS 332L2 Helicopters

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 
is applicable to Eurocopter France (ECF) Model AS 332C, AS 332L, AS 
332L1, and AS 332L2 helicopters. This action requires inserting 
instructions into the Model AS 332C, AS 332L, AS 332L1, and AS 332L2 
Rotorcraft Flight Manuals (RFMs) regarding actions to take if either 
the ``OVSP 1'' or ``OVSP 2'' amber warning light illuminates. This 
action also requires, for the Model AS 332C, AS 332L, and AS 332L1 
helicopters, measuring the vibration levels of the engine-to-main 
gearbox (MGB) shaft, inspecting the torque on the MGB coupling bolts, 
and conducting an engine-to-MGB coupling 23,000 revolutions per minute 
(RPM) input check. This amendment is prompted by an accident involving 
a Model AS 332L1 helicopter in which the helicopter experienced an 
engine overspeed resulting in failure of both engines. The actions 
specified in this AD are intended to prevent failure of the rotor drive 
engine-to-MGB coupling, which, if undetected, could result in an engine 
overspeed leading to an uncontained engine turbine wheel burst and 
subsequent loss of control of the helicopter.

DATES: Effective December 9, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before January 25, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-19-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: The Direction Generale De L'Aviation Civile 
(DGAC), which is the airworthiness authority for France, recently 
notified the FAA that an unsafe condition may exist on ECF Model AS 
332C, AS 332L, AS 332L1, and AS 332L2 helicopters. The DGAC advises 
that failure of the MGB coupling could cause loss of load on the 
engine, and result in engine overspeed. The DGAC warning stems from an 
accident involving a Model AS 332L1 helicopter in which the helicopter 
experienced an engine overspeed resulting in failure of both engines.
    ECF has issued Eurocopter Service Telex (Telex) No. 00047/0275/97, 
dated October 2, 1997. That service telex specifies checking the 
tightening torque loads on the MGB coupling tie-bolts; checking the 
condition of the splined flanges; confirming the presence of the O-ring 
on the splined sleeve; and checking the vibration level of the engine-
to-MGB 23,000 RPM input shaft every 25 flying hours. ECF has also 
issued Eurocopter Service Bulletin No. 63.00.21 Ed. 1., dated June 26, 
1998, which specifies the same inspections as the previously mentioned 
Telex, but also specifies a recurring 50 hour time-in-service (TIS) 
check of the tightening torque loads on the MGB coupling tie-bolts for 
couplings that have not been modified in accordance with certain ECF 
modifications. That service bulletin also specifies a recurring 550 
hour TIS engine-to-MGB coupling 23,000 RPM input check. The DGAC 
classified this service telex and service bulletin as mandatory and 
issued AD 97-303-066(AB), dated October 22, 1997, and AD 86-012-023(A) 
R4, dated July 29, 1998, in order to assure the continued airworthiness 
of these helicopters in France. The DGAC also issued AD 97-288-065(AB) 
for Model AS 332C, AS 332C1, AS 332L, and AS 332L1 helicopters, and AD 
97-289-008(AB) for Model AS 332L2 helicopters, both dated October 22, 
1998, which require inserting emergency instructions into the RFM 
regarding actions to take if either the ``OVSP 1'' or ``OVSP 2'' amber 
warning lights illuminate.
    These helicopter models are manufactured in France and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the DGAC has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the DGAC, reviewed all available information, and determined that AD 
action is necessary for products of this type design that are 
certificated for operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other ECF Model AS 332C, AS 332L, AS 332L1, and AS 
332L2 helicopters of the same type design registered in the United 
States, this AD is being issued to prevent failure of the rotor drive 
engine-to-MGB coupling, which, if undetected, could result in an engine 
overspeed leading to an uncontained engine turbine wheel burst and 
subsequent loss of control of the helicopter. This AD requires 
inserting an emergency procedure into the RFM regarding actions to take 
if either the ``OVSP 1'' or ``OVSP 2'' amber warning light illuminates; 
measuring the vibration levels of the engine-to-MGB shaft; inspecting 
the torque on the MGB coupling bolts; performing an engine-to-MGB 
coupling RPM input check; inspecting the spline and splined flanges; 
and inspecting the vibration level after the reassembly of the 
coupling. The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the

[[Page 64855]]

controllability of the helicopter. Therefore, the actions stated in 
this AD are required prior to further flight and this AD must be issued 
immediately.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.
    The FAA estimates that 4 helicopters will be affected by this 
proposed AD, that it will take approximately 13.5 work hours to measure 
the vibration levels; inspect the torque of the MGB coupling bolts; and 
conduct the other inspections. The average labor rate is $60 per work 
hour. Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $3,240.

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-19-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:

AD 98-24-21  Eurocopter France: Amendment 39-10906. Docket No. 98-
SW-19-AD.
    Applicability: Model AS 332C, AS 332L, AS 332L1, and AS 332L2 
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 as indicated, unless accomplished 
previously.
    To prevent failure of the rotor drive engine-to-main gearbox 
(MGB) coupling, which, if undetected, could result in an engine 
overspeed leading to an uncontained engine turbine wheel burst and 
subsequent loss of control of the helicopter, accomplish the 
following:
    (a) For Model AS 332C AS 332L, AS 332L1, and AS 332L2 
helicopters, before further flight, insert the following statement 
into the Emergency Procedures section, Chapter 3, of the Rotorcraft 
Flight Manual:
    ``If at any time during flight, either the ``OVSP 1'' or ``OVSP 
2'' amber warning light illuminates, even intermittently, reduce the 
affected engine to ground idle as soon as possible, then shut it 
down once all of the parameters on the remaining engine have been 
checked and found to be satisfactory.''
    (b) For Model AS 332C, AS 332L, and AS 332L1 helicopters, within 
8 hours time-in-service (TIS) and at intervals not to exceed 25 
hours TIS thereafter, measure the vibration level of the left and 
right 23,000 RPM input shaft (engine-to-MGB shaft). Record the mean 
value of the measured vibration level in the helicopter maintenance 
records.
    (1) If the vibration level exceeds 0.65 inches per second (IPS), 
perform the inspections described in paragraphs (c) and (d) of this 
AD before further flight.
    (2) If the vibration level is less than or equal to 0.65 IPS, 
perform the inspections described in paragraphs (c) and (d) of this 
AD within the next 25 hours TIS.
    (c) For Model AS 332C AS 332L, and AS 332L1 helicopters, measure 
and record the tightening torque on the three engine-to-MGB coupling 
bolts for the left and right 23,000 RPM input shafts. Accomplish 
this measurement every 50 hours TIS after the initial inspection if 
Eurocopter France MODs 0752316 and 0752317 have not been 
accomplished.
    (1) If Eurocopter France MOD 0752316 (tie bolt replacement) has 
not been accomplished, the tightening torque should be 1.5 to 1.9 
m.daN (133 to 168 in.-lbs.) (lubricated with NATO 0.156 oil or 
equivalent).
    (2) If Eurocopter France MOD 0752316 (tie bolt replacement) has 
been accomplished, the tightening torque should be 1.2 to 1.4 m.daN 
(106 to 124 in.-lbs.) (lubricated with NATO 0.156 oil or 
equivalent).
    (d) Perform the engine-to-MGB coupling 23,000 RPM input check in 
accordance with the applicable maintenance manual.

    Note 2: Section 63.10.00.602 of the applicable maintenance 
manual contains

[[Page 64856]]

procedures for accomplishing the engine-to-MGB coupling 23,000 RPM 
input check. Paragraph 5 or the Work Card date code 97-04 is not 
applicable to the subject of this AD.

    (1) While inspecting the splined flanges, inspect the splines 
for wear. Also inspect the MGB end of the splined flange for impact 
marks on the end of the splines. If wear exceeds the allowable 
limits, or if impact marks are found on the end of the splines, 
replace the splined flange with an airworthy splined flange.
    (2) Inspect for the presence of the O-ring on the splined 
flange.
    (3) After accomplishing the engine-to-MGB coupling 23,000 RPM 
input check and reassembly, measure the vibration level and record 
the results. If the vibration level remains above 0.65 IPS, conduct 
the vibration level correction procedure.

    Note 3: Maintenance Manual (MET) Work Card 63.20.00.501 provides 
correction procedures if the vibration level exceeds 0.65 IPS.

    (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, 
Rotorcraft Directorate, 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 4: 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 December 9, 1998.

    Note 5: The subject of this AD is addressed in Direction 
Generale De L'Aviation Civile (France) AD 97-288-065(AB), AD 97-303-
066(AB), AD 97-289-008(AB), all dated October 22, 1997, and AD 86-
012-023(A) R4, dated July 29, 1998.

    Issued in Fort Worth, Texas, on November 17, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-31329 Filed 11-23-98; 8:45 am]
BILLING CODE 4910-13-U

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