[Federal Register Volume 63, Number 250 (Wednesday, December 30, 1998)]
[Rules and Regulations]
[Pages 71741-71743]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34502]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-SW-40-AD; Amendment 39-10969; AD 99-01-02]
RIN 2120-AA64


Airworthiness Directives; Westland Helicopters Ltd. 30 Series 100 
and 100-60 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 Westland Helicopters Ltd. (Westland) 30 Series 100 and 
100-60 helicopters. This action requires the removal and replacement of 
conformal pinion quill shafts installed in certain main rotor gearboxes 
that fail to pass a magnetic drain plug inspection. This amendment is 
prompted by a report of a forced landing that occurred when a single 
conformal pinion quill shaft failed in a main rotor gearbox (MRGB). 
This condition, if not corrected, could result in the failure of a 
MRGB, and a subsequent forced landing or loss of control of the 
helicopter.

DATES: Effective January 14, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before March 1, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 97-SW-40, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.
    The service information referenced in this AD may be obtained from 
Westland Helicopters Ltd., Customer Support Division, Yeovil, Somerset 
BA20 2YB, England, telephone (01935) 703884, fax (01935) 703905. This 
information may be examined at the FAA, Office of the Regional Counsel, 
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or 
at the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Shep Blackman, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Fort Worth, Texas 76193-0111, telephone 
(817) 222-5296, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: The Civil Aviation Authority (CAA), which is 
the airworthiness authority for the United Kingdom (UK), notified the 
FAA that an unsafe condition may exist on Westland 30 series 
helicopters. The UK CAA advised that an incident of a conformal pinion 
quill shaft failure within an MRGB occurred, resulting in a forced 
landing. Further investigation revealed that this MRGB had a history of 
shock loading, defined as a slam engagement of the No. 1 engine free 
wheeling unit that can occur when the No. 1 engine condition lever is 
at ``GND'' or ``FLT'' position and the engine is driving accessories 
but the main rotor is not turning. If the No. 1 engine free wheel is 
slam engaged, the No. 1 engine power turbine will abruptly stop, 
causing potential damage to the MRGB and other drive system components. 
Westland has issued Westland Helicopters Ltd. Service Bulletin W30-63-
75, dated November 29, 1995 (SB), that requires the removal and 
replacement of the conformal pinion quill shafts within a MRGB 
identified by serial number or with a history of shock loading. The UK 
CAA classified this SB as mandatory and issued UK CAA AD 012-11-95, 
dated January 31, 1996, to ensure the continued airworthiness of these 
helicopters in the UK.
    These helicopter models are manufactured in Yeovil, England, and 
are type certificated for operation in the United States under the 
provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) and the applicable bilateral airworthiness agreement. Pursuant 
to this bilateral airworthiness agreement, the UK CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the UK CAA, 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.
    This AD is being issued to prevent a forced landing or possible 
loss of control of the helicopter due to failure of the conformal 
pinion quill shafts installed in the MRGB in certain Westland 30 series 
helicopters. This AD requires, prior to further flight, a magnetic 
drain plug inspection of an installed MRGB with a serial number listed 
in this AD or with a history of shock loading. If the magnetic drain 
plug passes inspection, the MRGB may

[[Page 71742]]

remain in service a maximum of 100 additional hours time-in-service 
(TIS) after the effective date of this AD. If the magnetic drain plug 
fails inspection, the MRGB must be removed from service prior to 
further flight and the conformal pinion quill shaft has to be replaced 
with an airworthy conformal pinion shaft in accordance with the 
Westland Maintenance Manual.
    None of the Westland 30 series helicopters affected by this action 
are on the U.S. Register. All helicopters included in the applicability 
of this rule are currently operated by non-U.S. operators under foreign 
registry; therefore, they are not directly affected by this AD action. 
However, the FAA considers this rule necessary to ensure that the 
unsafe condition is addressed in the event that any of these subject 
helicopters are imported and placed on the U.S. Register in the future.
    Should an affected helicopter be imported and placed on the U.S. 
Register in the future, it would require approximately 1.5 work hours 
to inspect the magnetic drain plug and 20 work hours to replace, if 
necessary, the MRGB. The average labor rate is $60 per work hour. A 
replacement MRGB, if needed, costs $350,000. Based on these figures, 
the cost impact of this AD would be $350,090 per helicopter; $90 for 
the inspection and $350,000 for the replacement, if necessary, of the 
MRGB.
    Since this AD action does not affect any helicopter that is 
currently on the U.S. Register, it has no adverse economic impact and 
imposes no additional burden on any person. Therefore, 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.

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. 97-SW-40-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 notice and prior public comment are 
unnecessary in promulgating this regulation and therefore, it can be 
issued immediately to correct an unsafe condition in aircraft since 
none of these model helicopters are registered in the United States, 
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 USC 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 99-01-02  Westland Helicopters Ltd (Westland): Amendment 39-
10969. Docket No. 97-SW-40-AD.

    Applicability: Westland 30 Series 100 and 100-60 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 (c) 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 rotorcraft from the applicability of this AD.

    Compliance: Required as indicated unless accomplished 
previously.
    To prevent failure of the conformal pinion quill shafts 
installed in certain Westland 30 series helicopters main rotor 
gearboxes that could result in a subsequent forced landing or loss 
of control of the helicopter, accomplish the following:
    (a) Prior to further flight, determine if the installed main 
rotor gearbox (MRGB) has a serial number included in the following 
list or has a history of shock loading. Shock loading is defined as 
a slam engagement of the No. 1 engine free wheeling unit that can 
occur when the No. 1 engine condition lever is at ``GND'' or ``FLT'' 
position and the engine is driving accessories but the main rotor is 
not turning. If the No. 1 engine freewheel is then engaged, the No. 
1 engine power turbine will abruptly stop, causing potential damage 
to the MRGB and other drive system components.

 
 
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AAT 4440........................  ABL 5602..........  ACD 2875
AAX 4726........................  ABN 8930..........  ACN 7996
ABC 9438........................  ABP 3947..........  ADE 6100
ABD 7294........................  ABP 9028..........  WAG 397
ABG 5056........................  ABT 3965..........  WAG 410
ABH 5075........................  ABW 0547..........  WAK 525
ABJ 9595........................  ACA 3707..........  WAK 561
ABK 9484........................  ..................  ..................


[[Page 71743]]

    (b) If the installed MRGB has a serial number listed in 
paragraph (a) of this AD or has a history of shock loading, perform 
a magnetic drain plug inspection.
    (1) If the magnetic drain plug passes inspection, the MRGB may 
remain in service a maximum of 100 additional hours time in service 
(TIS) after the effective date of this AD with a repetitive magnetic 
drain plug inspection at intervals not to exceed 25 hours TIS. The 
MRGB must then be removed from service and the conformal pinion 
quill shafts replaced.
    (2) If the magnetic drain plug fails inspection, remove the MRGB 
from service prior to further flight and replace the conformal 
pinion quill shafts.

    Note 2: Westland Helicopters, Ltd. Service Bulletin No. W30-63-
75, dated November 29, 1995 (SB) pertains to the subject of this AD.

    (c) 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. 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, 
Rotorcraft Directorate.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Standards Staff.

    (d) 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 helicopter to a location where 
the requirements of this AD can be accomplished.
    (f) This amendment becomes effective on January 14, 1999.

    Note 4: The subject of this AD is addressed in Civil Aviation 
Authority (United Kingdom) AD 012-11-95.

    Issued in Fort Worth, Texas, on December 21, 1998.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-34502 Filed 12-29-98; 8:45 am]
BILLING CODE 4910-13-U