Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-ANE-78; Amendment 39-9092; AD 94-25-08]

Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft

Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to Turbomeca Arriel 1 series turboshaft engines, that

currently requires a gearbox chip detector inspection prior to further

flight, subsequent inspection at designated intervals, and if

necessary, removal of the gearbox, and also requires modification of

the gearbox if not accomplished previously. This amendment requires

modification to the intermediate gear that would constitute terminating

action to the repetitive chip detector inspections. On certain engines

this amendment requires immediate modification of the intermediate gear

prior to further flight. This amendment is prompted by the availability

of design improvements to the intermediate gear. The actions specified

by this AD are intended to prevent damage to the aircraft resulting

from engine debris following an uncontained engine failure.

DATES: Effective January 17, 1995.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of January 17, 1995.

ADDRESSES: The service information referenced in this AD may be

obtained from Turbomeca Engine Corporation, 2709 Forum Drive, Grand

Prairie, TX 75051. This information may be examined at the Federal

Aviation Administration (FAA), New England Region, Office of the

Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA

01803-5299; or at the Office of the Federal Register, 800 North Capitol

Street NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mark A. Rumizen, Aerospace Engineer,

Engine Certification Office, FAA, Engine and Propeller Directorate, 12

New England Executive Park, Burlington, MA 01803-5299; telephone (617)

238-7137, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) by superseding airworthiness

directive (AD) 92-24-08, Amendment 39-8413 (57 FR 54293, November 18,

1992), which is applicable to Turbomeca Arriel 1B, 1D, 1D1, 1A with

TU13, and 1A1 with TU13, turboshaft engines, was published in the

Federal Register on March 15, 1994 (59 FR 11944). That action proposed

to require removing gearboxes that were overhauled prior to June 1,

1992, within 30 days after the effective date of that AD. Those

gearboxes have intermediate gears that are prone to gear teeth wear due

to mixing of used gear train components with new components. That

proposed AD would also require immediate modification of certain

engines to the TU39 which introduces a thicker web intermediate gear

that is more resistant to high cycle fatigue (HCF) failure. Finally,

that proposed AD would also continue to require repetitive inspections

of the chip detector for evidence of metal chips until installation of

modification TU232 to the intermediate gear at the next overhaul or

repair of the reduction gearbox. Installation of modification TU232

would constitute terminating action to the inspection requirements of

that AD. The actions would be required to be accomplished in accordance

with Turbomeca Service Bulletin (SB) No. 292 72 0157, Update No. 2,

dated July 30, 1993, and Turbomeca SB No. 292 72 0169, dated July 12,

1993.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter (the manufacturer) states that the economic analysis

in the proposed rule is incorrect, and provides revised economic

information. The FAA concurs and has revised the economic analysis of

this final rule accordingly.

One commenter states that the provision to allow the pilot to

perform the chip detector inspection that was specified in AD 92-24-08

should be included in this AD. The FAA concurs and the compliance

section has been revised to include this provision.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes described

previously. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

The FAA estimates that 270 engines installed on aircraft of U.S.

registry will be affected by this AD, that it will take approximately 4

work hours per engine to accomplish the required actions, and that the

average labor rate is $55 per work hour. Required parts will cost

approximately $4,222 per engine. Based on these figures, the total cost

impact of the AD on U.S. operators is estimated to be $1,199,340.

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.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it 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, Incorporation by

reference, 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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Amendment Section 39.13 is

amended by removing amendment 39-8413 (57 FR 54293, November 18, 1992)

and by adding a new airworthiness directive, Amendment 39-9092, to read

as follows:

94-25-08 Turbomeca: Amendment 39-9092. Docket 93-ANE-78. Supersedes

AD 92-24-08, Amendment 39-8413.

Applicability: Turbomeca Arriel Model 1B, 1D, 1D1, 1A with TU13,

and 1A1 with TU13, turboshaft engines installed on but not limited

to Aerospatiale AS-350B helicopters.

Compliance: Required as indicated, unless accomplished

previously.

To prevent damage to the aircraft resulting from engine debris

following an uncontained engine failure, accomplish the following:

(a) For the following Turbomeca Arriel engine models: 1D not

modified to TU232, 1D1 not modified to TU232, 1B modified to TU39

but not modified to TU232, 1A with TU13 modified to TU39 but not

modified to TU232, and 1A1 with TU13 modified to TU39 but not

modified to TU232, accomplish the following:

(1) Except for those engines that have been inspected in

accordance with AD 92-24-08 within 8 hours time in service (TIS)

prior to the effective date of this AD, prior to further flight

remove and inspect the reduction gearbox chip detector for evidence

of metal chips.

(2) Remove from service reduction gearbox modules that do not

meet the return to service criteria described in Turbomeca SB No.

292 72 0157, Update No. 2, dated July 30, 1993, and replace with a

serviceable part.

(3) Thereafter, at intervals not to exceed 8 hours TIS since the

last inspection, accomplish the following:

(i) Remove and inspect the reduction gearbox chip detector in

accordance with paragraph (a)(1) of this AD.

(ii) Remove from service, if necessary, the reduction gearbox

module in accordance with paragraph (a)(2) of this AD, and replace

with a serviceable part.

(4) At the next overhaul or repair of the reduction gearbox

module after the effective date of this AD, incorporate modification

TU232 in accordance with Turbomeca SB No. 292 72 0169, dated July

12, 1993. Incorporation of modification TU232 constitutes

terminating action to the inspections, and replacement, if

necessary, required in paragraphs (a)(1), (a)(2), and (a)(3) of this

AD.

(b) For the following Turbomeca Arriel engine models: 1B not

modified to TU39, 1A with TU13 not modified to TU39, and 1A1 with

TU13 not modified to TU39, prior to further flight replace reduction

gearbox module No. 5 with a reduction gearbox module No. 5 modified

to standard TU39.

(c) For the following Turbomeca Arriel engine models: 1B, 1A

with TU13, and 1A1 with TU13; with reduction gearbox modules

identified by serial numbers specified in paragraph C.(c) of

Turbomeca SB No. 292 72 0157, Update No. 2, dated July 30, 1993,

that were overhauled prior to June 1, 1992, but not overhauled

between that date and the effective date of this AD, and with less

than 200 hours TIS since overhaul, remove from service and return

for overhaul within 30 days after the effective date of this AD, in

accordance with Turbomeca Service Bulletin (SB) No. 292 72 0157,

Update No. 2, dated July 30, 1993.

(d) The checks required by paragraphs (a)(1) and (a)(3)(i) of

this AD may be performed by the pilot holding at least a private

pilot certificate as a n exception to the requirements of part 43 of

the Federal Aviation Regulations (14 CFR part 43). The checks must

be recorded in accordance with Sections 43.9 and 91.417(a)(2)(v) of

the Federal Aviation Regulations (14 CFR 43.9 and 14 CFR

91.417(a)(2)(v)), and the records must be maintained as required by

the applicable Federal Aviation Regulation.

(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, Engine Certification Office. The

request should be forwarded through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Engine Certification Office.

Note: Information concerning the existence of approved

alternative method of compliance with this AD, if any, may be

obtained from the Engine Certification Office.

(f) 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 aircraft to a location where

the requirements of this AD can be accomplished.

(g) The actions required by this AD shall be done in accordance

with the following service bulletins:

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Document No. Pages Update Date

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Turbomeca SB No. 292 72 0157. 1-5 2.......... July 30, 1993.

Total pages: 5.

Turbomeca SB No. 292 72 0169. 1-5 Original... July 12, 1993.

Total pages: 5.

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This incorporation by reference was approved by the Director of

the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR

part 51. Copies may be obtained from Turbomeca Engine Corporation,

2709 Forum Drive, Grand Prairie, TX 75051. Copies may be inspected

at the FAA, New England Region, Office of the Assistant Chief

Counsel, 12 New England Executive Park, Burlington, MA; or at the

Office of the Federal Register, 800 North Capitol Street NW., suite

700, Washington, DC.

(h) This amendment becomes effective on January 17, 1995.

Issued in Burlington, Massachusetts, on December 2, 1994.

James C. Jones,

Acting Manager, Engine and Propeller Directorate, Aircraft

Certification Service.

[FR Doc. 94-30180 Filed 12-14-94; 8:45 am]

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