[Federal Register: December 2, 2002 (Volume 67, Number 231)]
[Proposed Rules]
[Page 71493-71495]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02de02-28]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NE-12-AD]
RIN 2120-AA64
Airworthiness Directives; Turbomeca Turmo IV A and Turmo IV C
Series Turboshaft Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a
new airworthiness directive (AD) that is applicable to Turbomeca Turmo
IV A and IV C series turboshaft engines. This proposal would require
initial and repetitive borescope and eddy current or ultrasonic
inspections of centrifugal compressor intake wheel blades for cracks
and evidence of corrosion pitting, and, if found cracked or if there is
evidence of corrosion pitting, replacement with serviceable parts. This
proposal is prompted by reports of cracked centrifugal compressor
intake wheel blades, resulting in the release of one or more blade
fragments. The actions specified by the proposed AD are intended to
prevent centrifugal compressor intake wheel blade cracks, which can
result in in-flight engine power loss or shutdown.
DATES: Comments must be received by January 31, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 99-NE-12-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location, by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: 9-ane-adcomment@faa.gov.
Comments sent via the Internet must contain the docket number in the
subject line.
The service information referenced in the proposed rule may be
obtained from Turbomeca, 40220 Tarnos, France; telephone (33) 05 59 64
40 00; fax (33) 05 59 64 60 80. This information may be examined, by
appointment, at the FAA, New England Region, Office of the Regional
Counsel, 12 New England Executive Park, Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Antonio Cancelliere, Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone (781) 238-7751; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed 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 above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this
[[Page 71494]]
proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 99-NE-12-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRM's
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 99-NE-12-AD, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
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 Turbomeca Turmo IV A and IV C series
turboshaft engines. The DGAC advises that they have received reports of
cracked centrifugal compressor intake wheel blades. The phenomena of
blade cracking occurs in two phases; initiation after a single event,
such as foreign object damage or surge, and crack propagation due to
operating at a gas generator speed, between 80 percent and 83 percent,
that appears to set up a vibration. Although the exact cause of the
initiation of cracks has not yet been identified, cracks could initiate
at corrosion pits. The investigation is continuing. This condition, if
not corrected, could result in centrifugal compressor intake wheel
blade cracks, which can result in in-flight engine power loss or
shutdown.
Manufacturer's Service Information
Turbomeca has issued Turmo IV Service Bulletin (SB) No. 249 72
0100, Update No. 4, dated January 25, 2000, that specifies procedures
for the centrifugal compressor intake wheel blade inspections. The DGAC
classified this SB as mandatory and issued airworthiness directive (AD)
DGAC AD 97-122(A), Revision 3, dated April 5, 2000, in order to ensure
the airworthiness of these engines in France. Turbomeca has also issued
Turmo IV SB No. 249 72 0117, dated March 11, 2000, that specifies
procedures for installation of modification TU 224.
Bilateral Agreement Information
This engine model is manufactured in France and is 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.
Proposed Requirements of This AD
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require:
[sbull] Initial and repetitive borescope and eddy current or
ultrasonic inspections of centrifugal compressor intake wheel blades
for cracks and evidence of corrosion pitting; and
[sbull] Replacement with serviceable parts if found cracked or if
there is evidence of corrosion pitting.
At this time there is no modification available as terminating
action; as the investigation is ongoing into the cause of crack
initiation, future rulemaking may be necessary. The actions would be
required to be done in accordance with the SB described previously.
Economic Analysis
There are approximately 1,110 engines of the affected design in the
worldwide fleet. The FAA estimates that there are currently 11 engines
installed on helicopters of U.S. registry that would be affected by
this proposed AD, that it would take approximately 41 work hours per
engine to perform the proposed inspections, including disassembling and
assembling engines, and that the average labor rate is $60 per work
hour. A replacement centrifugal compressor assembly costs approximately
$21,651. Based on these figures, the cost per inspection is estimated
to be $265,221.
Regulatory Analysis
This proposed rule does not have federalism implications, as
defined in Executive Order 13132, because it would not have a
substantial direct effect 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.
Accordingly, the FAA has not consulted with state authorities prior to
publication of this proposed rule.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 the following new
airworthiness directive:
Turbomeca: Docket No. 99-NE-12-AD.
Applicability: This airworthiness directive (AD) is applicable
to Turbomeca Turmo IV A and IV C series turboshaft engines. These
engines are installed on but not limited to Aerospatiale FA 330-PUMA
helicopters.
Note 1: This AD applies to each engine 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 engines that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (e) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Compliance is required as indicated, unless already
done
To prevent centrifugal compressor intake wheel blade cracks,
which can result in in-flight engine power loss or shutdown, do the
following:
[[Page 71495]]
(a) For engines that have been modified to TU 197 standard, but
have not been modified to TU 191 or TU 224 standard, do the
following:
(1) Remove modification TU 197 and install modification TU 224
in accordance with Turmo IV SB 249 72 0117, dated March 11, 2000,
within the next 50 cycles or six months after the effective date of
the AD, whichever occurs first.
(2) Within 1,000 flight hours (FH) after the installation of
modification TU 224 standard, do the following:
(i) Perform a visual inspection and an ultrasonic inspection
(USI) in accordance with paragraph 2.B.(3) of Turbomeca Turmo IV SB
249 72 0100, Update 4, dated January 25, 2000.
(ii) Thereafter, perform a visual inspection and a USI at
intervals not to exceed 1,000 FH in accordance with paragraph
2.B.(3) of Turbomeca Turmo IV SB 249 72 0100, Update 4, dated
January 25, 2000.
(b) For engines that have not been modified to TU 191, TU 197,
or TU 224 standard, do the following in accordance with Turbomeca
Turmo IV SB 249 72 0100, Update 4, dated January 25, 2000:
(1) For centrifugal compressor intake wheels that, on the
effective date of this AD, have been operated for more than 250 FH
since the last inspection of the centrifugal compressor intake wheel
blades, do the following:
(i) Perform an initial borescope inspection of the blades for
evidence of corrosion within the next 50 FH, or six months after the
effective date of this AD, whichever occurs first, in accordance
with paragraph 2.B.(1) of the SB.
(ii) If corrosion is found, perform an ECI or USI, as
applicable, of the blades for cracks within 50 FH after the
borescope inspection performed in accordance with paragraph 2.B.(3)
of the SB, and if necessary, replace with serviceable parts.
(iii) If corrosion is not found, perform an ECI or USI, as
applicable, of the blades for cracks within 250 FH after the
borescope inspection performed in accordance with paragraph
(b)(1)(i) of this AD, and if necessary, replace with serviceable
parts.
(iv) Thereafter, perform borescope inspections and ECI's or
USI's, as applicable, of the blades for cracks and evidence of
corrosion, alternating at intervals not to exceed 250 FH since the
last inspection.
(v) Remove from service centrifugal compressor intake wheels
found cracked and replace with serviceable parts.
(2) For centrifugal compressor intake wheels that, upon the
effective date of this AD, have been operated for less than or equal
to 250 FH since the last inspection of the blades, do the following:
(i) Perform an initial borescope inspection of the blades for
evidence of corrosion prior to accumulating 250 FH since the last
inspection of the blades in accordance with paragraph 2.B.(1) of the
SB.
(ii) If corrosion is found, perform an ECI or USI, as
applicable, of the blades for cracks, and, if necessary, replace
with serviceable parts, within 50 FH after the borescope inspection
performed in accordance with paragraph 2.B.(3) of the SB.
(iii) If corrosion is not found, perform an ECI or USI, as
applicable, of the blades for cracks, and, if necessary, replace
with serviceable parts, within 250 FH after the borescope inspection
performed in accordance with paragraph (b)(2)(i) of this AD.
(iv) Thereafter, perform borescope inspections and ECI's or
USI's, as applicable, of the blades for cracks and evidence of
corrosion, alternating at intervals not to exceed 250 FH since the
last inspection.
Note 2: Alternating intervals means that if the last inspection
was an ECI or a USI, the next inspection will be a borescope
inspection. If the last inspection was a borescope inspection, the
next 250 FH inspection will be an ECI or a USI as applicable.
(v) Remove from service centrifugal compressor intake wheels
found cracked and replace with serviceable parts.
(c) For engines not modified to TU 197 but have been modified to
TU 191 or TU 224 standard, that have been operated for more than
1,000 flight hours since the last inspection of the blades, do the
following in accordance with Turbomeca Turmo IV SB 249 72 0100,
Update 4, dated January 25, 2000:
(1) Perform an initial ECI or USI, as applicable, of the blades
for cracks, in accordance with paragraph 2.B.(3) of the SB, within
the next 50 FH, or 6 months after the effective date of this AD,
whichever occurs first.
(2) Thereafter, inspect at intervals not to exceed 1,000 FH.
(3) Remove from service centrifugal compressor intake wheels
found cracked, and replace with a serviceable part
Alternative Methods of Compliance
(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 (ECO).
Operators must submit their request through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, ECO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the ECO.
Special Flight Permits
(f) Special flight permits may be issued in accordance with
Sec. Sec. 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 done.
Note 4: The subject of this AD is addressed in Direction
Generale de L'Aviation Civile airworthiness directive AD97-122(B),
dated May 21, 1997.
Issued in Burlington, Massachusetts, on November 21, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 02-30351 Filed 11-29-02; 8:45 am]
BILLING CODE 4910-13-P