[Federal Register Volume 62, Number 101 (Tuesday, May 27, 1997)]
[Rules and Regulations]
[Pages 28626-28628]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-13464]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-ANE-10; Amendment 39-10035; AD 97-11-06]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney PW4164 and PW4168
Series Turbofan Engines
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 certain Pratt & Whitney PW4164 and PW4168 series
turbofan engines. This action requires initial and repetitive visual
inspections of the fan blades for surface damage and cracks, initial
and repetitive lubrication of the fan blade part span shrouds, a one
time ultrasonic inspection (UI) of the fan blade root attachment area
for cracks, and a one time fan blade root attachment front corner radii
inspection for proper dimension. Also, this AD requires visual
inspection of the fan blades and removal of fan blades damaged by a
bird strike as well as removal of blades immediately adjacent to
damaged blades. In addition, this AD requires installation of an
improved fan blade assembly as terminating action to the inspection
requirements of this AD. This amendment is prompted by a report of a
high N1 rotor imbalance and liberation of the fan containment system
causing loss of structural support of the engine inlet cowl, following
loss of a fan blade during a test. The actions specified in this AD are
intended to prevent fan blade failure and separation at the root
section, which could result in high N1 rotor imbalance, and liberation
of the fan containment system, which can hazard the aircraft.
DATES: Effective June 11, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 11, 1997.
Comments for inclusion in the Rules Docket must be received on or
before July 28, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 97-ANE-10, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``engineprop@faa.dot.gov''. Comments sent via the Internet must contain
the docket number in the subject line.
The service information referenced in this AD may be obtained from
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860)
565-6600, fax (860) 565-4503; or Airbus Industrie, Customer Services
Directorate, Technical Documentation Services, 31707 Blagnac Cedex,
France. This information may be examined 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.
FOR FURTHER INFORMATION CONTACT: Chris Gavriel, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (617)
238-7147, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA)
received a report of a high level of N1 rotor imbalance on a Pratt &
Whitney (PW) PW4164/PW4168 series turbofan engine during a fan blade
out test. The high N1 rotor imbalance resulted from the loss of several
fan blades after fan blade, Part Number (P/N) 55A221, was intentionally
released for test purposes. This high imbalance of the N1 rotor also
caused liberation of the fan blade containment system and loss of
structural support to the engine inlet cowl. In revenue service,
failure of the fan blade near the root attachment could be caused by
metal fatigue. This condition, if not corrected, could result in fan
blade failure and separation at the root section, which could result in
high N1 rotor imbalance, and liberation of the fan containment system,
which can hazard the aircraft.
The FAA has reviewed and approved the technical contents of PW
Service Bulletin (SB) No. PW4G-100-72-69, dated August 6, 1996, that
describes procedures for visual inspections of fan blades for cracks
and surface damage, and lubrication of fan blade shrouds; PW SB No.
PW4G-100-72-81, dated December 18, 1996, that describes procedures for
ultrasonic inspection (UI) of the fan blade root attachment area for
cracks and fan blade root attachment front corner radii for proper
dimension; and PW SB No. PW4G-100-72-92, dated April 24, 1997, that
provides a new or a modified fan blade assembly design.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design, this AD is
being issued to prevent fan blade failure and separation at the root
section. This AD requires initial and repetitive visual inspections of
the fan blades for surface damage and cracks, initial and repetitive
lubrication of the fan blade shrouds, a one-time UI of the fan blade
root attachment area for cracks, and a one-time fan blade root
attachment front corner radii inspection for proper dimension. Fan
blades that do not meet the return to service criteria specified in the
applicable SBs must be replaced with serviceable parts. Also, this AD
would require visual inspection of the fan blades and removal of
damaged blades as well as removal of blades immediately adjacent to
damaged blades following a bird strike. Additionally, this AD would
require incorporation of a new or modified fan blade assembly prior to
December 31, 1998. The actions are required to be
[[Page 28627]]
accomplished in accordance with the SBs described previously.
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.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-ANE-10.'' 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 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, 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
97-11-06 Pratt & Whitney: Amendment 39-10035. Docket 97-ANE-10.
Applicability: Pratt & Whitney (PW) PW4164 and PW4168 series
turbofan engines, installed on but not limited to Airbus Industrie
A330 series aircraft.
Note 1: This airworthiness directive (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: Required as indicated, unless accomplished
previously.
To prevent fan blade failure and separation at the root section,
which could result in high N1 rotor imbalance, and liberation of the
fan containment system, which can hazard the aircraft, accomplish
the following:
(a) Perform visual inspections of fan blades, Part Number (P/N)
55A221, for surface damage and cracks, and lubricate the fan blade
shrouds, in accordance with the Accomplishment Instructions of PW SB
No. PW4G-100-72-69, dated August 6, 1996, as follows:
(1) At the next ``A'' check inspection, not to exceed 500 hours
time in service (TIS) after the effective date of this AD, whichever
occurs first, perform the initial inspection of the fan blades and
lubricate the fan blade shrouds.
(2) Thereafter, at each ``A'' check inspection, but not to
exceed 500 hours TIS since last inspection and lubrication,
whichever occurs first, inspect the fan blades and lubricate the fan
blade shrouds.
(3) Prior to further flight, remove from service fan blades that
do not meet the return to service criteria stated in the SB, and
replace with serviceable parts.
(b) Perform an ultrasonic inspection (UI) of the fan blade root
attachment area of fan blades, P/N 55A221, for cracks and perform a
radius dimension inspection in accordance with Attachments 1 and 2
of PW SB No. PW4G-100-72-81, dated December 18, 1996, as follows:
(1) Prior to accumulating 2,500 total part cycles (TPC), or
within 250 part cycles after the effective date of this AD,
whichever occurs later.
(2) Prior to further flight, remove from service fan blades that
do not meet the return to service criteria stated in the SB, and
replace with serviceable parts.
(c) Following a bird strike, prior to further flight remove from
service undamaged fan blades immediately adjacent on both sides to
any fan blades exhibiting bird ingestion damage in addition to the
damaged fan blades, in accordance with Airbus A330 Aircraft
Maintenance Manual, Section 72-00-00, Subtask 72-00-00-210-093,
Paragraph (A)(1), dated October 1, 1996, and replace with
serviceable parts.
(d) Install a new or a modified fan blade assembly, in
accordance with the requirements of PW SB No. PW4G-100-72-92, dated
April 24, 1997, prior to December 31, 1998. Installation of a new of
modified fan blade assembly, in accordance with PW SB No. PW4G-100-
72-92, dated April 24, 1997, constitutes terminating action to the
inspection requirements of paragraphs (a), (b), and (c) of this AD.
(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.
Operators shall submit their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(f) Special flight permits may be issued in accordance with
Secs. 21.197 and 21.199 of the
[[Page 28628]]
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 PW SBs:
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Document No. Pages Date
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PW4G-100-72-69..................... 1-10 Aug. 6, 1996.
Total pages: 10.
PW4G-100-72-81..................... 1-8 Dec. 18, 1996.
NDIP-883........................... 1-27 Dec. 11, 1996.
NDIP-893........................... 1-9 Dec. 11, 1996.
Total pages: 44.
PW4G-100-72-92..................... 1-24 Apr. 24, 1997.
Total pages: 24.
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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 Pratt & Whitney, 400 Main St.,
East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-
4503. 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 June 11, 1997.
Issued in Burlington, Massachusetts, on May 15, 1997.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 97-13464 Filed 5-22-97; 9:57 am]
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