[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: ``9-ad-
[email protected]''. 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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