Airworthiness Directives; Pratt & Whitney PW4164, PW4168, and PW4168A Series Turbofan Engines, 77075-77077 [E5-8020]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 70, Number 249 (Thursday, December 29, 2005)]
[Proposed Rules]
[Pages 77075-77077]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E5-8020]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-44-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4164, PW4168, and 
PW4168A Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for Pratt & Whitney (PW) PW4164, PW4168, and PW4168A 
series turbofan engines. That AD currently requires initial and 
repetitive torque checks for loose or broken front pylon mount bolts 
made from INCO 718 material and MP159 material, and initial and 
repetitive visual inspections of the primary mount thrust load path. 
This proposed AD would require the same actions, but at reduced 
intervals for front pylon mount bolts made from MP159 material. This 
proposed AD results from analysis by the manufacturer that the MP159 
material pylon bolts do not meet the full life cycle torque check 
interval requirement, in a bolt-out condition. We are proposing this AD 
to prevent front pylon mount bolt and primary mount thrust load path 
failure, which could result in an engine separating from the airplane.

DATES: We must receive any comments on this proposed AD by February 27, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     By mail: Federal Aviation Administration (FAA), New 
England Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 97-ANE-44-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
     By fax: (781) 238-7055.
     By e-mail: 9-ane-adcomment@faa.gov.
    Contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-7700, fax (860) 565-1605 for the service 
information identified in this proposed AD.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7146, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 97-ANE-44-AD'' in the 
subject line of your comments. If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us verbally, and that contact relates to a 
substantive part of this proposed AD, we will summarize the contact and 
place the summary in the docket. We will consider all comments received 
by the closing date and may amend the proposed AD in light of those 
comments.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    On December 19, 2002, we issued AD 2000-16-02R1, Amendment 39-12989 
(68 FR 28, January 2, 2003). That AD requires initial and repetitive 
torque

[[Page 77076]]

checks for loose or broken front pylon mount bolts made from INCO 718 
material and MP159 material. That AD also requires initial and 
repetitive visual inspections of the primary mount thrust load path. 
That AD was the result of component testing to assess the low-cycle-
fatigue life of the MP159 material bolts and the development of a new 
design forward engine mount bearing housing. That condition, if not 
corrected, could result in front pylon mount bolt and primary mount 
thrust load path failure, which could result in an engine separating 
from the airplane.

Actions Since AD 2000-16-02R1 Was Issued

    Since AD 2000-16-02R1 was issued, the manufacturer performed new 
fatigue load analysis of the engine mount system, as part of supporting 
a new 180-minute-flight airplane mission, and supporting updated flight 
liftoff calculations. The analysis revealed that the MP159 material 
pylon bolts do not meet the full life cycle torque check interval 
requirement, in a bolt-out condition.

Relevant Service Information

    We have reviewed and approved the technical contents of PW Alert 
Service Bulletin (ASB) PW4G-100-A71-32, dated April 15, 2005, that 
describes procedures for performing reduced interval initial and 
repetitive torque checks of MP159 material front pylon mount bolts.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would require 
the same torque checks and inspections specified in AD 2000-16-02R1 
except for bolts made from MP159 material. This proposed AD would 
reduce the torque check compliance times for the front pylon mount 
bolts made from MP159 material to the following:
     For bolts with fewer than 2,200 CSN on the effective date 
of the proposed AD, initial torque check before accumulating 2,700 CSN, 
or at the next engine removal for any cause, whichever occurs sooner.
     For bolts with 2,200 CSN or more on the effective date of 
the proposed AD, initial torque check within the next 500 CIS, or at 
the next engine removal for any cause, whichever occurs sooner.
     Thereafter, perform torque checks at intervals not to 
exceed 2,700 CIS since last torque inspection.
    The proposed AD would require that you do these actions using the 
service information described previously and listed in the proposed AD.

Costs of Compliance

    About 60 engines installed on airplanes of U.S. registry are 
affected by this proposed AD. We estimate that it would take about four 
work hours per engine to perform the proposed actions, and that the 
average labor rate is $65 per work hour. Required parts would cost 
about $26,500 per engine. Based on these figures, we estimate the total 
cost of the proposed AD to U.S. operators to be $1,605,600.

Special Flight Permits Paragraph Removed

    Paragraph (g) of the current AD, AD 2000-16-02R1, contains a 
paragraph pertaining to special flight permits. Even though this 
proposed AD does not contain a similar paragraph, we have made no 
changes with regard to the use of special flight permits to operate the 
airplane to a repair facility to do the work required. In July 2002, we 
published a new Part 39 that contains a general authority regarding 
special flight permits and airworthiness directives; see Docket No. 
FAA-2004-8460, Amendment 39-9474 (69 FR 47998, July 22, 2002). Thus, 
when we now supersede ADs we will not include a specific paragraph on 
special flight permits unless we want to limit the use of that general 
authority granted in Sec.  39.23.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We have prepared a summary of the costs to comply with this 
proposal and placed it in the AD Docket. You may get a copy of this 
summary by sending a request to us at the address listed under 
ADDRESSES. Include ``AD Docket No. 97-ANE-44-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by removing Amendment 39-12989 (68 FR 
28, January 2, 2003) and by adding a new airworthiness directive to 
read as follows:

Pratt & Whitney: Docket No. 97-ANE-44-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by February 27, 
2006.

Affected ADs

    (b) This AD supersedes AD 2000-16-02R1.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) PW4164, PW4168, and 
PW4168A series turbofan engines, with front pylon mount bolts, part 
number (P/N) 54T670 or 51U615, installed. These engines are 
installed on, but not limited to, Airbus A330 series airplanes.

[[Page 77077]]

Unsafe Condition

    (d) This AD results from analysis by the manufacturer that MP159 
material pylon bolts do not meet the full life cycle torque check 
interval requirement, in a bolt-out condition. We are issuing this 
AD to prevent front pylon mount bolt and primary mount thrust load 
path failure, which could result in an engine separating from the 
airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.

INCO 718 Material Bolts Torque Checks

    (f) Perform initial and repetitive torque checks of INCO 718 
material front pylon mount bolts, P/N 54T670, and replace, if 
necessary, with new bolts, using the Accomplishment Instructions of 
PW Alert Service Bulletin (ASB) PW4G-100-A71-9, Revision 1, dated 
November 24, 1997, as follows:
    (1) For front pylon mount bolts, P/N 54T670, with fewer than 
1,000 cycles-since-new (CSN) on the effective date of this AD, do 
the following using Part (A) of the Accomplishment Instructions of 
the ASB:
    (i) Perform an initial torque check before accumulating 1,250 
CSN or at the next engine removal for cause, whichever occurs 
sooner.
    (ii) Thereafter, perform torque checks at intervals of no fewer 
than 750 or no more than 1,250 cycles-in-service (CIS) since last 
torque check, not to exceed the life limit of 11,000 CSN.
    (2) For front pylon mount bolts, P/N 54T670, with 1,000 CSN or 
more but fewer than 5,750 CSN on the effective date of this AD, do 
the following using Part (A) of the Accomplishment Instructions of 
the ASB:
    (i) Perform an initial torque check within 250 CIS after the 
effective date of this AD, or at the next engine removal for any 
cause, whichever occurs sooner.
    (ii) Thereafter, perform torque checks at intervals of no fewer 
than 750 or no more than 1,250 CIS since last torque check, not to 
exceed the life limit of 11,000 CSN.
    (3) For front pylon mount bolts, P/N 54T670, with 5,750 CSN or 
more on the effective date of this AD, do the following using Part 
(B) of the Accomplishment Instructions of the ASB:
    (i) Perform an initial torque check within 250 CIS after the 
effective date of this AD, or before the next engine removal for any 
cause, whichever occurs sooner.
    (ii) Thereafter, perform torque checks at intervals of no fewer 
than 750 or no more than 1,250 CIS since last torque check, not to 
exceed the front pylon mount bolt P/N 54T670, life limit of 11,000 
CSN.
    (4) Before further flight, replace all four bolts using Part 
(A), Paragraph 1(D) of the Accomplishment Instructions of the ASB, 
if any of the bolts are loose or broken.

MP159 Material Bolts Inspections

    (g) Perform initial and repetitive torque checks of front pylon 
mount bolts, P/N 51U615, using the Accomplishment Instructions of PW 
ASB PW4G-100-A71-32, dated April 15, 2005, as follows:
    (1) For front pylon mount bolts with fewer than 2,200 CSN on the 
effective date of this AD, perform the initial torque inspection 
before accumulating 2,700 CSN, or at the next engine removal for any 
cause, whichever occurs sooner.
    (2) For front pylon mount bolts with 2,200 CSN or more on the 
effective date of this AD, perform the initial torque check within 
the next 500 CIS, or at the next engine removal for any cause, 
whichever occurs sooner.
    (3) Thereafter, perform torque inspections at intervals not to 
exceed 2,700 CIS since last torque inspection.
    (4) Before further flight, replace all four bolts using 
Paragraph 1.E. of the Accomplishment Instructions of the ASB, if any 
are loose or broken.

Primary Mount Thrust Load Path Inspections

    (h) Perform initial and repetitive visual inspections of the 
primary mount thrust load path using the Accomplishment Instructions 
of PW ASB PW4G-100-A71-18, Revision 2, dated January 15, 2002, as 
follows:
    (1) For forward engine mount assemblies with fewer than 1,000 
CSN on the effective date of this AD, perform the initial visual 
inspection at the earlier of the following:
    (i) Before accumulating 1,250 CSN; or
    (ii) The next engine removal for any cause.
    (2) For forward engine mount assemblies with 1,000 CSN or more 
on the effective date of this AD, perform the initial visual 
inspection within 250 CIS after the effective date of this AD, or 
the next engine removal for any cause, whichever occurs sooner.
    (3) Thereafter, perform visual inspections at intervals of no 
fewer than 750 or no more than 1,250 CIS since last visual 
inspection.
    (4) Before further flight, replace all cracked parts with 
serviceable parts and inspect the primary thrust load path 
components using Paragraph 4 of the Accomplishment Instructions of 
the ASB.

Terminating Action

    (i) Replacement of the forward engine mount bearing housing, P/N 
59T794 or P/N 54T659 with P/N 52U420, using SB PW4G-100-71-22, dated 
January 15, 2002, constitutes terminating action to the inspection 
requirements of paragraph (h) of this AD.

Alternative Methods of Compliance

    (j) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (k) None.

    Issued in Burlington, Massachusetts, on December 22, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E5-8020 Filed 12-28-05; 8:45 am]
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