Airworthiness Directives; Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4090, and PW4090-3 Turbofan Engines

[Federal Register Volume 68, Number 125 (Monday, June 30, 2003)]
[Rules and Regulations]
[Pages 38592-38594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-15992]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-24-AD; Amendment 39-13211; AD 2003-13-11]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4074, PW4074D, 
PW4077, PW4077D, PW4090, and PW4090-3 Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Pratt & Whitney (PW) PW4074, PW4074D, PW4077, PW4077D, PW4090, and 
PW4090-3 turbofan engines with high pressure compressor (HPC) rear 
cases, part numbers (P/Ns) 55H425-01, 55H385-01, and 56H396-01 
installed. This AD requires initial and repetitive visual or 
fluorescent penetrant inspections (FPI) of the J flange on the HPC rear 
case, and removal from service of the rear case based on certain 
inspection results. This AD is prompted by reports of cracks 
propagating from bolt holes in the HPC rear case J flange, and reports 
of high-cycle HPC rear cases exhibiting cracks propagating into the 
shell wall. The actions specified in this AD are intended to prevent 
fracturing and rupturing of the HPC rear case, resulting in uncontained 
engine failure.

DATES: Effective July 15, 2003. The Director of the Federal Register 
approved the incorporation by reference of certain publications listed 
in the regulations as of July 15, 2003.
    We must receive any comments on this AD by August 29, 2003.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD:
    [sbull] By mail: The Federal Aviation Administration (FAA), New 
England Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 2003-NE-24-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
    [sbull] By fax: (781) 238-7055.
    [sbull] By e-mail: [email protected]
    You may get the service information referenced in this AD from 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108, telephone (860) 
565-6600; fax (860) 565-4503.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information at the FAA, New 
England Region, Office of the Regional 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: Keith Lardie, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7189; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: This AD applies to PW PW4074, PW4074D, 
PW4077, PW4077D, PW4090, and PW4090-3 turbofan engines with HPC rear 
cases, P/Ns 55H425-01, 55H385-01, and 56H396-01 installed. This AD 
requires initial and repetitive visual or FPI inspections of the J 
flange on HPC rear cases, P/Ns 55H425-01, 55H385-01, and 56H396-01, 
which were previously produced with or modified to a scalloped flange 
configuration using PW Service Bulletin (SB) No. PW4G-112-72-150, dated 
April 16, 1998, or SB No. PW4G-112-72-151, dated April 16, 1998, or SB 
No. PW4G-112-72-195, dated May 5, 1999. This AD also requires removal 
from service of the rear case based on certain inspection results. This 
AD is prompted by 32 reports of cracks propagating from bolt holes in 
the HPC rear case J flange, and reports of high-cycle HPC rear cases 
exhibiting cracks propagating into the shell wall. The HPC rear cases, 
P/Ns 55H425-01, 55H385-01, and 56H396-01 were produced with or modified 
by PW SBs to incorporate a scalloped J flange design as corrective 
action to eliminate flange cracking at the bolt holes. The scalloped 
flange has not been effective in eliminating J flange cracking. Cracks 
found propagating into the shell wall could result in loss of case 
integrity, and require immediate removal before further flight. The 
actions specified in this AD are intended to prevent fracturing and 
rupturing of the HPC rear case, resulting in uncontained engine 
failure.

Relevant Service Information

    We have reviewed and approved the technical contents of PW SB No. 
PW4G-112-72-256, dated April 2, 2003, that describes procedures for 
initial and repetitive visual or FPI inspections of the J flange on HPC 
rear cases, and removal from service of the rear case based on certain 
inspection results.

[[Page 38593]]

Differences Between This AD and the Service Information

    This AD adds an additional inspection at bolt hole location number 
69, which was not originally listed in PW SB No. PW4G-112-72-256, 
because one report of a crack at that location has been received since 
the service bulletin was released. Future revisions of PW SB No. PW4G-
112-72-256 will include this inspection location.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other PW PW4074, PW4074D, PW4077, PW4077D, PW4090, and 
PW4090-3 turbofan engines of the same type design. Therefore, we are 
issuing this AD to prevent fracturing and rupturing of the HPC rear 
case, resulting in uncontained engine failure. This AD requires:
    [sbull] Initial and repetitive visual or FPI inspections of the J 
flange on HPC rear cases, P/Ns 55H425-01, 55H385-01, and 56H396-01.
    [sbull] Removal of the rear case from service based on certain 
inspection results.
    You must do these actions in accordance with the service 
information described previously.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
prior public comment are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Changes to 14 CFR Part 39--Effect on the AD

    On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 
47997, July 22, 2002), which governs our AD system. This regulation now 
includes material that relates to special flight permits, alternative 
methods of compliance, and altered products. This material previously 
was included in each individual AD. Since this material is included in 
14 CFR part 39, we will not include it in future AD actions.

Interim Action

    These actions are interim actions and we may take further 
rulemaking actions in the future.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment; however, we invite you to submit any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 2003-NE-24-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 rule 
that might suggest a need to modify it. If a person contacts us through 
a nonwritten communication, and that contact relates to a substantive 
part of this 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 AD in light of those comments.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications with you. You may get more information about plain 
language at http://www.plainlanguage.gov.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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 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. 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.
    We prepared a summary of the costs to comply with this AD 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. 2003-NE-24-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under 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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2003-13-11 Pratt & Whitney: Amendment 39-13211. Docket No. 2003-NE-
24-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 15, 
2003.

Affected ADs

    (b) None.

Applicability

    (c) This AD is applicable to Pratt & Whitney (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4090, and PW4090-3 turbofan engines with 
high pressure compressor (HPC) rear cases, part numbers (P/Ns) 
55H425-01, 55H385-01, and 56H396-01 installed. These engines are 
installed on, but not limited to, Boeing 777 series airplanes.

Unsafe Condition

    (d) This AD is prompted by 32 reports of cracks propagating from 
bolt holes in the HPC rear case J flange, two of which were reports 
of high-cycle HPC rear cases with cracks propagating into the shell 
wall, which required immediate removal before further flight. The 
actions specified in this AD are intended to prevent fracturing and 
rupturing of the HPC rear case, resulting in uncontained engine 
failure.

Compliance

    (e) Compliance with this AD is required as indicated, unless 
already done.

Initial Inspection

    (f) Perform an initial visual or fluorescent penetrant 
inspection (FPI) of the HPC rear case J flange for cracks at bolt 
hole location numbers 22, 67, 68, and 69, in accordance with 
Accomplishment Instructions of PW Service Bulletin (SB) No. PW4G-
112-72-256, dated April 2, 2003, using the compliance times 
specified in the following Table 1:

[[Page 38594]]



                  Table 1.--Initial Inspection Schedule
------------------------------------------------------------------------
                                      For cycles
        HPC rear case P/N           accumulated of:          Then:
------------------------------------------------------------------------
(1) 55H425-01 modified by PW SB   (i) 4,000 or more   Inspect within 50
 No. PW4G-112-72-150, dated        cycles-since SB     cycles-in-service
 April 16, 1998.                   modification        (CIS) after the
                                   (CSM).              effective date of
                                                       this AD.
                                  (ii) 2,500 CSM or   Inspect within 75
                                   more, but fewer     CIS after the
                                   than 4,000 CSM.     effective date of
                                                       this AD.
                                  (iii) 1,850 CSM or  Inspect within 150
                                   more, but fewer     CIS after the
                                   than 2,500 CSM.     effective date of
                                                       this AD.
                                  (iv) More than      Inspect within 300
                                   1,700 CSM, but      CIS after the
                                   fewer than 1,850    effective date of
                                   CSM.                this AD.
                                  (v) 1,700 CSM, or   Inspect before
                                   fewer.              accumulating
                                                       2,000 CSM
---------------------------------
(2) 55H385-01, 55H396-01, and     (i) 7,200 or more   Inspect within 300
 55H425-01 incorporating a         CSN.                CIS after the
 scalloped J.                                          effective date of
                                                       this AD.
                                  (ii) Fewer than     Inspect before
                                   7,200 CSN.          accumulating
                                                       7,500 CSN.
------------------------------------------------------------------------

Previous Credit

    (g) Previous credit is allowed for initial inspections for 
cracks at bolt hole location numbers 22, 67, and 68 that were done 
in accordance with PW SB PW4G-112-72-256, dated April 2, 2003, 
before the effective date of this AD. Previous credit is also 
allowed for initial inspection of bolt hole location number 69 if 
bolt hole location number 68 was previously inspected before the 
effective date of this AD.
    (h) Disposition the HPC rear cases using the criteria in the 
following Table 2:

              Table 2.--HPC Rear Case Disposition Criteria
------------------------------------------------------------------------
           If HPC rear case has:                        Then:
------------------------------------------------------------------------
(1) One or more inboard cracks that have    Remove HPC rear case before
 penetrated beyond the pedestal and into     further flight.
 the shell wall.
-------------------------------------------
(2) One or more inboard cracks that have    Remove HPC rear case within
 penetrated into the pedestal but not into   25 cycles-since-last
 the shell wall.                             inspection (CSLI).
-------------------------------------------
(3) One or more inboard cracks that have    Remove HPC rear case within
 not penetrated into the pedestal.           250 CSLI.
-------------------------------------------
(4) One or more outboard cracks...........  Perform repetitive
                                             inspections as specified in
                                             paragraph (i) of this AD.
-------------------------------------------
(5) No cracks.............................  Perform repetitive
                                             inspections as specified in
                                             paragraph (i) of this AD.
------------------------------------------------------------------------

Repetitive Inspections

    (i) Perform repetitive inspections of the HPC rear case J flange 
for cracks at bolt hole location numbers 22, 67, 68, and 69 in 
accordance with the Accomplishment Instructions of PW SB No. PW4G-
112-72-256, dated April 2, 2003, and the following:
    (1) If last inspection of HPC rear case was a visual inspection, 
then visually inspect or FPI within:
    (i) 600 CSLI if no cracks are found.
    (ii) 300 CSLI if one or more outboard cracks are found.
    (2) If last inspection of HPC rear case was an FPI, then 
visually inspect or FPI within:
    (i) 1,000 CSLI if no cracks are found.
    (ii) 600 CSLI if one or more outboard cracks are found.
    (3) Remove HPC rear cases from service or re-inspect rear cases 
using Table 2 of this AD.

Alternative Methods of Compliance

    (j) Alternative methods of compliance must be requested in 
accordance with 14 CFR part 39.19, and must be approved by the 
Manager, Engine Certification Office, FAA.

Material Incorporated by Reference

    (k) The inspections and removal from service of HPC rear cases 
must be done in accordance with Pratt & Whitney Service Bulletin No. 
PW4G-112-72-256, dated April 2, 2003. The Director of the Federal 
Register approved the incorporation by reference of this service 
bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You 
may get a copy from Pratt & Whitney, 400 Main St., East Hartford, CT 
06108, telephone (860) 565-6600; fax (860) 565-4503. You may review 
copies at the FAA, New England Region, Office of the Regional 
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.

Related Information

    (l) None.

    Issued in Burlington, Massachusetts, on June 18, 2003.
Robert Mann,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 03-15992 Filed 6-27-03; 8:45 am]
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