Airworthiness Directives; Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090D, PW4090-3, and PW4098 Turbofan Engines

[Federal Register Volume 68, Number 212 (Monday, November 3, 2003)]
[Rules and Regulations]
[Pages 62228-62231]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-27327]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-40-AD; Amendment 39-13357; AD 2003-22-09]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4074, PW4074D, 
PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090D, PW4090-3, and PW4098 
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 PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, 
PW4090, PW4090D, PW4090-3, and PW4098 turbofan engines. This AD 
requires borescope inspection of the No. 3 bearing weep tube, on 
engines with high oil consumption that troubleshooting procedures fail 
to determine the source of oil loss. This AD also requires for all 
engines, initial and repetitive visual inspections of the turbine 
exhaust case (TEC) in the vicinity of the No 3 bearing oil vent tube 
for evidence of oil wetting or staining. If the vent tube borescope 
inspection is unsuccessful due to tube blockage, this AD also requires 
borescope inspections of the high pressure turbine (HPT) assembly for 
oil wetting or staining. This AD also requires removal of the HPT 
assembly and replacement of any heat distressed HPT assembly hardware 
if oil wetting or staining is found. This AD is prompted by reports of 
engine HPT assembly hardware being damaged as a result of thermal 
distress from oil

[[Page 62229]]

igniting after leaking from the No. 3 bearing compartment. We are 
issuing this AD to prevent thermal distressed HPT assembly hardware 
from remaining in service, which could result in a cracked HPT stage 1 
disk or HPT stage 1-2 air seal and an uncontained engine failure.

DATES: Effective December 3, 2003. The Director of the Federal Register 
approved the incorporation by reference of certain publications listed 
in the regulations as of December 3, 2003.
    We must receive any comments on this AD by January 2, 2004.

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-40-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
    [sbull] By fax: (781) 238-7055.
    [sbull] By e-mail: [email protected].
    You can get the service information referenced in this AD from 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 
565-7700; fax (860) 565-1605.
    You may examine the AD docket, by appointment, at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA. You may examine the service 
information, by appointment, 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: The FAA is aware of seven reports of Pratt & 
Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, 
PW4090D, PW4090-3, and PW4098 turbofan engines with HPT thermal 
distress caused by ignition of oil in cavities of the HPT assembly. 
This oil ignition was the result of oil leaking from the No. 3 bearing 
compartment. Five of those engines were approaching or exceeded high 
oil consumption limits. Four of the engines had distress resulting in 
significant damage to the HPT assembly. Over time, the increased 
temperatures from oil ignition can cause cracking of the HPT stage 1 
disk anti-rotation lugs and HPT stage 1-2 air seal that may result in 
an uncontained engine failure. The root cause of the oil leakage is 
currently unknown. The manufacturer suspects the following three 
causes:
    [sbull] Clogging of the oil passages on the No. 3 seal plates.
    [sbull] Wear on the anti-rotation slots on the No. 3 carbon seal 
carriers.
    [sbull] Loose stack of the No. 3 bearing compartment.

Relevant Service Information

    We have reviewed and approved the technical contents of Pratt & 
Whitney Alert Service Bulletin (ASB) No. PW4G-112-A72-257, Revision 1, 
dated August 22, 2003, that describes procedures for:
    [sbull] Borescope inspection of the No. 3 bearing weep tube, on 
engines with high oil consumption that troubleshooting procedures fail 
to determine the source of oil loss.
    [sbull] For all engines, initial and repetitive visual inspections 
of the TEC, in the vicinity of the No. 3 bearing oil vent tube assembly 
and borescope inspections of the No. 3 bearing oil vent tube assembly, 
for evidence of oil wetting or staining.
    [sbull] Borescope inspection of the HPT assembly for evidence of 
oil wetting or staining if the borescope inspection of the No. 3 
bearing oil vent tube assembly is unsuccessful due to blockage.
    [sbull] Removal of the engine if oil wetting or staining is found.

Differences Between This AD and the Service Information

    Although ASB No. PW4G-112-A72-257, Revision 1, dated August 22, 
2003, requires removal of the engine from service if oil wetting or 
staining is found, this AD requires removal of the HPT assembly and 
replacement of any heat distressed HPT assembly hardware if oil wetting 
or staining is found.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, 
PW4084, PW4084D, PW4090, PW4090D, PW4090-3, and PW4098 turbofan engines 
of the same type design. We are issuing this AD to prevent thermal 
distressed HPT assembly hardware to remain in service, which could 
result in a cracked HPT stage 1 disk or HPT stage 1-2 air seal and an 
uncontained engine failure. This AD requires:
    [sbull] Borescope inspection of the No. 3 bearing weep tube on 
engines with high oil consumption that troubleshooting procedures fail 
to determine the source of oil loss.
    [sbull] For all engines, initial and repetitive visual inspections 
of the TEC, in the vicinity of the No. 3 bearing oil vent tube assembly 
and borescope inspections of the No. 3 bearing oil vent tube assembly, 
for evidence of oil wetting or staining.
    [sbull] Borescope inspections of the HPT assembly for oil wetting 
or staining, if the vent tube borescope inspection is unsuccessful due 
to tube blockage.
    [sbull] Removal of the HPT assembly and replacement of any heat 
distressed HPT assembly hardware if oil wetting or staining is found.

You must use the service information described previously to perform 
the actions required by this AD.

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 
public comment before issuing this AD 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 
47998, 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, when the manufacturer's investigation 
is completed.

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-40-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

[[Page 62230]]

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 verbally, 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.faa.gov/language and http://www.plainlanguage.gov.

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.

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-40-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:

2003-22-09 Pratt & Whitney: Amendment 39-13357. Docket No. 2003-NE-
40-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
3, 2003.

Affected ADs

    (b) None.
    Applicability: (c) This AD applies to Pratt & Whitney PW4074, 
PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, PW4090D, PW4090-
3, and PW4098 turbofan engines. These engines are installed on, but 
not limited to, Boeing 777 series airplanes.

Unsafe Condition

    (d) This AD is prompted by reports of engine high pressure 
turbine (HPT) assembly hardware being damaged as a result of thermal 
distress from oil igniting after leaking from the No. 3 bearing 
compartment. We are issuing this AD to prevent thermal distressed 
HPT assembly hardware from remaining in service, which could result 
in a cracked HPT stage 1 disk and HPT stage 1-2 air seal and an 
uncontained engine failure.

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.

Credit for Previous Inspections

    (f) Inspections performed before the effective date of this AD, 
using Pratt & Whitney Alert Service Bulletin (ASB) No. PW4G-112-A72-
257, dated June 30, 2003, may be counted toward satisfying the 
initial and repetitive inspection requirements of paragraphs (g) 
through (k) of this AD.

Borescope Inspection of Engines With High Oil Consumption

    (g) For engines with high oil consumption that troubleshooting 
procedures fail to determine the source of oil loss, borescope-
inspect No. 3 bearing oil vent tube assembly and or HPT assembly 
within 100 cycles-in-service (CIS) of the high oil consumption 
event, using paragraphs (g)(1) through (g)(2) of this AD. 
Information on troubleshooting engines with high oil consumption can 
be found in Boeing 777 Fault Isolation Manual (FIM), section 71-05, 
Task 830, dated January 5, 2003. See paragraph (l) of this AD for a 
definition of high oil consumption.
    (1) Borescope-inspect the No. 3 bearing oil vent tube assembly 
for evidence of oil wetting or staining. Follow Step 3, paragraphs 
1. through 1.A.(8)(a) of Accomplishment Instructions of Pratt & 
Whitney ASB No. PW4G-112-A72-257, Revision 1, dated August 22, 2003.
    (2) If the No. 3 bearing oil vent tube is blocked and attempts 
to clear it are unsuccessful, borescope-inspect the HPT assembly, 
following Step 4, paragraphs 1. through 1.B(14) of Accomplishment 
Instructions of ASB No. PW4G-112-A72-257, Revision 1, dated August 
22, 2003.
    (3) Remove the HPT assembly within 100 CIS of the high oil 
consumption event if evidence of oil wetting or staining is found in 
the No. 3 bearing oil vent tube or on the HPT first stage disk.
    (4) Replace any heat distressed HPT assembly hardware if oil 
wetting or staining is found.

Turbine Exhaust Case (TEC) Inspections Of All Engines

    (h) Inspect the TEC of all engines, within 500 hours-in-service 
(HIS) after the effective date of this AD as follows:
    (1) Visually inspect the TEC in the vicinity of the No. 3 
bearing oil vent tube assembly for evidence of oil wetting or 
staining, using Figure 2 of Pratt & Whitney ASB No. PW4G-112-A72-
257, Revision 1, dated August 22, 2003, for location of inspection.
    (2) If evidence of oil wetting or staining is found at the TEC, 
borescope-inspect the No. 3 bearing oil vent tube assembly within 
100 additional CIS, to confirm the oil is from the vent tube. Follow 
Step 1, paragraphs 1.B. through 1.D.(8)(a) of Accomplishment 
Instructions of Pratt & Whitney ASB No. PW4G-112-A72-257, Revision 
1, dated August 22, 2003.
    (3) If the No. 3 bearing oil vent tube is blocked and attempts 
to clear it are unsuccessful, borescope-inspect the HPT assembly 
following Step 4, paragraphs 1. through 1.B.(14) of Accomplishment 
Instructions of ASB No. PW4G-112-A72-257, Revision 1, dated August 
22, 2003.
    (4) Remove the HPT assembly within 100 CIS since performing the 
visual inspection of the TEC specified in paragraph (h)(1) of this 
AD, if evidence of oil wetting or staining is found in the No. 3 
bearing oil vent tube or found on the HPT first stage disk.
    (5) Replace any heat distressed HPT assembly hardware if oil 
wetting or staining is found.

Borescope Inspections of All Engines

    (i) Borescope-inspect the No. 3 bearing oil vent tube assembly 
of all engines at or before accumulating 600 CIS or 2,000 HIS, 
whichever occurs first, after the effective date of this AD, as 
follows:
    (1) Borescope-inspect the No. 3 bearing oil vent tube assembly 
for evidence of oil wetting or staining. Follow Step 2, paragraphs 
1. through 1.A.(8) of Accomplishment Instructions of Pratt & Whitney 
ASB No. PW4G-112-A72-257, Revision 1, dated August 22, 2003.
    (2) If the No. 3 bearing oil vent tube is blocked and attempts 
to clear it are unsuccessful, borescope-inspect the HPT assembly 
following Step 4, paragraphs 1. through 1.B.(14) of Accomplishment

[[Page 62231]]

Instructions of ASB No. PW4G-112-A72-257, Revision 1, dated August 
22, 2003.
    (3) Remove the HPT assembly within 100 CIS since performing the 
visual inspection of the TEC specified in paragraph (h)(1) of this 
AD, if evidence of oil wetting or staining is found in the No. 3 
bearing oil vent tube or found on the HPT first stage disk.
    (4) Replace any heat distressed HPT assembly hardware if oil 
wetting or staining is found.

Repetitive Inspections of All Engines

    (j) Repeat the inspections of the TEC of all engines by 
following paragraphs (h)(1) through (h)(3) of this AD, at intervals 
not to exceed 500 HIS since last visual check of the TEC, and 
disposition the engine as specified in paragraphs (h)(4) through 
(h)(5) of this AD.
    (k) Repeat borescope inspections of all engines by following 
paragraphs (i)(1) through (i)(2) of this AD, at intervals not to 
exceed 600 CIS or 2,000 HIS since last borescope inspection of the 
No. 3 oil vent tube, and disposition the engine as specified in 
paragraphs (i)(3) through (i)(4) of this AD.

Definition

    (l) For the purposes of this AD, high oil consumption is defined 
as an engine consuming more than 0.5 quarts of oil per hour, as 
provided in the Boeing 777 FIM.

Alternative Methods of Compliance

    (m) 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.

Material Incorporated by Reference

    (n) You must follow Pratt & Whitney Alert Service Bulletin 
specified in Table 1 to perform the inspections required by this AD. 
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 can get a copy from Pratt & Whitney, 
400 Main St., East Hartford, CT 06108; telephone (860) 565-7700; fax 
(860) 565-1605. 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.

                                      Table 1.--Incorporation by Reference
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       Alert service bulletin No.         Page Nos.            Revision                        Date
----------------------------------------------------------------------------------------------------------------
PW4G-112-A72-257.......................          1-5  1........................  August 22, 2003.
                                                 6-7  Original.................  June 30, 2003.
                                                   8  1........................  August 22, 2003.
                                                   9  Original.................  June 30, 2003.
                                                  10  1........................  August 22, 2003.
                                                  11  Original.................  June 30, 2003.
                                                  12  1........................  August 22, 2003.
                                               13-22  Original.................  June 30, 2003.
    Total pages: 22
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Related Information

    (o) Boeing 777 Fault Isolation Manual, section 71-05, Task 830, 
dated January 5, 2003, pertains to high oil consumption 
troubleshooting procedures referred to in this AD.

    Issued in Burlington, Massachusetts, on October 24, 2003.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 03-27327 Filed 10-31-03; 8:45 am]
BILLING CODE 4910-13-P

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