AD Amdt-39-11465

[Federal Register Volume 64, Number 244 (Tuesday, December 21, 1999)]
[Rules and Regulations]
[Pages 71280-71282]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-32506]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-32-AD; Amendment 39-11465; AD 99-26-06]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-200 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to Pratt & Whitney JT8D-200 series turbofan engines, that 
requires initial and repetitive fluorescent magnetic particle 
inspections or fluorescent penetrant inspections of the combustion 
chamber outer case (CCOC) for cracks, and, if necessary, replacement 
with serviceable parts. Also, this AD requires a one-time boss material 
verification, and, if necessary, replacement with serviceable parts. 
Finally, this AD requires replacement of CCOCs with welded-on bosses 
with improved, one-piece CCOCs. Installation of the one-piece CCOC 
constitutes terminating action to the inspection requirements of this 
AD. This amendment is prompted by a report of an uncontained engine 
failure caused by fatigue cracks originating at the weld joining the 
drain boss to the CCOC. The actions specified by this AD are intended 
to prevent CCOC cracks, which could result in an uncontained engine 
failure and damage to the airplane.

DATES: Effective February 22, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 22, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-8770, fax (860) 565-4503. This information may be 
examined at the Federal Aviation Administration (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: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; 
telephone (781) 238-7175, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to Pratt & Whitney (PW) JT8D-209, -
217, -217A, -217C, and -219 series turbofan engines was published in 
the Federal Register on September 23, 1999 (64 FR 51483). That action 
proposed to require initial and repetitive fluorescent magnetic 
particle inspections or fluorescent penetrant inspections of the 
combustion chamber outer case (CCOC) for cracks, and, if necessary, 
replacement with serviceable parts. Also, that AD proposed to require a 
one-time boss material verification, and, if necessary, replacement 
with serviceable parts. Finally, that AD proposed to require 
replacement of CCOCs with welded-on bosses with improved, one-piece 
CCOCs. Installation of the one-piece CCOC would constitute terminating 
action to the inspection requirements of the AD. That action was 
prompted by a report of an uncontained engine failure caused by fatigue 
cracks originating at the weld joining the drain boss to the CCOC. That 
condition, if not corrected, could result in CCOC cracks, which could 
result in an uncontained engine failure and damage to the airplane.

Comments Received

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Understated Financial Impact

    One commenter states that the Federal Aviation Administration (FAA) 
has understated the financial impact of the AD by not including the 
ancillary costs of removing a cracked CCOC. The FAA does not concur. 
The indirect costs associated with this AD are not directly related to 
this rule, and, therefore, are not addressed in the economic analysis 
for this rule. A full cost analysis for each AD, including such 
indirect costs, is not necessary since the FAA has already performed a 
cost benefit analysis when adopting the airworthiness requirements to 
which these engines were originally certificated. A finding that an AD 
is warranted means that the original design no longer achieves the 
level of safety specified by those airworthiness requirements, and that 
other required actions are necessary, such as inspections of existing 
CCOCs and replacement with a one-piece CCOC. Because the original level 
of safety was

[[Page 71281]]

already determined to be cost beneficial, these additional requirements 
needed to return the engine to that level of safety do not add any 
additional regulatory burden, and, therefore, a full cost analysis 
would be redundant and unnecessary.

SB Publication Date vs. Effective Date of This AD

    The same commenter expresses confusion as to how to compute the 
compliance intervals of this AD; specifically, if the effective date of 
the AD should be used vs. the publication date of the SB for a 
compliance baseline. The FAA concurs. For the purpose of this AD, all 
baseline compliance times should be calculated based upon the effective 
date of this AD. The FAA has added an explanatory paragraph (c) to this 
final rule to explicitly address this issue.

On-Wing Rejection of CCOC and Replacement of CCOC

    The same commenter states that there is no clear direction as to 
the time interval between an on-wing rejection and the subsequent 
removal of the CCOC. The FAA concurs. After an on-wing rejection, the 
CCOC must be removed prior to further flight. The FAA has added 
explicit phrasing to each inspection paragraph of this final rule to 
indicate that there is no operating interval between an on-wing 
rejection and the subsequent removal of the CCOC.

Concurrence

    One commenter supports the rule as proposed.

New Revision to Service Bulletin (SB)

    Since publication of the NPRM, PW has issued Revision 2 to SB No. 
6291, dated August 27, 1999. The original version of PW SB No. 6291, 
dated May 20, 1997, Revision 1, dated July 9, 1997, or Revision 2, 
dated August 27,1999, are all acceptable for performing the terminating 
action of installing a one-piece machined CCOC assembly, part number 
(P/N) 815556, as stated in paragraph (d) of this final rule.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Economic Analysis

    There are approximately 2,624 engines of the affected design in the 
worldwide fleet. The FAA estimates that 1,280 engines installed on 
aircraft of U.S. registry will be affected by this proposed AD, that it 
will take approximately 2.5 work hours per engine to accomplish the 
proposed inspections and that the average labor rate is $60 per work 
hour. Required parts will cost approximately $42,320 per engine. Based 
on these figures, the total cost impact of the AD on U.S. operators is 
estimated to be $54,361,600.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order (E.O.) 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under E.O. 12866; (2) is not a 
``significant rule'' under 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. A final 
evaluation has been prepared for this action and it is contained in the 
Rules Docket. A copy of it 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:

99-26-06 Pratt & Whitney: Amendment 39-11465. Docket 99-NE-32-AD.

    Applicability: Pratt & Whitney (PW) JT8D-209, -217, -217A, -
217C, and -219 series turbofan engines with combustion chamber outer 
case (CCOC), part numbers (P/Ns) 5000238-01, 797707, 807684, and 
815830 installed. These engines are installed on but not limited to 
McDonnell Douglas MD-80 series airplanes.

    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 (f) 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 CCOC cracks, which could result in an uncontained 
engine failure and damage to the airplane, accomplish the following:

Inspections

    (a) Perform initial and repetitive fluorescent magnetic particle 
inspections (FMPI) or fluorescent penetrant inspections (FPI) of 
drain bosses and Ps4 bosses of the CCOC for cracks, and, if 
necessary, replace with serviceable parts prior to further flight, 
in accordance with the procedures and intervals specified in 
paragraph 1.A. of the Accomplishment Instructions of PW Alert 
Service Bulletin (ASB) No. A6359, Revision 1, dated July 30, 1999.
    (b) For CCOCs listed by serial number (S/N) in Table 3 of PW ASB 
No. A6359, Revision 1, dated July 30, 1999, inspect for proper Ps4 
and drain boss material, and, if necessary, replace with serviceable 
parts prior to further flight, in accordance with the procedures and 
intervals specified in paragraph 1.B. of the Accomplishment 
Instructions of PW ASB No. A6359, Revision 1, dated July 30, 1999.

Effective Date for Computing Compliance Intervals

    (c) For the purpose of this AD, use the effective date of this 
AD for computing compliance intervals whenever PW ASB No. A6359, 
Revision 1, dated July 30, 1999, refers to the publication date of 
the ASB.

Terminating Action

    (d) At the next part accessibility after the effective date of 
this AD when the CCOC has accumulated cycles-in-service greater than 
the initial inspection threshold specified in

[[Page 71282]]

table 1 of PW ASB A6359, Revision 1, dated July 30, 1999, replace 
the CCOC with a one-piece machined CCOC assembly, part number (P/N) 
815556, in accordance with PW Service Bulletin (SB) No. 6291, dated 
May 20, 1997, or Revision 1 dated July 9, 1997, or Revision 2, dated 
August 27,1999. Installation of an improved, one-piece CCOC, P/N 
815556, constitutes terminating action to the inspections required 
by this AD.

Definition

    (e) For the purpose of this AD, part accessibility is defined as 
an engine disassembly in which the CCOC is removed from the engine.

Alternative Methods of Compliance

    (f) 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 request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Engine Certification Office.
    (g) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the 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.

Incorporation by Reference

    (h) The actions required by this AD shall be done in accordance 
with PW ASB No. A6359, Revision 1, dated July 30, 1999, and PW SB 
No. 6291, dated May 20, 1997, Revision 1, dated July 9, 1997, and 
Revision 2, dated August 27,1999. 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) 565-8770, fax (860) 565-4503. Copies may be inspected 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.
    (i) This amendment becomes effective on February 22, 2000.

    Issued in Burlington, Massachusetts, on December 8, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-32506 Filed 12-20-99; 8:45 am]
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