[Federal Register Volume 65, Number 210 (Monday, October 30, 2000)]
[Rules and Regulations]
[Pages 64597-64601]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-27507]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NE-29-AD; Amendment 39-11952; AD 2000-22-06]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan
Engines
AGENCY: Federal Aviation Administration, DOT.
[[Page 64598]]
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to Pratt & Whitney (PW) JT8D series turbofan engines, that
requires inspections of main fuel pump control shafts for excessive
spline wear. Additionally, as terminating action to the inspections,
this action requires the replacement of the main fuel pump control
shaft with parts of improved design, and reworking the main fuel pump
impeller, impeller gear train plate assembly, and impeller cover
assembly. This amendment is prompted by reports of failed main fuel
pump control shafts caused by excessive spline wear. The actions
specified by this AD are intended to prevent loss of engine throttle
control, uncommanded acceleration, uncommanded deceleration or inflight
shutdown, which could result in reduced airplane control during a
critical phase of flight.
DATES: Effective December 4, 2000. The incorporation by reference of
certain publications listed in the regulations is approved by the
Director of the Federal Register as of December 4, 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) Models JT8D-
1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A series turbofan
engines was published in the Federal Register on May 5, 2000 (65 FR
26152). That action proposed to require inspections of main fuel pump
control shafts for excessive spline wear. Additionally, as terminating
action to the inspections, this proposal would require the replacement
of the main fuel pump control shaft with parts of improved design, and
reworking the main fuel pump impeller, impeller gear train plate
assembly, and impeller cover assembly.
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.
Use of PMA Part Number
One comment requests that the FAA clarify the AD to allow the use
of a parts manufacturer approved (PMA) part for the new main fuel pump
control shaft. The FAA agrees that the addition of specific part number
language will clarifiy the requirements of the AD. Specific part number
language has been added to paragraph (e) of the AD.
Request To Clarify Gearbox Change Maintenance
One comment asks the FAA to clarify the requirements regarding a
gearbox change where the entire gearbox is removed and the hardware,
including the fuel pump, is transferred to the replacement gearbox. The
FAA does not agree that the inspection requirements need to be
clarified. In the case of the gearbox change, the accessibility of the
main fuel pump is clearly defined in paragraph (e)(1) of this AD and,
therefore, requires the inspections detailed in paragraph (a) of the
AD.
Requests for Extension of Inspection and Replacement Limits
Two comments request that inspection and replacement intervals be
extended or altered. One comment asks that the FAA extend the overhaul
limit for main fuel pumps with more that 12,000 hours TIS since
overhaul from 2000 hours TIS to 3000 hours TIS. Another comment
requests that the overhaul limit for a main fuel pump with over 12,000
TIS be extended to 6,000 hours if a successful inspection is performed
on the pump. Extensions are requested based on the impact the
additional fuel pump overhauls will have on an operator's fleet. The
FAA agrees in part with these comments. It is not the intent of this AD
to place any undue burden on an operator's fleet maintenance. The FAA
understands from these comments that some operators would prefer to
have an alternative plan that precludes performing the inspections and
the associated unplanned maintenance that may result from the
inspection program. These operators would prefer to be proactive and to
expedite the main fuel pump overhauls on a scheduled basis in order to
be fully compliant with the required closing action of the AD, rather
than having to perform line maintenance inspections. The FAA has
determined that this is an acceptable approach and has added an
optional accelerated fleet campaign program that will permit the
closing action for the AD to be performed for the entire fleet with the
highest time main fuel pumps being addressed first. However, the FAA
realizes that the optional plan still may not satisfy the fleet impact
concerns of all operators. Operators who believe that the actions
required by the AD are a significant burden on their operations and who
can show that an alternative plan meets the requirements of paragraph
(f) of this AD should submit those plans in accordance with the
instructions of paragraph (f).
Request for Extension of the Initial Inspection Threshold
A comment requests that the 1000 hours TIS threshold time for
conducting accessibility inspections be extended. The FAA concurs and
has extended the initial inspection threshold to 3000 hours TIS for
main fuel pumps that have not incorporated the reworked impeller,
impeller gear train plate assembly and impeller cover assembly. For
main fuel pumps that have incorporated the reworked impeller, impeller
gear train plate assembly and impeller cover assembly the initial
inspection threshold has been extended to 6000 hours TIS. These changes
are reflected in paragraph (a) of this AD.
Change Terminating Action
One comment recommends that the reworked impeller, impeller gear
train plate assembly and impeller cover assembly be deemed terminating
action to the inspections of paragraphs (a) and (b). This comment asks
that the FAA eliminate the replacement of the main fuel pump control
shaft as terminating action. The FAA agrees in part. The FAA recognizes
that partial incorporation of the terminating actions has some benefit
to the main fuel pump control shaft durability. However, the FAA does
not agree that it should be terminating action to the inspections.
Instead a relaxed inspection and replacement schedule has been added
for main fuel pumps that have incorporated the reworked impeller,
impeller gear train plate assembly and impeller cover assembly. These
changes are reflected in paragraphs (a)(1) and (c)(3)(iii) of this AD.
Modify Definition of Accessibility
One comment suggests that, to be consistent with the alert service
bulletin, the words ``on the engine'' be added to the definition of
accessibility.
[[Page 64599]]
The FAA agrees and has modified the definition in paragraph (e) for
clarity.
Typographical Errors in ASB
Two comments point out several typographical errors in ASB A6381.
The FAA agrees that some typographical errors may exist in the ASB,
however, the errors will not prevent proper execution of the
instructions in the ASB. The alleged typographical errors will be
forwarded to the manufacturer for possible corrections to later
revisions of the ASB.
Require Inspections at Shop Visits only
One comment states that the accessibility inspection requirements
place a burden on large complex maintenance operations because of the
variety of possible locations and fuel pump exposures. The comment
suggests that the FAA limit inspections to a shop visit to reduce the
training and tooling required for all of the line maintenance
facilities. The FAA agrees and has added an optional accelerated fleet
campaign in paragraph (d) of this AD for operators who choose not to
equip their line maintenance facilities with the necessary training and
tooling to perform the inspections of this AD.
Removal of Engine Models
One comment requests that the FAA remove JT8D-1, -1A and -1B models
from the applicability section of the AD. The FAA does not agree. While
these particular models are no longer believed to be operating, they
are still listed on the type certificate for the JT8D and, as such,
must be included in the applicability section of the rule.
Removal of Backlash Inspection
One comment recommends removal of the backlash inspection because
of the possibility of missing a worn control shaft. The FAA does not
agree. While no inspection program can be 100% effective, this
inspection minimizes the possibility of a badly worn main fuel pump
control shaft being returned to service prior to being replaced at the
next overhaul.
Use of Argo-Tech Parts List Number
One comment recommends that the AD be changed to state that a
certain Argo-Tech parts list number should be referenced as terminating
action to the inspections of the AD. The FAA does not agree that a
change needs to be made to the AD to reference the Argo-Tech parts list
number. The certified parts list for an engine build is based on the
engine manufacturer's part numbers. There is no top level part number
change on the engine manufacturer's top level part number for the main
fuel pump assembly, and, therefore, no change in the AD compliance
section. An operator may use the Argo-Tech parts list number as long as
they can demonstrate by the incorporation of that number that the
appropriate maintenance actions required by the AD have been complied
with.
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 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 Impact
There are approximately 5,800 engines of the affected design in the
worldwide fleet. The FAA estimates that 2962 engines installed on
aircraft of US registry would be affected by this proposed AD, that it
would take approximately 0.3 work hours to perform the required
inspections and 0.5 hours per engine to accomplish the replacements
proposed at overhaul, and that the average labor rate is $60 per work
hour. Required parts would cost approximately $3,996 per engine. Based
on these figures, the total cost impact of the proposed AD on US
operators is estimated to be $11,978,328.
Regulatory Impact
This rule does not have federalism implications, as defined in
Executive Order 13132, because it 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. Accordingly,
the FAA has not consulted with state authorities prior to publication
of this rule.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 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:
2000-22-06 Pratt & Whitney: Amendment 39-11952. Docket No. 99-NE-
29-AD.
Applicability: Pratt & Whitney (PW) Models JT8D-1, -1A, -1B, -7,
-7A, -7B, -9, -9A, -11, -15, -15A turbofan engines, installed on but
not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9
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 loss of engine throttle control, uncommanded
acceleration, uncommanded deceleration or inflight shutdown, which
could result in reduced airplane control during a critical phase of
flight, accomplish the following:
Initial Inspection
(a) Inspect and, if necessary, replace the main fuel pump
control shaft in accordance with procedures and intervals described
in paragraphs 1.B. and 1.C. of the Accomplishment Instructions of PW
Alert Service Bulletin (ASB) A6381, dated March 15, 2000, as
follows:
(1) For fuel pumps that have incorporated the modifications of
paragraph (c)(1) but not the modifications of paragraph (c)(2) as of
the effective date of this AD, perform the initial inspection at the
next main fuel pump accessibility after accumulating 6000 hours time
in service (TIS) since last main fuel pump overhaul.
[[Page 64600]]
(2) For fuel pumps that have not incorporated the modifications
of paragraph (c)(1) as of the effective date of this AD, perform the
initial inspection at the next main fuel pump accessibility after
accumulating 3000 hours TIS since last main fuel pump overhaul.
Repetitive Inspections
(b) Thereafter, reinspect the main fuel pump control shaft and
remove and replace, if necessary, in accordance with intervals and
procedures described in paragraphs 1.B. and 1.C. of the
Accomplishment Instructions of PW ASB A6381, dated March 15, 2000.
Installation and Terminating Action
(c) At the next main fuel pump overhaul perform the following:
(1) Install a reworked impeller, impeller gear train plate
assembly and impeller cover assembly in accordance with paragraph
2.A of PW ASB A6381, dated March 15, 2000.
(2) Replace the main fuel pump control shaft with a serviceable
main fuel pump control shaft.
(3) The next main fuel pump overhaul must occur no later than:
(i) 12,000 hours time in service (TIS) since last fuel pump
overhaul; or
(ii) 2000 hours TIS from the effective date of this AD; or
(iii) 3000 hours TIS from the effective date of this AD,
provided the main fuel pump has incorporated the modifications of
paragraph (c)(1) as of the effective date of this AD and the
inspection results from paragraph (a) of this AD are less than or
equal to 15 degrees; whichever occurs latest.
(4) Modifications required by paragraph (c)(1) and (c)(2) of
this AD constitute terminating action to the inspections required by
paragraphs (a) and (b) of this AD.
Optional Fleet Campaign
(d) It is not necessary to perform the inspections required by
paragraphs (a) and (b) or to adhere to the schedule of paragraph
(c)(3) of this AD if the main fuel control modifications of
paragraph (c)(1) and (c)(2) are performed throughout an operator's
fleet in accordance with the schedule of Table 1 or Table 2 of this
AD as follows:
(1) For fuel pumps that have incorporated the modifications of
paragraph (c)(1) but not the modifications of paragraph (c)(2) as of
the effective date of this AD, perform modifications in accordance
with the schedule of Table 1.
(2) For fuel pumps that have not incorporated the modifications
of paragraphs (c)(1) as of the effective date of this AD, perform
the modification in accordance with the schedule of Table 2.
Table 1.--Optional Accelerated Fleet Campaign Schedule
[For engines that have incorporated the modifications of paragraph
(c)(1) of this AD but not the modifications of paragraph (c)(2) of this
AD as of the effective date of this AD]
------------------------------------------------------------------------
Time in service since last main fuel Perform modifications of
pump overhaul: paragraph (c)(2) of this AD:
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Greater than or equal to 15,000 hours Within 1,000 hours TIS from the
TIS on the effective date of this AD. effective date of this AD.
Greater than or equal to 12,000 hours Within 2,000 hours TIS from the
and less than 15,000 hours TIS on the effective date of this AD.
effective date of this AD.
Greater than or equal to 8,000 hours Within 3,000 hours TIS from
and less then 12,000 hours TIS on the the effective date of this AD.
effective date of this AD..
Less than 8,000 hours TIS on the Within 4,000 hours TIS from
effective date of this AD. the effective date of this AD
or 8,000 TIS since last main
fuel pump overhaul, whichever
occurs later.
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Table 2.--Optional Accelerated Fleet Campaign Schedule
[For engines that have NOT incorporated the modifications of paragraph
(c)(1) of this AD as of the effective date of this AD]
------------------------------------------------------------------------
Perform modifications of
Time in service since last main fuel paragraph (c)(1) and (c)(2) of
pump overhaul: this AD:
------------------------------------------------------------------------
Greater than or equal to 12,000 hours Within 1,000 hours TIS from the
TIS on the effective date of this AD. effective date of this AD.
Greater than or equal to 10,000 hours Within 2,000 hours TIS from the
and less than 12,000 hours TIS on the effective date of this AD.
effective date of this AD.
Greater than or equal to 6,000 hours Within 3,000 hours TIS from the
and less than 10,000 hours TIS on the effective date of this AD.
effective date of this AD.
Less than 6,000 hours TIS on the Within 4,000 hours TIS from the
effective date of this AD. effective date of this AD or
6,000 hours TIS since last
main fuel pump overhaul,
whichever occurs later.
------------------------------------------------------------------------
Definitions
(e) For the purpose of this AD:
(1) Accessibility of the main fuel pump is defined as removal of
the fuel control from the fuel pump on the engine or removal of the
fuel pump from the engine.
(2) Main fuel pump overhaul is defined as compliance with the
manufacturer's recommended overhaul procedures described in Argo-
Tech Overhaul Manual 73-11-1.
(3) A serviceable main fuel pump control shaft is defined as
Argo Tech part number 219093 or Rogers Dierks part number RD219093.
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 (ECO).
Operators shall submit their request through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, ECO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the ECO.
Ferry Flights
(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 airplane to a location where
the requirements of this AD can be accomplished.
Incorporated by Reference
(h) The actions specified in this AD must be done in accordance
with the following Pratt & Whitney Alert Service Bulletin:
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Document no. Pages Revision Date
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JT8D A6381........................... All.................... Original............... March 15, 2000
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[[Page 64601]]
Total pages: 14.
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.
Effective Date of This AD
(i) This amendment becomes effective on December 4, 2000.
Issued in Burlington, Massachusetts, on October 20, 2000.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 00-27507 Filed 10-27-00; 8:45 am]
BILLING CODE 4910-13-U