AD Amdt-39-10947
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce | Limited | Airworthiness Directives; Rolls-Royce Limited, Bristol Engines Division, Viper Models Mk.521 and Mk.522 Turbojet Engines |
Unsafe Condition
Reports of high pressure (HP) fuel pump drive shaft failures resulting in in-flight engine shutdowns, attributed to reduced lubricity properties of fuel caused by water contamination.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove from service affected HP fuel pumps and replace with serviceable HP fuel pumps, as specified in Rolls-Royce Service Bulletins 73-A115 and 73-A118, depending on engine model and part number.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 18 months after the effective date of the AD, or earlier as specified.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Rolls-Royce Limited, Bristol Engines Division, Viper Models Mk.521 and Mk.522 turbojet engines with specific HP fuel pump part numbers (MGBB.167, MGBB.134, MGBB.137, MGBB.145, MGBB.168, MGBB.169).
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD), applicable to Rolls-Royce Limited, Bristol Engines Division, (R-R) Viper Models Mk.521 and Mk.522 turbojet engines, that requires replacement of certain high pressure (HP) fuel pumps with an improved design which is more tolerant of reduced lubricity fuel caused by water contamination. This amendment is prompted by reports of HP fuel pump drive shaft failures resulting in in-flight engine shutdowns. These failures have been attributed to the reduced lubricity properties of fuel which is contaminated by water. The actions specified by this AD are intended to prevent HP fuel pump failures, which can result in an in-flight engine shutdown.
Document Text
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[Federal Register Volume 63, Number 243 (Friday, December 18, 1998)]
[Rules and Regulations]
[Pages 70001-70002]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-33243]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-01-AD; Amendment 39-10947; AD 98-26-07]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Limited, Bristol Engines
Division, Viper Models Mk.521 and Mk.522 Turbojet Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to Rolls-Royce Limited, Bristol Engines Division, (R-R)
Viper Models Mk.521 and Mk.522 turbojet engines, that requires
replacement of certain high pressure (HP) fuel pumps with an improved
design which is more tolerant of reduced lubricity fuel caused by water
contamination. This amendment is prompted by reports of HP fuel pump
drive shaft failures resulting in in-flight engine shutdowns. These
failures have been attributed to the reduced lubricity properties of
fuel which is contaminated by water. The actions specified by this AD
are intended to prevent HP fuel pump failures, which can result in an
in-flight engine shutdown.
DATES: Effective February 16, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 16, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Rolls-Royce Limited, Bristol Engines Division, Technical
Publications Department CLS-4, P.O. Box 3, Filton, Bristol, BS34 7QE
England; telephone 117-979-1234, fax 117-979-7575. 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: James Lawrence, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7176, 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 Rolls-Royce Limited, Bristol
Engines Division, (R-R) Viper Models Mk.521, and Mk.522 turbojet
engines was published in the Federal Register on April 13, 1998 (63 FR
17972). That action proposed to require replacement of certain HP fuel
pumps with improved pumps in accordance with Rolls-Royce Service
Bulletins (SB's) No. 73-A115 and 73-A118.
The United Kingdom (UK) Civil Aviation Authority (CAA) classified
these SB's mandatory and issued AD's 003-02-96 and 004-02-96 in order
to assure the airworthiness of these engines in the UK. Interested
persons have been afforded an opportunity to participate in the making
of this amendment. Due consideration has been given to the comments
received.
Two commenters state that the AD should apply only if the
applicable engines are installed in specific aircraft. One commenter
states that the AD should be so limited because the failures have
occurred on only one particular aircraft design. The FAA disagrees. The
AD applies to the engine models that appear in the applicabilty
section, regardless of the aircraft on which the engines are installed.
Engine installation eligibilty may be determined either by the
aircraft's original or amended type certificate or a supplemental type
certificate. In addition, fuel pump failures have occurred on more than
one aircraft design. This AD does not implicate the fuel pump design,
but reflects the FAA's determination that the unsafe condition is
likely to exist or develop on other engines of the same type design.
One commenter states that a calendar end-date should be added to
proposed paragraph (a) in order to capture fuel pumps on engines
operated by low utilization users at an earlier time than the proposed
requirement of 160 hours TIS, the next shop visit, or the next fuel
pump removal. The FAA agrees. The compliance time is revised to require
fuel pump replacement at least by 18 months after the effective date of
the AD.
One commenter states that the proposed AD would allow engines that
are currently not installed on an aircaft and which contain the old
standard of pump to be installed on an aircraft without having the fuel
pumps replaced. The FAA concurs in part. While the proposed definition
of ``shop visit'' would seem to include any engine installation, the
FAA has clarified that definition to prevent engines that are not
installed on an aircraft on the effective date of the AD from being
operated without having the fuel pumps replaced.
One commenter asks that the service bulletin (SB) references be
updated to specify the latest revisions and dates to make certain that
the latest SB's, work hours per engine, and fuel pump part numbers (P/
N's) are referenced in this AD. The FAA concurs. The SB references have
been updated to reflect the latest revisions to the SB's. Therefore,
the number of work hours has been updated to include 4 hours per
installed engine, 8 hours per airplane, and 3 hours per uninstalled
engine. Finally, the compliance section has been updated to include
additional fuel pump P/N's MGBB.134, MGBB.145 and MGBB.169. The
addition of these part numbers does not increase the scope of the AD as
the number of affected engines remains the same.
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.
There are approximately 280 engines of the affected design in the
worldwide fleet. The FAA estimates that 104 engines installed on
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 4 work hours per engine installed on an
airplane, 8 hours per airplane, or 3 hours per uninstalled engine to
accomplish the proposed actions, and that the average labor rate is $60
per work hour. Required parts would cost approximately $18,000 per
engine. Based on these figures, the total cost impact of the proposed
AD on U.S. operators is estimated to be $1,896,960.
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism
[[Page 70002]]
implications to warrant the preparation of a Federalism Assessment.
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:
98-26-07 AD Rolls-Royce Limited, Bristol Engines Division:
Amendment 39-10947 Docket 98-ANE-01-AD.
Applicability: Rolls-Royce Limited, Bristol Engines Division,
(R-R) Viper Model Mk.521 turbojet engine with high pressure (HP)
fuel pump, part numbers (P/N's) MGBB.167 or MGBB.134 installed, and
Model Mk 522 turbojet engine with HP fuel pump MGBB.137, MGBB.145,
MGBB.168, or MGBB.169 installed. These engines are installed on but
not limited to Raytheon (formerly British Aerospace, Hawker
Siddeley) Model DH.125 series and BH.125 series 400A 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 (c) 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 HP fuel pump failures, which can result in an in-
flight engine shutdown accomplish the following:
(a) Remove from service affected HP fuel pumps, and replace with
serviceable HP fuel pumps, at the earliest of the following: prior
to 160 hours time in service (TIS) after the effective date of this
AD, at the next shop visit after the effective date of this AD, at
the next HP fuel pump removal after the effective date of this AD,
or prior to 18 months after the effective date of this AD, as
follows:
(1) For HP fuel pumps installed on R-R Viper Mk.521 engines,
replace HP fuel pumps P/N MGBB.167 or MGBB.134 with serviceable fuel
pump P/N MGBB.182, in accordance with R-R SB No. 73-A118, Revision
1, dated August 1997.
(2) For HP fuel pumps installed on R-R Viper Mk.522 engines,
replace HP fuel pumps P/Ns MGBB.137 or MGBB.145 with serviceable
fuel pump MGBB.183, or HP fuel pump P/N's MGBB.168 or MGBB.169 with
serviceable fuel pump P/N MGBB.184,in accordance with R-R SB No. 73-
A115, Revision 2, dated August 1997.
(b) For the purpose of this AD, a shop visit is defined as the
induction of an engine into the shop for any reason, including, but
not limited to, the installation of an engine on an aircraft.
(c) 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, Certification Office. Operators
shall submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Certification Office.
(d) 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.
(e) The actions required by this AD shall be done in accordance
with the following Rolls-Royce SB's:
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Document No. Pages Revision Date
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RR SB 73-A115....................................... 1-4 2 August 1997.
Total pages: 4
RR SB 73-A118....................................... 1-4 1 August 1997.
Total pages: 4
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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 Rolls-Royce Limited, Bristol Engines
Division, Technical Publications Department CLS-4, P.O. Box 3,
Filton, Bristol, BS34 7QE England; telephone 117-979-1234, fax 117-
979-7575. 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.
(f) This amendment becomes effective on February 16, 1998.
Issued in Burlington, Massachusetts, on December 9, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 98-33243 Filed 12-17-98; 8:45 am]
BILLING CODE 4910-13-U
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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