AD Amdt-39-10947

final rule

Airworthiness Directives; Rolls-Royce Limited, Bristol Engines Division, Viper Models Mk.521 and Mk.522 Turbojet Engines

AD Number
Amdt-39-10947
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. 98-ANE-01-AD
FR Citation
63 FR 70001

Applicability

TypeManufacturerModelDetails
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

Show stored source text (verify against official source)
[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]


-----------------------------------------------------------------------

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.

-----------------------------------------------------------------------

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:

----------------------------------------------------------------------------------------------------------------
                    Document No.                         Pages       Revision                 Date
----------------------------------------------------------------------------------------------------------------
RR SB 73-A115.......................................          1-4            2  August 1997.
    Total pages: 4
RR SB 73-A118.......................................          1-4            1  August 1997.
    Total pages: 4
----------------------------------------------------------------------------------------------------------------

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

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.