AD 98-26-07

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.
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.

Final rule.

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

Total pages: 4
1-4
2
August 1997
RR SB 73-A118

Total pages: 4
1-4
1
August 1997

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, 1999.

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 applicability section, regardless of the aircraft on which the engines are installed. Engine installation eligibility 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 aircraft 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 hoursper 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 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. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: