[Federal Register Volume 59, Number 248 (Wednesday, December 28, 1994)]
[Unknown Section]
[Page ]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-31871]


[Federal Register: December 28, 1994]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-ANE-39]


Airworthiness Directives; Rolls-Royce, plc RB.211 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Rolls-Royce, plc (R-R) RB.211 
series turbofan engines. This proposal would require removing and 
replacing the existing rigid low pressure (LP) fuel system tube 
assembly with a tube assembly having flexible sections and revised clip 
points to preclude cracking and subsequent fuel leakage. This proposal 
is prompted by multiple reports of fuel leaks. The actions specified by 
the proposed AD are intended to prevent a fuel system leak, which could 
result in rapid atomization of fuel and an engine fire.

DATES: Comments must be received by February 27, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 94-ANE-39, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Rolls-Royce, plc., P.O. Box 31, Derby, England. This 
information may be examined at the FAA, New England Region, Office of 
the Assistant Chief Counsel, 12 New England Executive Park, Burlington, 
MA.

FOR FURTHER INFORMATION CONTACT: Daniel Kerman, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7130, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-ANE-39.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 94-ANE-39, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the Federal 
Aviation Administration (FAA) that an unsafe condition may exist on 
Rolls-Royce, plc. (R-R) Models RB.211-535E4 series and -535E4-B series 
turbofan engines. The CAA advises that it has received multiple reports 
of fuel leaks. These fuel leaks have occurred due to fracture of the 
ferrule retainer of the existing low pressure (LP) fuel system tube 
assembly, which runs from the LP fuel filter to the inlet of the high 
pressure (HP) fuel pump. This condition, if not corrected, could result 
in a fuel system leak, which could result in rapid atomization of fuel 
and an engine fire.
    In response to this problem the Boeing Aircraft Co. has issued an 
Operations Manual Bulletin (OMB) to provide the flight crew with 
enhanced fuel loss detection capability. The FAA made this OMB 
mandatory through Airworthiness Directive (AD) 94-09-10 in order to 
prevent fuel exhaustion due to undetected fuel leakage. In addition, R-
R has issued Service Bulletin (SB) No. RB.211-73-B048, Revision 1, 
dated July 22, 1994, that specifies replacing the existing rigid LP 
fuel system tube assembly with a new soft mounting design that includes 
a flexible section at each end and revised clip points. Engineering 
analysis shows that the original rigid system under transient 
conditions is failure prone due to high stress levels that can induce 
low cycle fatigue cracking. The CAA classified this service bulletin as 
mandatory in order to assure the airworthiness of these R-R engines in 
the United Kingdom.
    This engine model is manufactured in the United Kingdom and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the 
applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the CAA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
CAA, reviewed all available information, and determined that AD action 
is necessary for engines of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other R-R engines of the same type design 
registered in the United States, the proposed AD would require 
replacement of the LP fuel tube assembly. This new fuel tube assembly 
has been redesigned to incorporate a flexible mounting system at both 
ends and revised clip points, which reduce stress loading by providing 
multiple degrees of freedom in which to deflect, thus eliminating the 
rigid constraint of the fuel tube. The proposed compliance time of one 
year after the effective date of this AD has been established based on 
FAA review of past service history. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.
    There are approximately 558 engines of the affected design in the 
worldwide fleet. The FAA estimates that 292 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 2 work hours per engine to accomplish the 
proposed actions, and that the average labor rate is $55 per work hour. 
Required parts would cost approximately $1,000 per engine. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $324,120.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13--[AMENDED]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Rolls-Royce, plc.: Docket No. 94-ANE-39.

    Applicability: Rolls-Royce, plc. (R-R) Models RB.211-535E4 
series and -535E4-B series turbofan engines, installed on but not 
limited to Boeing 757 series aircraft.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a fuel system leak, which could result in rapid 
atomization of fuel and an engine fire, accomplish the following:
    (a) Within one year after the effective date of this AD, remove 
the existing rigid low pressure (LP) fuel system tube assembly and 
replace with the new flexible LP fuel system tube design with 
revised clip points, in accordance with R-R Service Bulletin No. 
RB.211-73-B048, Revision 1, dated July 22, 1994.
    (b) 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. The 
request should be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    Issued in Burlington, Massachusetts, on December 14, 1994.
Kirk E. Gustafson,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 94-31871 Filed 12-27-94; 8:45 am]
BILLING CODE 4910-13-P