AD 2000-09-14

[Federal Register Volume 65, Number 93 (Friday, May 12, 2000)]
[Rules and Regulations]
[Pages 30527-30529]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-11862]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NE-04-AD; Amendment 39-11723; AD 2000-09-14]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc RB211-535 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is

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applicable to Rolls-Royce plc RB211-535 series turbofan engines. This 
AD will require removal from service of suspect radial drive steady 
bearings with certain serial number prefixes and replacement with 
serviceable parts. This amendment was prompted by reports of a number 
of radial drive steady bearing failures from distinct batches of parts. 
The actions specified by this AD are intended to prevent radial drive 
steady bearing failure, which could result in an in-flight engine 
shutdown and smoke and fumes in the cabin.

DATES: Effective date July 11, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, UK; 
telephone 011-44-1332-242424. 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: Jason Yang, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone 781-238-
7747, 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 plc (R-R) RB211-535 
series turbofan engines was published in the Federal Register on March 
23, 2000 (65 FR 15584). That action proposed to require removal from 
service of defective radial drive steady bearings manufactured during 
certain dates and replacement with serviceable parts.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Requests to Change Compliance Thresholds

    Four commenters request that the FAA change the threshold from xxx 
hours ``time-in-service'' to xxx hours ``since the effective date of 
this AD.'' The commenters state that, based on the fleet utilization 
rate, in certain cases engines installed with the suspect bearings 
would be out of compliance on the effective date of this AD.
    The FAA agrees. The FAA will revise paragraphs (a)(1) and (a)(2) to 
read ``time-in-service after the effective date of this AD,'' instead 
of ``time-in-service-since-new.''
    Three commenters request that the FAA increase the thresholds of 
paragraphs (a)(1) and (a)(2). One commenter requests an increase from 
1,500 and 2,400 hours time-in-service (TIS) to 2,100 and 3,300 hours 
TIS, respectively. A second commenter requests an increase from 1,500 
and 2,400 hours TIS to 2,000 and 3,200 hours TIS, respectively. These 
commenters state that, for the specific operators that will be affected 
by this AD, at least seven have higher utilization rates. Additionally, 
operator utilization historically increases during the summer months 
when the AD will be effective. Therefore, the commenters recommend the 
respective increases in compliance time in order to avoid a potential 
disruption to operators. A third commenter requests an increase from 
1,500 and 2,400 hours TIS to 1,700 and 2,720 hours TIS, respectively. 
The commenter states that the proposed limits impose a significant 
burden as several affected engines will exceed their respective hour 
limits before reaching their respective calendar days.
    The FAA partially agrees with these requests. The FAA will increase 
the threshold limits in paragraph (a)(1) from 1,500 hours to 1,700 
hours TIS after the effective date of this AD. The compliance end date 
will remain September 30, 2000. The FAA will increase the threshold 
limits in paragraph (a)(2) from 2,400 hours to 2,720 hours TIS after 
the effective date of this AD. The compliance end date will remain 
December 31, 2000.

Request to Use Manufacturer's Calendar Time Limit

    One commenter requests that the FAA use the manufacturer's calendar 
time limit only. The commenter states that the additional 1,500 hour 
limit placed on the suspect bearings, which is to be calculated from 
time-since-new, would make certain engines out of compliance from the 
effective date of the AD. The commenter states that by using only the 
manufacturer's calendar time limit, the operators would be allowed to 
source and properly schedule the replacement of these bearings.
    The FAA does not agree. The calendar compliance date in the AD was 
determined by a risk analysis with a normal utilization rate of the 
engine. To prevent unsafe conditions for certain high usage engines, 
the AD proposes a calendar compliance date in conjunction with 
operating hours limits. Additionally, based on other comments received, 
the ``time-in-service-since-new'' threshold will be revised in the 
final rule to ``time-in-service after the effective date of this AD.'' 
This change should enable the operators to source and schedule 
replacement of these bearings.

Revise Economic Analysis

    One commenter states that the number of engines installed on 
aircraft of U.S. registry should be revised. Since only engines that 
were built new or required a new radial drive steady bearing during the 
period of July 26, 1998, and September 30, 1999, are affected, the 
number installed on aircraft of U.S. registry is 102 engines.
    The FAA agrees. Based on the revised estimate of 102 affected 
engines installed on aircraft of U.S. registry, the total cost impact 
of the AD on U.S. operators is reduced from $160,000 to $40,800. The 
economic analysis section of the final rule will be revised 
accordingly.

Clarification of Paragraph (b)(2)

    One commenter requests clarification of paragraph (b)(2). The 
commenter believes that the FAA's intent is that two engines with 
suspect bearings must not be installed on the same aircraft, until all 
the suspect bearings are removed per paragraphs (a)(1) and (a)(2). The 
commenter states that this paragraph, as written, seems redundant and 
looks like a similar requirement to that of deleted service bulletin 
RB.211-72-C810.
    The FAA does not agree that paragraph (b)(2) is redundant. The 
intent of paragraph (b)(2) is to prevent the installation of two 
engines with suspect bearings on the same airplane. This additional 
requirement ensures that engines with the suspect bearings that have 
not yet reached the compliance thresholds of paragraphs (a)(1) and 
(a)(2) will not be installed on the same airplane, thereby reducing the 
potential for an unsafe condition.

Explanation of Change to Compliance Section

    The FAA has revised the compliance section to insert a note on 
service information. This note references Rolls-Royce Service Bulletin 
No. RB.211-72-C930, dated December 22, 1999, which provides additional 
information on identifying and replacing the suspect bearings. This 
note has been numbered Note 2; the proposed Note 2 has been renumbered 
Note 3.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air

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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 Analysis

    There are approximately 1,000 engines of the affected design in the 
worldwide fleet. The FAA estimates that 102 engines installed on 
aircraft of US registry will be affected by this AD. It will take 
approximately 4 work hours per engine to accomplish the required 
actions. The average labor rate is $60 per work hour. Required parts 
will cost approximately $160 per engine. Based on these figures, the 
total cost impact of the AD on US operators is estimated to be $40,800.

Regulatory Impact

    This rule does not have federalism implications, as defined in 
Executive Order 13132, because it does 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 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, 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:

2000-09-14  Rolls-Royce plc: Amendment 39-11723. Docket No. 2000-NE-
04-AD.

    Applicability: Rolls-Royce plc RB211-535 series turbofan 
engines, with radial drive steady bearings with outer race serial 
number (S/N) prefixes: DLJO, DLJP, DLOQ, DLSK, and DMBA, installed. 
Affected engines are those that have had a new bearing fitted at 
overhaul, were new production engines, or had a bearing changed in 
service between July 26, 1998, and September 30, 1999. These engines 
are installed on but not limited to Boeing 757 series aircraft and 
Tupolev Tu204 series aircraft.

    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; 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 radial drive steady bearing failure, which could 
result in an in-flight engine shutdown and smoke and fumes in the 
cabin, accomplish the following:
    Remove Suspect Bearings
    (a) Remove from service radial drive steady bearings identified 
in the applicability paragraph of this AD and replace with 
serviceable parts as follows:
    (1) For engines that had the suspect radial drive steady 
bearings installed during a shop visit or on-wing, remove from 
service before accumulating 1,700 hours time-in-service (TIS) after 
the effective date of this AD, but no later than September 30, 2000.
    (2) For engines that had the suspect radial drive steady 
bearings installed in factory production, remove from service before 
accumulating 2,720 hours TIS after the effective date of this AD, 
but no later than December 31, 2000.

    Note 2: Rolls-Royce plc Mandatory Service Bulletin No. RB.211-
72-C930, dated December 22, 1999, provides additional information on 
identifying and replacing the suspect bearings.

Do Not Install Suspect Bearings

    (b) As of the effective date of this AD, accomplish the 
following:
    (1) Do not install radial drive steady bearings from the five 
affected batches listed in the applicability paragraph of this AD at 
overhaul, in service, or at new production.
    (2) If performing an engine change, do not allow two engines 
that have bearings from any of the five affected batches listed in 
the applicability paragraph of this AD to be installed on the same 
airplane.

Serviceable Parts

    (3) For the purpose of this AD, serviceable bearings are those 
which are not listed in the applicability paragraph of this AD. 
Current outer race S/N prefix DPSF or alphabetically subsequent 
prefix is considered serviceable.

Alternative Methods of Compliance

    (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, 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 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Ferry Flights

    (d) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the aircraft to a location where the 
requirements of this AD can be accomplished.

Effective Date

    (e) This amendment becomes effective on July 11, 2000.

    Issued in Burlington, Massachusetts, on May 5, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-11862 Filed 5-11-00; 8:45 am]
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