[Federal Register: February 21, 2008 (Volume 73, Number 35)]
[Proposed Rules]
[Page 9502-9504]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21fe08-26]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-0078; Directorate Identifier 2007-NE-40-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan
Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the
products listed above. This proposed AD results from mandatory
continuing airworthiness information (MCAI) originated by an aviation
authority of another country to identify and correct an unsafe
condition on an aviation product. The MCAI describes the unsafe
condition as:
High pressure (HP) turbine discs recently inspected in
accordance with the Engine Manual have exhibited cracks in the disc
rim. The discs have failed to meet the inspection acceptance
criteria and have been returned to Rolls-Royce for engineering
investigation. This investigation has concluded that the cracks have
resulted from scores within the cooling air holes in the disc rim
that could have been introduced during new part
[[Page 9503]]
manufacture or during overhaul of the disc. The engineering
investigation has concluded that if this cracking was undetected
then it could result in uncontained disc failure and a potential
unsafe condition for the aircraft.
We are proposing this AD to prevent uncontained disc failure, possibly
resulting in damage to the airplane.
DATES: We must receive comments on this proposed AD by March 24, 2008.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility: U.S. Department of
Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov
; or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Operations office (telephone (800) 647-5527) is
the same as the Mail address provided in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
ian.dargin@faa.gov; telephone (781) 238-7178, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2007-0078; Directorate
Identifier 2007-NE-40-AD'' in the subject line of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD based on those comments.
We will post all comments we receive, without change, to http://www.regulations.gov
, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued AD
2006-0180, dated June 26, 2006, for RB211-524 series engines, AD 2006-
0181, dated June 26, 2006, for RB211-22B engines, and AD 2006-0182,
dated June 28, 2006, for RB211-535 series engines, to correct the same
unsafe condition for the specified products. The EASA ADs state:
HPT discs recently inspected in accordance with the Engine
Manual have exhibited cracks in the disc rim. The discs have failed
to meet the inspection acceptance criteria and have been returned to
Rolls-Royce for engineering investigation. This investigation has
concluded that the cracks have resulted from scores within the
cooling air holes in the disc rim that could have been introduced
during new part manufacture or during overhaul of the disc. The
engineering investigation has concluded that if this cracking was
undetected then it could result in uncontained disc failure and a
potential unsafe condition for the aircraft.
You may obtain further information by examining the MCAI ADs in the AD
docket.
Relevant Service Information
Rolls-Royce plc has issued Alert Service Bulletin No. RB.211-72-
AE969, dated May 9, 2006. The actions described in this service
information are intended to correct the unsafe condition identified in
the MCAI ADs.
FAA's Determination and Requirements of This Proposed AD
These products have been approved by the United Kingdom (UK), and
are approved for operation in the United States. Pursuant to our
bilateral agreement with the UK, they have notified us of the unsafe
condition described in the MCAI ADs, and service information referenced
above. We are proposing this AD because we evaluated all pertinent
information and determined an unsafe condition exists and is likely to
exist or develop on other products of the same type design. This
proposed AD would require initial and repetitive eddy current
inspections of HP turbine discs.
Costs of Compliance
Based on the service information, we estimate that this proposed AD
would affect about 506 products of U.S. registry. We also estimate that
it would take about 4 work-hours per product to comply with the basic
requirements of this proposed AD. The average labor rate is $80 per
work-hour. Based on these figures, we estimate the cost of the proposed
AD on U.S. operators to be $161,920.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, Section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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.
For the reasons discussed above, I certify 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. 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.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator,
[[Page 9504]]
the FAA proposes to amend 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. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive (AD):
Rolls-Royce plc: Docket No. FAA-2007-0078; Directorate Identifier
2007-NE-40-AD.
Comments Due Date
(a) We must receive comments by March 24, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce plc (RR) models RB211-535E4
series, RB211-535E4-B series, RB211-535E4-C series, RB211-535C
series, RB211-524 series, and RB211-22B series turbofan engines.
These engines are installed on, but not limited to, Boeing 747, 757,
and 767, Lockheed L-1011, and Tupulev Tu204 airplanes.
Reason
(d) European Aviation Safety Agency AD 2006-0180, dated June 26,
2006, AD 2006-0181, dated June 26, 2006, and AD 2006-0182, dated
June 28, 2006, state:
High pressure (HP) turbine discs recently inspected in
accordance with the Engine Manual have exhibited cracks in the disc
rim. The discs have failed to meet the inspection acceptance
criteria and have been returned to Rolls-Royce for engineering
investigation. This investigation has concluded that the cracks have
resulted from scores within the cooling air holes in the disc rim
that could have been introduced during new part manufacture or
during overhaul of the disc. The engineering investigation has
concluded that if this cracking was undetected then it could result
in uncontained disc failure and a potential unsafe condition for the
aircraft.
We are issuing this AD to prevent uncontained disc failure, possibly
resulting in damage to the airplane.
Actions and Compliance
(e) Unless already done, perform an initial eddy current
inspection (ECI) of the HP turbine disc air cooling holes.
Information on ECI of HP turbine disc cooling holes can be found in
RR Engine Overhaul Process Manual No. TSD594-J, Overhaul Process
223, dated May 1, 2001.
Initial Inspection for RB211-22B Series Turbofan Engines
(f) For RB211-22B series turbofan engines:
(1) If an installed HP turbine disc has more than 9,500 cycles-
since-new (CSN) on the effective date of this AD, then ECI the HP
turbine disc by whichever is the soonest of the following
conditions:
(i) Within 500 cycles from the effective date of this AD; or
(ii) At the next shop visit where the HP turbine rotor is
removed from the combustor outer casing.
(2) If an installed HP turbine disc has 9,500 or fewer CSN on
the effective date of this AD, then ECI the HP turbine disc by
whichever is the soonest of the following conditions:
(i) Before reaching 10,000 CSN; or
(ii) At the next shop visit where the HP turbine rotor is
removed from the combustor outer casing and the HP turbine disc has
more than 2,750 CSN.
(3) For HP turbine rotors at shop visit and already removed from
the combustor outer casing on the effective date of this AD, ECI the
HP turbine disc before reinstalling the HP turbine rotor in the
combustor outer casing.
Initial Inspection of RB211-524 Series Turbofan Engines
(g) For RB211-524 series turbofan engines, ECI the HP turbine
disc at the soonest of the following after the effective date of the
AD:
(1) At the next shop visit where the HP turbine blades are
removed from the HP turbine disc and when the HP turbine disc has
more than 2,750 CSN.
(2) For HP turbine rotors at shop visit and the HP turbine
blades are removed from the HP turbine disc and the HP turbine disc
life is more than 2,750 CSN, ECI the turbine disc before
reinstalling the HP turbine blades.
Initial Inspection of RB211-535C, -535E4, -535E4-B, and -535E4-C Series
Turbofan Engines
(h) For RB211-535C, -535E4, -535E4-B, and -535E4-C series
turbofan engines:
(1) If an installed HP turbine disc has 17,500 or fewer CSN on
the effective date of this AD, then ECI the HP turbine disc by
whichever is the soonest of the following conditions:
(i) Before reaching 18,000 CSN; or
(ii) At the next shop visit where the HP turbine rotor is
removed from the combustor outer casing, and the HP turbine disc has
5,000 or more CSN.
(iii) For HP turbine rotors at shop visit on the effective date
of this AD that are removed from the combustor outer casing, and
that have HP turbine discs with 5,000 or more CSN, ECI the HP
turbine disc before reinstalling the HP turbine rotor in the
combustor outer casing.
(2) If an installed HP turbine disc has more than 17,500 CSN on
the effective date of this AD, then ECI the HP turbine disc by
whichever is the soonest of the following conditions:
(i) Within 500 cycles from the effective date of this AD; or
(ii) At the next shop visit where the HP turbine rotor is
removed from the combustor outer casing.
(iii) For HP turbine rotors at shop visit on the effective date
of this AD that are removed from the combustor outer casing, ECI the
HP turbine disc before reinstalling the HP turbine rotor in the
combustor outer casing.
HP Turbine Disc Permanent Etching
(i) On successful completion of the initial inspection only,
permanently etch NMSB 72-AE969 onto the HP turbine disc, adjacent to
the part number.
Repetitive ECI Inspections
(j) Thereafter, perform repetitive ECIs at every shop visit
where the HP turbine blades are removed from the HP turbine disc.
Information on ECI of HP turbine disc air cooling holes can be found
in RR Engine Overhaul Process Manual No. TSD594-J, Overhaul Process
223, dated May 1, 2001.
(k) Alternative Methods of Compliance (AMOCs): The Manager,
Engine Certification Office, FAA, has the authority to approve AMOCs
for this AD, if requested using the procedures found in 14 CFR
39.19.
Previous Credit
(l) Initial inspections done before the effective date of this
AD on HP turbine discs with a disc life above the minimum threshold
(5,000 CSN for the RB211-535 engines and 2,750 CSN for both the
RB211-524 and the RB211-22B engines) at the time of inspection, per
paragraph 1.C.(2) of RR Alert Service Bulletin No. RB.211-72-AE969,
comply with the initial inspection requirements specified in this
AD.
Related Information
(m) Refer to EASA AD 2006-0180, dated June 26, 2006, AD 2006-
0181, dated June 26, 2006, and AD 2006-0182, dated June 28, 2006,
for related information.
(n) Contact Ian Dargin, Aerospace Engineer, Engine Certification
Office, FAA, Engine & Propeller Directorate, 12 New England
Executive Park, Burlington, MA 01803; e-mail: ian.dargin@faa.gov;
telephone 781 238-7178; fax 781 238-7199, for more information about
this AD.
Issued in Burlington, Massachusetts, on February 13, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E8-3192 Filed 2-20-08; 8:45 am]
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