Federal Register / Vol. 75, No. 79 / Monday, April 26, 2010 / Proposed Rules 21523 

§ 115.12 General program policies and 

provisions. 

* * * * * 

(e) * * * 

(5) Guarantee authority for Contracts 

and Orders related to a major disaster 

area. Subject to the availability of funds 

appropriated in advance specifically for 

the purpose of guaranteeing bonds for 

any Contract or Order related to a major 

disaster, SBA may guarantee bonds on 

any Contract or Order under the 

following terms and conditions: 

(i) The Contract or Order does not 

exceed $5,000,000 at the time of bond 

execution, and: 

(A) For products or services procured 

under a Federal Contract or Order, the 

products will be manufactured or the 

services will be performed in the major 

disaster area identified in the Federal 

Emergency Management Agency 

(FEMA) Web site at http:// 

www.fema.gov, or the products will be 

manufactured or the services will be 

performed outside the major disaster 

area and the products or services will 

directly assist in the recovery efforts in 

the major disaster area; or 

(B) For products or services procured 

under any other Contract or Order, the 

products will be manufactured or the 

services will be performed in the major 

disaster area identified in the FEMA 

Web site at http://www.fema.gov; 

(ii) At the request of the Head of the 

Agency involved in reconstruction 

efforts in response to a major disaster, 

SBA may guarantee bonds on Federal 

Contracts or Orders in excess of 

$5,000,000, but not more than 

$10,000,000; 

(iii) The restrictions set forth in 

§ 115.12(e)(3) do not apply to the 

guarantees issued under this paragraph 

(e)(5); and 

(iv) A guarantee may be issued under 

this paragraph (e)(5) for any Contract or 

Order for which an offer is submitted or 

an award is made within 12 months 

from the date an area is designated a 

major disaster area in the Federal 

Register. SBA may, at its discretion, 

extend this time period for any 

particular disaster, and will publish a 

notice of the extension in the Federal 

Register. 

* * * * * 

4. Amend § 115.16 as follows: 

a. Remove the word ‘‘and’’ at the end 

of paragraph (f)(3); 

b. Remove the punctuation ‘‘.’’ at the 

end of paragraph (f)(4); and 

c. Add paragraph (f)(5) to read as 

follows: 

§ 115.16 Determination of Surety’s Loss. 

* * * * * 

(f) * * * 

(5) Any costs that arise from the 

Principal’s failure to secure and 

maintain insurance coverage required 

by the Contract or Order, or any costs 

that result from any claims or judgments 

that exceed the amount of any insurance 

coverage required by the Contract or 

Order, as well as any costs that arise as 

a result of any agreement by the 

Principal in the Contract or Order to 

indemnify the Obligee or any other 

Persons. 

Karen G. Mills, 

Administrator. 

[FR Doc. 2010–9434 Filed 4–23–10; 8:45 am] 

BILLING CODE 8025–01–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 33 

[Docket No. FAA–2010–0398; Notice No. 10– 

06] 

RIN 2120–AJ62 

Airworthiness Standards; Rotor 

Overspeed Requirements 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to amend 

the aircraft turbine engine rotor 

overspeed type certification standards. 

This action would establish uniform 

rotor overspeed design and test 

requirements for aircraft engines and 

turbochargers certificated by the FAA 

and the European Aviation Safety 

Agency (EASA). The proposed rule 

would also establish uniform standards 

for the design and testing of engine rotor 

parts in the United States and in 

Europe, eliminating the need to comply 

with two differing sets of requirements. 

The proposed rule would improve 

safety by clarifying existing overspeed 

requirements for aircraft turbine engine 

rotor parts. 

DATES: Send your comments on or 

before July 26, 2010. 

ADDRESSES: You may send comments 

identified by docket number FAA– 

2010–0398 using any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov and follow 

the online instructions for sending your 

comments electronically. 

• Mail: Send Comments to Docket 

Operations, M–30; U.S. Department of 

Transportation, 1200 New Jersey 

Avenue, SE., West Building Ground 

Floor, Room W12–140, Washington, DC 

20590–0001. 

• Hand Delivery: Take comments to 

Docket Operations in Room W12–140 of 

the West Building Ground Floor at 1200 

New Jersey Avenue, SE., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

• Fax: 1–202–493–2251. 

For more information on the rulemaking 

process, see the SUPPLEMENTARY

INFORMATION section of this document. 

Privacy: We will post all comments 

we receive, without change, to http:// 

www.regulations.gov, including any 

personal information you provide. 

Using the search function of our docket 

Web site, anyone can find and read the 

comments received into any of our 

dockets, including the name of the 

individual sending the comment (or 

signing the comment for an association, 

business, labor union, etc.). You may 

review DOT’s complete Privacy Act 

Statement in the Federal Register 

published on April 11, 2000 (65 FR 

19477–78) or you may visit http:// 

DocketsInfo.dot.gov. 

Docket: To read background 

documents or comments received, go to 

http://www.regulations.gov at any time 

and follow the online instructions for 

accessing the docket or go to Docket 

Operations in Room W12–140 of the 

West Building Ground Floor at 1200 

New Jersey Avenue, SE., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

FOR FURTHER INFORMATION CONTACT: For 

technical questions concerning this 

proposed rule, contact Tim Mouzakis, 

Engine and Propeller Directorate 

Standards Staff, ANE–111, Engine and 

Propeller Directorate, Federal Aviation 

Administration, 12 New England 

Executive Park, Burlington, 

Massachusetts 01803–5299; telephone 

(781) 238–7114; fax (781) 238–7199; 

e-mail timoleon.mouzakis@.faa.gov. For 

legal questions concerning this 

proposed rule contact Vincent Bennett, 

ANE–7, Office of Regional Counsel, 

Federal Aviation Administration, 12 

New England Executive Park, 

Burlington, Massachusetts 01803–5299; 

telephone (781) 238–7044; fax (781) 

238–7055; e-mail 

vincent.bennett@faa.gov. 

SUPPLEMENTARY INFORMATION: Later in 

this preamble under the Additional 

Information section, we discuss how 

you can comment on this proposal and 

how we will handle your comments. 

Included in this discussion is related 

information about the docket, privacy, 

and the handling of proprietary or 

confidential business information. We 

also discuss how you can get a copy of 

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21524 Federal Register / Vol. 75, No. 79 / Monday, April 26, 2010 / Proposed Rules 

this proposal and related rulemaking 

documents. 

Authority for This Rulemaking 

The FAA’s authority to issue rules 

regarding aviation safety is found in 

Title 49 of the United States Code. 

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, including 

minimum safety standards for aircraft 

engines. This proposed rule is within 

the scope of that authority because it 

updates existing regulations for rotor 

overspeed for aircraft turbine engines. 

Background 

Part 33 of Title 14 of the Code of 

Federal Regulations prescribes aircraft 

engine airworthiness certification 

standards for products certified in the 

United States. The Certification 

Specifications for Engines (CS–E) 

prescribe the corresponding 

airworthiness standards for products 

certified in Europe by the European 

Aviation Safety Agency. While part 33 

and CS–E are similar, they differ in 

several respects. 

The FAA tasked the Aviation 

Rulemaking Advisory Committee 

through its Engine Harmonization 

Working Group to review existing 

regulations and recommend changes 

that would eliminate differences 

between the U.S. and European engine 

certification standards by harmonizing 

to the higher standards. This proposed 

rule is a result of this harmonization 

effort. 

This proposed rule would harmonize 

rotor overspeed requirements found in 

14 CFR part 33 with EASA CS–E 

specifications in CS–E 840, Rotor 

Integrity. The proposed rule would 

improve safety by establishing one 

harmonized standard requiring: 

(1) Rotors be designed with a burst/ 

failure speed that exceeds the certified 

operating speeds; 

(2) Burst speeds to exceed overspeed 

conditions that can result from the 

failure of other engine components; and 

(3) Limits on the amount of rotor 

growth or damage that results from an 

overspeed. 

Definition of Terms Used in the Rule 

For the purposes of the rule, the 

following definitions, which are 

consistent with part 33 and CS–E, 

apply: 

Maximum permissible rotor speed. 

The maximum approved rotor speed, 

including transients, for the maximum 

approved rating, including One-EngineInoperative (OEI) ratings. 

Overspeed Capability. The r.p.m. 

(revolutions per minute) at which the 

part fails or bursts. 

Rotor Growth. The permanent 

increase in a rotor part’s radial 

dimensions caused by an overspeed 

condition. 

General Discussion of the Proposal 

The proposed rule would require that 

rotor parts be designed with a safety 

margin large enough that the parts have 

an overspeed capability that exceeds the 

engine’s certified operating conditions, 

including overspeed conditions which 

can occur in the event of a failure of 

another engine component and/or 

system malfunction. For failures that 

may result in an overspeed, the 

proposed rule would limit rotor growth 

to that which would not lead to a 

hazardous condition as defined by 

§ 33.75. 

The proposed rule would harmonize 

U.S. requirements with EASA’s by: 

• Changing the current FAA 

overspeed design margin from 115 to 

120 percent of maximum permissible 

speed for all engine ratings except OEI 

ratings of less than 21⁄2 minutes; 

• Changing the current FAA 

overspeed design margin from100 to 105 

percent for operating conditions 

associated with multiple failures; 

• Introducing similar OEI overspeed 

design requirements; 

• Requiring new similar rotor pass/ 

fail design criteria; 

• Requiring similar overspeed margin 

requirements; 

• Allowing the use of validated 

structural analysis tools to demonstrate 

compliance; 

• Requiring that validated structural 

analysis tools be calibrated to actual 

overspeed tests of similar rotors; and 

• Allowing engine test durations of 

less than 5 minutes for failure 

conditions for which a 5-minute 

duration is not realistic. 

Like EASA’s CS–E, the proposed rule 

would specify that rotors may not burst 

for overspeed conditions that do not 

involve component or system failure. 

For component or engine failures that 

result in an overspeed, the proposed 

rule specifies that rotors may not burst 

and limits the amount of rotor growth. 

Overspeed Test Requirements 

The current rule allows the rotor part 

being tested to be selected at random 

and does not require the test speed to be 

adjusted to ensure a minimum 

specification rotor can achieve the 

required overspeed. The proposed rule 

would allow the test speed to be 

adjusted/increased to account for the 

most adverse combination of material 

properties and dimensional tolerances. 

This proposed change harmonizes our 

overspeed test requirements with CS–E 

840(a) and (d). 

Single or multiple failures of 

components and/or systems can result 

in an overspeed that is sudden, transient 

and continues for a brief period of time. 

In this situation, the FAA considers it 

unrealistic to require an engine test that 

is attempting to duplicate these types of 

failures to maintain an overspeed 

beyond that which can be expected to 

occur. Under the proposed rule, the 

FAA would accept the actual overspeed 

duration provided the required 

maximum rotor speed is achieved. 

Overspeed Requirements for OEI 

Ratings 

The current rule does not specify the 

overspeed requirements for one-engine 

inoperative ratings and assumes 

overspeed requirements are the same for 

any engine rating. The current rule 

requires an overspeed margin of 115 

percent of the maximum permissible 

speed if tested in an engine. The 

proposed rule requires an overspeed 

margin of 120 percent for all ratings, 

except for 115 percent for OEI ratings 

less than 21⁄2 minutes. The proposed 

change to overspeed requirements for 

OEI ratings would harmonize with CS– 

E 840(b). 

Overspeed Events Due to Failure of 

Components or Systems 

The current rule requires a 5 percent 

overspeed margin for the failure of a 

single component or system and zero 

overspeed margin for the failure of 

multiple components. The proposed 

rule specifies a 5 percent overspeed 

margin for both single and combined 

failure situations for all ratings except 

OEI ratings of less than 21⁄2 minutes. 

When operating at an OEI rating of 

less than 21⁄2-minute duration and a 

single failure occurs, the proposed rule 

requires that rotor components be 

designed and tested to withstand 100 

percent of the resulting overspeed. The 

proposed changes to overspeed 

requirements for OEI ratings harmonize 

with those in CS–E 840(b). 

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Federal Register / Vol. 75, No. 79 / Monday, April 26, 2010 / Proposed Rules 21525 

Exclusion of Certain Shaft Sections 

From Overspeed Tests 

The current rule in § 33.27(c)(2)(v) 

requires that all shaft locations be 

considered in determining the terminal 

rotor speed due to failure and be tested 

to 105 percent of the highest terminal 

rotor speed. The proposed rule in 

§ 33.27(f) would exclude certain shaft 

sections, but not the whole shaft system, 

from this requirement. The FAA finds 

the proposed rule is consistent with the 

way the FAA has applied the current 

rule to industry in certification tests. 

The FAA has consistently accepted 

engineering assessments that support 

the applicant’s findings that certain 

location(s) (sections) of a shaft system 

are considered ‘‘prime reliable,’’ which 

means that these shaft locations are not 

likely to fail during the life of the 

engine. The FAA is, therefore, 

proposing to change the current rule to 

be consistent with the current 

certification practices. The proposed 

changes to overspeed requirements due 

to shaft failures would be consistent 

with those in CS–E–850(b). 

Rulemaking Analyses and Notices 

Paperwork Reduction Act 

The Paperwork Reduction Act of 1995 

(44 U.S.C. 3507(d)) requires that the 

FAA consider the impact of paperwork 

and other information collection 

burdens imposed on the public. We 

have determined there is no current or 

new information collection 

requirements associated with this 

proposed rule. 

International Compatibility 

In keeping with U.S. obligations 

under the Convention on International 

Civil Aviation, it is FAA policy to 

comply with International Civil 

Aviation Organization (ICAO) Standards 

and Recommended Practices to the 

maximum extent practicable. We 

determined that no conflict with ICAO 

Standards and Recommended Practices 

exists, since there are no corresponding 

ICAO Standards and Recommended 

Practices. 

Regulatory Evaluation, Regulatory 

Flexibility Determination, International 

Trade Impact Assessment, and 

Unfunded Mandates Assessment 

Proposed changes to Federal 

regulations must undergo several 

economic analyses. First, Executive 

Order 12866 directs that each Federal 

agency propose or adopt a regulation 

only upon a reasoned determination 

that the benefits of the intended 

regulation justify its costs. Second, the 

Regulatory Flexibility Act of 1980 (Pub. 

L. 96–354) requires agencies to analyze 

the economic impact of regulatory 

changes on small entities. Third, the 

Trade Agreements Act (Pub. L. 96–39) 

prohibits agencies from setting 

standards that create unnecessary 

obstacles to the foreign commerce of the 

United States. In developing U.S. 

standards, this Trade Act requires 

agencies to consider international 

standards and, where appropriate, that 

they be the basis of U.S. standards. 

Fourth, the Unfunded Mandates Reform 

Act of 1995 (Pub. L. 104–4) requires 

agencies to prepare a written assessment 

of the costs, benefits, and other effects 

of proposed or final rules that include 

a Federal mandate likely to result in the 

expenditure by State, local, or tribal 

governments, in the aggregate, or by 

private sector, of $100 million or more 

annually (adjusted for inflation with 

base year of 1995). This portion of the 

preamble contains the FAA’s analysis of 

the economic impacts of this proposed 

rule. 

In conducting these analyses, the FAA 

has determined that this proposed rule: 

(1) Has benefits that justify its costs, (2) 

is not an economically ‘‘significant 

regulatory action’’ as defined in section 

3(f) of Executive Order 12866, (3) is not 

‘‘significant’’ as defined in DOT’s 

Regulatory Policies and Procedures; (4) 

would not have a significant economic 

impact on a substantial number of small 

entities; (5) would not create 

unnecessary obstacles to the foreign 

commerce of the United States; and (6) 

would not impose an unfunded 

mandate on State, local, or tribal 

governments, or on the private sector by 

exceeding the threshold identified 

above. 

Total Estimated Benefits and Costs of 

This Proposed Rule 

Presently, turbine aircraft engine 

manufacturers must satisfy both FAA 

part 33 and EASA CS–E regulations to 

certify their products in the United 

States and Europe. Certification to one 

standard would improve certification 

efficiency by eliminating duplicate 

testing and documentation. We have not 

attempted to quantify the cost savings 

that may accrue due to this improved 

certification efficiency beyond noting 

that these are expected to be minor. We 

have drawn that conclusion based on 

the consensus among potentially 

affected aircraft engine manufacturers. 

Industry must currently certificate to 

the two standards that are substantively 

similar, but have a few slightly different 

testing and documentation procedures 

and requirements. The proposed rule 

would harmonize these procedures and 

requirements to the higher standard 

and, thereby, may increase safety. In 

addition, by reducing the amount of 

duplicative testing that would need to 

be either witnessed or analyzed by the 

FAA, the FAA would be better able to 

prioritize its resources to other, more 

safety critical areas. Consequently, the 

FAA determines there could be 

unquantifiable future minimal benefits 

from the proposed rule. 

As a result, the FAA concludes that 

the combination of cost savings and 

potential increased safety benefits 

would make this proposed rule cost 

beneficial. 

The FAA requests comments on these 

estimates of potential cost savings and 

benefits from this proposed rule. 

The FAA has, therefore, determined 

that this proposed rule is not a 

‘‘significant regulatory action’’ as 

defined in section 3(f) of Executive 

Order 12866, and is not ‘‘significant’’ as 

defined in DOT’s Regulatory Policies 

and Procedures. 

Regulatory Flexibility Determination 

The Regulatory Flexibility Act of 1980 

(Pub. L. 96–354) (RFA) establishes ‘‘as a 

principle of regulatory issuance that 

agencies shall endeavor, consistent with 

the objectives of the rule and of 

applicable statutes, to fit regulatory and 

informational requirements to the scale 

of the businesses, organizations, and 

governmental jurisdictions subject to 

regulation. To achieve this principle, 

agencies are required to solicit and 

consider flexible regulatory proposals 

and to explain the rationale for their 

actions to assure that such proposals are 

given serious consideration.’’ The RFA 

covers a wide-range of small entities, 

including small businesses, not-forprofit organizations, and small 

governmental jurisdictions. 

Agencies must perform a review to 

determine whether a rule will have a 

significant economic impact on a 

substantial number of small entities. If 

the agency determines that it will, the 

agency must prepare a regulatory 

flexibility analysis as described in the 

RFA. 

However, if an agency determines that 

a rule is not expected to have a 

significant economic impact on a 

substantial number of small entities, 

section 605(b) of the RFA provides that 

the head of the agency may so certify 

and a regulatory flexibility analysis is 

not required. The certification must 

include a statement providing the 

factual basis for this determination, and 

the reasoning should be clear. 

The net effect of this proposed rule 

would provide regulatory cost relief. 

Second, all but one U.S. aircraft turbine 

engine manufacturer exceeds the Small 

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21526 Federal Register / Vol. 75, No. 79 / Monday, April 26, 2010 / Proposed Rules 

Business Administration small-entity 

criteria for aircraft engine manufacturers 

of 1,500 employees. U.S. transport 

category aircraft engine manufacturers 

include: General Electric (GE); CFM 

International (a joint company of GE 

and Snecma); Pratt & Whitney (P&W); 

Honeywell; Rolls-Royce Corporation 

(formerly Allison Engines); International 

Aero Engines (a privately-held 

consortium that includes P&W, RollsRoyce, Japanese Aero Engines 

Corporation, and MTU Aero Engines); 

and Williams International. Williams 

International is the only one of these 

manufacturers that is categorized as a 

U.S. small business by the SBA criteria. 

This proposed rule would reduce costs, 

and there is only one small entity 

manufacturing part 33 aircraft engines. 

Therefore, the FAA certifies that this 

action would not have a significant 

economic impact on a substantial 

number of small entities. The FAA 

solicits comments regarding this 

determination. 

International Trade Impact Assessment 

The Trade Agreements Act of 1979 

(Pub. L. 96–39), as amended by the 

Uruguay Round Agreements Act (Pub. 

L. 103–465), prohibits Federal agencies 

from establishing standards or engaging 

in related activities that create 

unnecessary obstacles to the foreign 

commerce of the United States. 

Pursuant to these Acts, the 

establishment of standards is not 

considered an unnecessary obstacle to 

the foreign commerce of the United 

States, so long as the standard has a 

legitimate domestic objective, such as 

protection of safety, and does not 

operate in a manner that excludes 

imports that meet this objective. The 

statute also requires consideration of 

international standards and, where 

appropriate, that they be the basis for 

U.S. standards. The FAA assessed the 

potential effect of this proposed rule 

and determined that it uses European 

standards as the basis for regulation and 

thus is consistent with the Trade 

Assessments Act. 

Unfunded Mandates Assessment 

Title II of the Unfunded Mandates 

Reform Act of 1995 (Pub. L. 104–4) 

requires each Federal agency to prepare 

a written statement assessing the effects 

of any Federal mandate in a proposed or 

final agency rule that may result in an 

expenditure of $100 million or more (in 

1995 dollars) in any one year by State, 

local, and tribal governments, in the 

aggregate, or by the private sector; such 

a mandate is deemed to be a ‘‘significant 

regulatory action.’’ The FAA currently 

uses an inflation-adjusted value of 

$136.1 million in lieu of $100 million. 

This proposed rule does not contain 

such a mandate, therefore, the 

requirements of Title II of the Act do not 

apply. 

Executive Order 13132, Federalism 

The FAA has analyzed this proposed 

rule under the principles and criteria of 

Executive Order 13132, Federalism. We 

determined that this action 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, and therefore 

would not have federalism implications. 

Environmental Analysis 

FAA Order 1050.1E defines FAA 

actions that are categorically excluded 

from preparation of an environmental 

assessment or environmental impact 

statement under the National 

Environmental Policy Act (NEPA) in the 

absence of extraordinary circumstances. 

The FAA has determined this proposed 

rulemaking action qualifies for the 

categorical exclusion identified in 

Chapter 3, paragraph 312d, and involves 

no extraordinary circumstances. 

Regulations That Significantly Affect 

Energy Supply, Distribution, or Use 

The FAA has analyzed this NPRM 

under Executive Order 13211, Actions 

Concerning Regulations that 

Significantly Affect Energy Supply, 

Distribution, or Use (May 18, 2001). We 

have determined that it is not a 

‘‘significant energy action’’ under the 

executive order and is not likely to have 

a significant adverse effect on the 

supply, distribution, or use of energy. 

Additional Information 

Comments Invited 

The FAA invites interested persons to 

participate in this rulemaking by 

submitting written comments, data, or 

views. We also invite comments relating 

to the economic, environmental, energy, 

or federalism impacts that might result 

from adopting the proposals in this 

document. The most helpful comments 

reference a specific portion of the 

proposal, explain the reason for any 

recommended change, and include 

supporting data. To ensure the docket 

does not contain duplicate comments, 

please send only one copy of written 

comments, or if you are filing comments 

electronically, please submit your 

comments only one time. 

We will file in the docket all 

comments we receive, as well as a 

report summarizing each substantive 

public contact with FAA personnel 

concerning this proposed rulemaking. 

Before acting on this proposal, we will 

consider all comments we receive on or 

before the closing date for comments. 

We will consider comments filed after 

the comment period has closed if it is 

possible to do so without incurring 

expense or delay. We may change this 

proposal in light of the comments we 

receive. 

Proprietary or Confidential Business 

Information 

Do not file in the docket information 

that you consider to be proprietary or 

confidential business information. Send 

or deliver this information directly to 

the person identified in the FOR FURTHER

INFORMATION CONTACT section of this 

document. You must mark the 

information that you consider 

proprietary or confidential. If you send 

the information on a disk or CD–ROM, 

mark the outside of the disk or CD–ROM 

and also identify electronically within 

the disk or CD–ROM the specific 

information that is proprietary or 

confidential. 

Under 14 CFR 11.35(b), when we are 

aware of proprietary information filed 

with a comment, we do not place it in 

the docket. We hold it in a separate file 

to which the public does not have 

access, and we place a note in the 

docket that we have received it. If we 

receive a request to examine or copy 

this information, we treat it as any other 

request under the Freedom of 

Information Act (5 U.S.C. 552). We 

process such a request under the DOT 

procedures found in 49 CFR part 7. 

Availability of Rulemaking Documents 

You can get an electronic copy using 

the Internet by— 

(1) Searching the Federal 

eRulemaking Portal (http:// 

www.regulations.gov); 

(2) Visiting the FAA’s Regulations and 

Policies Web page at http:// 

www.faa.gov/regulations_policies/; or 

(3) Accessing the Government 

Printing Office’s Web page at http:// 

www.gpo.gov/fdsys/search/home.action. 

You can also get a copy by sending a 

request to the Federal Aviation 

Administration, Office of Rulemaking, 

ARM–1, 800 Independence Avenue, 

SW, Washington, DC 20591, or by 

calling (202) 267–9680. Make sure to 

identify the docket number or notice 

number of this rulemaking. 

You may access all documents the 

FAA considered in developing this 

proposed rule, including economic 

analyses and technical reports, from the 

Internet through the Federal 

eRulemaking Portal referenced in 

paragraph (1). 

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Federal Register / Vol. 75, No. 79 / Monday, April 26, 2010 / Proposed Rules 21527 

List of Subjects in 14 CFR Part 33 

Air transportation, Aircraft, Aviation 

safety, Safety. 

The Proposed Amendment 

In consideration of the foregoing, the 

Federal Aviation Administration 

proposes to amend Chapter I of Title 14, 

Code of Federal Regulations as follows: 

PART 33—AIRWORTHINESS 

STANDARDS: AIRCRAFT ENGINES 

1. The authority citation for part 33 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701– 

44702, 44704. 

2. Revise § 33.27 to read as follows: 

§ 33.27 Turbine, compressor, fan, and 

turbosupercharger rotor overspeed. 

(a) For each fan, compressor, turbine, 

and turbosupercharger rotor, the 

applicant must establish by test, 

analysis, or a combination of both, that 

each rotor will not burst when operated 

in the engine for 5 minutes at whichever 

of the conditions defined in paragraph 

(b) of this section is the most critical 

with respect to the integrity of such a 

rotor. 

(1) Test rotors used to demonstrate 

compliance with this section that do not 

have the most adverse combination of 

material properties and dimensional 

tolerances must be tested at conditions 

which have been adjusted to ensure the 

minimum specification rotor possesses 

the required overspeed capability. This 

can be accomplished by increasing test 

speed, temperature, and/or loads. 

(2) When an engine test is being used 

to demonstrate compliance with the 

overspeed conditions listed in 

paragraph (b)(3) or (b)(4) of this section 

and the failure of a component or 

system is sudden and transient, it may 

not be possible to operate the engine for 

5 minutes after the failure. Under these 

circumstances, the actual overspeed 

duration is acceptable if the required 

maximum overspeed is achieved. 

(b) When determining the maximum 

overspeed condition applicable to each 

rotor in order to comply with 

paragraphs (a) and (c) of this section, the 

applicant must evaluate the following 

rotor speeds taking into consideration 

the part’s operating temperatures and 

temperature gradients throughout the 

engine’s operating envelope: 

(1) 120 percent of the maximum 

permissible rotor speed associated with 

any of the engine ratings except oneengine-inoperative (OEI) ratings of less 

than 21⁄2 minutes. 

(2) 115 percent of the maximum 

permissible rotor speed associated with 

any OEI ratings of less than 21⁄2 minutes. 

(3) 105 percent of the highest rotor 

speed that would result from either: 

(i) The failure of the component or 

system which, in a representative 

installation of the engine, is the most 

critical with respect to overspeed when 

operating at any rating condition except 

OEI ratings of less than 21⁄2 minutes, or 

(ii) The failure of any component or 

system in a representative installation of 

the engine, in combination with any 

other failure of a component or system 

that would not normally be detected 

during a routine pre-flight check or 

during normal flight operation, that is 

the most critical with respect to 

overspeed, except as provided by 

paragraph (c) of this section, when 

operating at any rating condition except 

OEI ratings of less than 21⁄2 minutes. 

(4) 100 percent of the highest rotor 

speed that would result from the failure 

of the component or system which, in 

a representative installation of the 

engine, is the most critical with respect 

to overspeed when operating at any OEI 

rating of less than 21⁄2 minutes. 

(c) The highest overspeed that results 

from a complete loss of load on a 

turbine rotor, except as provided by 

paragraph (f) of this section, must be 

included in the overspeed conditions 

considered by paragraphs (b)(3)(i), 

(b)(3)(ii), and (b)(4) of this section, 

regardless of whether that overspeed 

results from a failure within the engine 

or external to the engine. The overspeed 

resulting from any other single failure 

must be considered when selecting the 

most limiting overspeed conditions 

applicable to each rotor. Overspeeds 

resulting from combinations of failures 

must also be considered unless the 

applicant can show that the probability 

of occurrence is not greater than 10¥9

per flight. 

(d) In addition, the applicant must 

demonstrate that each fan, compressor, 

turbine, and turbosupercharger rotor 

complies with paragraphs (d)(1) and 

(d)(2) of this section for the maximum 

overspeed achieved when subjected to 

the conditions specified in paragraphs 

(b)(3) and (b)(4) of this section. The 

applicant must use the approach in 

paragraph (a) of this section which 

specifies the required test conditions. 

(1) Rotor Growth must not cause the 

engine to: 

(i) Catch fire, 

(ii) Release hazardous fragments 

through the engine casing or result in a 

hazardous failure of the engine casing, 

(iii) Generate loads greater than those 

ultimate loads specified in § 33.23(a), or 

(iv) Lose the capability of being shut 

down. 

(2) Following an overspeed event and 

after continued operation, the rotor may 

not exhibit conditions such as cracking 

or distortion which preclude continued 

safe operation. 

(e) The design and functioning of 

engine control systems, instruments, 

and other methods not covered under 

§ 33.28 must ensure that the engine 

operating limitations that affect turbine, 

compressor, fan, and turbosupercharger 

rotor structural integrity will not be 

exceeded in service. 

(f) Failure of a shaft section may be 

excluded from consideration in 

determining the highest overspeed that 

would result from a complete loss of 

load on a turbine rotor if the applicant: 

(1) Identifies the shaft as an engine 

life-limited-part and complies with 

§ 33.70. 

(2) Uses material and design features 

that are well understood and that can be 

analyzed by well-established and 

validated stress analysis techniques. 

(3) Determines, based on an 

assessment of the environment 

surrounding the shaft section, that 

environmental influences are unlikely 

to cause a shaft failure. This assessment 

must include complexity of design, 

corrosion, wear, vibration, fire, contact 

with adjacent components or structure, 

overheating, and secondary effects from 

other failures or combination of failures. 

(4) Identifies and declares, in 

accordance with § 33.5, any 

assumptions regarding the engine 

installation in making the assessment 

described above in paragraph (f)(3) of 

this section. 

(5) Assesses, and considers as 

appropriate, experience with shaft 

sections of similar design. 

(6) Does not exclude the entire shaft. 

(g) If analysis is used to meet the 

overspeed requirements, then the 

analytical tool must be calibrated to 

prior overspeed test results of a similar 

rotor. The tool must be calibrated for the 

same material, rotor geometry, stress 

level, and temperature range as the rotor 

being certified. Calibration includes the 

ability to accurately predict rotor 

dimensional growth and the burst 

speed. The predictions must also show 

that the rotor being certified does not 

have lower burst and growth margins 

than rotors used to calibrate the tool. 

Issued in Washington, DC, on April 20, 

2010. 

Dorenda D. Baker, 

Director, Aircraft Certification Service. 

[FR Doc. 2010–9588 Filed 4–23–10; 8:45 am] 

BILLING CODE 4910–13–P 

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