This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

793 

Vol. 75, No. 3 

Wednesday, January 6, 2010 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Parts 27 and 29 

[Docket No. FAA–2009–0660; Notice No. 09– 

12] 

RIN 2120–AJ52 

Damage Tolerance and Fatigue 

Evaluation of Composite Rotorcraft 

Structures 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: This proposal would revise 

airworthiness standards for type 

certification requirements of normal and 

transport category rotorcraft. The 

amendment would require evaluation of 

fatigue and residual static strength of 

composite rotorcraft structures using a 

damage tolerance evaluation, or a 

fatigue evaluation, if the applicant 

establishes that a damage tolerance 

evaluation is impractical. The 

amendment would address advances in 

composite structures technology and 

provide internationally harmonized 

standards. 

DATES: Send your comments on or 

before April 6, 2010 

ADDRESSES: You may send comments 

identified by Docket Number FAA– 

2009–0660 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., Room W12–140, West 

Building Ground Floor, Washington, DC 

20590–0001. 

• Hand Delivery or Courier: 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: Fax comments to Docket 

Operations at 202–493–2251. 

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 

website, anyone can find and read the 

electronic form of all 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 documents or 

comments received, go to http:// 

www.regulations.gov 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 Sharon Y. Miles, 

Regulations and Policy Group, 

Rotorcraft Directorate, ASW–111, 

Federal Aviation Administration, 2601 

Meacham Boulevard, Fort Worth, Texas 

76137–0111; telephone (817) 222–5122; 

facsimile (817) 222–5961; e-mail 

sharon.y.miles@faa.gov. For legal 

questions concerning this proposed rule 

contact Steve C. Harold, Directorate 

Counsel, ASW–7G1, Federal Aviation 

Administration, 2601 Meacham 

Boulevard, Fort Worth, Texas 76137– 

0007, telephone (817) 222–5099; 

facsimile (817) 222–5945, e-mail 

steve.c.harold@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 handling. 

We also discuss how you can get a copy 

of related rulemaking documents. 

Authority for This Rulemaking 

The FAA’s authority to issue rules on 

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. 

This rulemaking is issued under the 

authority described in Subtitle VII, Part 

A, Subpart III, Section 44701, ‘‘General 

Requirements,’’ Section 44702, 

‘‘Issuance of Certificates,’’ and Section 

44704, ‘‘Type Certificates, Production 

Certificates, and Airworthiness 

Certificates.’’ Under Section 44701, the 

FAA is charged with prescribing 

regulations and minimum standards for 

practices, methods, and procedures the 

Administrator finds necessary for safety 

in air commerce. Under Section 44702, 

the Administrator may issue various 

certificates including type certificates, 

production certificates, air agency 

certificates, and airworthiness 

certificates. Under Section 44704, the 

Administrator must issue type 

certificates for aircraft, aircraft engines, 

propellers, and specified appliances 

when the Administrator finds the 

product is properly designed and 

manufactured, performs properly, and 

meets the regulations and minimum 

standards prescribed under section 

44701(a). This regulation is within the 

scope of these authorities because it 

would promote safety by updating the 

existing minimum prescribed standards, 

used during the type certification 

process, to address advances in 

composite structural fatigue 

substantiation technology. It would also 

harmonize this standard with 

international standards for evaluating 

the fatigue strength of normal and 

transport category rotorcraft composite 

primary structural elements. 

Background and Statement of the Issues 

The evolution of composite 

technology used in rotorcraft structures 

is advancing rapidly. These rapid 

changes with the increased use of 

composites in rotorcraft structures, 

issues discovered during certification of 

composite structures, and service 

experiences of composite rotorcraft 

structures over the last 25 years have 

caused us to reconsider the current 

regulations and guidance materials for 

damage tolerance and fatigue evaluation 

and to address the state of technology in 

composite structures. The current 

certification process is based on a broad 

interpretation of metallic fatigue 

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794 Federal Register / Vol. 75, No. 3 / Wednesday, January 6, 2010 / Proposed Rules 

1Published in the Federal Register, April 5, 2000 

(65 FR 17936). 

substantiation and the design and 

construction airworthiness standards. 

However, composite and metal 

structures are different. Composites are 

complex materials that have unique 

advantages in fatigue strength, weight, 

and tolerance to damage. The 

methodologies for evaluating metallic 

structures are not necessarily suitable 

for composite structures. Since 

composite structures differ from 

metallic structures, the current 

regulations, §§ 27.571 and 29.571, do 

not adequately provide the fatigue 

certification requirements for composite 

rotorcraft structures. 

This may lead to inconsistent 

interpretations from one rotorcraft 

certification project to another, resulting 

in different burdens on industry to 

substantiate their composite rotorcraft 

structures. It has also caused confusion 

for some certification applicants. These 

applicants state there is no clear, 

complete guidance for certification of 

composite rotorcraft structures. 

To address these concerns, the FAA 

tasked the Aviation Rulemaking 

Advisory Committee (ARAC) 1 through 

its Composite Rotorcraft Structure 

working group to provide advice and 

recommendations as follows: 

• Recommend revisions to FAR/JAR 

27 and 29 for composite structures that 

are harmonized. 

• Evaluate and recommend, as 

appropriate, regulations, advisory 

material, and related guidance to 

achieve the goal of improved tolerance 

to flaws and defects in composite 

structure with methodology and 

procedures that are practical and 

appropriate to rotorcraft. 

This proposed rule is based on the 

ARAC’s recommendations to the FAA. 

The recommendations have been placed 

in the docket for this rulemaking. 

Related Activity 

At the same time the ARAC was 

tasked with providing advice and 

recommendations for composite 

rotorcraft structures, it was also tasked 

with providing advice and 

recommendations for metallic rotorcraft 

structures. Because of the unique 

characteristics and structural 

capabilities of composite structures, we 

believe a separate rule is needed for the 

damage tolerance and fatigue 

evaluations of rotorcraft composite 

structures. In response to the ARAC 

recommendations for improved 

standards for metallic structures, the 

FAA is developing an NPRM entitled 

Fatigue Tolerance Evaluation of Metallic 

Structures. 

General Discussion of Proposals 

Composite structures present unique 

material behaviors and react differently 

than metallic to damage and loading 

conditions. This separate rulemaking 

action for the damage tolerance and 

fatigue evaluation of composite 

structures is proposed to address the 

type certification requirements for 

substantiating and certifying composite 

rotorcraft structures including different 

aspects of the evaluation for the most 

critical issues for each class of materials. 

These proposals address the unique 

characteristics of composite materials 

and would enable applicants to evaluate 

these types of materials in a different 

manner from those of the traditional 

metallic materials. 

The proposed changes would clarify 

the certification standards in areas of 

frequent non-standardization and 

misinterpretation. These proposals are 

intended to address fatigue damage 

tolerance conditions that can reduce 

structural strength. In composites, low 

cycle fatigue often yields minimal 

damage growth, whereas accidental 

damage from impact can immediately 

reduce residual structural strength. 

Conversely, in metals, any critical 

damage to the structure would be 

sensitive to cyclic fatigue loads. 

These proposals also address material 

and process variability and 

environmental effects. The FAA 

proposes a strength requirement for 

ultimate loads that would be applied 

when maximum acceptable 

manufacturing defects and service 

damage are present. These proposals 

would provide an exception to a damage 

tolerance evaluation if the applicant 

establishes impracticability and, in that 

instance, would allow a fatigue 

evaluation for some rotorcraft structures 

and damage scenarios based on 

retirement times instead of inspection 

intervals more commonly associated 

with damage tolerance standards. Under 

this proposal, an applicant could 

demonstrate that certain damage would 

not grow or does not grow beyond a 

certain threshold or size, and that the 

damaged structure could still carry 

ultimate loads. In this instance, an 

inspection may not be necessary and the 

structure could be assigned a retirement 

life instead of a required inspection 

program. Further, this proposal would 

require an applicant to conduct a threat 

assessment, which is associated with 

the service history of composite 

structures. 

The proposals consider varying types 

of damage, loading conditions, threat 

assessments, manufacturing defects, and 

residual strength associated with 

composite structures. In developing 

these proposals, we have recognized 

that it may be impractical within the 

limits of geometry, inspectability, or 

good design practice to evaluate all the 

composite structures of a rotorcraft 

using a damage tolerance evaluation. 

Therefore, this proposal allows for a 

fatigue evaluation of particular 

rotorcraft composite structures under 

§§ 27.573(e) and 29.573(e) where 

appropriate, instead of requiring a 

damage tolerance evaluation for 

particular structures if the applicant can 

establish that an impracticability exists. 

As part of the approval process for 

fatigue evaluation of a particular 

rotorcraft composite structure, the 

applicant would be required to identify 

the Principal Structural Elements (PSEs) 

and the types of damage considered, 

establish supplemental procedures to 

minimize the risk of catastrophic failure 

associated with those types of damage, 

and include procedures in the 

Airworthiness Limitation section of the 

Instructions for Continued 

Airworthiness. The proposed 

requirements would minimize the risk 

of catastrophic failure of composite 

structures used on rotorcraft certificated 

in accordance with part 27 and part 29 

standards. 

Key Provisions in the New Rule 

Some of the proposed requirements 

for evaluating composite structures 

came from the current § 29.571 

standards. These requirements in the 

evaluation process include certain steps, 

such as identification of the PSEs, the 

in-flight measurements of loads, and the 

use of loading spectra as severe as those 

expected in-service. This proposal adds 

more detailed steps and does not refer 

to the current flaw tolerant safe-life and 

fail-safe evaluations because there are 

more suitable ways of describing each 

approach under damage tolerance. 

Further, these proposals do not refer to 

the traditional safe-life method because 

composites have sensitivities to defects 

and damage that must be considered in 

design and certification testing that 

make the traditional safe-life method 

inappropriate. 

These proposals would revise the 

standards for determining inspection 

intervals and retirement times based on 

results of damage tolerance and fatigue 

evaluation. Currently, the minimum 

residual structural strength requirement 

for any damage or defect that can be 

found by inspection is tied to limit 

loads (maximum loads to be expected in 

service). This proposal would link the 

required residual structural strength to 

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the probability of a given damage type, 

inspection interval, and damage 

detectability. This link is necessary for 

at least two reasons. First, one of the 

more critical threats—impact damage— 

could immediately lower residual 

structural strength well below ultimate 

loads (limit loads multiplied by 

prescribed factors of safety) if it occurs. 

The proposal would ensure, as the 

residual structural strength is lowered, 

the earlier damage would be detected 

and repaired. Inspections would be 

required that would be frequent and 

comprehensive enough to reveal any 

damage or defect growth to minimize 

the time that the rotorcraft might be 

operated at less than an ultimate load 

capability. Second, this proposal would 

address rare damage (such as a highenergy, blunt impact) that is not 

detectable with the currently prescribed 

inspection schemes issued for aircraft in 

operational service. Although such 

damage may have a low probability of 

occurring, this proposal would require 

that sufficient residual structural 

strength exists to compensate for such 

damage. 

These proposals would require that 

all PSEs, the failure of which could 

result in catastrophic failure of the 

rotorcraft, meet ultimate load residual 

structural strength requirements or 

require that a retirement time be 

established if there could be any damage 

that may not be found by a maintenance 

inspection. Under this proposal, an 

applicant would establish a retirement 

time to assess the damage that may not 

be found by inspection or to eliminate 

the burden of the repeated inspections 

by the rotorcraft owners. For damage 

detectable by inspection, the proposal 

would establish a limit load 

requirement to repair and restore the 

structure to its ultimate strength 

capability. 

The FAA proposes to include all PSE 

assessments for damage threats, residual 

strength and fatigue characteristics to 

the list of requirements for inspection 

intervals or replacement times as stated 

in proposed §§ 27.573(d)(1) and 

29.573(d)(1). As a minimum, the fatigue 

evaluation would include the PSEs of 

the: 

—Airframe, 

—Main and tail rotor drive systems, 

—Main and tail rotor blades and hubs, 

—Rotor controls, 

—Fixed and movable control surfaces, 

—Engine and transmission mountings 

(provided by the airframe 

manufacturer), and 

—Landing gear and other parts; as well 

as performing damage tolerance 

evaluations of the strength of 

composite: 

—Detail design points and 

—Fabrication techniques considered 

critical by the FAA to avoid 

catastrophic failure due to static or 

fatigue loads. 

The proposal would require 

consideration of the effects of fatigue 

damage on stiffness, dynamic behavior, 

loads, and functional performance of 

composite structures. In the existing 

rule, such requirements are limited to 

fail-safe evaluations. These 

characteristics are not considered to be 

a serious threat to residual structural 

strength. 

The FAA recognizes there may be 

limited cases in which a damage 

tolerance evaluation may be impractical. 

In these rare cases, the applicant would 

be required to identify the nature of the 

evaluation and provide a justification to 

the FAA for the determination of its 

impracticality. The justification would 

support the specific types of damage to 

the PSE that would qualify for a fatigue 

evaluation. Finally, the proposal would 

require the applicant to establish 

replacement times, structural inspection 

intervals, and related structural 

inspection procedures to minimize the 

risk of catastrophic failure because of 

such damage. The required replacement 

times, inspection intervals, and 

structural inspections would be 

included in the Instructions for 

Continued Airworthiness as required by 

§§ 27.1529 and 29.1529. 

Additionally, the FAA recognizes that 

rare types of damage, such as highenergy, blunt impacts may not be 

uncovered as part of a base field 

inspection during scheduled 

maintenance inspection intervals. This 

proposal would require that the 

applicant substantiate sufficient 

residual structural strength to maintain 

an adequate level of safety in the event 

of an occurrence of rare damage. 

Supplemental procedures may be 

required to adequately address rare 

impact damage. 

Airworthiness Limitations Section 

(Appendix A to Parts 27 and 29) 

This proposal would require the 

mandatory replacement times, structural 

inspection intervals, and related 

structural inspection procedures 

produced under the requirements of 

§§ 27.571 and 29.571, the new §§ 27.573 

and 29.573, and any other similar 

requirement for type certification be 

included in the Airworthiness 

Limitations Section of the Instructions 

for Continued Airworthiness. 

Paperwork Reduction Act 

This proposal contains the following 

new information collection 

requirements. As required by 44 U.S.C. 

3507(d) of the Paperwork Reduction Act 

of 1995, as implemented by 5 CFR part 

1320, the FAA has submitted the 

information requirements associated 

with this proposal to the Office of 

Management and Budget (OMB) for 

review. 

Title: Damage Tolerance and Fatigue 

Evaluation of Composite Rotorcraft 

Structures. 

Summary: This proposal would add 

new certification standards for normal 

and transport category rotorcraft to 

address advances in structural damage 

tolerance and fatigue substantiation 

technology for composite rotorcraft 

structures. These proposals would 

increase the current minimum safety 

standards to require compliance with 

certain current industry practices and 

FAA policies that would result in higher 

safety standards, and would result in 

harmonized international standards. 

These proposals would help ensure that 

if damage occurs to composite 

structures during manufacturing or 

within the operational life of the 

rotorcraft, the remaining structure could 

withstand fatigue loads that are likely to 

occur, without failure, until the damage 

is detected. The damaged structure must 

then be repaired to restore ultimate load 

capability, or the part must be replaced. 

Proposed §§ 27.573 and 29.573 would 

require that applicants get FAA 

approval of their proposed methods for 

complying with the certification 

requirements for damage tolerance and 

fatigue evaluation of composite 

structures. 

Use of information: The required 

damage tolerance and fatigue evaluation 

information would be determined for 

principal composite structural elements 

or components, detail design points, 

and fabrication techniques and would 

be collected from rotorcraft certification 

applicants. The FAA would use the 

approval process for the Applicant’s 

submitted compliance methodology to 

determine whether the proposed 

methods were sufficient to comply with 

the certification requirements for 

damage tolerance and fatigue evaluation 

of composite structures. The FAA also 

would use the approval process for the 

Applicant’s submitted compliance 

methodology to determine if the 

rotorcraft has any unsafe features in the 

composite structures. 

Respondents: The likely respondents 

to this proposed damage tolerance and 

fatigue evaluation information are 

applicants requesting type certification 

of composite structures. We anticipate 

about 10 normal and transport category 

rotorcraft certification applicants 

(including supplemental type certificate 

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applicants) over the 27-year analysis 

period or about 0.4 per year. 

Frequency: The frequency of 

determining the damage tolerance and 

fatigue evaluation methodologies would 

depend on how often an applicant seeks 

certification of a composite structure. 

This compliance methodology would be 

provided during each certification. We 

anticipate 16.5 certifications over the 27 

year analysis period or about 0.6 per 

year. 

Annual Burden Estimate: The 

compliance methodology would be 

required to be submitted and approved 

during each certification of a composite 

rotorcraft structure. We anticipate there 

would be 0.6 certifications each year 

and it would take 182 hours to submit 

and approve the compliance 

methodology for each certification, for a 

total annual time burden of 109 hours. 

We anticipate that submitting and 

approving the compliance methodology 

for each certification would cost 

$100.00 per hour. Therefore, the 

estimated total annual cost burden 

would be $10,900.00. 

The agency is asking for comments 

to— 

(1) evaluate whether the proposed 

information requirement is necessary for 

the proper performance of the functions 

of the agency, including whether the 

information will have practical utility; 

(2) evaluate the accuracy of the 

agency’s estimate of the burden; 

(3) improve the quality, utility, and 

clarity of the information to be 

collected; and 

(4) minimize the burden of collecting 

information on those who are to 

respond, by using appropriate 

automated, electronic, mechanical, or 

other technological collection 

techniques or other forms of information 

technology. 

Individuals and organizations may 

submit comments on the information 

collection requirement by March 8, 

2010, and should direct them to the 

address listed in the ADDRESSES section. 

Comments also should be submitted to 

the Office of Management and Budget, 

Office of Information and Regulatory 

Affairs, Attention: Desk Officer for FAA, 

New Executive Building, Room 10202, 

725 17th Street, NW., Washington, DC 

20053. 

According to the 1995 amendments to 

the Paperwork Reduction Act and 5 CFR 

1320.8(b)(3)(vi), an agency may not 

collect or sponsor the collection of 

information, nor may it impose an 

information collection requirement 

unless it displays a currently valid OMB 

control number. The OMB control 

number for this information collection 

will be published in the Federal 

Register, after the Office of Management 

and Budget approval. 

International Compatibility 

In keeping with U.S. obligations 

under the Convention on International 

Civil Aviation, it is FAA’s policy to 

comply with International Civil 

Aviation Organization (ICAO) Standards 

to the maximum extent practicable. The 

FAA has determined that the proposed 

rule is consistent with the ICAO 

standard in ICAO Annex 8, Part IV. 

European Aviation Safety Agency 

The European Aviation Safety Agency 

(EASA) was established by the 

European Community to develop 

standards to ensure safety and 

environmental protection, oversee 

uniform application of those standards, 

and promote them internationally. 

EASA formally became responsible for 

certification of aircraft, engines, parts, 

and appliances on September 28, 2003. 

The FAA and EASA are coordinating 

their rulemaking efforts to facilitate 

harmonized standards for evaluating the 

fatigue strength of composite rotorcraft 

structures. 

Regulatory Evaluation, Regulatory 

Flexibility Determination, International 

Trade Impact Assessment, and 

Unfunded Mandates Assessment 

Changes to Federal regulations must 

undergo several economic analyses. 

First, Executive Order 12866 directs that 

each Federal agency shall 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 (Public Law 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 the private sector, of 

$100 million or more annually (adjusted 

for inflation with base year of 1995). 

This portion of the preamble 

summarizes the FAA’s analysis of the 

economic impacts of this proposed rule. 

We suggest readers seeking greater 

detail read the full regulatory 

evaluation, a copy of which we have 

placed in the docket for this rulemaking. 

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) Has been determined by the Office 

of Management and Budget to be a 

‘‘non-significant regulatory action;’’ 

(4) Is not ‘‘significant’’ as defined in 

DOT’s Regulatory Policies and 

Procedures; 

(5) Would not have a significant 

economic impact on a substantial 

number of small entities; 

(6) Would not have a significant effect 

on international trade; and 

(7) Would not impose an unfunded 

mandate on State, local, or tribal 

governments by exceeding the monetary 

threshold identified. 

These analyses are summarized 

below. 

Total Benefits and Costs of This 

Rulemaking 

The estimated total cost of this 

proposed rule is about $713,000 

($392,000 in present value, discounted 

at 7% for 27 years). 

Who is Potentially Affected by this 

Rulemaking? 

• Manufacturers of U.S.-registered 

part 27 and part 29 rotorcraft, and 

• Operators of part 27 and part 29 

rotorcraft. 

Our Cost Assumptions and Sources of 

Information. 

• Discount rate—7% 

• Period of analysis of 27 years equals 

the 27 years of National Transportation 

Safety Board accident history. During 

this period, manufacturers will seek 

new certifications for 10.5 part 27 

rotorcraft and six part 29 rotorcraft. 

This proposed rule consolidates FAA 

and industry past activities including 

special conditions, advisory circulars, 

and industry practice regarding the use 

of composites on rotorcraft. The benefits 

of this action exceed the small costs of 

this proposed rule. 

We estimate the costs of this proposed 

rule to be about $713,000 ($392,000 in 

present value) over the 27-year analysis 

period. Manufacturers of 14 CFR part 27 

rotorcraft would incur costs of $101,000 

($55,000 in present value) and 

manufacturers of 14 CFR part 29 

helicopters would incur costs of 

$612,000 ($337,000 in present value). 

Regulatory Flexibility Determination 

The Regulatory Flexibility Act of 1980 

(RFA) establishes ‘‘as a principle of 

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regulatory issuance that agencies shall 

endeavor, consistent with the objective 

of the rule and of applicable statutes, to 

fit regulatory and informational 

requirements to the scale of the 

business, organizations, and 

governmental jurisdictions subject to 

regulation.’’ To observe that principle, 

the RFA requires agencies to solicit and 

consider flexible regulatory proposals 

and to explain the rationale for their 

actions. The RFA covers a wide-range of 

small entities, including small 

businesses, not-for-profit organizations 

and small governmental jurisdictions. 

Agencies must perform a review to 

determine whether a proposed or final 

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 Act. 

If an agency determines that a 

proposed or final rule is not expected to 

have a significant economic impact on 

a substantial number of small entities, 

section 605(b) of the 1980 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. 

This proposed rule would affect 

rotorcraft manufacturers and rotorcraft 

operators. Therefore, the effect on 

potential small entities is analyzed 

separately for helicopter manufacturers 

and operators. 

Part 27 Helicopter Manufacturers 

Size Standards 

Size standards for small entities are 

published by the Small Business 

Administration (SBA) on their Web site 

at http://www.sba.gov/size. The size 

standards used herein are from ‘‘SBA 

U.S. Small Business Administration, 

Table of Small Business Size Standards, 

Matched to North American Industry 

Classification System Codes.’’ The table 

is effective August 22, 2008 and uses the 

2007 NAICS codes. 

Helicopter manufacturers are listed in 

the above-referenced table under Sector 

31–33—Manufacturing; Subsector 336— 

Transportation Equipment 

Manufacturing; NAICS Code 336411— 

Aircraft Manufacturing. The small entity 

size standard is 1,500 employees. 

Table R1 shows there are six U.S. part 

27 helicopter manufacturers that 

produce composite helicopters. MD 

Helicopters, with 400 employees, is the 

only part 27 helicopter manufacturer to 

qualify as a small entity. It is estimated 

that MD Helicopters has annual 

revenues of $175,000,000. The cost of 

this rule for one part 27 helicopter 

certification for a part 27 manufacturer 

is estimated to be $9,600 over 27 years, 

and the total number of such 

certifications is estimated at 10.5, if only 

one of these were performed by MD 

Helicopters, the cost would be 

equivalent to 0.005 percent of their total 

revenue, which would not represent a 

significant cost. Therefore, it is not 

anticipated that this proposed rule 

would have a significant economic 

impact on a substantial number of part 

27 helicopter manufacturers. 

TABLE R1—U.S. PART 27 HELICOPTER MANUFACTURERS

Manufacturer Annual 

Number Name Ultimate owner Employees Small entity Revenues (AR) Proposal 

costs (PC) % PC of AR 

1 ............... Agusta (A) .................. Finmeccanica ............. 73,000 No ................ Ö15,037,000 N.A. N.A. 

2 ............... Bell Helicopter (B) ...... Textron ....................... 42,000 No ................ $14,200,000,000 N.A. N.A. 

3 ............... Eurocopter (C) ............ EADS .......................... 118,000 No ................ Ö43,3000,000,000 N.A. N.A. 

4 ............... Kaman Aerospace (D) Kaman Corp ............... 4,000 No ................ $1,200,000,000 N.A. N.A. 

5 ............... MD Helicopters (E)(F) None ........................... 400 Yes .............. $175,000,000 $9,600 0.01% 

6 ............... Sikorsky (G) ............... UTC ............................ 223,100 No ................ $58,700,000,000 N.A. N.A. 

7 ............... Robinson Helicopters 

(H).

..................................... .................... ...................... ................................ .................... ....................

Notes: 

(A) http://www.finmeccanica.com 

(B) http://www.Textron.com/about/company 

(C) http://www.eads.com 

(D) http://www.kaman.com 

(E) http://www.linkdin.com 

(F) http://www.jigsaw.com/id55718/md—helicopters—company.xhtml (Average of range of $100–$250 million) Cost is based on one helicopter 

certifcation during the analysis period. 

(G) http://www.utc.com/about—utc/fast—facts.Ihtml 

(H) Robinson Helicopters is not included because it produces only metallic helicopters and is not expected to produce composite heliopters in 

the future. 

8/10/2009 

Part 29 Helicopter Manufacturers 

Size Standards 

Size standards for part 29 

manufacturers are the same as the size 

standards for part 27 manufacturers. 

Table R2 shows there are four U.S. 

part 29 helicopter manufacturers 

currently producing helicopters. None 

of these manufacturers qualifies as a 

small entity. Therefore, it is not 

anticipated that this proposed rule 

would have a significant economic 

impact on a substantial number of part 

29 helicopter manufacturers. 

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798 Federal Register / Vol. 75, No. 3 / Wednesday, January 6, 2010 / Proposed Rules 

TABLE R1—U.S. PART 29 HELICOPTER MANUFACTURERS

Manufacturer Annual 

Number Name Ultimate owner Employees Small entity Revenues (AR) Proposal 

costs (PC) % PC of AR 

1 ............... Agusta (A) .................. Finmeccanica ............. 73,000 No ................ Ö15,037,000 N.A. N.A. 

2 ............... Bell Helicopter (B) ...... Textron ....................... 42,000 No ................ $14,200,000,000 N.A. N.A. 

3 ............... Eurocopter (C) ............ EADS .......................... 118,000 No ................ Ö43,3000,000,000 N.A. N.A. 

4 ............... Sikorsky (F) ................ UTC ............................ 223,100 No ................ $58,700,000,000 N.A. N.A. 

Notes: 

(A) http://www.finmeccanica.com 

(B) http://www.Textron.com/about/company 

(C) http://www.eads.com 

(F) http://www.utc.com/about—utc/fast—facts.lhtml 

8/10/2009 

Part 27 and Part 29 Helicopter 

Operators 

Size Standards 

While there are only seven part 27 

and four part 29 helicopter 

manufacturers in the United States, 

there are many small entities that are 

operators of part 27 and part 29 

helicopters. Each of these operators may 

provide many services or only one. 

Such services include offshore 

transportation, executive transportation, 

fire-fighting, Emergency Medical 

Services (EMS), and training in 

maintenance, repair, and modification. 

The SBA lists small entity size 

standards for air transportation under 

Sector 44–45, Retail Trade, Subsector 

481, Air Transportation. The small 

entity size standards are 1,500 

employees for scheduled and 

nonscheduled charter passenger and 

freight transportation. This standard is 

$28.0 million annually if the passenger 

or freight air transportation is offshore 

marine air transportation. Finally, the 

small entity size standard for other— 

non-scheduled air transportation is $7.0 

million annually. 

This proposed rule is not expected to 

increase the costs of part 27 or part 29 

helicopter operators, because we believe 

the helicopter inspection time for a 

composite part will be the same as or 

less than for a metallic part inspection. 

We request comments regarding this 

assumption. 

Consequently, the FAA certifies that 

this proposed rule would not have a 

significant economic impact on a 

substantial number of part 27 or part 29 

rotorcraft manufacturers or operators. 

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, establishing 

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 the 

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 has assessed 

the potential effect of this proposed rule 

and determined that it would impose 

the same costs on domestic and 

international entities and thus has a 

neutral trade impact. 

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 

(adjusted annually for inflation) in any 

1 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 threshold value of 

$141.3 million. This proposed rule does 

not contain such a mandate. 

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. 

Regulations Affecting Intrastate 

Aviation in Alaska 

Section 1205 of the FAA 

Reauthorization Act of 1996 (110 Stat. 

3213) requires the Administrator, when 

modifying regulations in Title 14 of the 

CFR in a manner affecting intrastate 

aviation in Alaska, to consider the 

extent to which Alaska is not served by 

transportation modes other than 

aviation, and to establish appropriate 

regulatory distinctions. Because this 

proposed rule would apply to the 

certification of future designs of 

rotorcraft and their subsequent 

operation, it could, if adopted, affect 

intrastate aviation in Alaska. The FAA, 

therefore, specifically requests 

comments on whether there is 

justification for applying the proposed 

rule differently in intrastate operations 

in Alaska. 

Environmental Analysis 

FAA Order 1050.1E identifies FAA 

actions that are categorically excluded 

from preparation of an environmental 

assessment or environmental impact 

statement under the National 

Environmental Policy Act in the 

absence of extraordinary circumstances. 

The FAA has determined this proposed 

rulemaking action qualifies for the 

categorical exclusion identified in 

paragraph 312f 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, 

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Federal Register / Vol. 75, No. 3 / Wednesday, January 6, 2010 / Proposed Rules 799 

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

have determined that it is not a 

‘‘significant regulatory action’’ under 

the executive order because it 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. 

Availability of Rulemaking Documents 

You can get an electronic copy of 

rulemaking documents 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.gpoaccess.gov/fr/index.html. 

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, notice 

number, or amendment 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. 

List of Subjects 

14 CFR Part 27 

Aircraft, Aviation safety. 

14 CFR Part 29 

Aircraft, Aviation safety. 

The Proposed Amendment 

In consideration of the foregoing, the 

Federal Aviation Administration 

proposes to amend parts 27 and 29 of 

Title 14, Code of Federal Regulations, as 

follows: 

PART 27—AIRWORTHINESS 

STANDARDS: NORMAL CATEGORY 

ROTORCRAFT 

1. The authority citation for part 27 

continues to read as follows: 

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

44702, 44704. 

2. Add a new § 27.573 to read as 

follows: 

§ 27.573 Damage Tolerance and Fatigue 

Evaluation of Composite Rotorcraft 

Structures. 

(a) Each applicant must evaluate the 

composite rotorcraft structure under the 

damage tolerance standards of 

paragraph (d) of this section unless the 

applicant establishes that a damage 

tolerance evaluation is impractical 

within the limits of geometry, 

inspectability, and good design practice. 

If an applicant establishes that it is 

impractical within the limits of 

geometry, inspectability, and good 

design practice, the applicant must do a 

fatigue evaluation in accordance with 

paragraph (e) of this section. 

(b) The compliance methodology of 

each applicant, and the results of that 

methodology, requires FAA approval. 

(c) Definitions: 

(1) Catastrophic failure is an event 

that could prevent continued safe flight 

and landing. 

(2) Principal Structural Elements 

(PSEs) are structural elements that 

contribute significantly to the carrying 

of flight or ground loads, the failure of 

which could result in catastrophic 

failure of the rotorcraft. 

(3) Threat Assessment is an 

assessment that specifies the locations, 

types, and sizes of damage, considering 

fatigue, environmental effects, intrinsic 

and discrete flaws, and impact or other 

accidental damage (including the 

discrete source of the accidental 

damage) that may occur during 

manufacture or operation. 

(d) Damage Tolerance Evaluation: 

(1) Each applicant must show that 

catastrophic failure due to static and 

fatigue loads, considering the intrinsic 

or discrete manufacturing defects or 

accidental damage, is avoided 

throughout the operational life or 

prescribed inspection intervals of the 

rotorcraft by performing damage 

tolerance evaluations of the strength of 

composite PSEs and other parts, detail 

design points, and fabrication 

techniques. Each applicant must 

account for the effects of material and 

process variability along with 

environmental conditions in the 

strength and fatigue evaluations. Each 

applicant must evaluate parts that 

include PSEs of the airframe, main and 

tail rotor drive systems, main and tail 

rotor blades and hubs, rotor controls, 

fixed and movable control surfaces, 

engine and transmission mountings, 

landing gear and other parts, detail 

design points, and fabrication 

techniques deemed critical by the FAA. 

Each damage tolerance evaluation must 

include: 

(i) The identification of all PSEs; 

(ii) In-flight and ground 

measurements for determining the loads 

or stresses for all PSEs for all critical 

conditions throughout the range of 

limits in § 27.309 (including altitude 

effects), except that maneuvering load 

factors need not exceed the maximum 

values expected in service; 

(iii) The loading spectra as severe as 

those expected in service based on loads 

or stresses determined under paragraph 

(d)(1)(ii) of this section, including 

external load operations, if applicable, 

and other operations including hightorque events; 

(iv) A threat assessment for all PSEs 

that specifies the locations, types, and 

sizes of damage, considering fatigue, 

environmental effects, intrinsic and 

discrete flaws, and impact or other 

accidental damage (including the 

discrete source of the accidental 

damage) that may occur during 

manufacture or operation; and 

(v) An assessment of the residual 

strength and fatigue characteristics of all 

PSEs that supports the replacement 

times and inspection intervals 

established under paragraph (d)(2) of 

this section. 

(2) Each applicant must establish 

replacement times, inspections, or other 

procedures for all PSEs to require the 

repair or replacement of damaged parts 

before a catastrophic failure. These 

replacement times, inspections, or other 

procedures must be included in the 

Airworthiness Limitations Section of 

the Instructions for Continued 

Airworthiness required by § 27.1529. 

(i) Replacement times for PSEs must 

be determined by tests, or by analysis 

supported by tests, and must show that 

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800 Federal Register / Vol. 75, No. 3 / Wednesday, January 6, 2010 / Proposed Rules 

the structure is able to withstand the 

repeated loads of variable magnitude 

expected in-service. In establishing 

these replacement times, the following 

items must be considered: 

(A) Damage identified in the threat 

assessment required by paragraph 

(d)(1)(iv) of this section; 

(B) Maximum acceptable 

manufacturing defects and in-service 

damage (i.e., those that do not lower the 

residual strength below ultimate design 

loads and those that can be repaired to 

restore ultimate strength); and 

(C) Ultimate load strength capability 

after applying repeated loads. 

(ii) Inspection intervals for PSEs must 

be established to reveal any damage 

identified in the threat assessment 

required by paragraph (d)(1)(iv) of this 

section that may occur from fatigue or 

other in-service causes before such 

damage has grown to the extent that the 

component cannot sustain the required 

residual strength capability. In 

establishing these inspection intervals, 

the following items must be considered: 

(A) The growth rate, including nogrowth, of the damage under the 

repeated loads expected in-service 

determined by tests or analysis 

supported by tests; 

(B) The required residual strength for 

the assumed damage established after 

considering the damage type, inspection 

interval, detectability of damage, and 

the techniques adopted for damage 

detection. The minimum required 

residual strength is limit load; and 

(C) Whether the inspection will detect 

the damage growth before the minimum 

residual strength is reached and restored 

to ultimate load capability, or whether 

the component will require 

replacement. 

(3) Each applicant must consider the 

effects of damage on stiffness, dynamic 

behavior, loads, and functional 

performance on all PSEs in establishing 

the allowable damage size and 

inspection interval. 

(e) Fatigue Evaluation: If an applicant 

establishes that the damage tolerance 

evaluation described in paragraph (d) of 

this section is impractical within the 

limits of geometry, inspectability, or 

good design practice, the applicant must 

do a fatigue evaluation of the particular 

composite rotorcraft structure and: 

(1) Identify all PSEs considered in the 

fatigue evaluation; 

(2) Identify the types of damage for all 

PSEs considered in the fatigue 

evaluation; 

(3) Establish supplemental procedures 

to minimize the risk of catastrophic 

failure associated with the damages 

identified in paragraph (e) of this 

section; and 

(4) Include these supplemental 

procedures in the Airworthiness 

Limitations section of the Instructions 

for Continued Airworthiness required 

by § 27.1529. 

Appendix A to Part 27 [Amended] 

3. Amend the second sentence of section 

A.27.4 of Appendix A to Part 27 by removing 

the phrase ‘‘approved under § 27.571’’ and 

adding the phrase ‘‘required for type 

certification’’ in its place. 

PART 29—AIRWORTHINESS 

STANDARDS: TRANSPORT 

CATEGORY ROTORCRAFT 

4. The authority citation for part 29 

continues to read as follows: 

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

44702, 44704. 

5. Add a new § 29.573 to read as 

follows: 

§ 29.573 Damage Tolerance and Fatigue 

Evaluation of Composite Rotorcraft 

Structures. 

(a) Each applicant must evaluate the 

composite rotorcraft structure under the 

damage tolerance standards of 

paragraphs (d) of this section unless the 

applicant establishes that a damage 

tolerance evaluation is impractical 

within the limits of geometry, 

inspectability, and good design practice. 

If an applicant establishes that it is 

impractical within the limits of 

geometry, inspectability, and good 

design practice, the applicant must do a 

fatigue evaluation in accordance with 

paragraph (e) of this section. 

(b) The compliance methodology of 

each applicant, and the results of that 

methodology, requires approval by the 

FAA. 

(c) Definitions: 

(1) Catastrophic failure is an event 

that could prevent continued safe flight 

and landing. 

(2) Principal Structural Elements 

(PSEs) are structural elements that 

contribute significantly to the carrying 

of flight or ground loads, the failure of 

which could result in catastrophic 

failure of the rotorcraft. 

(3) Threat Assessment is an 

assessment that specifies the locations, 

types, and sizes of damage, considering 

fatigue, environmental effects, intrinsic 

and discrete flaws, and impact or other 

accidental damage (including the 

discrete source of the accidental 

damage) that may occur during 

manufacture or operation. 

(d) Damage Tolerance Evaluation: 

(1) Each applicant must show that 

catastrophic failure due to static and 

fatigue loads, considering the intrinsic 

or discrete manufacturing defects or 

accidental damage, is avoided 

throughout the operational life or 

prescribed inspection intervals of the 

rotorcraft by performing damage 

tolerance evaluations of the strength of 

composite PSEs and other parts, detail 

design points, and fabrication 

techniques. Each applicant must 

account for the effects of material and 

process variability along with 

environmental conditions in the 

strength and fatigue evaluations. Each 

applicant must evaluate parts that 

include PSEs of the airframe, main and 

tail rotor drive systems, main and tail 

rotor blades and hubs, rotor controls, 

fixed and movable control surfaces, 

engine and transmission mountings, 

landing gear and other parts, detail 

design points, and fabrication 

techniques deemed critical by the FAA. 

Each damage tolerance evaluation must 

include: 

(i) The identification of all PSEs; 

(ii) In-flight and ground 

measurements for determining the loads 

or stresses for all PSEs for all critical 

conditions throughout the range of 

limits in § 29.309 (including altitude 

effects), except that maneuvering load 

factors need not exceed the maximum 

values expected in service; 

(iii) The loading spectra as severe as 

those expected in service based on loads 

or stresses determined under paragraph 

(d)(1)(ii) of this section, including 

external load operations, if applicable, 

and other operations including hightorque events; 

(iv) A threat assessment for all PSEs 

that specifies the locations, types, and 

sizes of damage, considering fatigue, 

environmental effects, intrinsic and 

discrete flaws, and impact or other 

accidental damage (including the 

discrete source of the accidental 

damage) that may occur during 

manufacture or operation; and 

(v) An assessment of the residual 

strength and fatigue characteristics of all 

PSEs that supports the replacement 

times and inspection intervals 

established under paragraph (d)(2) of 

this section. 

(2) Each applicant must establish 

replacement times, inspections, or other 

procedures for all PSEs to require the 

repair or replacement of damaged parts 

before a catastrophic failure. These 

replacement times, inspections, or other 

procedures must be included in the 

Airworthiness Limitations Section of 

the Instructions for Continued 

Airworthiness required by § 29.1529. 

(i) Replacement times for PSEs must 

be determined by tests, or by analysis 

supported by tests, and must show that 

the structure is able to withstand the 

repeated loads of variable magnitude 

expected in-service. In establishing 

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Federal Register / Vol. 75, No. 3 / Wednesday, January 6, 2010 / Proposed Rules 801 

these replacement times, the following 

items must be considered: 

(A) Damage identified in the threat 

assessment required by paragraph 

(d)(1)(iv) of this section; 

(B) Maximum acceptable 

manufacturing defects and in-service 

damage (i.e., those that do not lower the 

residual strength below ultimate design 

loads and those that can be repaired to 

restore ultimate strength); and 

(C) Ultimate load strength capability 

after applying repeated loads. 

(ii) Inspection intervals for PSEs must 

be established to reveal any damage 

identified in the threat assessment 

required by paragraph (d)(1)(iv) of this 

section that may occur from fatigue or 

other in-service causes before such 

damage has grown to the extent that the 

component cannot sustain the required 

residual strength capability. In 

establishing these inspection intervals, 

the following items must be considered: 

(A) The growth rate, including nogrowth, of the damage under the 

repeated loads expected in-service 

determined by tests or analysis 

supported by tests; 

(B) The required residual strength for 

the assumed damage established after 

considering the damage type, inspection 

interval, detectability of damage, and 

the techniques adopted for damage 

detection. The minimum required 

residual strength is limit load; and 

(C) Whether the inspection will detect 

the damage growth before the minimum 

residual strength is reached and restored 

to ultimate load capability, or whether 

the component will require 

replacement. 

(3) Each applicant must consider the 

effects of damage on stiffness, dynamic 

behavior, loads, and functional 

performance on all PSEs in establishing 

the allowable damage size and 

inspection interval. 

(e) Fatigue Evaluation: If an applicant 

establishes that the damage tolerance 

evaluation described in paragraph (d) of 

this section is impractical within the 

limits of geometry, inspectability, or 

good design practice, the applicant must 

do a fatigue evaluation of the particular 

composite rotorcraft structure and: 

(1) Identify all PSEs considered in the 

fatigue evaluation; 

(2) Identify the types of damage for all 

PSEs considered in the fatigue 

evaluation; 

(3) Establish supplemental procedures 

to minimize the risk of catastrophic 

failure associated with the damages 

identified in paragraph (e) of this 

section; and 

(4) Include these supplemental 

procedures in the Airworthiness 

Limitations section of the Instructions 

for Continued Airworthiness required 

by § 29.1529. 

Appendix A to Part 29 [Amended] 

6. Amend the second sentence of section 

A.29.4 of Appendix A to Part 29 by removing 

the phrase ‘‘approved under § 29.571’’ and 

adding the phrase ‘‘required for type 

certification’’ in its place. 

Issued in Washington, DC, on December 

18, 2009. 

K.C. Yanamura, 

Acting Director, Aircraft Certification Service. 

[FR Doc. E9–31381 Filed 1–5–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2009–0674; Directorate 

Identifier 2009–NE–25–AD] 

RIN 2120–AA64 

Airworthiness Directives; Rolls-Royce 

plc RB211–Trent 500, 700, and 800 

Series Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede an existing airworthiness 

directive (AD) for Rolls-Royce plc 

RB211–Trent 800 series turbofan 

engines. That AD currently requires 

replacing the fuel-to-oil heat exchanger 

(FOHE). This proposed AD would 

require replacing the FOHE on the 

RB211–Trent 500 and RB211–Trent 700 

series turbofan engines in addition to 

the RB211–Trent 800 series turbofan 

engines. This proposed AD results from 

mandatory continuing airworthiness 

information (MCAI) issued by an 

aviation authority of another country to 

identify and correct an unsafe condition 

on an aviation product, and results from 

the risk of engine FOHE blockage. The 

MCAI describes the unsafe condition as: 

In January 2008, a Boeing 777 powered by 

RB211–Trent 800 engines crashed short of 

the runway as a result of dual loss of engine 

response during the final stages of approach. 

The investigation of the incident has 

established that, under certain ambient 

conditions, ice can accumulate on the walls 

of the fuel pipes within the aircraft fuel 

system, which can then be released 

downstream when fuel flow demand is 

increased. This released ice can then collect 

on the FOHE front face and limit fuel flow 

through the FOHE. This type of icing event 

was previously unknown and creates ice 

concentrations into the fuel system beyond 

those specified in the certification 

requirements. 

In May 2009, an Engine Indicating and 

Crew Alerting System (EICAS) surge message 

was set following a successful go-around 

maneuver on a single RB211–Trent 700 

engine of an A330 aircraft. Subsequent 

analysis concluded the likely cause to be 

temporary ice accumulation causing fuel 

flow restriction in the FOHE. The incident 

has indicated the potential susceptibility to 

ice blockage for Airbus aircraft in 

combination with Rolls-Royce engines that 

feature similar fuel systems to the RB211– 

Trent 800. 

We are proposing this AD to prevent 

ice from blocking the FOHE, which 

could result in an unacceptable engine 

power loss and loss of control of the 

airplane. 

DATES: We must receive comments on 

this proposed AD by February 5, 2010. 

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. 

Contact Rolls-Royce plc, P.O. Box 31, 

DERBY, DE24 8BJ, UK; telephone 44 (0) 

1332 242424; fax 44 (0) 1332 249936, for 

the service information identified in this 

proposed AD. 

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: 

James Lawrence, Aerospace Engineer, 

Engine Certification Office, FAA, Engine 

and Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 

01803; e-mail: james.lawrence@faa.gov; 

telephone (781) 238–7176; fax (781) 

238–7199. 

SUPPLEMENTARY INFORMATION: 

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