Airworthiness Standards; Propellers, 18136-18148 [E7-6193]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 69 (Wednesday, April 11, 2007)]
[Proposed Rules]
[Pages 18136-18148]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-6193]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

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.

========================================================================


Federal Register / Vol. 72, No. 69 / Wednesday, April 11, 2007 / 
Proposed Rules

[[Page 18136]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 23, 25, 33, and 35

[Docket No. FAA 2007-27310; Notice No. 07-04]
RIN 2120-AI95


Airworthiness Standards; Propellers

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Federal Aviation Administration (FAA) is proposing to 
revise the airworthiness standards for the issuance of original and 
amended type certificates for airplane propellers. The existing 
propeller requirements do not adequately address the technological 
advances of the past twenty years. The proposed standards would address 
the current advances in technology and would harmonize FAA and European 
Aviation Safety Agency (EASA) propeller certification requirements, 
thereby simplifying airworthiness approvals for imports and exports.

DATES: Comments must be received on or before June 11, 2007.

ADDRESSES: You may send comments, identified by Docket No. FAA-2007-
27310, using any of the following methods:
    DOT Docket Web site: Got to https://dms.dot.gov and follow the 
instructions for sending your comments electronically.
    Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
    Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001
    Fax: 1-202-493-2251
    Hand Delivery: Room Pl-401 on the plaza level of the Nassif 
Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays.
    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 
https://dms.dot.gov, including any personal information that you 
provide. For more information, see the Privacy Act discussion in the 
SUPPLEMENTARY INFORMATION section of this document.
    Docket: To read background documents or comments received, go to 
https://dms.dot.gov at any time or to Room PL-401 on the plaza level of 
the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Jay Turnberg, Engine and Propeller 
Directorate Standards Staff, ANE-110, Federal Aviation Administration, 
12 New England Executive Park, Burlington, Massachusetts 01803-5299; 
telephone (781) 238-7116; facsimile (781) 238-7199, e-mail: 
jay.turnberg@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites interested persons to participate in rulemaking by 
submitting written data, views, or arguments on this proposed rule. We 
also invite comments relating to the environmental, energy, federalism, 
or economic impact that might result from adopting the proposals in 
this notice. The most helpful comments reference a specific portion of 
the proposal, explain the reason for any recommended change, and 
include supporting data. We ask that you send us two copies of written 
comments.
    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. The docket is available for public 
inspection before and after the comment closing date. If you wish to 
review the docket in person, go to the address in the ADDRESSES section 
of this preamble between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. You may also review the docket using the 
Internet at the web address in the ADDRESSES section.
    Privacy Act: 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 on behalf of 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 
https://dms.dot.gov.
    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 late if it is possible to do so without incurring 
expense or delay. We may change this proposal in light of the comments 
we receive.
    If you want the FAA to acknowledge receipt of your comments on this 
proposal, include with your comments a pre-addressed, stamped postcard 
on which the docket number appears. We will stamp the date on the 
postcard and mail it to you.

Availability of NPRMs

    You can get an electronic copy using the Internet by:
    1. Searching the Department of Transportation's electronic Docket 
Management System (DMS) Web page (https://dms.dot.gov/search);
    2. Visiting the FAA's Regulations and Policies Web page at https://
www.faa.gov/regulations_policies/; or
    3. Accessing the Government Printing Office's Web page at https://
www.gpoaccess.gov/fr/.
    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.

Background

    Advances in technology have meant that many propeller certification 
programs over the past decade have required repeated application of 
special conditions or special tests. In addition, the need to 
demonstrate compliance with both FAA and EASA requirements has placed 
additional burdens on propeller manufacturers who require

[[Page 18137]]

foreign certification. Therefore, we concluded that part 35 should be 
substantially revised.
    In 1994, the FAA began an initiative to harmonize FAA propeller 
certification requirements with Europe's Joint Aviation Authorities 
(JAA) regulations (now the EASA certification specifications). As part 
of this effort, the FAA tasked the Aviation Rulemaking Advisory 
Committee through its Engine Harmonization Working Group (EHWG) to 
compare part 35 with JAA requirements, and identify differences. The 
EHWG was also to update existing requirements to reflect advancements 
in propeller design, including design and construction of composite 
material propellers, propeller control systems (such as dual acting 
control systems), and electronic controls for propellers.
    To complete this task, the EHWG established the Propeller 
Harmonization Working Group, with members from industry and government 
from Canada, France, Germany, United Kingdom, and the United States. 
The Propeller Harmonization Working Group focused on requirement 
differences between part 35 and Joint Aviation Requirements--Propellers 
(JAR-P) in six areas:
    1. Those in part 35, but not in JAR-P;
    2. Those in both part 35 and JAR-P, but not accepted as equivalent 
for both;
    3. Those accepted as equivalent for both part 35 and JAR-P;
    4. Those in which intent is not clear;
    5. Those that may be simplified or deleted; and
    6. Those that are new requirements not in either part 35 or JAR-P.
    This NPRM proposes to harmonize FAA part 35 propeller certification 
requirements with most of the requirements of EASA's Certification 
Specifications for Propellers (CS-P).

Reference Material

    We relied on the following material as a basis for this proposed 
rule:
    1. Special Conditions No. 35-ANE-01, Hamilton Standard Model 247F 
Propeller, Docket No. 94-ANE-50.
    2. Special Conditions No. 35-ANE-02, Hamilton Standard Model 568F 
Propeller, Docket No. 94-ANE-60.
    3. Special Conditions No. 35-ANE-03, Hamilton Standard Model 568F 
Propeller, Docket No. 94-ANE-61.
    4. Special Conditions SC-92-03-NE, Hartzell Propeller, Inc. Model 
HD-E6C-3( )/E13482K Dual Acting Propeller, Docket No. 92-ANE-47.
    5. Joint Airworthiness Requirements--Propellers, JAR-P, Change 7, 
October 22, 1987.
    6. Certification Specifications for Propellers (CS-P), Decision No. 
2003/7/RM, October 24, 2003.
    7. 14 CFR Part 21, Certification Procedures for Products and Parts.
    8. 14 CFR Part 23, Airworthiness Standards: Normal, Utility, 
Acrobatic, and Commuter Category Airplanes.
    9. 14 CFR Part 25, Airworthiness Standards: Transport Category 
Airplanes.
    10. 14 CFR Part 33, Airworthiness Standards: Engines.
    11. 14 CFR Part 35, Airworthiness Standards: Propellers.

Section-by-Section Discussion of the Proposals

Sections 23.905 and 25.905 Propellers and Section 33.19 Durability

    We propose requiring that propeller controls that are certified as 
part of the airplane or engine type design meet the same requirements 
as propeller controls that are certified as part of the propeller type 
design.

Sections 23.907 and 25.907 Propeller Vibration and Fatigue

    We propose revising Sec. Sec.  23.907 and 25.907 to make them 
identical, and changing the titles of both sections from ``Propeller 
vibration'' to ``Propeller vibration and fatigue,'' to reflect the 
revised requirements.
    These sections require that a propeller demonstrate safe vibration 
compatibility with the airplane; they harmonize with CS-P 530, 
Vibration and Aeroelastic Effects and CS-P 550, Fatigue Evaluation. The 
vibration evaluation of a propeller on an airplane involves both 
vibration and fatigue requirements. The vibration evaluation of the 
propeller depends on the airplane and engine installation; the proposed 
requirements would show this dependency.
    The current requirements differ for part 23 and 25 airplanes and 
fail to address important areas. They do not address fatigue evaluation 
or require comparison to the fatigue limits and other structural data 
established in part 35. They do not require a revision of the propeller 
operating and airworthiness limitations, and they fail to address the 
flutter requirements of EASA's Certification Specifications for 
Propellers (CS-P). In the case of Sec.  23.907, they permit the use of 
service experience to show compliance, which is an unsatisfactory 
method to show the safety of the installation.
    Our proposed new paragraph (a) for Sec. Sec.  23.907 and 25.907 
would require that applicants determine the stresses throughout the 
declared operational envelope of the airplane. It would permit 
applicants to determine stresses by analysis based on direct testing or 
by interpolation and measured data extrapolation if testing the entire 
airplane operational envelope is not feasible. The paragraph would also 
permit the determination of stress by comparison with a similar 
airplane for which these measurements were made. Our proposed 
paragraph, however, would not permit the use of service experience to 
determine stresses.
    Proposed paragraph (a) harmonizes with CS-P 530(b) by requiring 
that applicants investigate stress peaks or resonant conditions.
    Proposed paragraph (b) harmonizes with CS-P 530(a) by requiring 
that applicants address flutter.
    Proposed paragraph (c) would harmonize with CS-P 550 by requiring 
that applicants conduct a fatigue evaluation on the propeller. It would 
also harmonize with CS-P 550 by requiring that applicants revise the 
airplane and propeller operating and airworthiness limitations sections 
as needed to show compliance with the fatigue requirements.
    Prior to the propeller vibration and fatigue evaluation for the 
airplane installation, the propeller undergoes a substantial amount of 
structural evaluation during its certification to show compliance with 
part 35. Proposed paragraph (c) would require that the data obtained 
from the part 35 evaluation be used in the propeller fatigue 
evaluation.

Section 25.901 Installation

    We propose to add a reference in this section to the propeller 
installation instructions in Sec.  35.3 to ensure that part 25 airplane 
comply with the installation instructions for the propeller.

Part 35--Airworthiness Standards: Propellers

    We propose to renumber certain part 35 regulations to harmonize 
part 35 with EASA's CS-P. Part 35 designation will differ from the CS-P 
designation by a zero added to the CS-P designation. For example, our 
proposed Sec.  35.35 Centrifugal load tests will be equivalent to the 
CS-P 350 Centrifugal Load Tests.

Subpart A--General

    This subpart addresses the requirements for issuing propeller type 
certificates and changes to those type certificates. Our proposed 
revisions clarify the propeller configuration to be certificated; list 
the requirements for installing and operating the propeller; and 
specify ratings and operating limitations.

[[Page 18138]]

Section 35.1 Applicability

    We propose adding a new paragraph (c) to establish the relationship 
between propeller and airplane certification.
    We propose adding a paragraph (d) to refine the propeller 
definition for this part. Paragraph (d) would define a propeller and 
propeller system consistent with how those terms are used in part 35.

Section 35.2 Propeller Configuration and Identification

    We propose a new Sec.  35.2(a) that would require the applicant to 
provide a list of all the components and parts, including references to 
the relevant drawings and software design data, that defines the type 
design of the propeller the applicant wants approved. This requirement 
would improve the documentation regarding the propeller components that 
is included within the propeller type design.
    We propose a new Sec.  35.2(b) that would reinforce the link 
between parts 35 and 45 and harmonize with the CS-P.

Section 35.3 Instructions for Propeller Installation and Operation

    We propose to revise Sec.  35.3 to require specific content in 
propeller installation and operation instructions. The revision would 
require applicants to prepare installation instructions containing the 
data required by the airplane manufacturer to install and operate the 
propeller within the limitations of the propeller type design.
    The proposed revision would rename Sec.  35.3 to ``Instructions for 
propeller installation and operation'' to reflect the revised 
requirements.

Section 35.5 Propeller Ratings and Operating Limitations

    We propose revising Sec.  35.5 by modifying the requirements about 
establishing ratings and operating limitations. In our proposed 
paragraph (a), the applicant would establish the ratings and operating 
limitations, which would be subject to approval by the Administrator. 
This change reflects the process used now to establish the propeller 
limitations and ratings.
    We propose adding paragraph (b), which lists specific ratings and 
limits applicants must address. The list would include ratings for 
takeoff power and rotational speed, maximum continuous power and 
rotational speed. The proposed paragraph would also document transient 
overspeed and overtorque limits that would not require maintenance. The 
overspeed and overtorque limits are intended for inadvertent or 
maintenance use.
    Our proposed list in paragraph (b) does not represent all the 
ratings and operating limits that may be required for safe propeller 
operation. Paragraph (a) would state that the ratings and operating 
limitations must include limitations based on the operating conditions 
demonstrated during the tests required by this part and any other 
information necessary for safe propeller operation.
    We propose changing the title of Sec.  35.5 to ``Propeller ratings 
and operating limitations'' to reflect the revised requirements and to 
harmonize with CS-P 50, Propeller Ratings and Operating Limitations.

Section 35.7 Features and Characteristics

    We propose a new Sec.  35.7 that will incorporate requirements 
formerly in Sec.  35.15, Design features.
    The proposed Sec.  35.7(a) requires that a propeller not have any 
features or characteristics that make it unsafe for the purposes for 
which it is being certified.
    The proposed Sec.  35.7(b) indicates the applicant's 
responsibilities if a failure occurs during a certification test.

Subpart B--Design and Construction

    Part 35 subpart B addresses design and construction requirements 
for propellers. This proposed revision would maintain the intent of the 
current subpart. We propose, however, to remove sections that are 
redundant or no longer applicable and to revise or add sections that 
address existing and future design and construction technology not 
adequately covered by the current requirements.

Section 35.11 Applicability

    Section 35.11 is a descriptive statement about subpart B compliance 
that is fully addressed within Sec.  35.1. Therefore, we propose to 
remove Sec.  35.11 and mark the section ``reserved.''

Section 35.13 General

    Section 35.13 is a descriptive statement about subpart B compliance 
that is fully addressed within Sec.  35.1. Therefore, we propose to 
remove Sec.  35.13 and mark the section ``reserved.''

Section 35.15 Safety Analysis

    We propose to revise Sec.  35.15, Design features, and rename it 
``Safety analysis'' to reflect its revised requirements.
    Our proposed revision would require that applicants conduct a 
safety analysis of the propeller. Safety analysis has been used to show 
compliance with the current requirement for the majority of new 
propeller certification programs during the past decade. The ultimate 
objective of the safety analysis is to ensure that the collective risk 
from all propeller failure conditions is acceptably low. The basis of 
safety analysis is the concept that an acceptable total propeller 
design risk is achievable by managing individual risks to acceptable 
levels. This concept emphasizes reducing the risk of an event 
proportionally with the severity of the hazard it represents.
    Our proposed revision would add definitions for hazardous and major 
propeller effects, based on CS-P, historical JAR-P requirements, and 
the propeller special conditions listed under ``Reference Material.'' 
These definitions would be used throughout part 35 and would only apply 
to this part.
    Showing compliance with the requirements of this section would not 
mean that a propeller is suitable for use on all or any airplane. For 
example, a part 25 airplane may require different failure effects and 
probabilities of failure than a part 23 airplane would.

Section 35.17 Materials and Manufacturing Methods

    We propose to revise and rename this section from ``Materials'' to 
``Materials and manufacturing methods'' to reflect the revised 
requirements. Our proposed revision would require that the materials 
specifications and manufacturing methods used by applicants be 
acceptable to the FAA. The revision would remove the list of examples 
of approved specifications and change the word ``approved'' to 
``acceptable.'' This change would reflect the level of review of the 
specifications by the FAA.
    Our proposed revision would also require that applicants consider 
the effects of environmental conditions expected in service when 
assessing material suitability and durability. We are including 
consideration for environmental effects in this proposed section 
because many materials used in the propeller design depend on the 
environment in which the propeller operates. This is especially 
relevant for composite materials that have age-dependent properties, as 
well as properties affected by humidity and temperature.
    Our proposed revision would also harmonize with CS-P requirements 
by requiring that applicants use the most adverse properties stated in 
the accepted specifications of their design values. This clarification 
would prevent misinterpretations regarding the

[[Page 18139]]

application of material properties to the propeller design.

Section 35.21 Variable and Reversible Pitch Propellers

    We propose to revise and rename this section to from ``Reversible 
propellers'' to ``Variable and reversible pitch propellers'' to reflect 
the revised requirements. The revision would incorporate the current 
pitch control and indication requirements of Sec.  35.23(c). It would 
also expand the current Sec.  35.23(c) requirement to include all 
airplane installations with reversible propellers, including 
reciprocating engine aircraft, because the flight safety aspect of this 
rule applies regardless of engine type. Proposed Sec.  35.21 harmonizes 
with CS-P 210, Variable and Reversible Pitch Propellers.

Section 35.22 Feathering Propellers

    We propose a new Sec.  35.22 that will incorporate requirements for 
feathering propellers currently located in Sec.  35.23(b) and in CS-P 
220, ``Feathering Propellers.'' We would incorporate the requirements 
of CS-P 220(a) into paragraph (a), which would require feathering 
propellers be designed to feather from all conditions in flight, taking 
into account expected wear and leakage. It would also require that 
applicants document the feathering characteristics and limitations in 
the appropriate manuals.
    We would move the feathering requirements of the current Sec.  
35.23(b) to the new Sec.  35.22(b).
    We propose that the requirements of CS-P 220(c) be incorporated 
into paragraph (c). This paragraph would require the applicant to 
design the propeller to be capable of unfeathering at the minimum 
declared outside air temperature after stabilization to a steady-state 
temperature.

Section 35.23 Propeller Control System

    We propose to revise and rename Sec.  35.23 from ``Pitch control 
and indication'' to ``Propeller control system'' to reflect the revised 
requirements and to harmonize with CS-P 230. We would retain and revise 
current paragraph (a), redesignate and revise current paragraph (c) as 
Sec.  35.21(b), redesignate and revise current paragraph (b) as Sec.  
35.22(b), and add several new paragraphs.
    Our proposed Sec.  35.23 would address propeller control design 
requirements concerning loss of normal control that may cause hazardous 
overspeeding and an alternative means to override or bypass the engine 
oil system for propellers that use engine oil to feather. It would also 
add requirements that address control system description, design, 
construction, validation, and software design, for all types of 
propeller mechanical, hydraulic, and electronic control systems.
    Our proposed Sec.  35.23(a)(1) would ensure that the control 
system, operating in normal and alternative modes and transitions 
between operating modes, performs the intended functions throughout the 
declared operating conditions and flight envelope. This requirement 
does not mandate flight test on an airplane. Substantiation by 
propeller tests, rig tests, airplane tests, analysis or a combination 
of these would be acceptable.
    Our proposed Sec.  35.23(a)(2) would ensure that the control system 
functionality is not adversely affected by declared environmental 
conditions.
    Our proposed Sec.  35.23(a)(3) would ensure that applicants provide 
methods to indicate to the flight crew, if crew action is required, 
that a mode change has occurred.
    Our proposed Sec.  35.23(b) would add system safety requirements in 
addition to those in Sec.  35.15. Paragraph (b)(1) would require that 
no single failure or malfunction of electronic or electrical components 
result in a hazardous propeller effect. Paragraph (b)(2) would address 
the relationship between failures of the linkages from the airplane to 
the propeller control, and the effects that airplane fires and 
overheating have on the propeller control. Paragraph (b)(3) would adopt 
the requirements of the current Sec.  35.23(a). Paragraph (b)(4) would 
address the effect of isolation between propellers on an airplane.
    Our proposed Sec.  35.23(c) would add a requirement that all 
software be designed and implemented by a method approved by the FAA. 
It would require that the software design be consistent with the 
criticality of the performed functions to minimize the existence of 
software errors.
    Our proposed Sec.  35.23(d) would add requirements for airplane-
supplied data so that no single failure or malfunction of airplane-
supplied data would result in a hazardous propeller effect.
    Our proposed Sec.  35.23(e) would add requirements for airplane-
supplied electrical power so that abnormalities of the power supply 
would not result in hazardous effects and would not require a 
declaration of the validated power supply characteristics.

Section 35.24 Strength

    We propose adding a new Sec.  35.24 to establish strength 
requirements for propellers consistent with those required by CS-P 240.

Subpart C--Type Substantiation

    We propose to remove those regulations in this subpart that are 
redundant or no longer apply and to modify and add sections to reflect 
existing industry practices. We also propose to change the subpart 
heading from ``Tests and Inspections'' to ``Type Substantiation,'' 
since subpart C applies to both testing and analysis.

Section 35.31 Applicability

    We propose to remove the content of Sec.  35.31 and to mark the 
section ``reserved'' since Sec.  35.31 is a descriptive statement about 
subpart C and not a requirement.

Section 35.33 General

    Section 35.33(a) does not adequately address part 21 certification 
requirements. We propose, therefore, to revise Sec.  35.33(a) to 
identify that the testing conducted in this subpart is also governed by 
the test requirements established in part 21.
    We propose a new Sec.  35.33(b) and (c) to harmonize with CS-P 
330(b), which requires that automatic controls operate during tests. 
Our proposed Sec.  35.33(b) would adopt this requirement and add that 
it also applies to propeller safety systems. Also, our proposed Sec.  
35.33(b) clarifies the conditions under which some tests may be 
conducted without the automatic controls or safety systems. For 
example, the applicant may have to disable a primary system to test a 
backup system.
    CS-P 440 requires that applicants address potential safety issues 
that may occur if required testing does not adequately test a component 
during propeller certification. Our proposed Sec.  35.33(c) would adopt 
this requirement.

Section 35.34 Inspections, Adjustments, and Repairs

    We propose a new Sec.  35.34 which would revise and incorporate 
inspection requirements from Sec.  35.45 and the adjustment and repairs 
requirements from Sec.  35.47.
    We propose a new Sec.  35.34(a) to harmonize with CS-P340 
requirements for pre-test inspections. Our proposal moves the post-test 
inspection requirements of the existing Sec.  35.45, Teardown 
inspection, and consolidates them here. Pre-test inspection establishes 
the condition of the test article prior to testing. This is 
particularly important for composite structures in which damage may be 
internal and not visible. If internal damage is present prior to the 
start of

[[Page 18140]]

the test, then the post-test inspection may not be valid without 
knowledge of the pre-test condition of the test article.
    Our proposal also would relocate the existing requirements of Sec.  
35.47 to a new Sec.  35.34(b), since the requirements in Sec.  35.47 
are related to testing.

Section 35.35 Centrifugal Load Tests

    We propose revising Sec.  35.35 and renaming it as ``Centrifugal 
load tests'' to reflect the revised requirements.
    Our proposal would define requirements for the entire propeller and 
include consideration of material degradation expected in service. 
Material degradation considerations apply to all types of construction, 
but would be specifically added to address composite materials, which 
may absorb moisture or show some evidence of delamination prior to 
retirement from service.
    We propose a Sec.  35.35(a) that would require the hub, blade 
retention, and counterweights be tested to twice the centrifugal load 
for one hour. This test is designed to assure a suitable static 
strength margin above the maximum rated rotational speed.
    Our proposed Sec.  35.35(b) would require the transition in a 
composite blade from the composite material to the metallic retention 
be tested to twice the centrifugal load for one hour. This requirement 
would also apply to other types of construction in which a blade to 
retention transition occurs.
    Our proposed Sec.  35.35(c) would harmonize with CS-P 350 by 
requiring that lower energy debris for the entire propeller be 
evaluated at 159 percent of the maximum centrifugal load. The low 
energy debris would include spinners, de-icing equipment, blade erosion 
shields, and other assemblies used with or attached to the propeller.

Section 35.36 Bird Impact

    We propose adding a new Sec.  35.36 to part 35 to address bird 
impact with the propeller. Our proposed Sec.  35.36 incorporates the 
use of special conditions for propellers with composite blades and 
would extend the bird impact certification requirement to all propeller 
designs, except fixed-pitch wood propellers of conventional design. 
Section 35.36 would exclude conventional fixed-pitch wood propellers 
because of their satisfactory experience. The new requirement would 
apply to metallic blades but would allow compliance by experience from 
similar designs.
    Industry recognized the need for bird impact requirements when 
composite blades were introduced in the 1970s. The safety issues have 
been addressed by special tests and special conditions for composite 
blade certifications. These special conditions were unique for each 
propeller and effectively stated that the propeller must withstand a 4-
pound bird impact without contributing to a major or hazardous 
propeller effect. The special tests and special conditions have been 
effective for over 50 million flight hours, and no accidents have been 
attributed to bird impact against composite propellers. The selection 
of a 4-pound bird is based on the extensive service history of blades 
that have been designed using the 4-pound bird criteria.

Section 35.37 Fatigue Limits and Evaluation

    We propose to rename Sec.  35.37 from ``Fatigue limit tests'' to 
``Fatigue limits and evaluation'' and revise it to harmonize with CS-P 
370, Fatigue Characteristics. The current requirement does not 
adequately address composite materials and is limited to hubs, blades, 
and primary load-carrying metal components of nonmetallic blades. Our 
proposed Sec.  35.37 would expand the requirement to all materials and 
components (including controls system components, if applicable) whose 
failure would cause a hazardous propeller effect and also include 
environmental effects. It would retain the fatigue evaluation 
requirement in paragraph (b), but would require that the fatigue 
evaluation be conducted on the intended airplane in accordance with 
Sec. Sec.  23.907 or 25.907 or on a typical airplane. Applicants may 
configure a typical airplane to develop design criteria for the 
propeller in those instances when the intended airplane installation is 
either unavailable or unknown at propeller type certification.

Section 35.38 Lightning Strike

    We propose a new Sec.  35.38, Lightning strike, to harmonize with 
CS-P 380, Lightning Strike. Part 35 currently has no lightning strike 
requirements. Our proposed Sec.  35.38 requires that composite 
propellers withstand a lightning strike without contributing to a major 
or hazardous propeller effect. It also reflects current practices in 
the industry and the special tests and special conditions we issued for 
lightning strikes when composite blades were first introduced.
    Our new Sec.  35.38 would exclude conventional fixed-pitch wood 
propellers because of their satisfactory experience. This new 
requirement would apply to metallic blades but allow compliance by 
experience from similar designs.

Section 35.39 Endurance Test

    We propose to revise Sec.  35.39 to harmonize with CS-P 390. We 
would remove the existing 10-hour endurance block test from this 
section because testing one propeller at the greatest pitch and 
diameter for 10 hours is not adequate for a family of propellers. All 
current fixed-pitch propellers are being tested in accordance with the 
current 50-hour test requirement, which provides an adequate test.
    The proposed revision would delete the requirement to test a 
propeller of the greatest diameter for which certification is 
requested. We are introducing this change because testing of the 
greatest diameter is restrictive and does not necessarily result in an 
increase in airworthiness.

Section 35.40 Functional Test

    We propose to redesignate the current Sec.  35.41 as Sec.  35.40 to 
harmonize with CS-P 400, Functional Test.

Section 35.41 Overspeed and Overtorque

    We propose a new overspeed and overtorque requirement to harmonize 
with CS-P 410(a). We will rename Sec.  35.41 ``Overspeed and 
overtorque'' to reflect the revised requirements. Our proposal would 
require that applicants verify the declared transient overspeed and 
overtorque limits of the propeller.

Section 35.42 Components of the Propeller Control System

    We propose to combine the current Sec.  35.42(a) and (b) into a 
single paragraph and rename Sec.  35.42 as ``Components of the 
propeller control system'' to reflect the revised requirements. We 
would expand the 1000-hour operation requirement to the initially 
declared inspection interval or to a minimum of 1000 hours.

Section 35.43 Propeller Hydraulic Components

    We propose to revise the current Sec.  35.43, Special tests, and 
rename it as ``Propeller hydraulic components'' to reflect the revised 
requirements. Our revision would delete the duplication common between 
Sec.  35.43 and Sec.  21.16 and would harmonize with CS-P 430.
    The Propeller Harmonization Working Group determined that it is in 
the best interest of the public to require special conditions be issued 
and made available to the public when testing is required for 
unconventional features of design, material, or construction. We are, 
therefore, proposing to remove the special tests requirement of Sec.  
35.43.
    Our proposed Sec.  35.43 would add requirements for testing 
propeller

[[Page 18141]]

components that contain hydraulic pressure. These tests have been 
previously required by special condition or special tests under the 
current Sec.  35.43. This proposal adopts the test procedures that are 
being conducted on applicable components.

Section 35.45 Reserved

    We propose to revise Sec.  35.45 by moving the teardown inspection 
requirements to Sec.  35.34, as noted above, and to mark Sec.  35.45 
``reserved.''

Section 35.47 Propeller Adjustments and Parts Replacements

    We propose to revise Sec.  35.47 by moving the propeller adjustment 
and repair requirements to Sec.  35.34, as noted above, and to mark 
Sec.  35.47 ``Reserved.''

Rulemaking Analyses and Notices

Authority for This Rulemaking

    Title 49 of the U.S. Code specifies the FAA's authority to issue 
rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce, including minimum safety 
standards for aircraft engines. This proposed rule is within the scope 
of that authority because it updates the existing regulations for 
airplane propellers.

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 that there 
are no current 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. The FAA has 
reviewed the corresponding ICAO Standards and Recommended Practices and 
has identified no differences with these proposed regulations.

Economic Assessment, Regulatory Flexibility Determination, 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 (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 also requires agencies to consider 
international standards and, where appropriate, to be the basis of U.S. 
standards. Fourth, the Unfunded Mandate 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.
    The Department of Transportation Order DOT 2100.5 prescribes 
policies and procedures for simplification, analysis, and review of 
regulations. If the expected cost impact is so minimal that a proposal 
does not warrant a full evaluation, this order permits a statement to 
that effect. The basis for the minimal impact must be included in the 
preamble, if a full regulatory evaluation of the cost and benefits is 
not prepared. Such a determination has been made for this rule. The 
reasoning for that determination follows.
    To a great extent this proposed rule would require propeller 
manufacturers to certificate future production propellers for sale in 
the United States to the same European standards that these firms 
already meet. The European Aviation Safety Agency, the European 
equivalent to the FAA, became responsible for certification of 
aircraft, engines, parts and appliances on September 28, 2003 by 
Commission Regulation (EC) 1702/2003. Because the U.S. and European 
effort to have common certification propeller regulations was almost 
completed when EASA became operational, the proposed part 35 and the 
European propeller requirements CS-P are almost identical. CS-P is now 
an official rule of a foreign regulatory agency while this is a 
proposed rule. To export propellers to Europe, U.S. manufacturers now 
must meet the European requirements. Before Europe made these 
requirements, industry provided us with a cost estimate of $31 million 
over a 25-year analysis period for them to be in compliance with the 
FAA proposed propeller requirements which would have codified existing 
special tests and conditions. But as manufacturers are already in 
compliance with these now harmonized proposed requirements, there are 
no additional compliance costs.
    This proposed rule has only one regulation stricter than EASA's CS-
P. The FAA proposes to extend the current special condition 4-pound 
bird strike test for composite propeller blades. CS-P requires newly 
certificated propellers to withstand a 4-pound bird strike for 
equivalent part 25 airplanes. However, CS-P requires newly certificated 
propellers to withstand a 2.8-pound bird strike for equivalent part 23 
commuter airplanes and does not require a bird strike test for other 
equivalent part 23 airplanes. U. S. propeller manufacturers provided us 
with their estimated costs to meet the proposed 4-pound requirement. 
Over a 25-year analysis period (based on the operational life of a 
propeller) we estimate the total cost for 635 future propellers to be 
$458,000 or $213,000 in present value (7 percent discount rate). The 
FAA considers this cost to be minimal.
    The benefits from this higher bird-strike requirement are an 
expected continuity of over fifty million flight hours with no 
accidents attributed to bird impacts against composite propellers 
despite many bird strikes. Between 1990 and 2004, there have been over 
150 bird strikes to part 23 propellers (see the FAA National Wildlife 
Strike Database, Version 6.0, February 26, 2005; available online at 
https://wildlife.pr.erau.edu/public/index1.html).
    We, therefore, have determined that this rulemaking action 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. In addition, the FAA has determined 
that this rulemaking action: (1) Would not have a significant economic 
impact on a substantial number of small entities; (2) would be in 
compliance with the Trade Agreements Act; and (3) would not impose an 
unfunded mandate on state,

[[Page 18142]]

local, or tribal governments, or on the private sector.

Regulatory Flexibility Determination

A. Introduction

    The Regulatory Flexibility Act of 1980 (RFA) establishes ``* * * as 
a principle of 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 achieve 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 would have a ``significant economic impact on a substantial 
number of small entities.'' If the determination is that it will, the 
agency must prepare a regulatory flexibility analysis as described in 
the RFA.
    However, 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.
    The purpose of this Initial Regulatory Flexibility Analysis (IRFA) 
is to ensure that the agency has considered all reasonable regulatory 
alternatives that would minimize the proposal's economic burdens for 
affected small entities, while achieving its safety objectives.
    Under Section 603 of the RFA, the analysis must address:
     Description of reasons the agency is considering the 
action.
     Statement of the legal basis and objectives for the 
proposal.
     Description of the recordkeeping and other compliance 
requirements of the proposal.
     All federal rules that may duplicate, overlap, or conflict 
with the proposal.
     Description and an estimated number of small entities to 
which the proposal would apply.
     Analysis of small firms' ability to afford the proposal.
     Conduct a competitive analysis.
     Estimation of the potential for business closures.
     Describe the alternatives considered.
     Conduct a disproportionality analysis.

B. Reasons for This Proposal

    The FAA proposes to revise the airworthiness standards for the 
issuance of original and amended type certificates for airplane 
propellers. The existing propeller requirements do not adequately 
address the technological advances of the past 20 years. The proposed 
standards would address the current advances in technology and would 
harmonize the FAA requirements with the existing requirements of 
Certification Specifications for Propellers of the EASA. This proposal 
would establish nearly uniform standards for aircraft propellers 
certified by the United States under FAA standards and by European 
countries under EASA standards, thereby simplifying airworthiness 
approvals for import and export products.

C. Statement of the Legal Basis and Objectives

    Under Title 49 of the U. S. Code, the FAA Administrator is required 
to consider the following matters, among others, as being in the public 
interest: Assigning, maintaining, and enhancing safety and security as 
the highest priorities in air commerce. (See 49 U.S.C. 40101(d)(1).). 
Additionally, it is the FAA Administrator's statutory duty to carry out 
his or her responsibilities ``in a way that best tends to reduce or 
eliminate the possibility or recurrence of accidents in air 
transportation.'' (See 49 U.S.C. 44701(c).)
    Accordingly, this proposal would amend Title 14 of the Code of 
Federal Regulations to update the propeller certification requirements 
to reflect technological changes in the last 10 to 20 years, reduce the 
need for and use of special tests and conditions for propeller 
certification, and to harmonize U.S. propeller certification 
requirements with European propeller certification requirements.

D. Projected Reporting, Recordkeeping and Other Requirements

    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 that there 
are no current new information collection requirements associated with 
this proposed rule.

E. Overlapping, Duplicative, or Conflicting Federal Rules

    The FAA is unaware that the proposal would overlap, duplicate, or 
conflict with existing Federal Rules.

F. Estimated Number of Small Firms Potentially Impacted

    Under the RFA, the FAA must determine whether or not a proposal 
significantly affects a substantial number of small entities. This 
determination is typically based on small entity size and cost 
thresholds that vary depending on the affected industry. The Small 
Business Administration (SBA) uses the NAICS (North American Industry 
Classification System) 2002 to determine size standards for small 
businesses. There is no entry in the NAICS 2002 for propeller 
manufacturers. However, the NAICS 2002 does list under Sectors 31-33, 
Manufacturing, Subsector 336, Transportation Equipment Manufacturing, 
which in turn lists the following numbers and number of employees as 
shown in the following table:

------------------------------------------------------------------------
                                                              Number of
           NAICS 2002 No.                  Description        employees
------------------------------------------------------------------------
336411.............................  Aircraft Manufacturing        1,500
336412.............................  Aircraft Engine and           1,000
                                      Engine Parts
                                      Manufacturing.
336413.............................  Other Aircraft Part           1,000
                                      and Auxiliary
                                      Equipment
                                      Manufacturing.
------------------------------------------------------------------------

    Propeller manufacturing could be included in 336412, 
Aircraft Engine and Aircraft Parts Manufacturing; or 336413, 
Other Aircraft Parts and Auxiliary Equipment Manufacturing. Both these 
categories use 1,000 employees to define a small business. Therefore, 
the FAA defines a small business in the variable pitch propeller 
manufacturing industry as a business with 1,000 or less employees. In 
accordance with SBA usage, this number applies to the ultimate 
ownership of the company.
    In 2004, the American airplane variable pitch propeller industry 
consisted of three firms. These firms were Hamilton Sundstrand, 
Hartzell, and McCauley. Hamilton Sundstrand is a subsidiary of United 
Technologies that employed approximately 210,000 people and had annual 
revenues of approximately $37 billion in 2004.\1\

[[Page 18143]]

McCauley Propeller Systems is owned by Cessna, which, in turn, is owned 
by Textron, Inc. Textron employed some 44,000 people and had annual 
revenues of some $10 billion in 2004.\2\ Hartzell Propeller, Inc. 
employed 295 employees in 2003 and had annual revenues between $20 and 
$50 million in 2002.\3\
---------------------------------------------------------------------------

    \1\ --, United Technologies Corporation--Our Profile, https://
www.utc.com/profile/profile/index.htm, 08/26/2005.
    \2\ www.textron.com/about/company/index.jsp (Accessed 08/26/
2005).
    \3\ --, Reference USA, Version 2003.1, https://
www.referenceusa.com/bd/
detail.asp?si=97350308854484&abinumber=402250104&t..., 11/25/02.
---------------------------------------------------------------------------

    Using the above criteria, Hartzell is a small business and Hamilton 
Sundstrand and McCauley are not small businesses. Because only one 
company is a small business, this proposal would not affect a 
substantial number of small entities.

G. Cost and Affordability for Small Entities

    The 25 year present value estimate of the costs of the proposal is 
$213,000 or $18,000 annually. Assuming that this cost is distributed 
evenly across the three firms in the American propeller industry, this 
results in a cost of $6,000 per company per year.
    Hartzell Propeller does not release its annual financial 
statements. The reference source ``Reference, USA, 2003,'' uses a model 
to estimate the annual revenues of privately held firms that do not 
release their financial statements. Therefore, this source provides a 
range estimate of firms such as Hartzell. The annual revenue of 
Hartzell Propellers was estimated to be between $20 and $50 million 
annually, or an average of $37.5 million, by ``Reference USA, 2003.''
    A comparison of the annual costs of the proposal per firm to the 
annual revenues of a firm provides a rough estimate of the burden the 
rule causes for a firm. Applying the above technique to the small 
propeller entity yields the following results:

----------------------------------------------------------------------------------------------------------------
                                                                                                    Percent of
                             Company                                Annual cost       Annual          annual
                                                                      of rule         revenue         revenue
----------------------------------------------------------------------------------------------------------------
Hartzell........................................................          $6,000     $37,500,000           0.016
----------------------------------------------------------------------------------------------------------------

    Given the estimated cost and revenue, the FAA believes that the 
cost would have only a minor impact on the small firm.

H. Competitive Analysis

    As the cost information is at the company level and the propeller 
firms do not all produce the same kind of propeller, the FAA does not 
have sufficient information to analyze the competitive impact of this 
proposal.

I. Disproportionality Analysis

    Relative to larger propeller manufacturers, smaller propeller 
manufacturers are more likely to be disproportionately impacted by this 
rulemaking because the larger manufacturers have relatively higher 
fixed costs than the smaller manufacturers. These fixed costs are not 
impacted by the costs that would be imposed by this proposal. The 
larger propeller manufacturers are expected to incur costs which are a 
relatively smaller percentage of their annual revenues than those of 
smaller propeller manufacturers.

J. Business Closure Analysis

    The one small business entity has a relatively low compliance cost 
per annual revenue ratio. We believe that this minor compliance cost 
would not cause firms to face a business closure. The FAA does not have 
sufficient information to provide a more refined estimate of a 
potential business closure.

K. Analysis of Alternatives

    The agency considered three alternatives to the proposal. These 
were:
    1. Exclude small entities.
    2. Extend compliance deadline for small entities.
    3. Establish lesser technical requirements for small entities.
    The FAA concludes that the option to exclude small entities from 
all the requirements of the proposal is not justified. If small 
entities were excluded the intended safety improvements would be 
forfeited.
    The FAA also considered options that would lengthen the compliance 
period for small operators. The FAA believes that the requirement, as 
proposed, would place a modest burden on small entities with respect to 
time constraints. Small entities would have sufficient time from the 
effective date of the rule to complete implementation work. Further 
time extensions would only provide modest cost savings and leave the 
system safety at risk.
    The FAA considered establishing lesser technical requirements for 
small entities. However, the FAA believes that this would result in a 
lower level of safety than would the implementation of the proposal. 
The FAA believes that the greatest safety benefits would come from a 
common certification rule for all manufacturers.
    The FAA concludes that the current proposal is the preferred 
alternative because the current proposal provides for a common 
certification system for all propeller manufacturers.
    In conclusion, as only one small entity would be affected there are 
not a substantial number of small entities. Therefore, the FAA 
certifies that this rule will not have a significant economic impact on 
a substantial number of small entities. The FAA solicits comments 
regarding this determination.

Trade Impact Assessment

    The Trade Agreements Act of 1979 (Pub. L. 96-39) prohibits Federal 
agencies from establishing any standards or engaging in related 
activities that create unnecessary obstacles to the foreign commerce of 
the United States. Legitimate domestic objectives, such as safety, are 
not considered unnecessary obstacles. 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 will 
accept European standards as the basis for U.S. regulations.

Unfunded Mandates Reform Act

    Title II of the Unfunded Mandate 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 with the base year 1995) in any one year by 
State, local, and tribal governments, in the aggregate, or by the 
private sector. The FAA currently uses an inflation-adjusted value of 
$128.1 million in lieu of $100 million.
    This proposed rule does not contain such a mandate. The 
requirements of Title II do not apply.

[[Page 18144]]

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. Therefore, we determined that this proposed rulemaking 
would not have federalism implications.

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 that this proposed rule 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 because it is 
not a ``significant regulatory action'' under Executive Order 12866, 
and it is not likely to have a significant adverse effect on the 
supply, distribution, or use of energy.

List of Subjects in 14 CFR Parts 23, 25, 33 and 35

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration proposes to amend parts 23, 25, 33, and 35 of Title 14 
Code of Federal Regulations as follows:

PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND 
COMMUTER CATEGORY AIRPLANES

    1. The authority citation for part 23 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

    2. Revise Sec.  23.905(d) to read as follows:


Sec.  23.905  Propellers.

* * * * *
    (d) The propeller blade pitch control system must meet the 
requirements of Sec. Sec.  35.21, 35.23, 35.42 and 35.43 of this 
chapter.
* * * * *
    3. Revise Sec.  23.907 to read as follows:


Sec.  23.907  Propeller vibration and fatigue.

    Sections 23.907(a), (b), and (c) do not apply to fixed-pitch wood 
propellers of conventional design.
    (a) The applicant must determine the magnitude of the propeller 
vibration stresses or loads, including any stress peaks and resonant 
conditions, throughout the operational envelope of the airplane by 
either:
    (1) Measurement of stresses or loads through direct testing or 
analysis based on direct testing of the propeller on the airplane and 
engine installation for which approval is sought; or
    (2) Comparison of the propeller to similar propellers installed on 
similar airplane installations for which these measurements have been 
made.
    (b) The applicant must demonstrate by tests, analysis based on 
tests, or previous experience on similar designs that the propeller 
does not experience harmful effects of flutter throughout the 
operational envelope of the airplane.
    (c) The applicant must perform an evaluation of the propeller to 
show that failure due to fatigue will be avoided throughout the 
operational life of the propeller using the fatigue and structural data 
obtained in accordance with part 35 and the vibration data obtained 
from compliance with paragraph (a) of this section. For the purpose of 
this paragraph, the propeller includes the hub, blades, blade retention 
component and any other propeller component whose failure due to 
fatigue could be catastrophic to the airplane. This evaluation must 
include:
    (1) The intended loading spectra including all reasonably 
foreseeable propeller vibration and cyclic load patterns, identified 
emergency conditions, allowable overspeeds and overtorques, and the 
effects of temperatures and humidity expected in service.
    (2) The effects of airplane and propeller operating and 
airworthiness limitations.

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

    4. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

    5. Revise Sec.  25.901(b)(1)(i) to read as follows:


Sec.  25.901  Installation.

* * * * *
    (b) * * *
    (1) * * *
    (i) The installation instructions provided under Sec. Sec.  33.5 
and 35.3 of this chapter; and
* * * * *
    6. Revise Sec.  25.905(c) to read as follows:


Sec.  25.905  Propellers.

* * * * *
    (c) The propeller blade pitch control system must meet the 
requirements of Sec. Sec.  35.21, 35.23, 35.42 and 35.43 of this 
chapter.
* * * * *
    7. Revise Sec.  25.907 to read as follows:


Sec.  25.907  Propeller vibration.

    Section 25.907 does not apply to fixed-pitch wood propellers of 
conventional design.
    (a) The applicant must determine the magnitude of the propeller 
vibration stresses or loads, including any stress peaks and resonant 
conditions, throughout the operational envelope of the airplane by 
either:
    (1) Measurement of stresses or loads through direct testing or 
analysis based on direct testing of the propeller on the airplane and 
engine installation for which approval is sought; or
    (2) Comparison of the propeller to similar propellers installed on 
similar airplane installations for which these measurements have been 
made.
    (b) The applicant must demonstrate by tests, analysis based on 
tests, or previous experience on similar designs that the propeller 
does not experience harmful effects of flutter throughout the 
operational envelope of the airplane.
    (c) The applicant must perform an evaluation of the propeller to 
show that failure due to fatigue will be avoided throughout the 
operational life of the propeller using the fatigue and structural data 
obtained in accordance with part 35 and the vibration data obtained 
from compliance with paragraph (a) of this section. For the purpose of 
this paragraph, the propeller includes the hub, blades, blade retention 
component and any other propeller component whose failure due to 
fatigue could be catastrophic to the airplane. This evaluation must 
include:
    (1) The intended loading spectra including all reasonably 
foreseeable propeller vibration and cyclic load patterns, identified 
emergency conditions, allowable overspeeds and overtorques, and the 
effects of

[[Page 18145]]

temperatures and humidity expected in service.
    (2) The effects of airplane and propeller operating and 
airworthiness limitations.

PART 33--AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES

    8. The authority citation for part 33 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

    9. Revise Sec.  33.19(b) to read as follows:


Sec.  33.19  Durability.

* * * * *
    (b) Each component of the propeller blade pitch control system 
which is a part of the engine type design must meet the requirements of 
Sec. Sec.  35.21, 35.23, 35.42 and 35.43 of this chapter.
* * * * *

PART 35--AIRWORTHINESS STANDARDS: PROPELLERS

    10. The authority citation for part 35 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

Subpart A--General

    11. In Sec.  35.1, add