[Federal Register Volume 72, Number 69 (Wednesday, April 11, 2007)]
[Proposed Rules]
[Pages 18136-18148]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-6193]
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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.
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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 http://dms.dot.gov and follow the
instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://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
http://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
http://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:
[email protected].
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
http://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 (http://dms.dot.gov/search);
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.
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
http://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, http://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, http://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 paragraphs (c) and (d) to read as follows:
Sec. 35.1 Applicability.
* * * * *
(c) An applicant is eligible for a propeller type certificate and
changes to those certificates after demonstrating compliance with
subparts A, B and C of this part. However, the propeller may not be
installed on an airplane unless the applicant has shown compliance with
either Sec. 23.907 or Sec. 25.907, as applicable, or compliance is
not required for installation on that airplane.
(d) For the purposes of this part, the propeller consists of those
components listed in the type design, and the propeller system consists
of the propeller plus all the components necessary for its functioning,
but not necessarily included in the propeller type design.
12. Add Sec. 35.2 to read as follows:
Sec. 35.2 Propeller configuration and identification.
(a) The applicant must provide a list of all the components,
including references to the relevant drawings and software design data,
that define the type design of the propeller to be approved under Sec.
21.31.
(b) The propeller identification must comply with Sec. Sec. 45.11
and 45.14.
13. Revise Sec. 35.3 to read as follows:
Sec. 35.3 Instructions for propeller installation and operation.
The applicant must provide instructions that are approved by the
Administrator. Those approved instructions must contain:
(a) Instructions for installing the propeller, which:
(1) Include a description of the operational modes of the propeller
control system and functional interface of the control system with the
airplane and engine systems;
(2) Specify the physical and functional interfaces with the
airplane, airplane equipment and engine;
(3) Define the limiting conditions on the interfaces from paragraph
(a)(2) of this section;
(4) List the limitations established under Sec. 35.5;
(5) Define the hydraulic fluids approved for use with the
propeller, including grade and specification, related operating
pressure, and filtration levels; and
(6) State the assumptions made to comply with the requirements of
this part.
(b) Instructions for operating the propeller which must specify all
procedures necessary for operating the propeller within the limitations
of the propeller type design.
14. Revise Sec. 35.5 to read as follows:
Sec. 35.5 Propeller ratings and operating limitations.
(a) Propeller ratings and operating limitations must:
(1) Be established by the applicant and approved by the
Administrator.
(2) Be included directly or by reference in the propeller type
certificate data sheet, as specified in Sec. 21.41 of this chapter.
(3) Be based on the operating conditions demonstrated during the
tests required by this part as well as any other information the
Administrator requires as necessary for the safe operation of the
propeller.
(b) Propeller ratings and operating limitations must be established
for the following, as applicable:
(1) Power and rotational speed for:
(i) Takeoff.
(ii) Maximum continuous.
(iii) If requested by the applicant, other ratings may also be
established.
(2) Overspeed and overtorque limits.
15. Add Sec. 35.7 to read as follows:
Sec. 35.7 Features and characteristics.
(a) The propeller must not have features or characteristics,
revealed by any test or analysis or known to the applicant, that make
it unsafe for the uses for which certification is requested.
(b) If a failure occurs during a certification test, the applicant
must determine the cause and assess the effect on the airworthiness of
the propeller. The applicant must make changes to the design and
conduct additional tests that the Administrator finds necessary to
establish the airworthiness of the propeller.
Subpart B--Design and Construction
Sec. 35.11 [Removed]
16. Remove and reserve Sec. 35.11.
Sec. 35.13 [Removed]
17. Remove and reserve Sec. 35.13.
18. Revise Sec. 35.15 to read as follows:
Sec. 35.15 Safety analysis.
(a)(1) The applicant must analyze the propeller system to assess
the likely consequences of all failures that can reasonably be expected
to occur. This analysis will take into account, if applicable:
(i) The propeller system in a typical installation. When the
analysis depends on representative components, assumed interfaces, or
assumed installed conditions, the assumptions must be stated in the
analysis.
(ii) Consequential secondary failures and dormant failures.
(iii) Multiple failures referred to in paragraph (d) of this
section, or that result in the hazardous propeller effects defined in
paragraph (g)(1) of this section.
(2) The applicant must summarize those failures that could result
in major propeller effects or hazardous propeller effects defined in
paragraph (g) of this section, and estimate the probability of
occurrence of those effects.
(3) The applicant must show that hazardous propeller effects are
not predicted to occur at a rate in excess of that defined as extremely
remote (probability of 10-7 or less per propeller flight
hour). Since the estimated probability for individual failures may be
insufficiently precise to enable the applicant to assess the total rate
for hazardous propeller effects, compliance may be shown by
demonstrating that the probability of a hazardous propeller effect
arising from an individual failure can be predicted to be not greater
than 10-8 per propeller flight hour. In dealing with
probabilities of this low order of magnitude, absolute proof is not
possible and reliance must be placed on engineering judgment and
previous experience combined with sound design and test philosophies.
(4) It must be shown that major propeller effects are not predicted
to
[[Page 18146]]
occur at a rate in excess of that defined as remote (probability of
10-5 or less per propeller flight hour).
(b) If significant doubt exists as to the effects of failures or
likely combination of failures, the Administrator may require
assumptions used in the analysis to be verified by test.
(c) The primary failures of certain single elements (for example,
blades) cannot be sensibly estimated in numerical terms. If the failure
of such elements is likely to result in hazardous propeller effects,
then compliance may be shown by reliance on the prescribed integrity
requirements of this part. These instances must be stated in the safety
analysis.
(d) If reliance is placed on a safety system to prevent a failure
progressing to hazardous propeller effects, the possibility of a safety
system failure in combination with a basic propeller failure must be
included in the analysis. Such a safety system may include safety
devices, instrumentation, early warning devices, maintenance checks,
and other similar equipment or procedures. If items of the safety
system are outside the control of the propeller manufacturer, the
assumptions of the safety analysis with respect to the reliability of
these parts must be clearly stated in the analysis and identified in
the propeller installation and operation instructions required under
Sec. 35.3.
(e) If the safety analysis depends on one or more of the following
items, those items must be identified in the analysis and appropriately
substantiated.
(1) Maintenance actions being carried out at stated intervals. This
includes the verification of the serviceability of items that could
fail in a latent manner. When necessary to prevent hazardous propeller
effects, these maintenance actions and intervals must be published in
the instructions for continued airworthiness required under Sec. 35.4
of this part. Additionally, if errors in maintenance of the propeller
system could lead to hazardous propeller effects, the appropriate
procedures must be included in the relevant propeller manuals.
(2) Verification of the satisfactory functioning of safety or other
devices at pre-flight or other stated periods. The details of this
satisfactory functioning must be published in the appropriate manual.
(3) The provisions of specific instrumentation not otherwise
required. Such instrumentation must be published in the appropriate
documentation.
(4) A fatigue assessment.
(f) If applicable, the safety analysis must include, but not be
limited to, assessment of indicating equipment, manual and automatic
controls, governors and propeller control systems, synchrophasers,
synchronizers, and propeller thrust reversal systems.
(g) Unless otherwise approved by the Administrator and stated in
the safety analysis, the following failure definitions apply to
compliance with part 35.
(1) The following are regarded as hazardous propeller effects:
(i) A significant overspeed of the propeller.
(ii) The development of excessive drag.
(iii) A significant thrust in the opposite direction to that
commanded by the pilot.
(iv) The release of the propeller or any major portion of the
propeller.
(v) A failure that results in excessive unbalance.
(vi) The unintended movement of the propeller blades below the
established minimum in-flight low-pitch position.
(2) The following are regarded as major propeller effects for
variable pitch propellers:
(i) An inability to feather the propeller for feathering
propellers.
(ii) An inability to change propeller pitch when commanded.
(iii) A significant uncommanded change in pitch.
(iv) A significant uncontrollable torque or speed fluctuation.
19. Revise Sec. 35.17 to read as follows:
Sec. 35.17 Materials and manufacturing methods.
(a) The suitability and durability of materials used in the
propeller must:
(1) Be established on the basis of experience, tests, or both.
(2) Account for environmental conditions expected in service.
(b) All materials and manufacturing methods must conform to
specifications acceptable to the Administrator.
(c) The design values of properties of materials must be suitably
related to the most adverse properties stated in the material
specification.
20. Revise Sec. 35.21 to read as follows:
Sec. 35.21 Variable and reversible pitch propellers.
(a) No single failure or malfunction in the propeller system will
result in unintended travel of the propeller blades to a position below
the in-flight low-pitch position. The extent of any intended travel
below the in-flight low-pitch position must be documented by the
applicant in the appropriate manuals. Failure of structural elements
need not be considered if the occurrence of such a failure is shown to
be extremely remote under Sec. 35.15(c).
(b) For propellers incorporating a method to select blade pitch
below the in-flight low pitch position, provisions must be made to
sense and indicate to the flight crew that the propeller blades are
below that position by an amount defined in the installation manual.
The method for sensing and indicating the propeller blade must be such
that its failure does not affect the control of the propeller.
21. Add Sec. 35.22 to read as follows:
Sec. 35.22 Feathering propellers.
(a) Feathering propellers must be designed to feather from all
conditions in flight, taking into account expected wear and leakage.
Feathering and unfeathering limitations must be documented in the
appropriate manuals.
(b) Propeller pitch control systems that use engine oil to feather
must incorporate a method to allow the propeller to feather if the
engine oil system fails.
(c) Feathering propellers must be designed to be capable of
unfeathering at the minimum declared outside air temperature after
stabilization to a steady-state temperature.
22. Revise Sec. 35.23 to read as follows:
Sec. 35.23 Propeller control system.
The requirements of this section apply to any system or component
that controls, limits or monitors propeller functions.
(a) The propeller control system must be designed, constructed and
validated to show that:
(1) The propeller control system, operating in normal and
alternative operating modes and in transition between operating modes,
performs the functions defined by the applicant throughout the declared
operating conditions and flight envelope.
(2) The propeller control system functionality is not adversely
affected by the declared environmental conditions, including
temperature, electromagnetic interference (EMI), high intensity
radiated fields (HIRF) and lightning. The environmental limits to which
the system has been satisfactorily validated must be documented in the
appropriate propeller manuals.
(3) A method is provided to indicate that an operating mode change
has occurred if flight crew action is required. In such an event,
operating instructions must be provided in the appropriate manuals.
(b) The propeller control system must be designed and constructed
so that, in addition to compliance with Sec. 35.15:
[[Page 18147]]
(1) No single failure or malfunction of electrical or electronic
components in the control system results in a hazardous propeller
effect.
(2) Failures or malfunctions directly affecting the propeller
control system in a typical airplane, such as structural failures of
attachments to the control, fire, or overheat, do not lead to a
hazardous propeller effect.
(3) The loss of normal propeller pitch control does not cause a
hazardous propeller effect under the intended operating conditions.
(4) The failure or corruption of data or signals shared across
propellers does not cause a hazardous propeller effect.
(c) Electronic propeller control system imbedded software must be
designed and implemented by a method approved by the Administrator that
is consistent with the criticality of the performed functions and that
minimizes the existence of software errors.
(d) The propeller control system must be designed and constructed
so that the failure or corruption of airplane-supplied data does not
result in hazardous propeller effects.
(e) The propeller control system must be designed and constructed
so that the loss, interruption or abnormal characteristic of airplane-
supplied electrical power does not result in hazardous propeller
effects. The power quality requirements must be described in the
appropriate manuals.
23. Add Sec. 35.24 to read as follows:
Sec. 35.24 Strength.
The maximum stresses developed in the propeller must not exceed
values acceptable to the Administrator considering the particular form
of construction and the most severe operating conditions. Due
consideration must be given to the effects of any residual stresses.
Subpart C--Type Substantiation
Sec. 35.31 [Removed]
24. Remove and reserve Sec. 35.31.
25. Revise Sec. 35.33 to read as follows:
Sec. 35.33 General.
(a) Each applicant must furnish test article(s) and suitable
testing facilities, including equipment and competent personnel, and
conduct the required tests in accordance with part 21.
(b) All automatic controls and safety systems must be in operation
unless it is accepted by the Administrator as impossible or not
required because of the nature of the test. If needed for
substantiation, the applicant may test a different propeller
configuration if this does not constitute a less severe test.
(c) Any systems or components that cannot be adequately
substantiated by the applicant to the requirements of this part are
required to undergo additional tests or analysis to demonstrate that
the systems or components are able to perform their intended functions
in all declared environmental and operating conditions.
26. Revise Sec. 35.34 to read as follows:
Sec. 35.34 Inspections, adjustments and repairs.
(a) Before and after conducting the tests prescribed in this part,
the test article must be subjected to an inspection, and a record must
be made of all the relevant parameters, calibrations and settings.
(b) During all tests, only servicing and minor repairs are
permitted. If major repairs or part replacement is required, the
Administrator must approve the repair or part replacement prior to
implementation and may require additional testing. Any unscheduled
repair or action on the test article must be recorded and reported.
27. Revise Sec. 35.35 to read as follows:
Sec. 35.35 Centrifugal load tests.
The applicant must demonstrate that a propeller complies with
paragraphs (a), (b) and (c) of this section without evidence of
failure, malfunction, or permanent deformation that would result in a
major or hazardous propeller effect. When the propeller could be
sensitive to environmental degradation in service, this must be
considered. This section does not apply to fixed-pitch wood or fixed-
pitch metal propellers of conventional design.
(a) The hub, blade retention system, and counterweights must be
tested for a period of one hour to a load equivalent to twice the
maximum centrifugal load to which the propeller would be subjected
during operation at the maximum rated rotational speed.
(b) Blade features associated with transitions to the retention
system (for example, a composite blade bonded to a metallic retention)
must be tested either during the test of Sec. 35.35(a) or in a
separate component test.
(c) Components used with or attached to the propeller (for example,
spinners, de-icing equipment, and blade erosion shields) must be
subjected to a load equivalent to 159 percent of the maximum
centrifugal load to which the component would be subjected during
operation at the maximum rated rotational speed. This must be performed
by either:
(1) Testing at the required load for a period of 30 minutes; or
(2) Analysis based on test.
28. Add Sec. 35.36 to read as follows:
Sec. 35.36 Bird impact.
The applicant must demonstrate, by tests or analysis based on tests
or experience on similar designs, that the propeller can withstand the
impact of a 4-pound bird at the critical location(s) and critical
flight condition(s) of a typical installation without causing a major
or hazardous propeller effect. This section does not apply to fixed-
pitch wood propellers of conventional design.
29. Revise Sec. 35.37 to read as follows:
Sec. 35.37 Fatigue limits and evaluation.
This section does not apply to fixed-pitch wood propellers of
conventional design.
(a) Fatigue limits must be established by tests, or analysis based
on tests, for propeller:
(1) Hubs;
(2) Blades;
(3) Blade retention components;
(4) Components which are affected by fatigue loads and which are
shown under Sec. 35.15 to have a fatigue failure mode leading to
hazardous propeller effects.
(b) The fatigue limits must take into account:
(1) All known and reasonably foreseeable vibration and cyclic load
patterns that are expected in service; and
(2) Expected service deterioration, variations in material
properties, manufacturing variations, and environmental effects.
(c) A fatigue evaluation of the propeller must be conducted to show
that hazardous propeller effects due to fatigue will be avoided
throughout the intended operational life of the propeller on either:
(1) The intended airplane by complying with Sec. 23.907 or Sec.
25.907, as applicable; or
(2) A typical airplane.
30. Add Sec. 35.38 to read as follows:
Sec. 35.38 Lightning strike.
The applicant must demonstrate, by tests, analysis based on tests,
or experience on similar designs, that the propeller can withstand a
lightning strike without causing a major or hazardous propeller effect.
The limit to which the propeller has been qualified must be documented
in the appropriate manuals. This section does not apply to fixed-pitch
wood propellers of conventional design.
31. Revise Sec. 35.39 to read as follows:
Sec. 35.39 Endurance test.
Endurance tests on the propeller system must be made on a
[[Page 18148]]
representative engine in accordance with paragraph (a) or (b) of this
section, as applicable, without evidence of failure or malfunction.
(a) Fixed-pitch and ground adjustable-pitch propellers must be
subjected to one of the following tests:
(1) A 50-hour flight test in level flight or in climb. The
propeller must be operated at takeoff power and rated rotational speed
during at least five hours of this flight test, and at not less than 90
percent of the rated rotational speed for the remainder of the 50
hours.
(2) A 50-hour ground test at takeoff power and rated rotational
speed.
(b) Variable-pitch propellers must be subjected to one of the
following tests:
(1) A 110-hour endurance test that must include the following
conditions:
(i) Five hours at takeoff power and rotational speed and thirty 10-
minute cycles composed of:
(A) Acceleration from idle,
(B) Five minutes at takeoff power and rotational speed,
(C) Deceleration, and
(D) Five minutes at idle.
(ii) Fifty hours at maximum continuous power and rotational speed,
(iii) Fifty hours, consisting of ten 5-hour cycles composed of:
(A) Five accelerations and decelerations between idle, takeoff
power and rotational speed;
(B) Four and one-half hours at approximately even incremental
conditions from idle up to, but not including, maximum continuous power
and rotational speed; and
(C) Thirty minutes at idle.
(2) The operation of the propeller throughout the engine endurance
tests prescribed in part 33 of this chapter.
(c) An analysis based on tests of propellers of similar design may
be used in place of the tests of Sec. 35.39(a) and (b).
32. Add Sec. 35.40 to read as follows:
Sec. 35.40 Functional test.
The variable-pitch propeller system must be subjected to the
applicable functional tests of this section. The same propeller system
used in the endurance test (Sec. 35.39) must be used in the functional
tests and must be driven by a representative engine on a test stand or
on an airplane. The propeller must complete these tests without
evidence of failure or malfunction. This test may be combined with the
endurance test for accumulation of cycles.
(a) Manually-controllable propellers. Five hundred representative
flight cycles must be made across the range of pitch and rotational
speed.
(b) Governing propellers. Fifteen hundred complete cycles must be
made across the range of pitch and rotational speed.
(c) Feathering propellers. Fifty cycles of feather and unfeather
operation must be made.
(d) Reversible-pitch propellers. Two hundred complete cycles of
control must be made from lowest normal pitch to maximum reverse pitch.
During each cycle, the propeller must be run for 30 seconds at the
maximum power and rotational speed selected by the applicant for
maximum reverse pitch.
(e) An analysis based on tests of propellers of similar design may
be used in place of the tests of Sec. 35.40.
33. Revise Sec. Sec. 35.41, 35.42, and 35.43 to read as follows:
Sec. 35.41 Overspeed and overtorque.
(a) When the applicant seeks approval of a transient maximum
propeller overspeed, the applicant must demonstrate that the propeller
is capable of further operation without maintenance action at the
maximum propeller overspeed condition. This may be accomplished by:
(1) Performance of 20 runs, each of 30 seconds duration, at the
maximum propeller overspeed condition; or
(2) Analysis based on test or service experience.
(b) When the applicant seeks approval of a transient maximum
propeller overtorque, the applicant must demonstrate that the propeller
is capable of further operation without maintenance action at the
maximum propeller overtorque condition. This may be accomplished by:
(1) Performance of 20 runs, each of 30 seconds duration, at the
maximum propeller overtorque condition; or
(2) Analysis based on test or service experience.
Sec. 35.42 Components of the propeller control system.
The applicant must demonstrate by tests, analysis based on tests,
or service experience on similar components, that each propeller blade
pitch control system component, including governors, pitch change
assemblies, pitch locks, mechanical stops, and feathering system
components, can withstand cyclic operation that simulates the normal
load and pitch change travel to which the component would be subjected
during the initially declared overhaul period or during a minimum of
1000 hours of typical operation in service.
Sec. 35.43 Propeller hydraulic components.
Applicants must show that propeller components that contain
hydraulic pressure and whose structural failure or leakage from a
structural failure could cause a hazardous propeller effect demonstrate
structural integrity by:
(a) A proof pressure test to 1.5 times the maximum operating
pressure for one minute without permanent deformation or leakage that
would prevent performance of the intended function.
(b) A burst pressure test to 2.0 times the maximum operating
pressure for one minute without failure. Leakage is permitted and seals
may be excluded from the test.
Sec. 35.45 [Removed]
34. Remove and reserve Sec. 35.45.
Sec. 35.47 [Removed]
35. Remove and reserve Sec. 35.47.
Issued in Washington, DC, on March 26, 2007.
John J. Hickey,
Director, Aircraft Certification Service.
[FR Doc. E7-6193 Filed 4-10-07; 8:45 am]
BILLING CODE 4910-13-P