27390 Federal Register / Vol. 66, No. 95 / Wednesday, May 16, 2001 / Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA–1999–5835; Amendment

No. 25–103]

RIN 2120–AG72

Revised Landing Gear Shock

Absorption Test Requirements

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This amendment revises the

airworthiness standards for landing gear

shock absorption test requirements for

transport category airplanes by

incorporating changes developed in

cooperation with the Joint Aviation

Authorities (JAA) of Europe and the

U.S. and European aviation industry

through the Aviation Rulemaking

Advisory Committee (ARAC). This

amendment reduces the number of

design weight conditions required to be

demonstrated by shock absorption tests

and changes the objective of the tests to

include the complete validation of the

landing gear dynamic characteristics.

This amendment also removes some

means of compliance criteria from the

rule since it is more appropriately set

forth in advisory material.

EFFECTIVE DATE: June 15, 2001.

FOR FURTHER INFORMATION CONTACT:

James Haynes, Airframe and Cabin

Safety Branch, ANM–115, Transport

Airplane Directorate, Aircraft

Certification Service, FAA, 1601 Lind

Ave. SW., Renton, WA 98055–4056;

telephone (425) 227–2131.

SUPPLEMENTARY INFORMATION:

Availability of Final Rules

You can get and electronic copy using

the Internet by taking the following

steps:

(1) Go to the search function of the

Department of Transportation’s

electronic Docket Management System

(DMS) Web page http://dms.dot.gov/

search.

(2) On the search page type in the last

four digits of the Docket number shown

at the beginning of this amendment.

Click on ‘‘search.’’

(3) On the next page, which contains

the Docket summary information for the

Docket you selected, click on the final

rule.

You can also get and electronic copy

using the Internet through FAA’s web

page at http://www.faa.gov/avr/arm/

nprm/nprm.htm or the Federal

Register’s web page at http://

www.access.gov/su_docs/aces/

aces140.html.

You can also get a copy by submitting

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 amendment number or

docket number of this final rule.

Small Business Regulatory Enforcement

Fairness Act

The Small Business Regulatory

Enforcement Fairness Act (SBREFA) of

1996, requires the FAA to comply with

small entity requests for information or

advice about compliance with statutes

and regulations within its jurisdiction.

Therefore, any small entity that has a

question regarding this document may

contact their local FAA official, or the

person listed under FOR FURTHER

INFORMATION CONTACT. You can find out

more about SBREFA on the Internet at

our site http://www.faa.gov/avr/arm/

sbrefa.htm For more information on

SBREFA, e-mail us at 9–AWA–

SBREFA@faa.gov.

Background

The manufacturing, marketing and

certification of transport airplanes is

increasingly an international endeavor.

In order for United States manufacturers

to export transport airplanes to other

countries, the airplane must be designed

to comply, not only with the U.S.

airworthiness requirements for transport

airplanes (14 CFR part 25), but also with

the transport airworthiness

requirements of the countries to which

the airplane is to be exported.

The European countries have

developed a common airworthiness

code for transport airplanes that is

administered by the JAA of Europe. This

code is the result of a European effort

to harmonize the various airworthiness

codes of the European countries and is

called the Joint Aviation Requirements

(JAR)–25. It was developed in a format

similar to part 25. Many other countries

have airworthiness codes that are

aligned closely to part 25 or to JAR–25,

or they use these codes directly for their

own certification purposes.

The ARAC was established by the

FAA on February 15, 1991, with the

purpose of providing information,

advice, and recommendations to be

considered in rulemaking activities. By

notice in the Federal Register (59 FR

30081, June 10, 1994), the FAA assigned

several new tasks to an ARAC working

group of industry and government

structural loads specialists from Europe,

the United States, and Canada. Task 6

of the working group charter concerned

the shock absorption test requirements

for landing gear. The ARAC working

group completed its work for this task

and the ARAC made recommendations

to the FAA by letter dated October 29,

1997.

Although the requirements for

landing gear shock absorption tests are

essentially the same between the

Federal Aviation Regulations (FAR) and

JAR, the requirements do not address

the capabilities of modern technology

and do not take into account other

related changes in the requirements for

landing gear load conditions that have

already been incorporated into other

sections of the FAR. When the landing

loads requirements for transport

airplanes were originally developed, the

required the landing load factors to be

determined and applied to the airplane.

The airplane was treated as a rigid body

and the landing loads were applied to

this rigid representation of the airplane

for the purpose of structural analysis.

For the early landing gear systems,

analysis alone was considered sufficient

for determining the landing load factor

that will be applied to the rigid airplane.

It was only necessary to determine the

landing load factor (by analysis or tests)

and this load factor will then be used to

design and substantiate the airplane for

the landing load conditions.

The development of more complex

landing gear systems, for which analysis

alone was unreliable, led to the

adoption of a requirement to verify the

landing factor by actual shock

absorption tests. This requirement was

added to the Civil Air Regulations

(CAR) 4b, which was the predecessor to

part 25. These shock absorption tests

were allowed by § 4b.200 of the CAR to

be free drop tests in which the gear

alone, could be dropped in free fall to

impact the ground. In these tests, mass

is added to represent the proportion of

the airplane weight on the landing gear

unit, and the mass may be reduced to

account for the effects of airplane lift

acting during the landing impact. Later,

the corresponding requirement in

§ 25.723(a), was modified to allow the

substantiation of some changes to the

landing gear shock absorption systems

by analysis alone without verification

by tests.

Prior to this amendment, §§ 25.473(d)

and 25.723(a) for shock absorption tests

required just the determination of the

limit landing load factor from the shock

absorption test. However, the landing

gear shock absorption systems had

become even more sophisticated and the

airplane had become more flexible. Part

25 was previously revised to require

that determinations of airplane loads in

the landing configuration take into

Federal Register / Vol. 66, No. 95 / Wednesday, May 16, 2001 / Rules and Regulations 27391

account the dynamic flexibility of the

airplane. In order to determine the

airplane loads in the landing load

conditions, it was no longer sufficient to

determine just the load factor from a

drop test of a landing gear unit. A

comprehensive analysis of the

combined dynamic systems for the

landing gear and airplane had become

essential in order to determine the

structural design loads for the airplane.

In developing the mathematical model,

it is necessary to provide an accurate

representation of all the landing gear

dynamic characteristics. This includes

the energy absorption characteristics

and the time histories of force and

displacement during a landing impact.

Notice 99–08 was published in the

Federal Register on June 18, 1999 (64

FR 32978). The notice proposes to revise

the main objective of the shock

absorption tests to be the validation of

the landing gear dynamic characteristics

which make up the analytical model

rather than just to determine the landing

load factors. In addition, the number of

actual design weight conditions were

proposed to be reduced to include just

the landing weight, or design take-off

weight, whichever provided the greatest

landing impact energy. Furthermore,

§§ 25.725 and 25.727 were proposed to

be removed from part 25, since these

sections only contained criteria for one

means of compliance to the shock

absorption test requirement. These

criteria were proposed to be set forth as

acceptable means of compliance in

Advisory Circular (AC) 25.723–1

‘‘Shock Absorption Tests.’’

Discussion of Comments

There are 6 commenters from aviation

manufacturers and foreign airworthiness

authorities. Although one commenter

objects to the proposed rule, most of the

commenters support the proposed

changes. Several of the commenters

provide suggestions for clarity,

consistency and organization.

Comments are summarized as follows

along with disposition.

One commenter objects to the

proposed change in the basic purpose of

the shock absorption tests from the

validation of the load factors to the

validation of the dynamic

characteristics of the landing gear. The

commenter believes that the new

proposal has the potential for requiring

a significant volume of recalculation for

refinement of load values and this

would be neither productive nor cost

effective. Furthermore, the commenter

believes that this approach would not fit

well in the timeline between design

concept and the development of the first

prototype and so would bring the

potential for discovering a different

answer for the completed product late

in the design process. Finally, the

commenter believes the existing

regulations are sufficient. The FAA

agrees that validation of dynamic

characteristics by test always brings a

risk if the assumptions made in the

prediction of these characteristics are

not sufficiently accurate or conservative.

However, the process of prediction,

design, and validation are normal, and

expected, in the development of aircraft

and the risks can be minimized by the

use of conservative assumptions.

Furthermore, the FAA does not agree

that the existing shock absorption test

requirements are sufficient. The

development of airplane loads for

dynamic landing conditions requires a

valid analytical model of the landing

gear which includes a valid

representation of the energy absorbing

characteristics of the gear. The dynamic

landing requirement has existed in 14

CFR part 25 for a number of years but

the validation shock absorption test

requirement has remained outdated,

since it requires only the validation of

a simple static landing load factor

which may not even be used in design

of the airplane. Because of the existing

dynamic landing requirement, it has

become a standard practice to develop

the design loads for the airplane

structure based on a mathematical

model of the airplane and landing gear

and to validate the assumed gear

characteristics by shock absorption

tests. Therefore, the requirement is

being updated to be consistent with the

related design landing load

requirements and also to be consistent

with standard practice.

One commenter points out that the

terminology used in the proposed

§ 25.723(a)(1) for design weight

conditions was inconsistent with that

used in § 25.473, ‘‘Landing load

conditions and assumptions,’’ which is

the same as that used in the proposed

AC 25.723–1. The FAA agrees, and the

language in the new § 25.723(a)(1) has

been changed to refer to these design

weight conditions as ‘‘limit design

conditions’’ and to use the terms

‘‘design landing weight’’ and ‘‘design

takeoff weight’’ to be consistent with

§ 25.473(a).

One commenter is concerned that the

proposed location of the requirement for

shock absorption tests in § 25.473(d)

implies that the individual tests would

be required for each of the landing

conditions and configurations specified

in § 25.473, including unsymmetrical

conditions. The FAA does not agree

since the specific landing conditions are

referenced in § 25.473(a) while the

requirement related to validating

landing gear dynamic characteristics,

potentially of use in some or all

conditions, is set forth in § 25.473(d).

Validation is intended to mean that the

adequacy of the dynamic characteristics

would be confirmed by shock

absorption tests to whatever extent

necessary to provide confidence in the

analysis of the specified landing

conditions. To clarify this intent, an

additional sentence is added to

§ 25.723(a) which would require that a

range of tests be conducted to ensure

that the analytical representation is

valid for the design condition specified

in § 25.723.

The same commenter suggests that the

terms, ‘‘dynamic characteristics,’’ are

ambiguous and that the rule should

completely define dynamic

characteristics and specify which

dynamic characteristics must be

validated by tests. The FAA agrees that

these terms are general. However, the

FAA does not agree that an exhaustive

list of dynamic characteristics or shock

absorption characteristics can be

provided in the rule. The relevant

landing gear dynamic characteristics

depend on the parameter chosen by the

applicant for use in the analysis. The

analysis must represent the full energy

absorbing characteristics of the landing

gear and it would be impossible to

provide an exhaustive list of

characteristics that would apply to all

designs. Typically the manufacturer will

validate the dynamic characteristics

used in the analysis in a gross fashion

by using the analytical mathematical

model to predict the shock absorption

response time histories in the test for a

range of test conditions. In response to

this comment, changes have been made

to the proposed advisory material to

identify some of the energy absorption

components and characteristics that are

usually of significance and the extent

that they could be changed or revised

without additional testing.

One commenter is concerned that the

elimination of § 25.723(b) means that

the reserve energy shock absorption

tests would no longer be required.

Removal of § 25.723(b) was not a

proposal of Notice 99–08. The

commenter fails to recognize that the

paragraph is represented in the notice as

a set of asterisks at the end of § 25.723(a)

signifying that the remaining paragraphs

of § 25.723 would remain unchanged.

However, consideration of the

commenters concern brings to light the

fact that the allowance provided in

§ 25.723(a)(3) for using analysis in lieu

of tests, would not necessarily apply to

the reserve energy drop test of

§ 25.723(b). In order to correct this

27392 Federal Register / Vol. 66, No. 95 / Wednesday, May 16, 2001 / Rules and Regulations

oversight, § 25.723(b) is clarified, and

the allowance in the proposed

§ 25.723(a)(3) is now set forth in a

separate § 25.723(c) and made

applicable to both §§ 25.723(a) and (b).

One commenter is concerned that the

removal of the free drop test

requirements in §§ 25.725 and 25.727 of

the rules means that these tests would

no longer be required and that this

could result in a reduction in the degree

of safety. These specific types of tests,

known as free drop tests, have never

been required. They have always been a

means of compliance to the general

requirement to conduct shock

absorption tests. This general

requirement for conducting shock

absorption tests remains in the revised

§ 25.723. The free drop test criteria are

provided for the manufacturer that

chooses to use this particular method of

performing the required shock

absorption tests. In the free drop test,

the manufacturer may represent the

airplane lift by using a reduced effective

weight for the test. However many

manufacturers represent the lifting force

directly in a drop test or perform other

types of shock absorption tests. The

criteria for establishing the effective

drop weight is applicable to only this

one means of compliance and would be

more appropriately presented in an

advisory circular (AC). To this end, AC

25.723–1 ‘‘Shock Absorption Tests,’’

was made available to provide this

means of compliance.

Two commenters are concerned that

the removal of the free drop test criteria

from the regulation would result in the

loss of the current method for

establishing the effective mass over the

nose gear for the free drop test. As stated

above, this information is not being lost

but is being moved to an AC as

acceptable means of compliance.

Except for the minor editorial and

organizational changes mentioned

above, the amendment is issued as

proposed.

Paperwork Reduction Act

In accordance with the Paperwork

Reduction Act of 1995 (44 U.S.C.,

3507(d)), there are no requirements for

information collection associated with

this amendment.

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 regulations.

Executive Order 12866 and DOT

Regulatory Policies and Procedures

Executive Order 12866, Regulatory

Planning and Review, directs the FAA

to assess both the costs and benefits of

a regulatory change. We are not allowed

to propose or adopt a regulation unless

we make a reasoned determination that

the benefits of the intended regulation

justify its costs. Our assessment of this

proposal indicates that its economic

impact is minimal. Since its costs and

benefits do not make it a ‘‘significant

regulatory action’’ as defined in the

Order, we have not prepared a

‘‘regulatory impact analysis.’’ Similarly,

we have not prepared a ‘‘regulatory

evaluation,’’ which is the written cost/

benefit analysis ordinarily required for

all rulemaking proposals under the DOT

Regulatory and Policies and Procedures.

We do not need to do the latter analysis

where the economic impact of a

proposal is minimal.

Economic Evaluation, Regulatory

Flexibility Determination, International

Trade Impact Assessment, and

Unfunded Mandates Assessment

Changes to Federal regulations must

undergo several economic analyses.

First, Executive Order 12866 directs that

each Federal agency shall propose or

adopt a regulation only upon a reasoned

determination that the benefits of the

intended regulation justify its costs.

Second, the Regulatory Flexibility Act

of 1980 requires agencies to analyze the

economic impact of regulatory changes

on small entities. Third, the Trade

Agreements Act (19 U.S.C. section

2531–2533) prohibits agencies from

setting standards that create

unnecessary obstacles to the foreign

commerce of the United States. In

developing U.S. standards, this Trade

Act requires agencies to consider

international standards and, where

appropriate, that they be the basis of U.S

standards. And fourth, the Unfunded

Mandates Reform Act of 1995 requires

agencies to preparer 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, in any one year (adjusted for

inflation).

However, for regulations with an

expected minimal impact, the abovespecified analyses are not required. The

Department of Transportation Order

DOT 2100.5 prescribes policies and

procedures for simplification, analysis,

and review of regulations. If it is

determined that the expected impact is

so minimal that the proposal does not

warrant a full Evaluation, a statement to

that effect and the basis for it is

included in proposed regulation. Since

this final rule makes landing gear

requirements consistent with other

requirements in the FAR, harmonizes

these standards to be consistent with the

European JAR, and since industry is

currently in compliance with the new

requirements, the expected outcome is

to have a minimal cost impact with

positive net benefits.

The regulatory evaluation summary

examines the costs and benefits of a

Final Rule entitled Revised Landing

Gear Shock Absorption Test

Requirements. The rule changes the

transport category airplane certification

requirements for landing gear shock

absorption tests. This amendment to

part 25 updates the current standards to

take into account the structural dynamic

flexibility of modern airplanes, the

complexity of landing gear shock

absorption systems, and the ability of

highly sophisticated computer models

to simulate dynamic structural loads.

The amendment also makes landing

gear requirements consistent with other

requirements in the FAR, harmonizes

these standards with those being

proposed for the European JAR, and is

expected to maintain the level of safety

provided by the test requirements.

Background

Landing load requirements have

evolved as the designs of transport

category airplanes have changed.

Initially, analysis alone was considered

sufficient for determining the landing

load factor that would be applied to a

rigid airplane. The development of more

complex landing gear systems and

flexible airplanes led to the requirement

for actual shock absorption tests. Later,

the requirement for tests was modified

to allow analysis alone to substantiate

some changes to landing gear systems.

The current landing load

requirements in Subpart D (Design and

Construction) of part 25 require

determination of the landing load

factors for landing gear by means of

energy absorption tests (drop tests) at

maximum takeoff and landing weights.

To comply with the landing load

requirements of Subpart D and the

requirements of Subpart C (Structure) of

part 25, manufacturers build

sophisticated computer models that

comprehensively analyze landing gear

and airplane structure and accurately

represent landing gear shock absorption

characteristics. These analytical models

for landing conditions are validated

Federal Register / Vol. 66, No. 95 / Wednesday, May 16, 2001 / Rules and Regulations 27393

through shock absorption tests (usually

drop tests) at the maximum takeoff

weight and the maximum landing

weight.

The rule will allow manufacturers to

validate the analytical representation of

the dynamic characteristics of landing

gear by conducting energy absorption

tests at the weight (maximum takeoff

weight or maximum landing weight)

which provides the maximum impact

energy. Because of the ability of the

computer models to describe landing

gear characteristics, tests at weights

other than that of maximum impact

energy are unnecessary. The rule will

continue to provide for the

substantiation of minor changes in

landing gear systems through the use of

the analyses.

The current §§ 25.725 and 25.727 are

deleted as regulatory requirements and

moved to a new proposed Advisory

Circular 25.723–1, except that current

§ 25.725(c), which describes conditions

for the attitude of the landing gear and

the representation of drag loads during

the tests, is included in § 25.723.

This amendment was developed by

the ARAC and presented to the FAA as

a recommendation for rulemaking. This

amendment will harmonize shock

absorption tests with those being

proposed by the JAA.

Costs and Benefits

The requirements, applicable to future

type certificated transport category

airplanes, will result in two regulatory

changes: Utilizing landing gear energy

absorption tests to validate the landing

gear dynamic characteristics rather than

the limit load factor value, and

confirming energy absorption in

characteristics by requiring tests at

either the maximum landing weight or

maximum takeoff weight condition,

whichever provides the maximum

landing impact energy. This is in

contrast to current requirements, which

require tests at both weight conditions.

The tests results will be used to

develop the analytical modeling of the

landing gear dynamic characteristics.

These regulatory changes are not

expected to result in any physical

change in the way landing gears are

tested: the attitude of the gear being

usually simulated directly by orienting

the gear on the rig and drag loads being

applied by spinning the wheel up to the

ground speed. Therefore, it is not

expected to impose additional costs on

manufacturers. This was confirmed by

two manufacturers. No comments to the

contrary were received in response to

the Notice of Proposed Rulemaking.

Significant cost savings may result

from not having to test both at

maximum landing weight and

maximum takeoff weight, but instead,

conducting shock absorption in tests

only for the conditions associated with

maximum energy. One manufacturer

estimates that this would result in 15

fewer test conditions per airplane

certification. At a cost of $5,000 per

condition, the total cost savings as a

result of this provision equals $75,000

per airplane certification. Another

manufacturer estimates a cost saving of

approximately $190,000 for a ten-year

period.

Additionally, by harmonizing the

standards of the FAR ad JAR, the rule

is expected to yield cost savings by

eliminating duplicate certification

activities. One manufacturer ‘‘applauds’’

this FAA/JAA harmonization effort and

its influence on the regulations.

The imposition of this rule is

expected to maintain the current level of

aviation safety.

Based on the finding of regulatory

cost savings, coupled with the cost

savings realizable from harmonization,

and the expectation that these revisions

will maintain the existing level of safety

provided by the test requirements, the

FAA has determined that the rule is

expected to be cost-beneficial.

Regulatory Flexibility Determination

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 Act requires agencies to solicit and

consider flexible regulatory proposals

and to explain the rationale for their

actions. The Act covers a wide-range of

small entities, including small

businesses, not-for-profit organizations

and small governmental jurisdictions.

Agencies must perform a review to

determine whether a proposed or final

rule will have a significant economic

impact on a substantial number of small

entities. If the determination is that it

will, the agency must prepare a

regulatory flexibility analysis as

described in the Act.

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 act

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 primary effect of this rule is

expected to be cost savings for aircraft

manufacturers. The FAA received no

comments regarding its earlier

assessment of no impact on small

entities. The U.S. Small Business

Administration specifies in its Table of

Size Standards of March 1, 1996 that,

for aircraft manufacturers, a small entity

is one with 1,500 or fewer employees.

Since no part 25 airplane manufacturer

is believed to have 1,500 or fewer

employees, and the rule is expected to

reduce manufacturing costs, the FAA

certifies that the rule is not expected to

have a significant economic impact on

a substantial number of small entities.

Unfunded Mandates Reform Act

The Unfunded Mandates Reform Act

of 1995 (the Act), enacted as Pub. L.

104–4 on March 22, 1995, is intended,

among other things, to curb the practice

of imposing unfunded Federal mandates

on State, local, and tribal governments.

Title II of the Act 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 a $100

million or more expenditure (adjusted

annually for inflation) in any one year

by State, local, and tribal governments,

in the aggregate, or by the private sector;

such a mandate is deemed to be a

‘‘significant regulatory action.’’

This final rule does not contain such

a mandate. Therefore, the requirements

of Title II of the Unfunded Mandates

Reform Act of 1995 do not apply.

International Trade Impact Assessment

The Trade Agreement Act of 1979

prohibits Federal agencies from setting

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. In addition, consistent

with the Administration’s belief in the

general superiority and desirability of

free trade, it is the policy of the

Administration to remove or diminish,

to the extent feasible, barriers to

international trade, including both

barriers affecting the export of American

goods and services to foreign countries

and barriers affecting the import of

foreign goods and services into the

United States.

In accordance with the above statute

and policy, the FAA has assessed the

27394 Federal Register / Vol. 66, No. 95 / Wednesday, May 16, 2001 / Rules and Regulations

potential effect of this rule and has

determined that it is not expected to

constitute a barrier to international

trade, including the export of American

airplanes to foreign countries and the

import of foreign airplanes into the

United States. The requirements in this

rule are expected to have no adverse

impact on trade opportunities for U.S.

manufacturers selling airplanes in

foreign markets and foreign

manufacturers selling airplanes into the

U.S. market. Instead, by harmonizing

the standards of the FAR and the JAR,

it will serve to facilitate international

trade.

Executive Order 13132, Federalism

The FAA has analyzed this final rule

under the principles and criteria of

Executive Order 13132, Federalism. We

determined that this action will not

have a substantial direct effect on the

States, or 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 final rule does not

have federalism implications.

Regulations Affecting Intrastate

Aviation in Alaska

Section 1205 of the FAA

Reauthorization Act of 1996 (110 Stat.

3213) requires the Administrator, when

modifying regulations in Title 14 of the

CFT in a manner affecting intrastate

aviation in Alaska, to consider the

extent to which Alaska is not served by

transportation modes other than

aviation, and to establish such

regulatory distinctions, as he or she

considers appropriate. Because this final

rule applies to the certification of future

designs of transport category airplanes

and their subsequent operation, it could

affect intrastate aviation in Alaska. The

Administrator has considered the extent

to which Alaska is not served by

transportation modes other than

aviation, and how the final rule could

have been applied directly to intrastate

operations in Alaska. However, the

Administrator has determined that

airplanes operated solely in Alaska

would present the same safety concerns

as all other affected airplanes; therefore,

it would be inappropriate to establish a

regulatory distinction for the intrastate

operation of affected airplanes in

Alaska.

Environmental Analysis

Federal Aviation Administration

Order 1050.1D defines FAA actions that

may be categorically excluded from

preparation of a National Environmental

Policy Act (NEPA) environmental

impact statement. In accordance with

FAA Order 1050.ID, appendix 4,

paragraph 4(j), this amendment qualifies

for a categorical exclusion.

Energy Impact

The energy impact of the amendment

has been assessed in accordance with

the Energy Policy and Conservation Act

(EPCA) Pub. L. 94–163, as amended (42

U.S.C. 6362) and FAA Order 1053.1. It

has been determined that the final rule

is not a major regulatory action under

the provisions of the EPCA.

List of Subjects in 14 CFR Part 25

Air transportation, Aircraft, Aviation

safety, Safety.

The Amendment

In consideration of the foregoing, the

Federal Aviation Administration

amends part 25 of Title 14, Code of

Federal Regulations (14 CFR part 25) as

follows:

PART 25—AIRWORTHINESS

STANDARDS: TRANSPORT

CATEGORY AIRPLANES

1. The authority citation for part 25

continues to read as follows:

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

44702, 44704.

2. Section 25.473 is amended by

revising paragraph (d) to read as

follows:

§ 25.473 Landing load conditions and

assumptions.

* * * * *

(d) The landing gear dynamic

characteristics must be validated by

tests as defined in § 25.723(a).

* * * * *

3. Section 25.723 is revised to read as

follows:

§ 25.723 Shock absorption tests.

(a) The analytical representation of

the landing gear dynamic characteristics

that is used in determining the landing

loads must be validated by energy

absorption tests. A range of tests must

be conducted to ensure that the

analytical representation is valid for the

design conditions specified in § 25.473.

(1) The configurations subjected to

energy absorption tests at limit design

conditions must include at least the

design landing weight or the design

takeoff weight, whichever produces the

greater value of landing impact energy.

(2) The test attitude of the landing

gear unit and the application of

appropriate drag loads during the test

must simulate the airplane landing

conditions in a manner consistent with

the development of rational or

conservative limit loads.

(b) The landing gear may not fail in

a test, demonstrating its reserve energy

absorption capacity, simulating a

descent velocity of 12 f.p.s. at design

landing weight, assuming airplane lift

not greater than airplane weight acting

during the landing impact.

(c) In lieu of the tests prescribed in

this section, changes in previously

approved design weights and minor

changes in design may be substantiated

by analyses based on previous tests

conducted on the same basic landing

gear system that has similar energy

absorption characteristics.

§ 25.725 [Reserved]

4. By removing and reserving

§ 25.725.

§ 25.727 [Reserved]

5. By removing and reserving

§ 25.727.

Issued in Renton, Washington, on May 9,

2001.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 01–12231 Filed 5–15–01; 8:45 am]

BILLING CODE 4910–13–M