[Federal Register Volume 68, Number 56 (Monday, March 24, 2003)]
[Proposed Rules]
[Pages 14276-14289]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-6918]



[[Page 14275]]

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Part II





Department of Transportation





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Federal Aviation Administration



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14 CFR Part 93



Noise Limitations for Aircraft Operations in the Vicinity of Grand 
Canyon National Park; Proposed Rule

  Federal Register / Vol. 68, No. 56 / Monday, March 24, 2003 / 
Proposed Rules  

[[Page 14276]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 93

[Docket No. FAA 2003-14715; Notice No. 03-05]
RIN 2120-AG34


Noise Limitations for Aircraft Operations in the Vicinity of 
Grand Canyon National Park

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: This supplemental notice of proposed rulemaking (SNPRM) amends 
the notice of proposed rulemaking (NPRM) published on December 31, 1996 
(Noise Limitations NPRM, 61 FR 69334; Notice 96-15), which proposed to 
establish noise efficiency limitations for certain aircraft operations 
at Grand Canyon National Park (GCNP). It proposes standards for quiet 
technology that are reasonably achievable, as mandated by Congress. The 
standards for quiet technology proposed in this SNPRM will help the 
National Park Service (NPS) achieve its statutory mandate to provide 
for the substantial restoration of natural quiet and experience in the 
GCNP. To meet this mandate, the FAA is proposing to use a noise 
efficiency approach (larger aircraft with more passenger seats are 
allowed to generate proportionally more noise) to define quiet 
technology. This SNPRM does not require any action by operators, as it 
is intended solely to make clear what the FAA is proposing as the 
standard for quiet technology.

DATES: Comments must be received on or before June 23, 2003.

ADDRESSES: Address your comments to the Docket Management System, U.S. 
Department of Transportation, Room PL401, 400 Seventh Street, SW., 
Washington, DC 20590-0001. You must identify Docket Number FAA-2003-
14715 at the beginning of your comments.
    You may also submit comments through the Internet to http://dms.dot.gov. You may review the entire public docket for this SNPRM at 
that same site.
    You may also review the public docket in person in the Docket 
Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office is on the plaza level.

FOR FURTHER INFORMATION CONTACT: Mr. Thomas L. Connor, AEE-100, Federal 
Aviation Administration, 800 Independence Avenue, SW., Washington, DC 
20591; Telephone: (202) 267-8933.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting written comments, data, or views. We also 
invite comments relating to the economic, environmental, energy, or 
federalism impacts that might result from adopting the proposals in 
this document. The most helpful comments reference a specific portion 
of the proposal, explain the reason for any recommended change, and 
include supporting data. 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 both before and after the closing date for receiving 
comments. Before taking any final action on this proposal, we will 
consider all comments made on or before the closing date for comments.
    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 the SNPRM

    You can get an 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 five digits of the Docket 
number shown at the beginning of this notice. Click on ``search.''
    (3) On the next page, which contains the Docket summary information 
for the Docket you selected, click on the document number for the item 
you wish to view.
    You can also get an electronic copy using the Internet through the 
Office of Rulemaking's Web page at http://www.faa.gov/avr/armhome.htm 
or the Federal Register's Web page at http://www.access.gpo.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 docket number, notice number or amendment number 
of this rulemaking.

Overview

    This supplemental notice of proposed rulemaking (SNPRM) amends the 
notice of proposed rulemaking (NPRM) published on December 31, 1996 
(Noise Limitations NPRM, 61 FR 69334; Notice 96-15), which proposed to 
establish noise efficiency limitations for certain aircraft operations 
at Grand Canyon National Park (GCNP). It proposes standards for quiet 
technology that are reasonably achievable, as mandated by Congress. The 
standards for quiet technology proposed in this SNPRM will help the 
National Park Service (NPS) achieve its statutory mandate to provide 
for the substantial restoration of natural quiet and experience in the 
GCNP. To meet this mandate, the FAA is proposing to use a noise 
efficiency approach (larger aircraft with more passenger seats are 
allowed to generate proportionally more noise) to define quiet 
technology. This SNPRM does not require any action by operators, as it 
is intended solely to make clear what the FAA is proposing as the 
standard for quiet technology. Further, this SNPRM does not relieve 
operators of the currently established operational limitations. As this 
SNPRM does not require any immediate action by operators, it has 
minimal costs or benefits. Any eventual costs and benefits will be 
assessed in any later rulemaking recommendations of how the quiet 
technology standards are applied. All decisions about implementing 
these standards, including possible establishment of quiet technology 
routes, incentives to encourage adoption of quiet technology, 
imposition of a phase out of aircraft that do not meet the quiet 
technology designation or other actions will be dealt with through the 
advisory group procedures as directed by the National Park Air Tour 
Management Act. This SNPRM, as it disposes of the comments that the FAA 
received in response to the Noise Limitations NPRM (95-15), also offers 
a short history of the legislative and regulatory actions with respect 
to air tour operations in the GCNP.

History

    Table 1 provides a timeline of events related to the effort to 
designate quiet technology requirements for commercial air tour 
operations in GCNP. These events are described in this and succeeding 
sections.
    Beginning in the summer of 1986, the FAA initiated regulatory 
action to

[[Page 14277]]

address increasing air traffic over GCNP. On March 26, 1987, the FAA 
issued Special Federal Aviation Regulation (SFAR) No. 50 (subsequently 
amended on June 15, 1987; 52 FR 22734) establishing flight regulations 
in the vicinity of the GCNP. The purpose of the SFAR was to reduce the 
risk of midair collisions, reduce the risk of terrain contact accidents 
below the rim level, and reduce the impact of aircraft noise on the 
park environment.

   Table 1.--Timeline of Events Related to the Designation of Quiet Technology for Air Tour Operations in GCNP
----------------------------------------------------------------------------------------------------------------
                  Year                                       Month                               Event
----------------------------------------------------------------------------------------------------------------
1987...................................  March/June..................................  The FAA publishes SFAR
                                                                                        No. 50 to establish
                                                                                        special flight
                                                                                        regulations in vicinity
                                                                                        of GCNP (52 FR 22734).
                                         August......................................  Congress enacts National
                                                                                        Parks Overflights Act
                                                                                        (Pub. L. 100-91).
                                         December....................................  The DOI transmits ``Grand
                                                                                        Canyon Aircraft
                                                                                        Management
                                                                                        Recommendation'' to the
                                                                                        FAA.
1988...................................  May/June....................................  The FAA publishes SFAR
                                                                                        No. 50-2 to revise
                                                                                        flight procedures in
                                                                                        GCNP airspace (53 FR
                                                                                        20264).
1994...................................  March.......................................  The FAA and NPS issue
                                                                                        ANPRM seeking public
                                                                                        comment on quiet
                                                                                        technology and
                                                                                        incentives (59 FR
                                                                                        12740).
                                         September...................................  The DOI submits to
                                                                                        Congress ``Report on
                                                                                        Effects of Aircraft
                                                                                        Overflights on the
                                                                                        National Park Systems''.
1995...................................  June........................................  The FAA extends SFAR No.
                                                                                        50-2 until June 15, 1997
                                                                                        (60 FR 31608).
                                         July........................................  The DOI report to
                                                                                        Congress is published.
1996...................................  April.......................................  The President publishes a
                                                                                        memorandum directing the
                                                                                        substantial restoration
                                                                                        of natural quiet in
                                                                                        GCNP.
                                         July........................................  The FAA publishes NPRM
                                                                                        (Notice 96-11) to amend
                                                                                        14 CFR part 93 to codify
                                                                                        SFAR No. 50-2 (61 FR
                                                                                        40120).
                                         December....................................  The FAA publishes final
                                                                                        rule to codify SFAR No.
                                                                                        50-2 into a new subpart
                                                                                        U of 14 CFR part 93 (61
                                                                                        FR 69302).
                                         December....................................  The FAA publishes NPRM
                                                                                        (Notice 96-15) on noise
                                                                                        limitations for air tour
                                                                                        operations in GCNP (61
                                                                                        FR 69334).
                                         December....................................  The FAA publishes notice
                                                                                        of availability of
                                                                                        proposed commercial air
                                                                                        tour routes (61 FR
                                                                                        69356).
1997...................................  February....................................  The FAA delays the
                                                                                        effective date of 14 CFR
                                                                                        sections 93.301, 93.305,
                                                                                        and 93.307 and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (62 FR
                                                                                        8862).
                                         May.........................................  The FAA publishes NPRM
                                                                                        (Notice 97-6) to
                                                                                        establish Bright Angel
                                                                                        incentive corridor and
                                                                                        the National Canyon
                                                                                        corridor for air tour
                                                                                        routes (62 FR 26902).
                                         October.....................................  The FAA publishes
                                                                                        clarification of its
                                                                                        reevaluation of the
                                                                                        economic and
                                                                                        environmental impacts of
                                                                                        the final rule published
                                                                                        on 12/31/96 (62 FR
                                                                                        58898).
                                         December....................................  The FAA further delays
                                                                                        the effective date of 14
                                                                                        CFR sections 93.301,
                                                                                        93.305, and 93.307 and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (62 FR
                                                                                        66248).
1998...................................  July........................................  The FAA withdraws the
                                                                                        National Canyon corridor
                                                                                        proposal (63 FR 38232).
                                         July........................................  The FAA also withdraws
                                                                                        Notice 97-6, which
                                                                                        proposed two quiet
                                                                                        technology incentive
                                                                                        corridors (63 FR 38233).
                                         December....................................  The FAA delays the
                                                                                        effective date of 14 CFR
                                                                                        sections 93.301, 93.305,
                                                                                        and 93.307 and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (63 FR
                                                                                        67544).
1999...................................  January.....................................  The NPS publishes a
                                                                                        notice of agency policy,
                                                                                        ``Evaluation Methodology
                                                                                        for Air Tour Operations
                                                                                        Over Grand Canyon
                                                                                        National Park'' (64 FR
                                                                                        3969).
                                         February....................................  The FAA delays the
                                                                                        effective date of 14 CFR
                                                                                        sections 93.301, 93.305,
                                                                                        and 93.307 and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (64 FR
                                                                                        5152).
                                         July........................................  The FAA published an NPRM
                                                                                        (Notice 99-11) to modify
                                                                                        the dimensions of the
                                                                                        GCNP SFRA (64 FR 37296).
                                         July........................................  The FAA also published
                                                                                        NPRM (Notice 99-12) to
                                                                                        limit the number of
                                                                                        commercial air tours
                                                                                        conducted in GCNP (64 FR
                                                                                        37304).
                                         July........................................  The NPS evaluation
                                                                                        methodology becomes
                                                                                        effective (64 FR 38006).
2000...................................  February....................................  The FAA delays the
                                                                                        effective date of 14 CFR
                                                                                        sections 93.301, 93.305,
                                                                                        and 93.307 and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (65 FR
                                                                                        5395).
                                         April.......................................  The FAA publishes the
                                                                                        commercial air tour
                                                                                        limitations final rule
                                                                                        (65 FR 17708).
                                         April.......................................  The FAA publishes the
                                                                                        airspace modification
                                                                                        final rule (65 FR
                                                                                        17736).
                                         April.......................................  Congress enacts the
                                                                                        National Parks Air Tour
                                                                                        Management Act of 2000
                                                                                        (Pub. L. 106-181, Title
                                                                                        VIII).
                                         May.........................................  The commercial air tour
                                                                                        limitations final rule
                                                                                        becomes effective (14
                                                                                        CFR 93.315, 317, 319,
                                                                                        321, 323, and 325).
                                         November....................................  The FAA delays the
                                                                                        effective date of the
                                                                                        airspace modification
                                                                                        final rule (65 FR
                                                                                        69846).
2001...................................  January.....................................  The FAA delays the
                                                                                        effective date of the
                                                                                        airspace modification
                                                                                        final rule and
                                                                                        reinstates portions of
                                                                                        SFAR No. 50-2 (66 FR
                                                                                        1002).
                                         March.......................................  The FAA and the NPS
                                                                                        jointly issue a notice
                                                                                        establishing the NPOAG
                                                                                        (66 FR 14429).
                                         March.......................................  The FAA delays the
                                                                                        effective date of the
                                                                                        airspace modification
                                                                                        final rule (66 FR
                                                                                        16582).
                                         April.......................................  The airspace
                                                                                        modifications final rule
                                                                                        becomes effective (14
                                                                                        CFR 93.301, 93.305,
                                                                                        93.307, and 93.309).
                                         June........................................  The FAA and the NPS
                                                                                        announce the National
                                                                                        Parks Overflights
                                                                                        Advisory Group
                                                                                        membership (66 FR
                                                                                        32974).
                                         December....................................  The FAA delays the
                                                                                        effective date of the
                                                                                        airspace modification
                                                                                        final rule (66 FR
                                                                                        63294).
----------------------------------------------------------------------------------------------------------------


[[Page 14278]]

    In August 1987, Congress enacted Public Law (Pub. L.) 100-91, 
commonly known as the National Parks Overflights Act (or the 
Overflights Act). The Overflights Act stated, in part, that noise 
associated with aircraft overflights at GCNP was causing ``a 
significant adverse effect on the natural quiet and experience of the 
park and current aircraft operations at the Grand Canyon National Park 
have raised serious concerns regarding public safety, including 
concerns regarding the safety of park users.''
    Section 3 of the Overflights Act required the Department of the 
Interior (DOI) to submit to the FAA recommendations to protect 
resources in the GCNP from adverse impacts associated with aircraft 
overflights. The law mandated that the recommendations: (1) Provide for 
substantial restoration of the natural quiet and experience of the park 
and protection of public health and safety from adverse effects 
associated with aircraft overflight; (2) with limited exceptions, 
prohibit the flight of aircraft below the rim of the canyon; and (3) 
designate flight-free zones except for purposes of administration and 
emergency operations.
    In December 1987, the DOI transmitted its ``Grand Canyon Aircraft 
Management Recommendation'' to the FAA. The Overflights Act required 
the FAA to prepare and issue a final plan for the management of air 
traffic above the GCNP, implementing the recommendations of the DOI 
without change unless the FAA determined that executing the 
recommendations would adversely affect aviation safety.
    On May 27, 1988, the FAA issued SFAR No. 50-2 revising the 
procedures for operation of aircraft in the airspace above the GCNP (53 
FR 20264). SFAR No. 50-2 established a Special Flight Rules Area (SFRA) 
from the surface to 14,499 feet above mean sea level (MSL) in the area 
of the GCNP. The SFAR prohibited flight below a certain altitude in 
each of five sectors of this area, with certain exceptions. The SFAR 
established four flight-free zones from the surface to 14,499 feet MSL 
covering large areas of the park. The SFAR provided for special routes 
for commercial sightseeing operators. These operators are required to 
conduct sightseeing operations under either part 121 or part 135 of 
Title 14 of the Code of Federal Regulations (CFR) as specified in their 
operations specifications. Finally, SFAR 50-2 contained certain terrain 
avoidance and communications requirements for flights in the area.
    In March 1994, the two agencies jointly issued an advance notice of 
proposed rulemaking (ANPRM) seeking public comment on policy 
recommendations addressing the effects of aircraft overflights on 
national parks, including GCNP (59 FR 12740). The recommendations 
presented for comment included: (1) Voluntary measures; (2) altitude 
restrictions; (3) flight-free periods; (4) flight-free zones; (5) 
allocation of noise equivalencies; and (6) incentives to encourage use 
of quiet aircraft technology. In response to the ANPRM, the FAA 
received 644 comments that specifically addressed GCNP.
    A second major provision of section 3 of the Overflights Act 
required the DOI to submit a report to Congress discussing whether SFAR 
No. 50 ``has succeeded in substantially restoring the natural quiet in 
the park; and such other matters, including possible revisions in the 
plan, as may be of interest.'' The report was to include comments by 
the FAA ``regarding the effect of the plan's implementation on aircraft 
safety.'' The Overflights Act mandated a number of studies related to 
the effect of overflights on parks.
    On September 12, 1994, the DOI submitted its final report and 
recommendations to Congress. This report entitled ``Report on Effects 
of Aircraft Overflights on the National Park System,'' was published in 
July 1995. The report recommended numerous revisions to SFAR No. 50-2 
in order to substantially restore natural quiet in GCNP. Recommendation 
No. 10, ``Improve SFAR 50-2 to Effect and Maintain the Substantial 
Restoration of Natural Quiet at Grand Canyon National Park,'' is of 
particular interest to this rulemaking. This recommendation 
incorporated the following general concepts: (1) Simplification of the 
commercial sightseeing route structure; (2) expansion of flight-free 
zones; (3) accommodation of the forecast growth in the air tour 
industry; (4) phased-in use of quieter aircraft technology; (5) 
temporal restrictions (``flight-free'' time periods); (6) use of the 
full range of methods and tools for problem solving; and (7) 
institution of changes in approaches to park management, including the 
establishment of an acoustic monitoring program by the NPS in 
coordination with the FAA. On June 15, 1995, the FAA published a final 
rule that extended the provisions of SFAR No. 50-2 to June 15, 1997 (60 
FR 31608).\1\ This action allowed the FAA sufficient time to review the 
NPS recommendations and to initiate and complete appropriate rulemaking 
action.
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    \1\ The provisions of SFAR No. 50-2 have been extended numerous 
times (60 FR 31608, 62 FR 8862; 62 FR 66248; 63 FR 67544; 64 FR 
5152; 65 FR 5395) with the last extension in January 2001 (66 FR 
1002).
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President's Memorandum

    The President, on April 22, 1996, issued a Memorandum for the Heads 
of Executive Departments and Agencies to address the significant 
impacts on visitor experience in national parks. Specifically, the 
President directed the Secretary of Transportation to issue proposed 
regulations for GCNP that would appropriately limit sightseeing 
aircraft to reduce the noise immediately and to further restore natural 
quiet, as defined by the Secretary of the Interior, while maintaining 
aviation safety in accordance with the Overflights Act.

Regulations

    On July 31, 1996, the FAA published an NPRM (61 FR 40120; Notice 
96-11) to reduce the impact of aircraft noise on GCNP and to assist the 
NPS in achieving its statutory mandate imposed by the Overflights Act 
to provide for the substantial restoration of natural quiet and 
experience in GCNP. A final rule was issued on December 31, 1996 (61 FR 
69302) to amend 14 CFR part 93 with a new subpart U (sections 93.301 to 
93.317). The amendment adopted the following: (1) Modification of the 
dimensions of the GCNP SFRA; (2) establishment of new flight-free zones 
and flight corridors, as well as modification of existing flight-free 
zones and flight corridors; (3) establishment of flight-free periods 
(curfews) in the Dragon and Zuni Point Corridors; and (4) establishment 
of reporting requirements for commercial sightseeing companies 
operating in the SFRA. This final rule also placed a temporary limit on 
the number of aircraft that could be used for commercial sightseeing 
operations in the GCNP SFRA. These provisions were to become effective 
on May 1, 1997. Only the reporting requirements, and aircraft cap were 
actually implemented. Implementation of the remaining provisions had 
been delayed.
    Additionally, on December 31, 1996, the FAA published an NPRM on 
Noise Limitations for Aircraft Operations in the Vicinity of Grand 
Canyon National Park (61 FR 69334; Notice 96-15), and a Notice of 
Availability of Proposed Commercial Air Tour Routes in the Federal 
Register (61 FR 69356). These two documents were part of an overall 
strategy to reduce further the impact of aircraft noise on the park 
environment

[[Page 14279]]

and to assist the NPS in achieving its statutory mandate imposed by the 
Overflights Act.

1996 Proposal for Quiet Technology Designation

    In the 1996 NPRM (Noise Limitations NPRM), Noise Limitations for 
Aircraft Operations in the Vicinity of Grand Canyon National Park, FAA 
proposed to establish noise limitations for certain aircraft operating 
in the vicinity of GCNP. The proposed aircraft noise limitations rule 
generally would have required air tour aircraft to be categorized 
according to each aircraft's noise efficiency. This NPRM sought to 
reduce the impact of air tour aircraft noise on GCNP and to assist NPS 
in achieving substantial restoration of natural quiet in GCNP. The 1996 
proposal had three parts: (1) Provide an incentive flight corridor 
through the National Canyon for noise efficient aircraft; (2) 
categorize aircraft by noise efficiency; and (3) remove the aircraft 
cap for the most noise efficient aircraft.
    First, the proposed rule would have implemented incentives to 
encourage operators to convert to the most noise efficient category of 
air tour aircraft. The NPRM also provided an incentive route for the 
use of noise efficient aircraft within the GCNP.
    Second, the NPRM proposed to divide air tour aircraft into three 
categories according to their level of noise efficiency, as measured by 
the relationship between the certificated noise level of the aircraft 
and the number of passenger seats on the typical configuration of that 
aircraft type. The noise efficiency concept was preferred because it 
encouraged the replacement of a tour aircraft with a larger, more noise 
efficient aircraft, which would both reduce the noise of each operation 
and reduce the number of air tour operations while still accommodating 
the same number of passengers. Additionally, the NPRM defined the three 
categories of noise efficiency as, Category A, the least noise 
efficient; Category B, more noise efficient than Category A; and, 
Category C, the most noise efficient. The NPRM proposed phasing-out the 
use of the least noise efficient aircraft.
    Third, the NPRM proposed removing the temporary cap placed on the 
number of aircraft permitted to be used for commercial sightseeing 
operations in the GCNP for operators using Category C air tour 
aircraft, the most noise efficient air tour aircraft in GCNP.
    The FAA's findings and recommendations were presented in full 
detail in the publication of the NPRM. Following the publication of the 
NPRM, as well as a number of other related rulemakings at the end of 
December 1996, the FAA and NPS jointly agreed that the best approach to 
substantially restore natural quiet in GCNP was to devote their 
resources to the development of those final rules that addressed 
critical near-term needs. Thus, priority was given to the promulgation 
of final rules on changes to the airspace over GCNP and establishment 
of operations limitations for air tour flights. The agencies again 
focused on the quiet technology rulemaking as soon as the airspace and 
operations limitation final rules were published in April 2000.

Related Federal Rulemaking and Policies Since 1996

    On February 26, 1997, the FAA published a final rule (62 FR 8862) 
that amended the effective date of modifications to the GCNP SFRA that 
were codified in an earlier final rule published on December 31, 1996. 
This action delayed the effective date for 14 CFR sections 93.301, 
93.305, and 93.307 of the final rule and reinstated portions of SFAR 
50-2 and amended the expiration date of that SFAR.\2\
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    \2\ The effective date for 14 CFR 93.301, 93.305, and 93.307 was 
delayed by subsequent amendments (62 FR 66248; 63 FR 67544; 64 FR 
5152; 65 FR 5395; 65 FR 69846; 66 FR 1002, 66 FR 16582) until 
finally becoming effective on April 19, 2001.
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    On May 15, 1997, the FAA published an NPRM (62 FR 26902; Notice 97-
6), which proposed to amend two of the flight-free zones within the 
GCNP by establishing two corridors through the flight-free zones. The 
first corridor through the Bright Angel Flight-Free Zone would have 
been an incentive corridor to be used only by the most noise efficient 
air tour aircraft. The second corridor in the Toroweap/Shinumo Flight-
Free Zone through the National Canyon area would have created a 
marketable air tour route in the central section of the Park while 
addressing some concerns of the Native Americans.
    After implementation of certain provisions of the final rule, the 
FAA discovered that it had underestimated the number of commercial air 
tour aircraft operating in GCNP in 1995. The FAA reevaluated the 
economic and environmental analyses completed for the final rule in 
light of this new information and determined that the changes were not 
of such magnitude as to affect the Agency's position on the 
implementation of the final rule. On October 31, 1997, the FAA 
published a notice of clarification (62 FR 58898) to set forth its 
reevaluation of the economic and environmental impacts associated with 
the Special Flight Rules in the Vicinity of Grand Canyon National Park 
(GCNP) Final Rule, published on December 31, 1996.
    On July 15, 1998, the FAA published an SNPRM (63 FR 38232) to the 
Noise Limitations NPRM published on December 31, 1996, removing from 
consideration two sections that proposed to establish a corridor in the 
Toroweap/Shinumo Flight-Free Zone through the National Canyon area as 
an incentive route for quiet technology aircraft. The FAA, in 
consultation with the NPS, removed these two sections from the NPRM 
because comments submitted by the air tour operators, the 
environmentalists, and the Native Americans led the two agencies to 
conclude that the National Canyon air tour route was not a viable 
option. At the same time, the FAA withdrew NPRM Notice 97-6, which had 
proposed quiet technology incentive corridors in the Park (63 FR 
38233)-- Bright Angel and the National Canyon corridors.
    On January 26, 1999, the NPS published for comment a public notice 
of agency policy, ``Evaluation Methodology for Air Tour Operations Over 
Grand Canyon National Park'' (64 FR 3969). This noise assessment 
methodology became effective on July 14, 1999 (64 FR 38006). The new 
policy adopted refinements to NPS' noise evaluation (i.e., impact 
assessment) methodology for air tour operations over GCNP. 
Specifically, the refinements adopted a two-zone system for assessing 
impacts related to substantial restoration of natural quiet at GCNP. In 
Zone One, encompassing about one-third of the Park's area, the 
threshold of noticeability previously used in noise modeling for 
environmental analyses related to GCNP air tours remains unchanged 
(i.e., the level at which people, otherwise preoccupied, would notice 
the noise, determined to be the average A-weighted natural ambient 
level plus 3 decibels(dB)). In Zone Two, encompassing about two-thirds 
of the Park's area, the threshold for the onset of impact is audibility 
(i.e., the level at which aircraft can begin to be heard by people with 
normal hearing, determined to be 8dB below the average A-weighted 
natural ambient level at GCNP). Because the noise model used to assess 
air tour overflight noise in the park is based upon A-weighted data, 
the adjustments of +3 and -8 dB are the respective conversion factors 
related to the thresholds of noticeability and audibility in terms of 
the noise frequency on the one-third-octave band.
    On July 9, 1999, the FAA published two NPRMs. One proposed to 
modify

[[Page 14280]]

the dimensions of the GCNP SFRA (64 FR 37296; Notice 99-11); the other 
(64 FR 37304; Notice 99-12) to limit the number of commercial air tours 
that could be conducted in the GCNP SFRA and to revise the reporting 
requirements for commercial air tours in the SFRA. A final rule on the 
latter proposal was published on April 4, 2000 (65 FR 17708). The rule 
temporarily limits commercial air tours in the SFRA at the level 
reported to the FAA by the operators for the year May 1, 1997-April 30, 
1998 (the base year), pending implementation of the comprehensive noise 
management plan. During the implementation of the commercial air tour 
limitation, the FAA and the NPS will collect further information 
regarding commercial SFRA operations and aircraft noise in GCNP. The 
NPS and the FAA will use the information collected during this time to 
determine whether the ``substantial restoration of natural quiet'' had 
been achieved at GCNP. In the event that the agencies determine that 
the statutory goal is not met through the various noise mitigation 
techniques adopted, the FAA and NPS will need to take further steps to 
achieve the substantial restoration of natural quiet. The commercial 
air tour limitation replaced the aircraft cap set forth in Sec.  
93.316(b).
    On April 4, 2000, the FAA also published a final rule (65 FR 17736) 
again modifying the airspace in the SFRA. This rule went into effect on 
April 19, 2001.\3\
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    \3\ The effective date for the airspace modification rule was 
delayed by subsequent amendments (65 FR 69846; 66 FR 1002; 66 FR 
16582) until becoming effective on April 19, 2001.
---------------------------------------------------------------------------

The National Parks Air Tour Management Act of 2000

    The National Parks Air Tour Management Act of 2000 (the Air Tour 
Act) was enacted on April 5, 2000, as Title VIII of Public Law 106-181 
(Pub. L. 106-181). The Air Tour Act applies to ``commercial air tour 
operations'' occurring over a unit of the national park, or within \1/
2\ mile outside the boundary of any national park, or tribal lands 
within or abutting a national park. Section 804 of the Air Tour Act 
states that ``within 12 months after the date of its enactment [April 
5, 2000], the Administrator shall designate reasonably achievable 
requirements for fixed-wing and helicopter aircraft necessary for such 
aircraft to be considered as employing quiet aircraft technology for 
purposes of this section.'' If the Administrator determines that it is 
not possible to make such designation before April 5, 2001, the 
Administrator shall transmit to Congress a report on the reasons for 
not meeting such time period and the expected date of such designation. 
Additionally, Congress mandated that once such a designation had been 
made, those commercial air tour operators who employ quiet aircraft 
technology shall not be subject to the commercial air tour operations 
flight allocations at GCNP, ``* * * provided that the cumulative impact 
of such operations does not increase noise at Grand Canyon.'' Finally, 
the Air Tour Act also directs that the Administrator, in consultation 
with the Director and the advisory group, shall establish, by rule, 
routes or corridors for commercial air tour operations by fixed-wing or 
helicopter aircraft that employ quiet aircraft technology at Grand 
Canyon National Park, ``* * * provided that such routes or corridors 
can be located in areas that will not negatively impact the substantial 
restoration of natural quiet, tribal lands, or safety.''

National Parks Overflights Advisory Group (NPOAG)

    On March 12, 2001, the NPS and FAA in accordance with the Air Tour 
Act, invited persons interested in participating on the NPOAG to send a 
letter to the FAA by April 2, 2001 (66 FR 14429). The NPOAG membership 
was announced on June 19, 2001 (66 FR 32974).
    In accordance with the Air Tour Act, the advisory group will 
provide advice, information, and recommendations to the Administrator 
and the Director--
    (1) On the implementation of this title [the Air Tour Act] and the 
amendments made by this title;
    (2) On commonly accepted quiet aircraft technology for use in 
commercial air tour operations over a national park or tribal lands, 
which will receive preferential treatment in a given air tour 
management plan;
    (3) On other measures that might be taken to accommodate the 
interests of visitors to national parks; and
    (4) At the request of the Administrator and the Director, safety, 
environmental, and other issues related to commercial air tour 
operations over a national park or tribal lands.
    The Air Tour Act also requires FAA to consult with the advisory 
group and the NPS on the establishment of routes or corridors for 
commercial air tour operations by fixed-wing and helicopter aircraft 
that employ quiet aircraft technology for--
    (1) Tours of the Grand Canyon originating in Clark County, Nevada; 
and
    (2) `Local loop' tours originating at the Grand Canyon National 
Park Airport, in Tusayan, Arizona.

GCNP Aircraft Noise Model Validation Study

    The noise modeling used in all of the GCNP environmental documents 
to date, remains the best science currently available and produces 
results consistent with available data. However, as noise modeling is a 
constantly evolving technology, both agencies are committed to making 
appropriate adjustments to the approaches and methodologies as new 
knowledge or science becomes available. In 1999, the NPS and the FAA 
jointly funded a noise model validation study to determine the degree 
of accuracy and precision of existing computer models. This study 
compares the existing candidate models for assessing air tour noise 
exposure with noise measurements taken in GCNP.\4\ The ongoing noise 
model validation effort is part of the FAA and NPS commitment to work 
cooperatively to meet the mandated goal of a substantial restoration of 
natural quiet in GCNP. The final results of this project, when they 
become available, could have an effect on both the determination of 
substantial restoration of natural quiet already achieved and the 
evaluation of alternative means of implementing quiet technology.
---------------------------------------------------------------------------

    \4\ The candidate models being validated are:
    1. The FAA's Integrated Noise Model, which has been modified to 
address air tour aircraft noise exposure in GCNP and is referred to 
as the GCNP Integrated Noise Model (GCINM).
    2. The National Park Service Overflight Decision Support System 
(NODSS) designed and programmed specifically for park applications 
to consider audibility, significant changes in terrain elevation, 
and shielding due to terrain.
    3. NOISEMAP Simulation Model (NMSIM) developed by the U.S. Air 
Force and the National Aeronautics and Space Administration (NASA) 
to simulate aircraft single event noise levels.
---------------------------------------------------------------------------

    As part of the Noise Model Validation Study efforts, the agencies 
jointly formed the Technical Review Committee (TRC) to review and 
comment on various technical issues that may arise related to the 
measurement, quantification and analysis of soundscapes. The TRC is 
composed of eight acoustics and statistical experts from academia, 
private companies, and government agencies.

Environmental Review

    In accordance with FAA Order 1050.1D, Appendix 4, Paragraph 4.j, 
the FAA has determined that this proposed rulemaking is categorically 
excluded from environmental review. The proposed rulemaking establishes 
quiet

[[Page 14281]]

technology designations for air tour aircraft operating in GCNP. It 
does not impose a phase-out or any alteration of any air tour 
operator's fleet of aircraft. In addition, the proposed rulemaking does 
not lift the operations limitation, alter any flight corridors through 
the Park, or make any change to the SFRA. Finally, the FAA notes that 
this proposed rulemaking has no impact on substantial restoration of 
natural quiet at GCNP and environmental and economic impacts will 
depend upon other future incentives yet to be defined. Accordingly, 
this proposed rulemaking will not individually or cumulatively have a 
significant effect on the human environment.

Consultation With Affected Indian Tribes

    Six Native American communities represented by eight separate 
tribal governments have ancestral ties to the Grand Canyon. Three of 
these communities have reservations that border the GCNP, the Navajo 
Nation to the east, and the Havasupai and Hualapai Tribes to the south. 
The Department of Transportation (DOT), FAA, DOI, NPS, Advisory Council 
on Historic Preservation (ACHP), Bureau of Indian Affairs (BIA), and 
Arizona State Historic Preservation Officer (SHPO) have consulted with 
these tribes, on a Government-to-Government basis, according to the 
provisions of the National Environmental Policy Act (NEPA), the 
National Historic Preservation Act (NHPA), and the Council on 
Environmental Quality regulations and other applicable laws and 
Executive Orders.
    In accordance with section 106 of the NHPA, the FAA issued a 
Determination of No Adverse Effect to the Traditional Cultural 
Properties (TCPs) for all of the tribes and/or nations, except the 
Hualapai Tribe, for the April 2000, rulemaking actions associated with 
the SFRA in the vicinity of the GCNP. As to the Hualapai Tribe, the FAA 
along with the NPS, the Advisory Council on Historic Preservation, the 
Hualapai Tribal Historic Preservation Officer (THPO) and the Hualapai 
Department of Cultural Resources signed a Programmatic Agreement on 
January 24, 2000, related to section 106 compliance and their TCPs.
    Due to new safety concerns raised by the Air Tour Operators related 
to the route and airspace modifications on the East End of the SFRA, 
only those modifications from west of the Dragon Corridor were 
implemented on April 19, 2001. In accordance with section 106 of the 
NHPA, if modifications are proposed for the East End commercial air 
tour routes and airspace to address the new safety concerns, the Navajo 
Nation and the other interested Native American tribes, specifically 
the Hopi Tribe and Pueblo of Zuni will be notified.

Public Input

    The FAA has reexamined the Noise Limitations NPRM in light of the 
direction provided in section 804 of the Air Tour Act. The mandate 
requires the Administrator to designate reasonably achievable 
requirements for airplanes and helicopters necessary for such aircraft 
to be considered as employing quiet aircraft technology for purposes of 
this section of the Act. The proposed quiet technology designations 
require air tour aircraft to be categorized according to each 
aircraft's noise efficiency. The eventual goal is to assist the NPS in 
achieving its statutory mandate imposed by Pub. L. 100-91 to provide 
for the substantial restoration of natural quiet and experience in the 
GCNP. This proposed rulemaking is related to and consistent with other 
rulemaking actions being implemented by the FAA concerning the GCNP.
    In addition, the SNPRM does not propose to implement the provision 
of the National Parks Air Tour Management Act of 2000 that would permit 
lifting the cap on commercial air tour operations in the Park. The 
implementation of any quiet technology incentive flight corridors and 
the removal of operations limitation for quiet technology aircraft will 
be the subject of future rulemaking as the FAA, in consultation with 
the NPS, works with an advisory group composed of representatives of 
general aviation, commercial air tour operations, environmental 
concerns, and Indian Tribes.
    The SNPRM also disposes of the comments that were received in 
response to the Noise Limitations NPRM (61 FR 69334). That NPRM 
proposed to establish noise limitations for certain aircraft operated 
in the vicinity of GCNP. The Noise Limitations NPRM had three parts: 
(1) Establish incentive flight corridor through the National Canyon; 
(2) categorize aircraft by noise efficiency; and (3) remove the 
aircraft cap for the most noise efficient aircraft.
    Interested persons were invited to participate in the rulemaking 
action by submitting written data, views, or comments. The comment 
period for the NPRM closed March 31, 1997. The comment period for the 
draft Environmental Assessment also closed on March 31, 1997. In 
response to the NPRM the FAA received 107 comments. All comments 
received were considered before issuing this SNPRM. An analysis of the 
comments not previously addressed in other rulemakings is provided 
below. The FAA responses take into account related Federal actions 
since 1996.
    Commenters include air tour operators and their representatives, 
environmental groups, sightseeing organizations, Native American 
tribes, pilots and pilot associations, and individuals. Most commenters 
do not support some or all aspects of the proposal. Generally, air tour 
operators who do not currently operate quiet aircraft are against a 
phase-out of noisier aircraft as proposed in 1996; one Native American 
tribe was against the proposal in the Noise Limitations NPRM to 
reintroduce a flight route through the National Canyon; while 
environmental organizations argue that by itself the Noise Limitations 
NPRM would not adequately restore the natural quiet to GCNP.

1. General Comments on Proposal

    The FAA received a number of general comments on the NPRM, 
including comments related to statutory issues, procedural complaints, 
and environmental concerns. Eagle Canyon Airlines (Eagle) (54), Vision 
Air (Vision) (61), and King Airlines, Inc. (King) (56) state that the 
Noise Limitations NPRM failed to identify the basis for the FAA's 
statutory authority for the proposed rulemaking.
    These commenters state that the Overflights Act gave the FAA the 
legal authority to issue SFAR 50, but not to take further action beyond 
that. These commenters also state that the FAA's reliance on its 
general authority, as stated in the FAA Act, for the Noise Limitations 
NPRM is misplaced. The FAA Act of 1958 does not give the FAA authority 
to protect ``environmental values'' or to promulgate a noise management 
plan, according to these commenters.
    The Helicopter Association International (HAI) (63) states that the 
proposals are arbitrary and capricious because unbiased data 
demonstrate that natural quiet has been restored at GCNP and air tour 
aircraft currently operating at GCNP are fully certificated by the FAA 
and in compliance with all applicable FAA safety and operating 
regulations.
    The General Aviation Manufacturers Association (GAMA) (64) states 
that the NPRM does not contain the necessary scientific data or 
substantiation to prove that the proposal will accomplish its goal. 
GAMA believes that basing a rulemaking on a broad and indefinite range 
of terms and objectives, such as

[[Page 14282]]

``interference'' or ``annoyance'' of visitors and ``substantial 
restoration of natural quiet,'' is subjective and arbitrary. GAMA fears 
that introducing noise limitations and forced attrition for aircraft 
presently operating in the vicinity of GCNP could be the beginning of a 
process that could progressively tear down the entire U.S. aviation 
system. GAMA believes that, if FAA's strategy were applied to the vast 
holding of federal lands, federal parks, state lands and state parks, 
it would severely impact the use of general aviation aircraft and some 
commercial airliners as well.
    Twin Otter (45) believes that quiet technology is the solution to 
the problem of achieving substantial restoration of natural quiet to 
the GCNP. However, the alternative, caps, curfews, and more limitations 
on how air tours can be conducted, is totally unacceptable.
    Lake Mead Air (26, 53) suggests that protecting the park experience 
from noise will be more effectively accomplished by routing traffic 
away from the park visitors than by use of quiet technology and 
altitude.
    Clark County Department of Aviation and the Las Vegas Convention 
and Visitors Authority (Clark County) (62) believe that the piecemeal 
nature of the FAA's Grand Canyon rulemaking makes it impossible for the 
public to meaningfully comment on the proposals. Clark County suggests 
that the FAA propose its entire Grand Canyon strategy--flight-free 
zones, tour routes, quiet aircraft requirements, and other measures--as 
one package, so that the public can determine the overall program.
    The United States Air Tour Association (USATA) (60) states that all 
of the various regulatory actions being implemented by the FAA should 
be combined into a single rulemaking effort to ensure that all the 
relevant issues are addressed as an integrated whole.
    Bell Helicopter Textron (91) and the Professional Helicopter Pilots 
Association (85) believe that there are substantial issues in 
controversy in this proposal, which should necessitate the use of 
negotiated rulemaking by means of the Aviation Rulemaking Advisory 
Committee (ARAC) process.
    The Sierra Club, Angeles and Grand Canyon Chapters (38, 75, 76), 
opposes the permissive growth of the air tour industry in the GCNP. The 
level of flight operations should be reduced to the 1975 levels.
    The Sierra Club, Grand Canyon Chapter, believes that the Noise 
Limitations NPRM can be part of an acceptable plan, but would not by 
itself substantially restore natural quiet at GCNP. The proposal would 
not bring GCNP into compliance with the Overflights Act, nor would it 
bring the park into compliance with the management objectives of the 
GCNP General Management Plan. Furthermore, the proposal would not 
implement the actions directed by President Clinton in his Earth Day 
memorandum (April 1996). The Overflights Act directs the FAA to 
implement the recommendations of the NPS, revised only for safety. The 
FAA has ignored the law in this regard and continues to promote the air 
tour industry.

FAA Response

    The Overflights Act charged the FAA, in concert with the DOI, to 
enact rulemaking and take what action is necessary to substantially 
restore the natural quiet and experience of our national parks, and to 
protect the public health and safety from adverse effects associated 
with overflights. This mandate granted the FAA with the necessary 
authority to promulgate any rule recommended by the NPS to effect the 
substantial restoration of the natural quiet and experience provided 
the FAA did not have any safety concerns. The practical effect of this 
second requirement is to ensure safe overflight of the GCNP by air tour 
aircraft.
    With the enactment of the Air Tour Act, the FAA has the authority 
to ``preserve, protect, and enhance the environment by minimizing, 
mitigating, or preventing the adverse effects of aircraft overflights 
on public and tribal lands.'' See section 802 of the Act. Thus, it is 
clear that the FAA has the authority to promulgate these rules. 
Additionally, in accordance with the Air Tour Act, the FAA has 
established the NPOAG to provide advice and counsel on the 
implementation of quiet aircraft technology at GCNP.
    The FAA notes that in order to accomplish the goal of substantial 
restoration of natural quiet, it is necessary to proceed with different 
types of regulations: (1) Those rules restricting airspace and limiting 
where air tour flights may go; (2) those rules limiting the number of 
air tours; and (3) those rules limiting the noise generated by air tour 
aircraft. It is for this reason that the FAA has adopted rules to 
enhance flight-free zones, modify the route structure, and limit the 
number of air tours in GCNP.

2. Natural Quiet

    A number of commenters address the question of whether the 
proposals would contribute to the substantial restoration of natural 
quiet in the GCNP. Grand Canyon Trust (Trust) (72) makes the following 
general observations:
    (1) Whatever regulatory scheme is ultimately implemented, that 
scheme must comply with the Overflights Act, and NPS, not the FAA, must 
determine whether and when natural quiet is substantially restored.
    (2) The FAA must implement rules that immediately restore natural 
quiet to the canyon.
    (3) The proposed rule must be substantially revised and 
strengthened because it will permit an immediate degradation of natural 
quiet.
    (4) Any revisions to the proposed rule will have to include an 
immediate conversion to the quietest aircraft and a cap on the number 
of tour operators at well below the 1987 level.
    The Sierra Club, Grand Canyon Chapter (76), states that the 
detectability level for defining natural quiet should be less than 5, 
rather than 17, which is used by NPS. The higher criterion shows an 
unrealistic prevalence of natural quiet. Furthermore, the definition of 
``substantial restoration of natural quiet'' is flawed. A more 
appropriate definition would require natural quiet all of the time in 
most of the park, and would require natural quiet most of the day in 
the rest of the park. Congress mandated action to restore natural quiet 
and to reduce negative impact from aircraft. The FAA and NPS policy of 
ignoring the effects of all aircraft except tour aircraft is 
inappropriate.
    HAI (63) states that banning some aircraft is not necessary to 
achieve ``restoration of natural quiet'' in GCNP, even when natural 
quiet is measured in the terms used by the NPS. HAI points out that the 
FAA's Draft Environmental Assessment (DEA), which accompanied the Noise 
Limitations NPRM, states that natural quiet at GCNP is within one 
percent of the NPS's goals without the imposition of any aircraft ban. 
HAI also believes that, in estimating aircraft operational and 
performance data, the FAA used inaccurate data and incorrect 
assumptions, thereby substantially overestimating the sound generated 
by the aircraft used in tour operations at GCNP. HAI further states 
that the FAA substantially underestimated the degree to which natural 
quiet has been restored under SFAR 50-2, and that, if the impact of 
aircraft overflight sound is measured in terms of visitor experience at 
GCNP, the data demonstrate that natural quiet has been restored to the 
Park. HAI believes that the FAA's aircraft sound prediction model 
substantially underestimates ground attenuation effects and that FAA

[[Page 14283]]

estimates of ambient sound at GCNP are unrealistically low.
    Bell Helicopter Textron (91) states that the ambient noise 
projections assigned to different areas of the Park are unrealistically 
low. This has the resultant effect of greatly overstating how long the 
aircraft's sound is detectable. Equally as damaging as this unrealistic 
projection is the assumption that there is no lateral attenuation of 
aircraft sound in the Grand Canyon. Such false assumptions understate 
the substantial restoration of natural quiet that currently exists in 
the GCNP.
    Clark County (62) comments that the FAA has provided no adequate 
basis to demonstrate the reasonableness of the defined ``natural 
quiet'' goal. Further, the FAA's ``time audible'' metric does not 
reasonably measure natural quiet. Clark County also states that the 
models used to estimate aircraft audibility have not been adequately 
explained and may overstate the extent to which aircraft can be heard.

FAA Response

    Since the issuance of the Noise Limitations NPRM, the NPS published 
a public notice of agency policy (64 FR 3969) titled Evaluation 
Methodology for Air Tour Operations Over Grand Canyon National Park. 
Comments to this notice were solicited and addressed by NPS. The policy 
refined the NPS' noise evaluation (i.e., impact assessment) methodology 
for air tour operations over GCNP. Specifically, the refinements 
included a two-zone system for assessing impacts related to substantial 
restoration of natural quiet at GCNP.
    The ongoing noise model validation effort is also part of the FAA 
and NPS commitment to work cooperatively to meet the mandated goal of 
substantial restoration of natural quiet in GCNP. The noise modeling 
used in all of the GCNP environmental documents to date, is the best 
science currently available. However, as noise modeling is a constantly 
evolving technology, both agencies are committed to making appropriate 
adjustments to the approaches and methodologies as new knowledge or 
science becomes available.
    With regard to the ambient noise database and the lateral 
attenuation calculation, the GCNP aircraft noise model validation 
project will address these facets. All existing evidence, including 
field measurements, support both the choice of an ambient noise level 
data file for the Park and the decision to suppress INM's lateral 
attenuation algorithm for GCNP noise modeling. In accordance with the 
Air Tour Act, the implementation of quiet technology is part of the 
Advisory Group consultative process. The FAA and NPS recognize that 
conversion to quiet technology aircraft in the GCNP will not likely 
result in achieving complete substantial restoration of natural quiet 
at GCNP.

3. Native American Tribal Concerns

    The Hualapai Tribe (52) states that it supports the use of quiet 
technology and generally supports the NPRM with the following 
exceptions: (1) The FAA has failed to consult with the Hualapai Tribe 
on a government-to-government basis as required by federal law; (2) the 
multiple rulemakings published by the FAA on the GCNP make the comment 
process more cumbersome, more expensive, and obscures the cumulative 
impact of the respective parts of the rulemakings; (3) there has been a 
double standard with respect to testing noise impact since no on-the-
ground noise testing and modeling has been undertaken with respect to 
the Hualapai Reservation, in collaboration with the Tribe; (4) the FAA 
needs to look at alternatives to quiet technology such as location of 
air tour routes and caps; (5) there need to be ``Tribal Flight Free 
Zones'' to protect cultural resources and practices, natural resources, 
and tourism industry, as well as limitations on the number of NPS 
flights over the Hualapai Reservation; (6) the FAA should delegate to, 
or share with, the Hualapai Tribe oversight authority to make sure that 
the quiet technology rules are being complied with over the 
Reservation; and (7) there should be an exemption from quiet technology 
requirements for tribal administrative flights, analogous to the NPS 
exemption, to avoid burdening the Tribe's sovereign authority to run 
its own government and administer its lands.

FAA Response

    The FAA has been consulting with the Hualapai in accordance with 
the provisions of the President's April 24, 1994, memorandum on 
Government-to-Government Consultation with Native American Tribes, and 
section 106 of the NHPA. The FAA has had numerous meetings with 
representatives of the Tribe's natural resources and cultural resource 
agencies since 1996. Additionally, the Hualapai have been part of the 
FAA and the NPS ongoing discussions with the other individual tribes. 
The Hualapai have also commented on several issues that have been 
addressed in previous rulemakings and were a cooperating agency on the 
February 2000 Final Supplemental Environmental Assessment (FSEA). The 
FAA responded to Hualapai comments similar to those noted above in the 
2000 FSEA. See Appendix G of the FSEA.
    The FAA has moved forward to implement recommendations from the NPS 
after completing a safety review of the NPS recommendations. This is 
consistent with the provisions of the Overflights Act. In each 
rulemaking the FAA attempts to outline the rulemaking history and 
economic impact. Some of these recommendations that have been finalized 
in the last two years are consistent with the Hualapai's comments on 
revising air tour routes and adopting limitations on the number of air 
tours in GCNP. See 65 FR 17708 and 65 FR 17736.
    In accordance with section 106 of the NHPA, the FAA issued a 
Determination of No Adverse Effect to the Traditional Cultural 
Properties (TCPs) for all of the tribes and/or nations, except the 
Hualapai Tribe, for the rulemaking actions associated with the SFRA in 
the vicinity of the GCNP. As to the Hualapai Tribe, the FAA along with 
the NPS, the Advisory Council on Historic Preservation, the Hualapai 
THPO, and the Hualapai Department of Cultural Resources signed a 
Programmatic Agreement on January 24, 2000 related to section 106 
compliance and their TCPs. The FAA notes that the United States 
generally supports leaving the skies open to aviation, with exceptions 
primarily for safety and security reasons. Flight-free zones were 
created in GCNP to help NPS achieve substantial restoration of natural 
quiet, pursuant to the mandates of the Overflights Act.
    The FAA notes that the sole purpose of this rule is to define quiet 
technology. This rule contains no specific requirements for operators 
to convert to quiet aircraft. Thus, the question of which entities are 
responsible for oversight of this rule is not relevant.
    In response to the request for an exemption to conduct 
administrative flights, the FAA reiterates that this and other 
rulemakings affect only flights satisfying the definition of a 
commercial air tour operation contained in 14 CFR 93.303. Moreover, 
this rule does not phase out aircraft that are not designated as quiet 
technology.

4. Classification of Aircraft by Noise Characteristics

    A number of commenters address the issues related to classification 
based on aircraft certification, as well as the three categories of 
aircraft classification contained in the Noise Limitations NPRM.
    Lake Mead Air (26, 53) believes that the standard for quiet 
aircraft should not be linked to the Aircraft Noise

[[Page 14284]]

Certification provisions prescribed in 14 CFR part 36, and listed in AC 
36-1F, since it is possible for aircraft to be reconfigured and flown 
differently than AC 36-1F. The FAA should make sound measuring 
equipment available at Las Vegas and Grand Canyon for determining 
actual flyover sound levels in the tour ``cruise configuration.'' If 
Category A aircraft can be retrofitted to Category B it should be 
encouraged since such a conversion would be more easily implemented 
than direct conversion to Category C.
    Clark County (62) states that the NPRM will unreasonably and 
arbitrarily burden air tour operators and the Las Vegas tourist 
economy. However, if the FAA based its categorization of aircraft on 
noise performance, rather than on certification, and provided options 
for compliance flexibility, there would be significantly less burden on 
tour operators, airborne visitors, and the economy of the Las Vegas 
area. Clark County states that it conducted a study of actual ambient 
and aircraft noise in GCNP in an attempt to validate FAA's methodology 
and found that using certification data, as a basis does not accurately 
represent aircraft noise levels in the GCNP, because it does not 
account for actual atmospheric and operational conditions in the GCNP. 
As a result, the FAA has placed aircraft in the noisier A or B 
categories that should belong in the B or C categories. Clark County 
states that the NPRM provides no means for operators to comply with the 
performance standards through the use of retrofitted equipment, quiet 
operating procedures, or other enforceable steps to reduce noise. This 
is at odds with the federal government's increasing attempt to use 
performance standards and provide compliance flexibility to reduce 
regulatory burden.
    An airline transport pilot (40) states that the noise propagation 
of a propeller driven airplane is largely dependent on the design and 
speed of its propeller. Design and speed are responsible for a greater 
share of the decibel level discernible in the hearing range than 
exhaust output, wing shape, loading of the airplane, cowl and airframe 
vibration, or accessory operation (e.g., flap extension, gear drag and 
parasitic friction). Since the design and speed factors affect all 
aircraft operating in the Grand Canyon a simple change, for example, 
operating a Cessna 207 at 2300 RPM instead of 2400 or 2500 RPM, can 
affect whether an aircraft should be placed in one category or another, 
if the categories are defined by noise values.
    Lake Mead Air (26, 53) states that the decibel range for quiet 
Category C helicopters starts at 80 dB whereas the fixed-wing threshold 
is 69 dB. If 80 dB meets Category C standards for helicopters it should 
also meet Category C standards for fixed-wing.
    Eagle (54) states that its F27 aircraft would not be covered under 
the NPRM. Size (48 passenger), noise tests, and decibel adjustments do 
not take the F27 into consideration.
    Professional Helicopter Pilots Association (85) states that the 
existence of aircraft capable of achieving the lower sound levels is 
still in the developmental stage such that only one manufacturer has 
any such helicopters available which have the performance capability 
for air tour operations. As a result the NPRM is premature and should 
not be implemented until technology improves.
    The Grand Canyon River Guides (GCRG) (50) state that helicopters, 
which are generally accepted to be the most obnoxious of aircraft and 
carry fewer people, should not fall into Category B, but should be put 
into Category A.
    Twin Otter (45) states that it is appropriate to take into account 
both the flyover sound level and aircraft passenger seating capacity in 
establishing which models qualify as Category C aircraft because a 
single Vistaliner replaces two flights with the nine passenger Cessna 
402/Piper Chieftain, nearly three flights in the seven passenger Cessna 
207 and four flights in the 4-5 passenger Bell Jetranger.
    Twin Otter adds that the Beechcraft C-99 and the Piper Chieftain 
could be retrofitted with four bladed props, as have the Vistaliners, 
thus converting them to Category C aircraft.
    Air Vegas (57) believes that its 15 Beechcraft C-99 aircraft should 
be deemed Category C since it utilizes the same basic power plant, the 
PT-6, as the Caravan and the Vistaliner, and has been modified for 
sightseeing operations to include extra windows. The average price for 
these aircraft, configured to meet Air Vegas specifications, is in 
excess of $1,300,000. These aircraft are adequately available and have 
proven to be cost effective. Furthermore, the FAA studies, which placed 
the Beechcraft C-99 into Category B, were based on max RPM level 2200 
RPM. If the RPM is reduced to 1900 (a reduction of 14 percent), there 
is an equal reduction of 14 percent in the dB level of the propeller, 
thus 68.2 dB. Air Vegas operations specifications require pilots to 
maintain propeller RPM at 1900 and with this power setting a Beechcraft 
C-99 is well below the Category C cutoff of 78 dB for a 15 passenger 
aircraft. Air Vegas believes there should be an incentive for 
decreasing the percent of time audible for the aircraft. Because of the 
higher speeds achievable by the Beechcraft C-99, as compared to the 
Vistaliner, the C-99's have an impact for less time.
    Scenic Airlines (74) states that the deHavilland DHC-6-300 Twin 
Otter with quiet propellers and the Cessna 208 (A & B models) must be 
classified as quiet aircraft technology (Category C). Furthermore, in 
developing Sound Exposure Level (SEL) dB limits, consideration must be 
given to the speed of an aircraft. Since disruption of natural quiet is 
measured in terms of ``Time of exposure'' the faster of two aircraft 
with the same dB output should be shown as the quieter.
    The Grand Canyon Trust (72) states that by defining the aircraft 
categories in terms of sound exposure level per passenger seat, the FAA 
obscures the fact that some Category C aircraft (e.g., the Vistaliner) 
are noisier than some Category A or B aircraft. The Trust further 
states that unless a cap is established on the number of operations 
Category C can fly, ultimately there will be no advantage to conversion 
to certain Category C aircraft. Therefore, the Trust's additional 
comments assume that such a cap will be implemented.
    Clark County (62) states that the FAA should set default noise 
levels and GCNP noise categories for the aircraft operating in GCNP 
using methodologies that accurately reflect conditions in GCNP and 
should validate the noise levels through field-testing. If this were 
done, some aircraft, such as the Beechcraft C-99 would actually meet 
Category C standards.
    Eagle (54), King (56), and Vision (61) state that the FAA's 
formulation of the aircraft categories in the NPRM is arbitrary and 
capricious for the following reasons:
    (1) The FAA fails to justify its placement of the dividing line 
between categories and has not consulted operators on this issue before 
establishing the categories.
    (2) Use of part 36 test results is not appropriate.
    (3) The proposed 4-dB distinction between Category A and Category C 
is inappropriate since it attempts to draw distinctions that cannot be 
discerned by most humans.
    (4) Distinctions between categories fail to account for the effect 
of speed on aircrafts' ``noiseprint.''
    (5) Tests that serve as a certification basis do not simulate 
actual operating conditions.
    (6) Categories discriminate against propeller-driven airplanes.

[[Page 14285]]

    (7) Proposed Category C could be met by only two types of existing 
aircraft, one of which is unavailable while the other is prohibitively 
expensive.
    Bell Helicopter Textron (91) states that the FAA's noise analysis 
incorrectly assumed that there is no lateral attenuation of aircraft 
sound. The effect of this false assumption is great considering that if 
the sound exposure levels attributed to aircraft were even 5 dB less, 
then up to six additional aircraft would be in compliance with the 
proposed Category C noise efficiency criteria.

FAA Response

    While this SNPRM replaces the three noise efficiency categories 
proposed in the Noise Limitations NPRM, the currently proposed quiet 
technology designation is based upon the same rationale and criteria. 
The FAA criteria for ``reasonably achievable'' quiet technology 
requirements include what is technologically practicable, economically 
reasonable, appropriate to the aircraft type design, and, in the final 
analysis, environmentally beneficial. The FAA also set forth the 
following attributes for any quiet technology designation. 
Specifically, the designation should:
    [sbull] Be based on aircraft noise certification (14 CFR part 36);
    [sbull] Judge fixed- and rotary-wing aircraft on a common basis;
    [sbull] Correlate with aircraft performance and operation at GCNP;
    [sbull] Offer basis for incentives; and
    [sbull] Be manageable.
    Noise levels obtained from aircraft noise certification represent 
the highest quality of data available. The flight tests are conducted 
under controlled conditions with an FAA representative or designee in 
attendance to witness the test setup and test activities. Data obtained 
during these flight tests are corrected to standard reference 
conditions as prescribed in 14 CFR part 36. The certification tests are 
designed to acquire noise levels representing the noisiest flight 
configurations for small propeller-driven airplanes and helicopters. 
FAA believes that this is appropriate for the GCNP situation as the 
certification flight configurations are also the noisiest 
configurations that could be used over the park. Thus, the sightseeing 
aircraft can be judged equally, fairly, and without the concern that 
the noise levels are undervalued.
    The airport community has many years of experience using the 
certificated noise levels. FAA publishes these levels in Advisory 
Circular (AC) 36-1, ``Noise Levels for U.S. Certificated and Foreign 
Aircraft.'' The current version of this AC is 36-1G, dated August 27, 
1997. These data have been used to establish use restrictions, curfews, 
and noise budgets at some airports in the country. The certificated 
noise levels are not only available in the advisory circulars, which 
are updated and published periodically, but the levels are readily 
available to the aircraft owners from aircraft flight manuals (AFM).
    The quiet technology designation based on certificated noise levels 
is proposed not only because of the long-standing precedent, but also 
because it eliminates the need for someone to make such measurements in 
the field. Years of experience with using data obtained from airport 
noise monitoring systems have shown that noise levels obtained under 
uncontrolled conditions are highly variable. This problem can only be 
overcome by obtaining very large samples of measured data to reduce the 
statistical uncertainty. Thus, FAA believes that a quiet technology 
designation based on measured data taken at GCNP would be economically 
unreasonable and susceptible to statistical error.
    Unfortunately, there is no single method applicable to all aircraft 
for determining the certificated noise level. Depending on date of 
application for type certificate and whether the aircraft is a 
helicopter or small propeller-driven airplane, the noise level could 
have been obtained from one of four different tests. With measurements 
taken for different flight operations, at three different altitudes, 
and in three different units of noise, it is not possible to directly 
compare certificated noise levels obtained for helicopters with those 
of small propeller-driven airplanes. As reported in the study, 
``Methodology to Categorize the Noise Efficiency of Air Tour Aircraft 
in GCNP,'' FAA developed a procedure for: (1) extrapolating from the 
controlled conditions of a certification test to the operating 
conditions at GCNP and (2) converting levels to a common noise unit, 
thus making it possible to judge airplanes and helicopters on a common 
basis under conditions that pertain to air tour operations over GCNP. 
As a result of the study, FAA found that it is possible to extrapolate 
from the certification conditions applicable to helicopters and small 
propeller-driven airplanes to produce a consistent set of noise levels 
under conditions similar to those at GCNP.
    FAA finds that the noise efficiency concept, which was proposed in 
the Noise Limitations NPRM and re-proposed in this SNPRM, albeit 
modified to designate quiet technology, exhibits all of the desired 
attributes for the quiet technology designation. The concept is 
technically sound as it takes into account aircraft design, flight 
configuration, acoustic characteristics, productivity, and economic 
reasonableness. As the concept is based upon the certificated noise 
levels, the FAA is able to judge the noise of the commercial 
sightseeing aircraft consistently, fairly, and without the additional 
cost and technical problems found in field monitoring. In concert with 
related actions with respect to the airspace and air tour operations, 
the quiet technology designation can be an effective means toward 
substantially restoring natural quiet at GCNP.
    The FAA notes that this SNPRM is essentially a definition of quiet 
technology taking into account the technological capabilities of 
aircraft available in the used marketplace, including the existence of 
aircraft type design modifications to reduce noise levels. As this 
action merely defines quiet technology but does not impose any 
requirements, the FAA does not expect any economic impact on the 
operators of GCNP air tours. The FAA seeks comments before moving to 
future related rulemaking in consultation with the NPS and in 
coordination with an advisory group composed of general aviation, 
commercial air tour operations, environmental concerns, and Native 
American interest.

5. Phase Out of Less Noise Efficient Aircraft

    A number of commenters addressed the proposal to phase out noisier 
aircraft to further reduce noise impacts in GCNP. As described in the 
Noise Limitations NPRM, less noise efficient aircraft would have been 
gradually phased out starting in the year 2000 with the phase out of 
Category A aircraft and continuing through to the end of 2008 at which 
point all Category B aircraft would be phased out and only Category C 
aircraft would remain. The phase out would have limited future use of 
less noise efficient aircraft in GCNP and would also have provided an 
incentive for the use of the most noise efficient aircraft.
    This SNPRM only proposes to define the quiet aircraft technology 
designation. The quiet technology designation is predicated on the 
notion that the use of larger, relatively quieter aircraft (on a per 
seat basis) is helpful in reaching the goal of substantial restoration 
of natural quiet through a combination of reduction of noise at the 
source and reduction in the number of tour operations. Under the 
provisions of section 804 of the Air Tour Act, all

[[Page 14286]]

incentives to replace current aircraft with those satisfying the 
definition must be recommended by the NPOAG. Thus, any proposals to 
encourage the transition to quiet technology will be addressed in 
subsequent FAA rulemaking in consultation with the NPS and the NPOAG.

6. Removal of Temporary Cap

    A number of commenters addressed the proposal to remove the cap on 
air tour aircraft for all Category C aircraft. This change was proposed 
as an incentive for conversion to noise efficient aircraft.
    Since the Noise Limitations NPRM, the FAA has issued a final rule 
that replaced the cap on the number of air tour aircraft with an 
operations limitation on the annual number of commercial air tour 
operations in the GCNP SFRA (65 FR 17708). Thus, a discussion of the 
comments on the removal of the air tour aircraft cap is irrelevant. The 
Air Tour Act provides that ``Commercial air tour operations by any 
fixed-wing or helicopter aircraft that employs quiet aircraft 
technology and that replaces an existing aircraft shall not be subject 
to the operational flight allocations that apply to other commercial 
air tour operations of the Grand Canyon, provided that the cumulative 
impact of such operations does not increase noise at the Grand 
Canyon.'' (See section 804(c) of the Act; emphasis added). As discussed 
below, the FAA does not foresee at this time that the operations 
limitations would be lifted in any meaningful way since once commercial 
air tour operations increased, noise would increase, even if all 
operators used quiet technology aircraft.
    As documented in the February 2000 FSEA accompanying the commercial 
air tour limitation final rule, only 44 percent of the Park (on an 
annual average day) achieved substantial restoration of natural quiet 
upon implementation of the air tour limitations and changes to routes 
and airspace adopted in April 2000. The FAA and NPS note that this 
percentage may change once the revised east end routes are adopted and 
implemented. The FAA has evaluated whether the designation of quiet 
technology requirements, contained in this SNPRM, will enable the FAA 
to relieve commercial air tour operators from the present commercial 
air tour operations limitation. More specifically, the FAA conducted 
studies to determine the extent to which use of quiet technology 
aircraft could possibly enable air tour operators to increase 
operations without increasing cumulative noise levels at GCNP pursuant 
to section 804 of the Air Tour Act.
    The FAA test was conducted by assessing the sensitivity of the 25% 
TA12hr \5\ contour to increases in quiet technology aircraft 
operations using the GCINM. The 25% TA12hr contour has been 
the measure used in the environmental assessments associated with all 
GCNP SFRA rulemaking to assess progress towards the goal of substantial 
restoration of natural quiet. The particular GCNP air tour scenario 
chosen for this test was the preferred alternative of the February 2000 
FSEA that accompanied the April 2000 final rules (65 FR 17708 and 65 FR 
17736). Two separate runs of the GCINM were performed; airplane 
operations on Zuni Reverse and helicopter operations on the Green 1 
loop. The analysis found that adding less than four annual airplane 
operations or three annual helicopter operations would increase the 25% 
TA12hr contour area by 0.01 sq. mi. FAA chose a hundredth of 
a square mile as the threshold of significance because contour areas in 
the GCNP EA documents have been reported to that significant digit.
---------------------------------------------------------------------------

    \5\ The time above (TA) metric provides the duration that 
aircraft related noise exceed specified sound threshold. For 
assessment of aircraft noise in GCNP, the %TA12h 
represents the percentage of time aircraft are audible during the 
12-hour daytime period of primary visitor activity. The 25% 
TA12h contour (the area where aircraft are audible 
greater 25% of the time) measures the extent that the criterion for 
substantial restoration of natural quiet is met. When the 25% 
TA12h contour for a particular alternative occupies less 
than half of the area of GCNP then that alternative has achieved 
substantial restoration of natural quiet at the Park.
---------------------------------------------------------------------------

    The above result supports the FAA's preliminary finding that 
aircraft that meet the quiet technology designation operating without 
operations limitation will likely cumulatively increase noise in the 
GCNP. Given that the Air Tour Act only provides relief from the 
operations limitation when the cumulative impact of such operations 
does not increase noise at GCNP, the FAA would likely be unable to 
remove the commercial air tour operations limitation. Removal of the 
operations limitation will be addressed in subsequent FAA rulemaking in 
consultation with the NPS and the NPOAG as directed by the Air Tour 
Act.

7. Other or Alternative Incentives

    A number of commenters responded to the FAA's request for comments 
regarding alternative or additional incentives for operators to convert 
to noise efficient technology.
    Lake Mead Air (26, 53) states that with the conversion to ``quieter 
aircraft'' several companies will not be able to meet the standard and 
will sell or close. Other incentives for quiet aircraft technology 
should be considered such as tax credits or subsidies, for example the 
FAA could pay the air tour operators not to fly Category A aircraft, 
similar to soil banks. Furthermore, more noise efficient aircraft 
should be phased in rather than phasing out the less noise efficient 
aircraft.
    Twin Otter (45) states that it is an oversight that the FAA has not 
provided for a quiet aircraft corridor in the eastern section of the 
canyon. Twin Otter then comments on routes proposed in 1996 that are no 
longer part of this rulemaking.
    Twin Otter recommends the following additional incentives for 
Category C aircraft: (1) Lift the aircraft cap immediately on the 
number of Category C aircraft that may be operated; (2) eliminate the 
curfew for Category C aircraft, and if this is not possible, then 
permit Category C aircraft to operate one hour before and one hour 
later than curfew hours for conventional aircraft (official sunrise at 
GCNP is two hours earlier than the curfew permits for most of the 
summer); (3) roll back the overflights fee for Category C aircraft as 
an additional incentive; and (4) require helicopters to fly at the 
highest possible altitude in the Zuni Corridor so that airplanes can 
conduct tours at a lower altitude and establish the lowest airplane 
tours in the Zuni for Category C qualifying aircraft.
    Grand Canyon Airlines (GCA) (46) supports the concept of the 
proposed amendment to part 93. GCA also believes that the FAA needs to 
provide quiet aircraft incentive routes in the eastern region. Category 
B helicopters are permitted to operate at the lowest possible altitude 
in the eastern region and they are even encouraged to fly in the most 
sensitive Dragon Corridor with the lowest altitudes and shortest direct 
routes. This makes the airplane Category C air tours less attractive 
than the noisier Category B helicopters in this region. To correct this 
disparity the Category C aircraft should be given the lowest possible 
routes in the eastern region. GCA makes the following recommendations: 
(1) Provide a Category C incentive route over the existing Black 1 
route; (2) minimize advantages to Category B helicopter routes by 
creating new Category C routes that provide superior tour features; (3) 
waive overflight fees to Category C aircraft; and (4) eliminate caps 
and curfews on Category C aircraft.
    Papillon (55) also supports the timeframe for transition to quiet 
technology and the guidelines for qualifying aircraft as quiet 
technology,

[[Page 14287]]

but recommends 35 dB as the threshold of substantial natural quiet for 
the GCNP. The following incentives for quiet technology should be 
implemented for Category C aircraft only: (1) Eliminate the GCNP 
overflight fee; (2) create a route across the North Rim (through the 
Bright Angel Flight-Free Zone); (3) permit Category C aircraft to use 
alternate routes that may enter flight-free zones to show specific 
landmarks; (4) establish new curfews of one hour after sunrise and one 
hour before sunset; and (5) restore the two-way helicopter loop in the 
Zuni Corridor.
    An individual commenter (68) states that more incentives need to be 
utilized to help air tour operators convert to quiet technology. This 
commenter suggests the following incentives: (1) Waiving overflight 
fees and park admission fees for passengers; (2) offering and approving 
low-cost government loans and tax credits; and (3) establishing new 
quality view corridors through which only Category C aircraft could fly 
at lower altitudes.
    Scenic Airlines (Scenic) (74) states that while 75 percent of the 
passengers it flew in 1996 were flown in Category C aircraft about one 
half of its air tour fleet are Category A aircraft. While Scenic would 
like to convert these Category A to Category C, it must be provided 
with incentives, in the form of privileges that operators and 
passengers can value, before it would voluntarily do so. Operators have 
only invested in Category C aircraft in the past based on the promise 
by the NPS that they will be rewarded in the future. If no such rewards 
materialize there will be a disincentive to convert to Category C's in 
the future.
    Scenic states that the following Category C incentives should be 
provided: (1) A route through the northern portion of the expanded 
Bright Angel Flight-Free Zone using the existing Black 1A and Green 1A 
(SFAR 50-2); (2) a route along the current Brown 3 (SFAR 50-2) 
departure which goes through the northwest corner of the Toroweap 
Flight-Free Zone; (3) waiver of curfews in Dragon and Zuni corridors to 
extend the hours of operation to Daylight hours; (4) waiver of 
overflight fees; (5) investment tax credits; and (6) low cost 
government loans.
    AirStar Helicopters, Inc. (AirStar) (84) states that the following 
incentives for transition to noise efficient aircraft should be 
considered: low cost loans, overflight fee rebates or investment tax 
credits. AirStar also states that it has already begun the transition 
to quiet technology.
    The Grand Canyon Trust (72) proposes the use of Dragon and Zuni 
Corridors as quiet aircraft incentives routes for Category C aircraft 
only.

FAA Response

    This SNPRM only proposes to define quiet aircraft technology. Under 
the provisions of section 804 of the Air Tour Act, all incentives to 
replace current aircraft with those satisfying the definition must be 
developed through the consultative process with the NPOAG. Thus, 
proposals to encourage the transition to quiet technology will be 
addressed in subsequent FAA rulemaking. The NPOAG will provide advice 
and recommendations on, among other things, the establishments of 
routes and corridors for the operation of quiet technology aircraft for 
tours originating in Clark County, Nevada and for ``local loop'' tours 
originating at the GCNP Airport in Tusayan, Arizona. The FAA notes that 
section 804(b) of the Air Tour Act allows such incentive routes 
``provided that such routes or corridors can be located in areas that 
will not negatively impact the substantial restoration of natural 
quiet, tribal lands, or safety.''

8. Draft Environmental Assessment (DEA)

    In 1996, the DEA analyzed a different Federal action than is now 
proposed by the FAA. Therefore, the FAA is not pursuing completion of 
that NEPA document for this SNPRM and the comments received on the DEA 
are no longer relevant.
    Rather, in accordance with FAA Order 1050.1D, the FAA has 
determined that this proposed rulemaking is categorically excluded from 
environmental review under section 102(2)(C) of the National 
Environmental Policy Act of 1969 (NEPA). The proposed rule is 
categorically excluded under FAA Order 1050.1D, Appendix 4, Paragraph 
4.j, which covers regulations ``excluding those that if implemented may 
cause a significant impact on the human environment.'' Unlike the DEA 
completed with the Noise Limitations NPRM, this proposed rulemaking 
simply establishes quiet technology designations for air tour aircraft 
operating in GCNP. It does not impose a phaseout or any alteration of 
any air tour operator's fleet of aircraft. In addition, the proposed 
rulemaking does not lift the operations limitation, alter any flight 
corridors through the Park, or make any change to the SFRA. Finally, 
the FAA notes that this proposed rulemaking alone has no impact on 
substantial restoration of natural quiet at GCNP and environmental and 
economic impacts will depend upon other future incentives yet to be 
defined. Accordingly, this proposed rulemaking will not individually or 
cumulatively have a significant effect on the human environment.

Potential Further Action

    As proposed, the FAA would designate a standard for quiet 
technology that would apply to certain aircraft in commercial air tour 
operations over GCNP. Under the provisions of Section 804 of the Air 
Tour Act, the implementation of quiet technology will be addressed in 
subsequent FAA rulemaking in consultation with the NPS and the NPOAG. 
The NPOAG will provide advice and recommendations on, among other 
things, the establishments of routes and corridors for the operation of 
quiet technology aircraft for tours originating in Clark County, Nevada 
and for ``local loop'' tours originating at the GCNP Airport in 
Tusayan, Arizona. The FAA notes that section 804(b) of the Air Tour Act 
allows such incentive routes ``provided that such routes or corridors 
can be located in areas that will not negatively impact the substantial 
restoration of natural quiet, tribal lands, or safety.'' Since the 
ultimate objective is to determine the role of quiet technology in 
achieving substantial restoration of natural quiet, the FAA is 
requesting specific comments to address quiet technology within the 
context of the implementation issue:
    1. How reasonable is the noise efficiency approach (larger aircraft 
with more passenger seats are allowed to generate proportionally more 
noise) to define quiet technology and how appropriate is the use of 
certificated noise level as the basis?
    2. What provisions should be made for changes in technology that 
result in source noise reduction and/or increased noise efficient 
aircraft designs?
    3. What economic and operational incentives should be considered in 
order to achieve the transition to quieter aircraft and how should the 
quiet technology designation be used in the establishment of the 
incentives?
    4. Should incentives include a ``flexible'' cap that would permit 
increasing operations of aircraft based upon the acquisition of leading 
edge noise efficient technology by operators?
    5. Should growth be tied to an incentive system for existing 
operators to convert their fleet to quiet technology?
    6. What operational limitations (phase-out, expanded curfews, noise 
budgets, quota system, etc.) should be considered and how should the 
quiet

[[Page 14288]]

technology designation be used in the setting of the limitations?

Economic summary

    Proposed 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. 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 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, in any one year (adjusted for inflation).
    However, for regulations with an expected minimal impact the above-
specified 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 SNPRM serves only to refine the 
quiet technology definition applied to air tour aircraft operating in 
GCNP developed in the Noise Limitations NPRM, and removes all 
compliance requirements proposed in that NPRM, the expected outcome is 
to have a minimal impact.
    The SNPRM retains the ``noise efficiency'' concept defined by the 
relationship between the certificated noise level of an aircraft and 
the number of passenger seats on the typical configuration of that 
aircraft type as initially proposed in the Noise Limitations NPRM. 
However, the three principal rulemaking elements of 61 FR 69334 have 
been eliminated. The SNPRM replaces the three noise efficiency 
categories that were proposed in the Noise Limitations NPRM and 
proposes to temporarily continue to rely on the designation of quiet 
technology aircraft, those that were formerly described as Category C. 
Furthermore, the SNPRM does not propose any phaseout of air tour 
aircraft that do not comply with the Category C quiet technology 
designation. Nor does it include any incentive flight corridors through 
the park as proposed in December 1996. Finally, as noted above, the 
SNPRM does not lift the operations limitation on commercial air tour 
operations conducted in the Park that has replaced the 1996 aircraft 
cap for those aircraft meeting the Category C noise efficiency 
standard.
    Therefore, this SNPRM is essentially a definition of quiet 
technology and has negligible economic impact on the operators of GCNP 
air tours. The FAA seeks public comment before moving to future FAA 
rulemaking in consultation with the NPS. Future rulemaking would be 
coordinated with an advisory group composed of representatives of 
general aviation, commercial air tour operations, environmental 
concerns, and Native American interests.

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 RFA requires agencies to 
solicit and consider flexible regulatory proposals and to explain the 
rationale for their actions. The RFA covers a wide-range of small 
entities, including small businesses, not-for-profit organizations and 
small governmental jurisdictions.
    Agencies must perform a review to determine whether a proposed or 
final rule will have a significant economic impact on a substantial 
number of small entities. If the 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 RFA provides that the 
head of the agency may so certify and a regulatory flexibility analysis 
is not required. The certification must include a statement providing 
the factual basis for this determination, and the reasoning should be 
clear.
    This action merely defines quiet technology but does not impose any 
requirements. Therefore, the FAA does not expect this rule to impose 
any cost on small entities. Consequently, the FAA certifies that the 
rule will not have a significant economic impact on a substantial 
number of small air tour operators.

International Trade Impact Analysis

    The Trade Agreement Act of 1979 prohibits Federal agencies from 
engaging in any standards or 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 accordance with the above statute, the FAA has assessed the 
potential effect of this proposed rule to be minimal and, therefore, 
has determined that this rule will not result in an impact on 
international trade by companies doing business in or with the United 
States.

Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 (the Act), enacted as 
Public Law 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 proposed rule does not contain such a mandate. Therefore, the 
requirements of Title II of the Unfunded Mandates Reform Act of 1995 do 
not apply.

Federalism Implications

    The regulations herein would not have substantial direct effects 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, in accordance with Executive 
Order 12866, it is determined that this rule does not have sufficient 
federalism implications to warrant the preparation of a Federalism 
Assessment.

[[Page 14289]]

Consultation with Tribal Governments

    Executive Order 13084 provides for consultation and coordination 
with Indian tribal governments in certain circumstances that are set 
forth in the executive order. We have discussed above the ways in which 
we have consulted with Indian tribal governments about this proposed 
rule and taken their concerns into account. The FAA determined that 
additional consultations were not necessary because the proposed rule 
is required by statute and would not impose any substantial direct 
compliance costs on the communities of Indian tribal governments.

Paperwork Reduction Act

    In accordance with the Paperwork Reduction Act of 1995 (Pub. L. 
104-13), there are no requirements for information collection 
associated with the SNPRM.

List of Subjects in 14 CFR Part 93

    Air traffic control, Airports, Navigation (Air), Reporting and 
recordkeeping requirements.

The Amendment

    For reasons set forth above, the Federal Aviation Administration 
proposes to amend part 93, in Chapter I of Title 14, Code of Federal 
Regulations, as follows:

PART 93--SPECIAL AIR TRAFFIC RULES AND AIRPORT TRAFFIC PATTERNS

    1. The authority citation for part 93 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40103, 40106, 40109, 40113, 44502, 
44514, 44701, 44719, 46301.

    2. Section 93.303 is amended by adding a definition to read as 
follows:


Sec.  93.303  Definitions.

* * * * *
    Quiet technology aircraft means an aircraft that is subject to 
Sec.  93.301 and has been shown to comply with the noise limit 
specified in appendix A of this part.
* * * * *
    3. Appendix A is added to read as follows:

Appendix A to Part 93--GCNP Aircraft Quiet Technology Designation

    This appendix contains procedures for determining the quiet 
technology status for each aircraft subject to Sec.  93.301 
determined during the noise certification process as prescribed 
under part 36 of this chapter. Where no certificated noise level is 
available, the Administrator may approve an alternative measurement 
procedure.

1. Aircraft Noise Limit for Quiet Technology

    A. For helicopters with a flyover noise level obtained in 
accordance with the measurement procedures prescribed in Appendix H 
of 14 CFR part 36, the limit is 80 dB for helicopters having two or 
fewer passenger seats, increasing at 3 dB per doubling of the number 
of passenger seats for helicopters having three or more passenger 
seats. The limit at number of passenger seats of three or more can 
be calculated by the formula:

EPNL(H) = 80+10log( PAX seats/2) dB

    B. For helicopters with a flyover noise level obtained in 
accordance with the measurement procedures prescribed in Appendix J 
of 14 CFR part 36, the limit is 77 dB for helicopters having two or 
fewer passenger seats, increasing at 3 dB per doubling of the number 
of passenger seats for helicopters having three or more passenger 
seats. The limit at number of passenger seats of three or more can 
be calculated by the formula:

SEL(J) = 77+10log( PAX seats/2) dB

    C. For propeller-driven airplanes with a measured flyover noise 
level obtained in accordance with the measurement procedures 
prescribed in Appendix F of 14 CFR part 36 without the performance 
correction defined in Sec. F36.201(c), the limit is 69 dB for 
airplanes having two or fewer passenger seats, increasing at 3 dB 
per doubling of the number of passenger seats for airplanes having 
three or more passenger seats. The limit at number of passenger 
seats of three or more can be calculated by the formula:

LAmax(F) = 69+10log( PAX seats/2) dB

    D. In the event that a flyover noise level is not available in 
accordance with Appendix F of 14 CFR part 36, the noise limit for 
propeller-driven airplanes with a takeoff noise level obtained in 
accordance with the measurement procedures prescribed in Appendix G 
is 74 dB for airplanes having two or fewer passenger seats, 
increasing at 3 dB per doubling of the number of passenger seats for 
airplanes having three or more passenger seats. The limit at number 
of passenger seats of three or more can be calculated by the 
formula:

LAmax(G) = 74+10log( PAX seats/2) dB

    Issued in Washington, DC on March 18, 2003.
Paul R. Dykeman,
Acting Director, Office of Environment and Energy.

[FR Doc. 03-6918 Filed 3-21-03; 8:45 am]
BILLING CODE 4910-13-P