##  Before the

**Federal Communications Commission**

**Washington, D.C. 20554**

In the Matter of )

)

Amendment of Parts 2 and 87 of the Commission\'s ) WT Docket No. 00-77

Rules to Accommodate Advanced Digital )

Communications in the 117.975-137 MHz Band ) RM Nos. 9376, 9462

and to Implement Flight Information Services in the )

136-137 MHz Band )

**NOTICE OF PROPOSED RULEMAKING**

**Adopted:** May 8, 2000 **Released:** May 15, 2000

**Comment Date:** July 14, 2000

**Reply Comment Date:** August 14, 2000

By the Commission:

**TABLE OF CONTENTS**

**Title Paragraph**

I. INTRODUCTION AND EXECUTIVE SUMMARY 1

II\. BACKGROUND 2

III\. DISCUSSION 7

A. Table of Frequency Allocations for the 136-137 MHz Band (47 C.F.R. §
2.106) 8

B. Aviation Service Rules (47 C.F.R. Part 87) 13

IV\. PROCEDURAL MATTERS 19

Appendix A Initial Regulatory Flexibility Analysis

Appendix B Proposed Rules

**I. INTRODUCTION AND EXECUTIVE SUMMARY**

1\. In this *Notice of Proposed Rulemaking* (*Notice*), we seek comment
on proposals regarding the use of the 136-137 MHz frequency band by the
Aviation Services and certain modifications to Parts 2 and 87 of the
Commission's Rules in response to two Petitions for Rulemaking.[^1]
SAMA, in its Petition, proposes revision of the aviation rules to allow
the use of advanced digital data transmissions and to designate four
channels, to be suggested by the FAA, for the implementation of Flight
Information Services (FIS)[^2] in the 136-137 band.[^3] The FAA, in its
Petition and Revised Petition, seeks reallocation of the 136-136.475 MHz
portion of the 136-137 MHz band to allow Federal Government operations
to share this band with non-Federal Government operations. The FAA also
requests amendment of various aviation rules to permit the
implementation of FIS and to promote the transition to high-capacity
digital communications systems for future requirements of air traffic
control (ATC)[^4] for civil aviation.[^5] In response to the petitions
and comments received, this *Notice* proposes to:  (1) modify the
footnote allocation in Part 2 of the Commission's Rules to permit the
FAA use of twenty channels in the 136-136.475 MHz band on a shared basis
with non-Federal Government users for ATC purposes, including FIS;[^6]
(2) revise certain technical rules in Part 87 for the 117.975-137 MHz
band to accommodate digital communications systems; and (3) modify those
rules pertaining to special purpose enroute services in the Gulf of
Mexico.[^7]

**II. BACKGROUND**

2\. In 1990, the Commission amended Parts 2 and 87 of its Rules to
permit stations in the aviation services to use certain frequencies in
the 136-137 MHz band.[^8] The Commission allotted forty 25 kHz channels
in the 136-137 MHz band for assignment to aeronautical mobile (R) radio
service.[^9] Specifically, the Commission allocated fifteen channels on
a shared basis with the FAA for ATC purposes, such as automatic weather
observation services (AWOS),[^10] automatic terminal information service
(ATIS),[^11] and airport control tower communications (ACTC)[^12] for
general aviation. Additionally, the Commission allocated twenty channels
for aeronautical enroute services (with six of these channels being
allotted for special purpose enroute services in the Gulf of Mexico).
The Commission also held five channels temporarily in reserve for future
general aviation purposes.[^13]

3\. On May 1, 1998, the Administrator of the FAA issued the Airborne
Flight Information Services Policy Statement (FAA Policy Statement). In
the FAA Policy Statement, the FAA stated its goal for FIS as follows:
"FIS in the cockpit is to use digital data link to deliver information
to the pilot, . . . improve safety, reduce costs to users and the FAA,
and increase the utility efficiency and capacity of the National
Airspace System."[^14] Additionally, the FAA stated that its objective
was to ensure development and provision of services for sending FIS to
aircraft via data link.[^15] FIS includes information necessary for
continued safe flight and for flight planning whether in the air or on
the ground.[^16] The FAA indicated that it would work with the aviation
industry to develop a joint petition to the FCC to assign four 25 kHz
radio frequency channels in the 136.0-136.9 MHz VHF band and to select
qualified vendors on a competitive basis to be providers of FIS.[^17]

4\. On September 14, 1998, SAMA filed a petition requesting revision of
the Commission's Rules to permit the implementation of the FAA's FIS
program in the 136-137 MHz frequency band.[^18] SAMA indicates that FIS
includes broadcasts of weather and other advisory information that are
identical in purpose to AWOS and ATIS weather reports, except that
instead of voice transmission, they are sent using advanced data
transmissions.[^19] SAMA indicates that this data is provided to the
flight crew on a display, depicting either textual or graphical
information.[^20] Examples of FIS include: text of weather observations
identical to the type of information provided over AWOS by voice;
graphical representation of weather hazard areas, such as thunderstorms;
Notices to Airmen; and status of special use airspace.[^21] In order to
implement the FAA\'s FIS program, SAMA also seeks amendment of Section
87.131[^22] of the Rules to modify the aeronautical authorized emissions
classification to allow not only A3E (double sideband amplitude
modulation), but also to allow F1D and G1D (frequency and phase
modulated digital).[^23] Three parties filed comments in response to the
SAMA Petition: the National Air Transportation Association (NATA);[^24]
the National Business Aviation Association (NBAA);[^25] and Aeronautical
Radio, Inc. (ARINC).[^26]

5\. On November 19, 1998, the FAA filed a petition seeking a shared
allocation for the 136-137 MHz band[^27] for the future requirements of
civil aviation ATC.[^28] Specifically, the FAA proposes that the 136-137
MHz band be changed from a non-Federal Government allocation with shared
access to fifteen channels to a shared Federal Government/non-Federal
Government allocation. It further suggests a channeling plan as follows
-- twenty-four frequencies for ATC with four (specifically, 136.525 MHz,
136.625 MHz, 136.725 MHz and 136.825 MHz) designated as FIS, and the
remaining sixteen frequencies for aeronautical operational control
(AOC).[^29] The FAA avers that it has decided to implement a new digital
communications system as a solution to the growing spectrum congestion
in the aeronautical mobile communications spectrum.[^30] The FAA further
noted it has adopted an FIS policy statement, which seeks to implement
an FIS system in the 136-137 MHz band; and therefore, it supports the
SAMA petition.[^31] On April 19, 1999, ARINC and Air Transport
Association of America (ATA) filed joint comments opposing the FAA
Petition and submitted further revisions based on an agreement
negotiated among the various elements of the air transport industry,
including the FAA.[^32]

6\. On August 3, 1999, the FAA filed a Revised Petition to take into
account agreements reached between the FAA and air transport industry on
implementation of FIS[^33] data link capability.[^34] In its Revised
Petition, the FAA requested a shared allocation of the 136-136.475 MHz
portion of the 136-137 MHz,[^35] and proposed four other frequencies
(namely, 136.425 MHz, 136.450 MHz, 136.475 MHz, and 136.500 MHz) for
FIS.[^36] Additionally, the FAA proposed changes to technical parameters
such as emissions and frequency stability.[^37] On November 15, 1999,
further comments were filed on behalf of ARINC. [^38]

**III. DISCUSSION**

7\. Currently, the 136-137 MHz band is allocated to the non-Federal
Government aeronautical mobile (R) service on a primary basis.[^39] This
one megahertz of spectrum is used by the civil aviation community, in
particular ARINC, for AOC communications, and pursuant to footnote
US244, by the FAA for general aviation ATC purposes.[^40] SAMA, in its
Petition, requests the FCC to set aside four channels in the 136-137 MHz
band for FIS to support general aviation.[^41] The FAA, in its Revised
Petition, supports this request but also seeks a reallocation of
approximately half of the band (136-136.475 MHz) to accommodate a new,
digital communications system.[^42] While generally supporting both
requests, it appears that the aviation community challenges the amount
of spectrum needed and the manner in which it is allocated. The
community counsels caution when evaluating the petitions and stresses
the need to balance future Federal Government services against the
existing and planned improvements in non-Federal Government data
communications services.[^43] All parties also request that 47 C.F.R.
Part 87 be amended to permit digital communications for general
aviation.

**A. The Table of Frequency Allocations for the 136-137 MHz Band (47
C.F.R. § 2.106)**.

8\. In its initial petition, the FAA sought a shared Federal
Government/non-Federal Government allocation of the 136-137 MHz band in
its entirety, but later, after subsequent talks with industry, the FAA
revised its request to the 136-136.475 MHz band only.[^44] The FAA
stated that it requires the Federal Government allocation because
spectrum congestion within the 117.975-136 MHz band, due to increasing
ATC communications requirements, has caused frequency assignments in
this band to grow about four percent annually.[^45] The FAA believes
that the 136-137 MHz band segment should be reallocated in order to
accommodate the requirements of civil aviation, and, in particular, to
provide benefits to general aviation by \"freeing up\" radio frequencies
below 136 MHz where most general aviation radios operate.[^46] Moreover,
the FAA reiterates that it does not use this spectrum for its own
operations, but that this radio spectrum is used to provide
communications regarding air traffic services to private sector
aircraft.[^47] Finally, the FAA contends that the new Federal Government
allocation is solely to allow the FAA to implement ground facilities
that will support the critical safety communications needs of civil
aviation.[^48] The FAA indicates that it needs a sufficient "sub-band"
so that current air/ground communications will not receive interference
during the transition to the future, digital air/ground communications
system.[^49]

9\. ARINC/ATA oppose the FAA's proposal for a shared Federal
Government/non-Federal Government allocation in the 136-137 MHz band.
Specifically, ARINC/ATA assert that the FAA Petition exceeds the FAA's
future needs concerning its transition to a digital system and the
implementation of FIS.[^50] By exceeding its future requirements,
ARINC/ATA maintain that the FAA's proposals would negatively impact the
current use of the band by ARINC and civil aviation for AOC
communications.[^51] In this regard, ARINC notes that presently it has
6,740 frequency assignments on the 148 channels available in the
aeronautical enroute service, which equals more than forty-five
assignments per channel.[^52] ARINC/ATA further assert that the FAA's
proposals would be devastating to the existing and planned safety
services of the civil aviation community.[^53]

10\. After reviewing the matter, we agree with ARINC/ATA and believe
that a Federal Government allocation within the 136-137 MHz band is
unnecessary to achieve the goals of both the FAA and industry. Instead,
we propose to amend 47 C.F.R § 2.106, n. US244 to extend FAA's access
from fifteen to twenty channels within the 136-136.475 MHz band on a
shared basis with non-Federal Government users. Specifically, we propose
to add channels 136.100 MHz, 136.200 MHz, 136.275 MHz, 136.375 MHz, and
136.475 MHz to the list of FAA\'s shared channels.[^54] SAMA, NATA,
NBAA, and ARINC all support providing the FAA with access to these
additional channels.[^55] In making this proposal, we emphasize that
this band is first and foremost a non-Federal Government band. When the
band was available for aeronautical use on January 1, 1990, the
Commission designated the entire band as non-Federal Government and
determined that the FAA\'s spectrum requirements would be satisfied with
an allotment of fifteen channels for general aviation ATC use.[^56] We
continue to believe that the FAA's spectrum requirements can be met in
ways other than taking spectrum from the private sector and reallocating
it as shared Federal Government/non-Federal Government spectrum. We
invite comments on these views.

11\. As requested by SAMA and supported by the FAA and industry, we
further propose that FIS be accommodated in the 136-137 MHz band. SAMA
contends that locating the FIS within in the 136-137 MHz band is most
appropriate. [^57] It notes that frequencies in the 136-137 MHz band are
not currently being used because very few general aviation aircraft have
voice radios that can tune to this band.[^58] NATA, NBAA, and ARINC/ATA
all support authorization of FIS within the 136-137 MHz band.[^59]
According to SAMA, most general aviation aircraft have 720-channel
transceivers that tune up to 136 MHz; only the newest radios are
760-channel transceivers that also tune to the forty channels in the
136-137 MHz band.[^60] SAMA maintains that aircraft desiring to receive
FIS broadcasts could purchase an FIS receiver that tunes to these
frequencies only.[^61] Finally, SAMA avers that avionics manufacturers
have already introduced low-cost radio receivers for FIS broadcasts for
the general aviation market in anticipation of the FAA\'s initiation of
this service.[^62]

12\. Consequently, we propose to add the FIS designation to footnote
US244; however, we tentatively conclude that specifying four channels
for FIS in US244 is unnecessary and could curtail flexibility. In its
Revised Petition, the FAA proposes that the four channels jointly
selected by the FAA and industry representatives (136.425 MHz, 136.450
MHz, 136.475 MHz, and 136.500 MHz) be added to footnote US244.[^63]
Three of the channels are from the ATC portion of the band and the
fourth is from the AOC portion of the band.[^64] In its Petition, SAMA
also proposes modifying our Rules to permit FIS on the frequencies that
the FAA selects.[^65] Although both the FAA and SAMA requested that four
frequencies be designated for the FIS, ARINC/ATA argues that specific
FIS frequencies need not be listed in our Rules.[^66] In this
connection, ARINC contends that FIS could be implemented in the
136-136.475 MHz band by adding FIS to footnote US244 and modifying 47
C.F.R. § 87.137 to include the 14K0G1D emission designator.[^67] NBAA
also states that further FIS studies by RTCA, Inc., should be completed
and its recommendations considered before decisions are made regarding
specific applications on assigned channels.[^68] In further comments,
ARINC clarifies that although the FAA will make three of the ATC
channels available for FIS and ARINC will make one of the AOC channels
available to an FIS provider, such commitment would expire on December
31, 2004. [^69] ARINC/ATA avers that adding the FIS designation to
footnote US244 rather than specifying the frequencies would fully meet
FAA and SAMA's requirements while providing for future
requirements.[^70] We seek comments on our tentative conclusion to add
FIS but not list specific frequencies in the footnote allocation 47
C.F.R § 2.106, n. US244. Finally, in their filings, both SAMA and the
FAA use the term "Flight Information Service (FIS)," while ARINC/ATA use
the term "Flight Information Service-Broadcast (FIS-B)." [^71] It is
unclear whether these terms reflect actual and distinct characteristics
and requirements or are synonymous. However, it appears that FIS-B
permits user-customized data display whereas FIS is intended for uniform
user presentation. We therefore seek comment clarifying whether the term
"FIS" is more suitable than "FIS-B" for our Rules.

**B. Aviation Service Rules (47 C.F. R. Part 87).**

13\. To foster improved spectrum efficiencies, we also propose to amend
various service and technical rules pertaining to the aviation services,
47 C.F.R. Part 87. The specific rule provisions we propose to amend are:
(1) 47 C.F.R. § 87.131 (Power and emissions); (2) 47 C.F.R. § 87.133
(Frequency stability); (3) 47 C.F.R. § 87.137 (Types of emission); (4)
47 C.F.R. § 87.139 (Emission limitations); (5) 47 C.F.R. § 87.173
(Frequencies) \[General List\]; (6) 47 C.F.R. § 87.187 (Frequencies)
\[Aircraft Stations\]; and (7) 47 C.F.R. § 87.263 (Frequencies)
\[Aeronautical Enroute and Aeronautical Fixed Stations\]. We believe
that these changes would serve to promote the transition from analog
voice communications to digital voice and data transmissions. NBAA
contends that recent studies indicate a twenty percent per annum growth
in the use of the 136-137 MHz band for data communications alone.[^72]
Because aviation communications represent a vital area of public safety,
and due to the increased demand by the aviation industry for radio
spectrum, we wish to assist the FAA and the aviation industry as they
bring aviation communications into the digital age.

14\. First, we propose to amend our Rules concerning emission standards
to include phase modulation data transmissions (G1D and G7D)[^73] for
the 117.975-137 MHz bands.[^74] To accommodate FIS, SAMA suggests that
we amend the aviation emission rules to allow not only the current A3E
(double sideband amplitude modulation) but also to add F1D and/or G1D
(digital frequency and phase modulation, respectively) as suggested by
FAA.[^75] The FAA, in its Revised Petition, proposes to add G1D and G7D
to the 117.975-137 MHz band.[^76] ARINC/ATA agree.[^77] It asserts that
to meet requirements for future systems, we should permit these
emissions throughout the 117.975-137 MHz band.[^78]

15\. In its Petition, the FAA notes that there is a long history of
spectrum congestion in the 117.975-136 MHz band due to increasing ATC
communications requirements which cause frequency assignments to grow
approximately four percent a year.[^79] After several years of
comprehensive study within the aviation community, RTCA, Inc.,
recommended implementation of a future air/ground communications system
based on time division multiple access (TDMA).[^80] Parallel studies
within the International Civil Aviation Organization (ICAO) reached
similar conclusions. Based on these recommendations, the FAA indicates
that it has decided to start replacing its current amplitude modulated
air/ground voice communications system with the modern digital VHF
digital link (VDL) Mode 3 system as the future air/ground communications
system in the 117.975-137 MHz band.[^81] Implementation of that system
is to begin by the year 2002.[^82] This new system provides four
independent voice/data links on each 25 kHz radio frequency channel, and
is defined by ICAO as VDL Mode 3 using TDMA transmissions.[^83]

16\. Although the parties agree to add both G1D and G7D emission
standards, they disagree on certain limitations. While the FAA proposes
both G1D and G7D emission designators, it appears to suggest that
communications within the ATC 136-136.475 MHz band be limited to VDL
Mode 3 data transmissions.[^84] Noting that the frequencies in the
136-137 MHz band are currently not widely used, the FAA states that this
is the ideal "sub band" to be used for transition to the new digital ATC
communications system -- VDL Mode 3.[^85] Additionally, the FAA seeks to
limit the use of the 136-137 MHz band to digital-only communications
systems using ICAO standards for VDLs or systems compatible with those
standards.[^86] ARINC/ATA submit that we should not place any
restrictions, such as digital-only communications, on the use of the
136.5-137 MHz band that is used by civil aviation for AOC.[^87] They
further state that the FIS system would use VDL Mode 2 as least
initially.[^88] To accommodate future requirements, ARINC/ATA urges the
FCC to permit VDL Mode 2 (14K0G1D) and VDL Mode 3 (14K0G7D) emissions
throughout the 136-137 MHz band.[^89] NBAA agrees that the VDL Mode 3
system should be the eventual communications format.[^90] NBAA adds,
however, that subsequent to approving the VDL Mode 3 recommendation for
future systems, the industry has continued to develop standards for VDL
Mode 2.[^91] According to NBAA, the VDL Mode 2 standards were developed
because a transition period is necessary while VDL Mode 3 development
occurs.[^92]

17\. Considering the varying views expressed, we propose to allow the
use of both VDL Mode 2 and VDL Mode 3 for the 117.975-137 MHz band
without limitations. Specifically, we propose to add both G1D and G7D
emission designators to 47 C.F.R. § 87.131 (Power and emissions), 47
C.F.R. § 87.133 (Frequency stability), 47 C.F.R. § 87.137 (Types of
emission), and 47 C.F.R. § 87.139 (Emission limitations) as set forth in
Appendix B hereto. We believe this approach would promote compatibility,
flexibility, and efficiency while the aviation community transitions to
the future digital air/ground communications system. We further believe
that these proposed revisions will allow single-channel, phase
modulation digital transmission (14K0G1D) to accommodate the VDL Mode 2
system of communications, needed for FIS and ARINC's system; they will
also allow the FAA to implement its TDMA multiple-channel, phase
modulation digital transmission (14K0G7D) for the VDL Mode 3 system of
communications. We seek comments on this approach. Comments should
address the standard that will meet future and current requirements.

18\. Additionally, we propose to modify 47 C.F.R. § 87.173 (Frequencies)
\[General List\] to reflect the proposed realignment of frequency use of
the 136-137 MHz band, and 47 C.F.R. § 87.187 (Frequencies) \[Aircraft
Stations\] to identify the four FIS frequencies and prohibit aircraft
transmissions on these frequencies.[^93] The FAA, in its Revised
Petition, recommends adding the four FIS frequencies to 47 C.F.R. §
87.187.[^94] ARINC/ATA suggests slightly broader text regarding the FIS
frequencies: it would identify the same four frequencies for one-way
broadcast service (rather than FIS) and prohibit aircraft transmissions
on these frequencies.[^95] Our proposal is a combination of these
recommendations. We seek comments on the proposed revisions to 47 C.F.R.
§§ 87.173 and 87.187 as set forth in Appendix B hereto.

19\. Finally, we propose to modify 47 C.F.R. § 87.263 (Frequencies)
\[Aeronautical Enroute and Aeronautical Fixed Stations\] regarding the
six frequencies reserved for special purpose enroute services in the
Gulf of Mexico. In 1990, in response to a request by American Petroleum
Institute (API), we reserved these frequencies for special purpose
enroute services such as "helicopter flight following systems" through
December 31, 1993.[^96] To date, only two frequencies (*viz*., 136.750
and 136.825 MHz) have been implemented.[^97] ARINC/ATA recommends
deleting this provision for all but the licensed frequencies.[^98] It
contends that the rapid growth of the aeronautical enroute service
throughout the Nation requires these channels to be unambiguously
available.[^99] We seek comments on the proposed revisions to 47 C.F.R.
§§ 87.263 as set forth in Appendix B hereto.

**IV. PROCEDURAL MATTERS**

***Ex Parte* Rules \-- Permit-but-Disclose Proceeding**

20\. This is a permit-but-disclose notice and comment rulemaking
proceeding. *Ex parte* presentations are permitted, except during the
Sunshine Agenda period, if they are disclosed as provided in the
Commission\'s Rules. *See generally* 47 C.F.R. §§ 1.1200(a), 1.1203,
1.1206.

**Regulatory Flexibility Act**

21\. An Initial Regulatory Flexibility Analysis with respect to the
*Notice* is included in Appendix A.

**Paperwork Reduction Act**

22\. This *Notice* contains either a new or modified information
collection. The Commission, as part of its continuing effort to reduce
paperwork burdens, invites the general public to comment on the
information collection contained in this *Notice* as required by the
Paperwork Reduction Act of 1995, Pub. L. No. 104-13. Public and agency
comments are due 60 days from date of publication of this *Notice* in
the Federal Register. Comments should address: (a) whether the new or
modified collection of information is necessary for the proper
performance of the functions of the Commission, including whether the
information shall have practical utility; (b) the accuracy of the
Commission\'s burden estimates; (c) ways to enhance the quality,
utility, and clarity of the information collected; and (d) ways to
minimize the burden of the collection of information on the respondents,
including the use of automated collection techniques or other forms of
information technology. These comments should be submitted to Judy
Boley, Federal Communications Commission, 445 12th Street, SW,
Washington, D.C. 20554, or via the Internet to \<jboley@fcc.gov\>.
Furthermore, a copy of any such comments should be submitted to Virginia
Huth, OMB Desk Officer, 725 17th Street, N.W., Room 10236 NEOB,
Washington, D.C. 20503, or via the Internet to \<vhuth@omb.eop.gov\>.

**Alternative Formats**

23\. Alternative formats (computer diskette, large print, audio cassette
and Braille) are available from Martha Contee at (202) 418-0260, TTY
(202) 418-2555, or at \<mcontee@fcc.gov\>. This *Notice* can also be
downloaded at \<http://www.fcc.gov/dtf/\>.

**Pleading Dates**

24\. Pursuant to Sections 1.415 and 1.419 of our Rules, 47 C.F.R. §§
1.415, 1.419, interested parties may file comments on or before July 14,
2000, and reply comments on or before August 14, 2000. Comments may be
filed using the Commission\'s Electronic Comment Filing System (ECFS),
or by filing paper copies. *See Electronic Filing of Documents in
Rulemaking Proceedings*, 63 Fed. Reg. 24,121 (1998).

25\. Comments filed through the ECFS can be sent as an electronic file
via the Internet to \<http://www.fcc.gov/e-file/ecfs.html\>. Generally,
only one copy of an electronic submission must be filed. If multiple
docket or rulemaking numbers appear in the caption of this proceeding,
however, commenters must transmit one electronic copy of the comments to
each docket or rulemaking number referenced in the caption. In
completing the transmittal screen, commenters should include their full
name, Postal Service mailing address, and the applicable docket or
rulemaking number. Parties may also submit an electronic comment by
Internet e-mail. To get filing instructions for e-mail comments,
commenters should send an e-mail to \<ecfs@fcc.gov\>, and should include
the following words in the body of the message, \"get form \<your e-mail
address.\" A sample form and directions will be sent in reply.

26\. Parties who choose to file by paper must file an original and four
copies of each filing. If more than one docket or rulemaking number
appear in the caption of this proceeding, commenters must submit two
additional copies for each additional docket or rulemaking number. All
filings must be sent to the Commission\'s Secretary, Magalie Roman
Salas, Office of the Secretary, Federal Communications Commission, 445
Twelfth Street, S.W., TW-A325, Washington, D.C. 20554.

**V. ORDERING CLAUSES**

27\. Accordingly, IT IS ORDERED that, pursuant to Sections 1, 4(i), 302,
303(f) and (r), 332, and 337 of the Communications Act of 1934, as
amended, 47 U.S.C. §§ 1, 154(i), 302, 303(f) and (r), 332, 337, NOTICE
IS HEREBY GIVEN of the proposed regulatory changes described in this
*Notice of Proposed Rulemaking*, and that COMMENT IS SOUGHT on these
proposals.

28\. IT IS FURTHER ORDERED that the Commission\'s Office of Public
Affairs, Reference Operations Division, SHALL SEND a copy of this
*Notice of Proposed Rulemaking*, WT Docket No. 00-77, including the
Initial Regulatory Flexibility Analysis, to the Chief Counsel for
Advocacy of the Small Business Administration in accordance with Section
603(a) of the Regulatory Flexibility Act.[^100]

**Contact for Information**

29\. For further information, contact John Fernández or Ghassan Khalek,
Policy and Rules Branch, Public Safety and Private Wireless Division,
Wireless Telecommunications Bureau, (202) 418-0680, \<jfernand@fcc.gov\>
or \<gkhalek@fcc.gov\>.

FEDERAL COMMUNICATIONS COMMISSION

Magalie Roman Salas

Secretary

**APPENDIX A**

**Initial Regulatory Flexibility Analysis**

As required by the Regulatory Flexibility Act (\"RFA\"),[^101] the
Commission has prepared this present Initial Regulatory Flexibility
Analysis (\"IRFA\") of the possible significant economic impact on small
entities by the policies and rules proposed in this *Notice*. Written
public comments are requested on this IRFA. Comments must be identified
as responses to the IRFA and must be filed by the deadlines for comments
on this *Notice* provided above in paragraph 24. The Commission will
send a copy of the *Notice*, including this IRFA, to the Chief Counsel
for Advocacy of the Small Business Administration (\"SBA\"). *See* 5
U.S.C. § 603(a). In addition, the *Notice* and IRFA will be published in
the Federal Register. *See* *id*.

**A. Need for, and Objectives of, the Proposed Rules:**

1\. Increased spectrum congestion within the 117.975-136 MHz band, due
to increasing air traffic control communications requirements that cause
frequency assignments in this band to grow about four percent annually,
compels the transition to digital communications technology. Further
pressuring our aviation communications spectrum capacity is the
explosive growth in data communications within the civil aviation
communications spectrum band. This, combined with the FAA\'s role in
administering the civil aviation communications spectrum, along with the
public safety issues inherent with aviation communications, provides
justification for our proposals in this *Notice*. The objective is to
develop aviation communications spectrum policies for the civil aviation
community while providing the FAA with the latitude it needs to meet its
statutory requirements. Our proposals are aimed at being as least
intrusive on the private sector as feasible, while achieving our public
interest objectives.

**B. Legal Basis.**

2\. The proposed action is authorized by sections 4(i), 303(r), and
332(a)(2) of the Communications Act of 1934, as amended, 47 U.S.C. §§
154(i), 303(r) and 332(a)(2).

**C. Description and Estimate of the Number of Small Entities to Which
the Proposed Rules Will Apply.**

3\. Under the RFA, small entities may include small organizations, small
businesses, and small governmental jurisdictions, or entities. 5 U.S.C.
§ 601(6). The RFA directs agencies to provide a description of and,
where feasible, an estimate of the number of small entities that may be
affected by the proposed rules, if adopted. The RFA generally defines
the term \"small entity\" as having the same meaning as the terms
\"small business,\" \"small organization,\" and \"small governmental
jurisdiction.\" 5 U.S.C. § 601(3). In addition, the term \"small
business\" has the same meaning as the term \"small business concern\"
under the Small Business Act. A small business concern is one that: (1)
is independently owned and operated; (2) is not dominant in its field of
operation; and (3) satisfies any additional criteria established by the
SBA. Pursuant to 5 U.S.C. § 601(3), the statutory definition of a small
business applies \"unless an agency after consultation with the Office
of Advocacy of the SBA, and after opportunity for public comment,
establishes one or more definitions of such term which are appropriate
to the activities of the agency and publishes such definition(s) in the
Federal Register.\"

4\. The Commission has not adopted a definition of small business
specific to the Air‑Ground Radiotelephone Service, which is defined in
section 22.99 of the Commission\'s Rules. 47 C.F.R. § 22.99.
Accordingly, we will use the SBA\'s definition applicable to
radiotelephone companies, *i.e*., an entity employing no more than 1,500
persons. There are approximately 100 licensees in the Air‑Ground
Radiotelephone Service, and we estimate that almost all of them qualify
as "small" under the SBA definition.

**D. Description of Projected Reporting, Recordkeeping, and Other
Compliance Requirements.**

5\. No new reporting, recordkeeping, or other compliance requirements
would be imposed on applicants or licensees as a result of the actions
proposed in this rulemaking proceeding.

**E. Steps Taken to Minimize Significant Economic Impact on Small
Entities, and Significant Alternatives Considered.**

6\. Throughout this *Notice*, we seek comment on the impact of the
proposals in the *Notice* on small entities.

**F. Federal Rules that May Duplicate, Overlap, or Conflict with the
Proposed Rules.**

7\. None.

**APPENDIX B**

**Proposed Rules**

Parts 2 and 87 of Title 47 of the Code of Federal Regulations are
proposed to be amended as follows:

1\. The authority citation for Part 2 continues to read as follows:

AUTHORITY: 47 U.S.C. 154, 302, 303, 307, 336, and 337, unless otherwise
noted.

2\. Footnote US244 to the Table of Frequency Allocations is amended as
follows:

§ 2.106 Table of Frequency Allocations.

\*\*\*\*\*

US244 The band 136.000-137.000 MHz is allocated to the non-Federal
Government aeronautical mobile (R) service on a primary basis, and is
subject to pertinent international treaties and agreements. The
frequencies 136.000, 136.025, 136.050, 136.075, 136.100, 136.125,
136.150, 136.175, 136.200, 136.225, 136.250, 136.275, 136.300, 136.325,
136.350, 136.375, 136.400, 136.425, 136.450, and 136.475 MHz are
available on a shared basis to the Federal Aviation Administration for
air traffic control purposes, such as automatic weather observation
stations (AWOS), automatic terminal information services (ATIS), flight
information services (FIS), and airport control tower communications.
Existing operational meteorological satellites in the band 136-137 MHz
may continue to operate on a not-to-interfere basis to aeronautical
mobile (R) stations, until January 1, 2002. No new assignments will be
made to stations in the meteorological-satellite service.

\*\*\*\*\*

**Part 87 - AVIATION SERVICES**

3\. The authority citation for Part 87 continues to read as follows:

AUTHORITY: 48 Stat. 1066, 1082, as amended; 47 U.S.C. 154, 303, 307(e)
unless otherwise noted. Interpret or apply 48 Stat. 1064-1068,
1081-1105, as amended; 47 U.S.C. 151-156, 301-609.

4\. Section 87.131 is revised to read as follows:

**§ 87.131 Power and emissions.**

\*\*\*

+---------------------+-------------+-------------------+-------------+
| Class of station    | Frequency   | Authorized        | Maximum     |
|                     | band/       | emission(s)       | power^1^    |
|                     |             |                   |             |
|                     | frequency   |                   |             |
+---------------------+-------------+-------------------+-------------+
| \*\*\*              | \*\*\*      | \*\*\*            | \*\*\*      |
|                     |             |                   |             |
| Aeronautical        | \*\*\*      | \*\*\*            | \*\*\*      |
| enroute and         |             |                   |             |
| aeronautical fixed. | VHF........ | A3E, A9W,         | 200         |
|                     | ........... | G1D..             | watts.^2^   |
|                     |             | .............\... |             |
+---------------------+-------------+-------------------+-------------+
| \*\*\*              | \*\*\*      | \*\*\*            | \*\*\*      |
+---------------------+-------------+-------------------+-------------+
| Airport control     | VHF........ | A3E, G1D,         | 50 watts.   |
| to                  | ........... | G7D.              |             |
| wer................ |             | ................. |             |
+---------------------+-------------+-------------------+-------------+
| \*\*\*              | \*\*\*      | \*\*\*            | \*\*\*      |
+---------------------+-------------+-------------------+-------------+
|                     | A           |                   |             |
|                     | eronautical |                   |             |
|                     | Frequencies |                   |             |
+---------------------+-------------+-------------------+-------------+
| Aircraft            | \*\*\*      | \*\*\*            | \*\*\*      |
| (Commu              |             |                   |             |
| nication).......... |             |                   |             |
+---------------------+-------------+-------------------+-------------+
| \*\*\*              | VHF........ | A3E, A9W, G1D,    | 55 watts.   |
|                     | ........... | G7D..........     |             |
+---------------------+-------------+-------------------+-------------+
| \*\*\*              | \*\*\*      | \*\*\*            | \*\*\*      |
+---------------------+-------------+-------------------+-------------+

\*\*\*

5\. Section 87.133(a) is revised to read as follows:

**§ 87.133 Frequency stability.**

\(a\) \*\*\*

+--------------------------------+-------------+-----------------------+
| Frequency band (lower limit    | T           | Tolerance^2^          |
| exclusive, upper limit         | olerance^1^ |                       |
| inclusive), and categories of  |             |                       |
| stations                       |             |                       |
+--------------------------------+-------------+-----------------------+
| \*\*\*                         | \*\*\*      | \*\*\*                |
|                                |             |                       |
| \(5\) Band---108 to 137 MHz:   | \*\*\*      | \*\*\*                |
+--------------------------------+-------------+-----------------------+
| Aeronautical                   | ^4^50       | 20^12^                |
| stations.....                  |             |                       |
| .............................. |             |                       |
+--------------------------------+-------------+-----------------------+
| \*\*\*                         | \*\*\*      | \*\*\*                |
+--------------------------------+-------------+-----------------------+
| Aircraft and other mobile      | 50^5^       | 30^13^                |
| stations in the Aviation       |             |                       |
|                                | \*\*\*      | \*\*\*                |
| Services.                      |             |                       |
|                                |             |                       |
| \*\*\*                         |             |                       |
+--------------------------------+-------------+-----------------------+

\*\*\*

^12^ For emissions G1D and G7D, the tolerance is 2 parts per 10^6^.

^13^ For emissions G1D and G7D, the tolerance is 5 parts per 10^6^.

\*\*\*\*\*

6\. Section 87.137(a) is amended, by adding new entries to the table, to
read as follows:

**§ 87.137 Types of emission.**

\(a\) \*\*\*

+-------------+-------------+-------------+-------------+-------------+
| Class of    | Emission    | Authorized  |             |             |
| emission    | designator  | bandwidth   |             |             |
|             |             | (kilohertz) |             |             |
+-------------+-------------+-------------+-------------+-------------+
|             |             | Below 50    | Above 50    | Frequency   |
|             |             | MHz         | MHz         | deviation   |
+-------------+-------------+-------------+-------------+-------------+
| \*\*\*      | \*\*\*      | \*\*\*      | \*\*\*      | \*\*\*      |
|             |             |             |             |             |
| G1D         | 14K0G1D     |             | 25          |             |
|             |             |             |             |             |
| \*\*\*      | \*\*\*      |             | \*\*\*      |             |
|             |             |             |             |             |
| G7D         | 14K0G7D     |             | 25          |             |
|             |             |             |             |             |
| \*\*\*      | \*\*\*      |             | \*\*\*      |             |
+-------------+-------------+-------------+-------------+-------------+

\*\*\*\*\*

7\. Section 87.139 is amended, by adding paragraphs (j), (1), (2), and
(3), to read as follows:

**§ 87.139 Emission limitations.**

\*\*\*\*\*

j.  \(j\) For VHF aeronautical stations and aircraft stations operating
    with G1D or G7D emissions:

\(1\) The amount of power measured across either first adjacent 25 kHz
channel shall not exceed 0 dBm.

\(2\) The amount of power measured across either second adjacent channel
share less than -25 dBm and the power measured in any other adjacent 25
kHz channels shall monotonically decrease at a rate of at least 5 dB per
octave to a maximum value of ‑52 dBm.

\(3\) The amount of power measured over a 16 kHz channel bandwidth
centered on the first adjacent 25 kHz channel shall not exceed -20 dBm.

8\. Section 87.173(b) is amended to read as follows:

**§ 87.173 Frequencies.**

\*\*\*\*\*

\(b\) Frequency table:

+---------------------+-------+------------+--------------------------+
| Frequency or        | Su    | Class of   | Remarks                  |
| frequency band      | bpart | station    |                          |
+---------------------+-------+------------+--------------------------+
| \*\*\*              | \     | \*\*\*     | \*\*\*                   |
|                     | *\*\* |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.000-136.400 MHz | O, S  | MA, FAC,   | Air traffic control      |
| .............       |       | FAW        | operations;              |
|                     |       |            |                          |
|                     |       |            | 25 kHz channel spacing.  |
+---------------------+-------+------------+--------------------------+
| 136.425             | O, S  | MA, FAC,   | Air traffic control      |
| MHz.......          |       | FAW        | operations.              |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.450             | O, S  | MA, FAC,   | Air traffic control      |
| MHz...\....         |       | FAW        | operations.              |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.475             | O, S  | MA, FAC,   | Air traffic control      |
| MHz\.......         |       | FAW        | operations.              |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.500             | O, S  | MA, FAC,   | Domestic VHF.            |
| MHz\.......         |       | FAW        |                          |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.525-136.875     | I     | MA, FAE    | Domestic VHF; 25 kHz     |
| MHz..............   |       |            | channel spacing.         |
+---------------------+-------+------------+--------------------------+
| 136.900             | I     | MA, FAE    | International and        |
| MHz...\....         |       |            | domestic VHF.            |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.925             | I     | MA, FAE    | International and        |
| MHz\.......         |       |            | domestic VHF.            |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.950             | I     | MA, FAE    | International and        |
| MHz\.......         |       |            | domestic VHF.            |
| ................... |       |            |                          |
+---------------------+-------+------------+--------------------------+
| 136.975             | I     | MA, FAE    | International and        |
| MHz\.......         |       |            | domestic VHF.            |
| ................... | \     | \*\*\*     |                          |
|                     | *\*\* |            | \*\*\*                   |
| \*\*\*              |       |            |                          |
+---------------------+-------+------------+--------------------------+

9\. Section 87.187 is amended, by adding paragraph (z)(dd), to read as
follows:

**§ 87.187 Frequencies.**

\*\*\*\*\*

(dd) The frequencies 136.425, 136.450, 136.475, and 136.500 MHz are
designated for flight information services (FIS) and may not be used by
aircraft for transmission.

10\. Section 87.263 is amended, by revising paragraphs (a)(1) and
(a)(5), to read as follows:

**§ 87.263 Frequencies.**

\(a\) *Domestic VHF service.* (1) Frequencies in the 128.8125-132.125
MHz and 136.4875 -137.00 MHz bands are available to serve domestic
routes, except that the frequencies 136.750 MHz and 136.825 MHz are also
available to aeronautical enroute stations located at least 288
kilometers (180 miles) from the Gulf of Mexico shore line (outside the
Gulf of Mexico Region). Frequency assignments are based on 25 kHz
spacing. Use of these frequencies must be compatible with existing
operations and must be in accordance with pertinent international
treaties and agreements.

\*\*\*\*\*

\(5\) The frequencies 136.750 MHz and 136.825 MHz are available in the
Gulf of Mexico Region to serve domestic routes over the Gulf of Mexico
and adjacent coastal areas. Assignment of these frequencies in the Gulf
of Mexico Region shall be to licensees first licensed on this frequency
in the Gulf of Mexico Region prior to January 1, 1994, their successors
and assigns, and is not subject to the conditions in § 87.261(c) and
paragraph (a)(2) of this section. For the purpose of this paragraph, the
Gulf of Mexico Region is defined as an area bounded on the east, north,
and west by a line 288 km (180 miles) from the Gulf of Mexico shore
line. Inland stations must be located within forty-eight kilometers (30
miles) of the Gulf of Mexico shore line.

\*\*\*\*\*

[^1]: *See* Small Aircraft Manufacturers Association (SAMA) Petition for
    Rulemaking, filed September 14, 1998 (SAMA Petition); Federal
    Aviation Administration (FAA) Petition for Rulemaking, filed
    November 19, 1998 (FAA Petition); FAA Comments (revising its
    original Petition), filed August 3, 1999 (FAA Revised Petition).

[^2]: FIS are defined as the non-air traffic control (non-ATC)
    information needed by pilots to operate in domestic and
    international airspace. It may incorporate information such as
    automatic terminal information services (ATIS), Notices to Airmen
    (NOTAMs), Visual Flight Rules (VFR, rules for conducting flights
    under visual conditions), pilot initiated weather reports (PIREPs),
    and other non-ATC data. *See* *Aeronautical Spectrum Planning for
    1997-2010*, Doc. No. RTCA/DO-210 January 27, 1997, published by
    RTCA, Inc., Appendix A at page A-2 and A-3. For these and other
    aeronautical communications services and designations discussed
    *infra*, *see generally* FAA *Aeronautical Information Manual*,
    chapters 4-5.

[^3]: SAMA Petition at 2.

[^4]: Air Traffic Control (ATC) is a service operated by an appropriate
    authority to promote the safe, orderly and expeditious flow of air
    traffic. It consists of communications between aircraft pilots and
    airport control towers or FAA aeronautical enroute stations
    regarding aircraft landings and take-offs, aircraft transiting the
    airport traffic area on approach and departure, and aircraft
    traveling along domestic or international air routes. *See* 47
    C.F.R. §§ 87.237, 87.261, and 87.417.

[^5]: *See* FAA Petition at 1.

[^6]: *See* 47 C.F.R. § 2.106, n. US244.

[^7]: These include the following: (1) 47 C.F.R. § 87.131 (Power and
    emissions); (2) 47 C.F.R. § 87.133 (Frequency stability); (3) 47
    C.F.R. § 87.137 (Types of emission); (4) 47 C.F.R. § 87.139
    (Emission limitations); (5) 47 C.F.R. § 87.173 (Frequencies)
    \[General List\]; (6) 47 C.F.R. § 87.187 (Frequencies) \[Aircraft
    Stations\]; and (7) 47 C.F.R. § 87.263 (Frequencies) \[Aeronautical
    Enroute and Aeronautical Fixed Stations\].

[^8]: *See* Amendment of Parts 2 and 87 of Commission\'s Rules to Permit
    the Aviation Services to Use Frequencies in the 136‑137 MHz Band,
    *Report and Order*, Gen. Dkt. No. 89-295, 5 FCC Rcd. 3954 (1990),
    *Memorandum Opinion and Order,* 6 FCC Rcd. 2291 (1991).

[^9]: This allocation was added immediately adjacent to the VHF
    aeronautical mobile (R) radio band at 117.975-136 MHz*. See* *Report
    and Order*, 5 FCC Rcd. at 3958 ¶ 32.

[^10]: Automatic Weather Observation Services (AWOS) provide pilots with
    up-to-date weather information including the time of the latest
    weather sequence, altimeter setting, wind speed and direction,
    dewpoint, temperature, visibility, and other pertinent data for
    airports lacking either a full-time control tower or a full-time FAA
    Flight Service Station. *See* 47 C.F.R. § 87.525.

[^11]: Automatic Terminal Information Services (ATIS) provide pilots
    with information regarding aircraft movement within an airport.
    *See* 47 C.F.R. § 87.525.

[^12]: Air Traffic Control Tower Communications (ACTC) are operational
    control communications between aircraft pilots and airport control
    towers regarding aircraft landings and take-offs, and aircraft
    transiting the airport traffic area on approach and departure. *See*
    47 C.F.R. § 87.417.

[^13]: *See* *Report and Order*, 5 FCC Rcd. at 3958 ¶ 32.

[^14]: FAA Policy Statement at 1.

[^15]: *Id.*

[^16]: *Id.*

[^17]: *Id.*

[^18]: SAMA Petition at 1. The SAMA Petition was assigned RM-9376, and
    placed on Public Notice, Report No. 2301 (October 14, 1998).

[^19]: *See* SAMA Petition at 3.

[^20]: *Id*.

[^21]: *Id*. at 3-4.

[^22]: 47 C.F.R. § 87.131.

[^23]: SAMA Petition at 2.

[^24]: NATA, an association of 2,000 members, represents the interests
    of aviation businesses nationwide, including such industries as
    aircraft fueling, maintenance, and flight instruction. NATA Comments
    at 1.

[^25]: NBAA represents the interests of business aviation in the U.S.,
    and whose membership is comprised of more than 5,650 companies that
    operate more than 7,200 aircraft. NBAA Comments at 1.

[^26]: ARINC is the communications company of the air transport
    industry, and has been entrusted by that industry and the Commission
    with the management of the aeronautical enroute spectrum. ARINC
    Comments at 1.

[^27]: The FAA proposed to modify the Table of Frequency Allocations, 47
    C.F.R. § 2.106, and consequential changes to footnote US244. FAA
    Petition at 4.

[^28]: FAA Petition at 1. The FAA Petition was assigned RM-9462, and
    placed on Public Notice, Report No. 2315 (February 5, 1999).

[^29]: FAA Petition at 4. Aircraft Operational Control (AOC) is
    communications required for the exercise of authority over the
    initiation, continuation, diversion, or termination of a flight in
    the interest of the safety of the aircraft and the regularity and
    efficiency of a flight. (Such communications are normally required
    for the exchange of messages between aircraft and aircraft operating
    agencies.)

[^30]: FAA Petition at 1.

[^31]: FAA Petition at 5-6.

[^32]: ATA is the national trade and service association of the United
    States airline industry, representing 23 major U.S. passenger and
    cargo carriers and 5 associated (non-U.S.) carriers. ARINC/ATA Joint
    Comments at 2. *See* footnote 22, *supra*, for a description of
    ARINC.

[^33]: FAA Revised Petition refers to a broadcast mode of delivery for
    FIS known as "Flight Information Services-Broadcast (FIS-B)," a
    concept currently under development. With FIS-B, an on-board server
    will be responsible for personalizing products to pilot's needs.
    *See* *Aeronautical Spectrum Planning for 1997-2010*, Doc. No.
    RTCA/DO-210 January 27, 1997, published by RTCA, Inc., Section
    4.1.2.3. For this *Notice*, we will use the term FIS that appears to
    encompass FIS-B. We seek comments on the use of these terms. *See*
    para. 12 and note 73, *infra*.

[^34]: The FAA states that the original petition remains valid except as
    amended in its revision. FAA Revised Petition at 1.

[^35]: The FAA proposes a 25 kHz channeling plan for the 136-137 MHz
    band as follows: seventeen channels in the 136-136.400 MHz band for
    ATC; four channels in the 136.425-136.500 MHz band for FIS; and
    nineteen channels in the 136.525-136.975 MHz band for AOC. FAA
    Revised Petition at 2-3.

[^36]: FAA Revised Petition at 3.

[^37]: FAA Revised Petition at 3-4.

[^38]: *See* Letter from John Bartlett to D'wana Terry seeking to
    clarify necessary rule changes (dated November 15, 1999) (ARINC
    Clarification).

[^39]: *See* 47 C.F.R. § 2.106.

[^40]: Pursuant to footnote US244, the FAA shares fifteen channels in
    the 136-136.475 MHz band for general aviation ATC purposes. *See* 47
    C.F.R. § 2.106, n. US244.

[^41]: SAMA Petition at 2.

[^42]: *See* FAA Revised Petition at 2 and 5.

[^43]: ARINC/ATA Joint Comments at 2-3.

[^44]: *See* FAA Petition at 4 and FAA Revised Petition at 2.

[^45]: FAA Petition at 2.

[^46]: *Id*. at 1.

[^47]: *Id*.

[^48]: *Id*.

[^49]: *Id*.

[^50]: *Id.*

[^51]: *Id*.

[^52]: ARINC/ATA Joint Comments at 2.

[^53]: *Id*. at 2-3.

[^54]: These are the five channels originally held in reserve. *See*
    para. 2, *supra*.

[^55]: SAMA Petition at 1 and4; NATA Comments at 1; NBAA Comments at 3
    (supports channels for digital use); ARINC/ATA Joint Comments at 5
    (support providing access to additional channels in the lower half
    of the 136-137 MHz band).

[^56]: *See* *Report and Order*, 5 FCC Rcd. at 3954, 3958.

[^57]: SAMA Petition at 2.

[^58]: *Id.* at 3.

[^59]: NATA Comments at 1, NBAA Comments at 3, and ARINC/ATA Joint
    Comments at 4.

[^60]: SAMA Petition at 3.

[^61]: *Id*.

[^62]: *Id*. at 4.

[^63]: FAA Revised Petition at 3.

[^64]: The 136-136.475 MHz band, which contain the 20 channels that are
    shared with FAA for ATC purposes, are commonly referred to as ATC
    channels or band, while the remainder of the band 135.5-137 MHz,
    which contains 20 channels used for AOC by the industry, is commonly
    referred to as the AOC channels or band. *See* discussion in para.
    7, *supra*.

[^65]: SAMA Petition at 2.

[^66]: ARINC/ATA Joint Comments at 8.

[^67]: ARINC Clarification at 2-3.

[^68]: NBAA Comments at 2.

[^69]: ARINC Clarification at 2.

[^70]: ARINC/ATA Joint Comments at 5.

[^71]: *See* SAMA Petition at 2-4, FAA Revised Petition at 1-3; *but
    see* ARINC/ATA Joint Comments at 1 and Appendix A, ARINC
    Clarification at 1-2 and Appendix A. *See also* notes 2 and 33,
    *supra*.

[^72]: NBAA Comments at 1.

[^73]: G1D refers to a phase-modulated emission of a single channel
    containing quantized or digital information without the use of a
    modulating sub-carrier, excluding time division multiplex for data
    transmission. G7D refers to a phase-modulated emission of two or
    more channels containing quantized or digital information, together
    with one or more channels containing analog information, for data
    transmission. *See* 47 C.F.R. § 2.201.

[^74]: *See* 47 C.F.R. §§ 87.131, 87.133, 87.137, and 87.139.

[^75]: SAMA Petition at 2 and 5.

[^76]: FAA Revised Petition at 3-4.

[^77]: ARINC/ATA Joint Comments at 6*.*

[^78]: ARINC/ATA Joint Comments at 6*.*

[^79]: FAA Petition at 2.

[^80]: Time division multiple access (TDMA) is a multiple access
    technique whereby users share a transmission medium by being
    assigned and using (one-at-a-time) for a limited number of time
    division multiplexed channels; implies that several transmitters use
    one channel for sending several bit streams. *See* 47 C.F.R. § 27.5.
    In other words, it is a communications technique that uses a common
    channel, multipoint or broadcast, for communications among multiple
    users by allocating unique time slots to different users. *See*
    National Communications System, Technology and Standards Division,
    *Telecommunications: Glossary of Telecommunications Terms*, Federal
    Standard 1037C (1996).

[^81]: *Id*.

[^82]: *Id*.

[^83]: FAA Petition at 2.

[^84]: FAA Petition at 4-5 and FAA Revised Petition at 2-3.

[^85]: FAA Petition at 3.

[^86]: FAA Petition at 2.

[^87]: ARINC/ATA Joint Comments at 6.

[^88]: *Id*. at 8.

[^89]: *Id at 6*.

[^90]: NBAA Comments at 2.

[^91]: *Id*.

[^92]: *Id*.

[^93]: These proposed modifications are consequential to the proposed
    new division of use between ATC and AOC, as discussed in para. 12,
    *supra*.

[^94]: FAA Revised Petition at 4.

[^95]: *See* ARINC/ATA Joint Comments at 6-7 and A-3, and ARINC
    Clarification at 3-4 and 8.

[^96]: *See* Amendment of Parts 2 and 87 of Commission's Rules to permit
    the Aviation Services to use frequencies in the 136-137 MHz band,
    *Report and Order*, 5 FCC Rcd 3954, 3957 ¶ 27 (1990).

[^97]: FCC license records indicate that frequency 136.750 MHz is
    licensed to Chevron USA, Inc. (issued on December 30, 1993) and
    frequency 136.825 MHz is licensed to Offshore Logistics, Inc.
    (issued on June 12, 1997).

[^98]: ARINC/ATA Joint Comments at 7.

[^99]: ARINC/ATA aver that only one frequency (136.750 MHz) is licensed.
    *See* ARINC Clarification at 4-5.

[^100]: Pub. L. No. 96-354, 94 Stat. 1165, 5 U.S.C. §§ 601-612 (1980).

[^101]: *See* 5 U.S.C. § 603.