817
Federal Aviation Administration, DOT
§ 171.11
(c) The monitor is checked periodi-
cally, during the in-service test evalua-
tion period, for calibration and sta-
bility The tests are made with a stand-
ard ‘‘Reference and variable phase sig-
nal generator’’ and associated test
equipment, including an oscilloscope
and portable field detector. In general,
the ground check is conducted in
accord- ance with section 8.4 of FAA
Handbook AF P 6790.9 ‘‘Maintenance
Instruction for VHF Omniranges’’,
adapted for the facility concerned.
(d) Flight tests to determine the fa-
cility’s adequacy for operational re-
quirements and compliance with appli-
cable ‘‘Standards and Recommended
Practices’’ are conducted in accordance
with the ‘‘U.S. Standard Flight Inspec-
tion Manual’’, particularly section 201.
(e) After January 1, 1975, the owner of
the VOR shall modify the facility to
perform in accordance with paragraph
3.3.5.7 of Annex 10 to the Convention on
International Civil Aviation within 180
days after receipt of notice from the
Administrator that 50 kHz channel
spacing is to be implemented in the
area and that a requirement exists for
suppression of 9960 Hz subcarrier
harmonics.
[Doc. No. 5034, 29 FR 11337, Aug. 6, 1964, as
amended by Amdt. 171–7, 35 FR 12711, Aug. 11,
1970; Amdt. 171–9, 38 FR 28557, Oct. 15, 1973]
§ 171.9 Installation requirements.
(a) The facility must be installed ac-
cording to accepted good engineering
practices, applicable electric and safe-
ty codes, and the installation must
meet at least the Federal Communica-
tion Commission’s licensing require-
ments.
(b) The facility must have a reliable
source of suitable primary power, ei-
ther from a power distribution system
or locally generated, with a supple-
mental standby system, if needed.
(c) Dual transmitting equipment
with automatic changeover is preferred
and may be required to support certain
IFR procedures.
(d) There must be a means for deter-
mining, from the ground, the perform-
ance of the equipment, including the
antenna, initially and periodically.
(e) A facility intended for use as an
instrument approach aid for an airport
must have or be supplemented by (de-
pending on circumstances) the fol-
lowing ground-air or landline commu-
nications services:
(1) At facilities outside of and not im-
mediately adjacent to controlled air-
space, there must be ground-air com-
munications from the airport served by
the facility. Separate communications
channels are acceptable.
(2) At facilities within or imme-
diately adjacent to controlled airspace,
there must be the ground-air commu-
nications required by paragraph (e)(1)
of this section and reliable communica-
tions (at least a landline telephone)
from the airport to the nearest FAA
air traffic control or communication
facility.
Paragraphs (e) (1) and (2) of this sec-
tion are not mandatory at airports
where an adjacent FAA facility can
communicate with aircraft on the
ground at the airport and during the
entire proposed instrument approach
procedure. In addition, at low traffic
density airports within or immediately
adjacent to controlled airspace and
where extensive delays are not a fac-
tor, the requirements of paragraphs (e)
(1) and (2) of this section may be re-
duced to reliable communications (at
least a landline telephone) from the
airport to the nearest FAA air traffic
control or communication facility, if
an adjacent FAA facility can commu-
nicate with aircraft during the pro-
posed instrument approach procedure,
at least down to the minimum en route
altitude for the controlled airspace
area.
[Doc. No. 5034, 29 FR 11337, Aug. 6, 1964, as
amended by Amdt. 171–7, 35 FR 12711, Aug. 11,
1970; Amdt. 171–16, 56 FR 65664, Dec. 17, 1991]
§ 171.11 Maintenance and operations
requirements.
(a) The owner of the facility must es-
tablish an adequate maintenance sys-
tem and provide qualified maintenance
personnel to maintain the facility at
the level attained at the time it was
commissioned. Each person who main-
tains a facility must meet at least the
Federal Communications Commission’s
licensing requirements and show that
he has the special knowledge and skills