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 

818 

14 CFR Ch. I (1–1–24 Edition) 

§ 171.11 

needed to maintain the facility includ-
ing proficiency in maintenance proce-
dures and the use of specialized test 
equipment. 

(b) The owner must prepare, and ob-

tain FAA approval of, an operations 
and maintenance manual that sets 
forth mandatory procedures for oper-
ations, preventive maintenance, and 
emergency maintenance, including in-
structions on each of the following: 

(1) Physical security of the facility. 
(2) Maintenance and operations by 

authorized persons only. 

(3) FCC licensing requirements for 

operating and maintenance personnel. 

(4) Posting of licenses and signs. 
(5) Relations between the facility and 

FAA air traffic control facilities, with 
a description of the boundaries of con-
trolled airspace over or near the facil-
ity, instructions for relaying air traffic 
control instructions and information 
(if applicable), and instructions for the 
operation of an air traffic advisory 
service if the VOR is located outside of 
controlled airspace. 

(6) Notice to the Administrator of 

any suspension of service. 

(7) Detailed and specific maintenance 

procedures and servicing guides stating 
the frequency of servicing. 

(8) Air-ground communications, if 

provided, expressly written or incor-
porating appropriate sections of FAA 
manuals by reference. 

(9) Keeping of station logs and other 

technical reports, and the submission 
of reports required by § 171.13. 

(10) Monitoring of the facility. 
(11) Inspections by United States per-

sonnel. 

(12) Names, addresses, and telephone 

numbers of persons to be notified in an 
emergency. 

(13) Shutdowns for routine mainte-

nance and issue of ‘‘Notices to Airmen’’ 
for routine or emergency shutdowns 
(private use facilities may omit the 
‘‘Notices to Airmen’’). 

(14) An explanation of the kinds of 

activity (such as construction or grad-
ing) in the vicinity of the facility that 
may require shutdown or recertifi-
cation of the facility by FAA flight 
check. 

(15) Procedures for conducting a 

ground check of course accuracy. 

(16) Commissioning of the facility. 

(17) An acceptable procedure for 

amending or revising the manual. 

(18) The following information con-

cerning the facility: 

(i) Location by latitude and lon-

gitude to the nearest second, and its 
position with respect to airport lay-
outs. 

(ii) The type, make, and model of the 

basic radio equipment that will provide 
the service. 

(iii) The station power emission and 

frequency. 

(iv) The hours of operation. 
(v) Station identification call letters 

and method of station identification, 
whether by Morse code or recorded 
voice announcement, and the time 
spacing of the identification. 

(vi) A description of the critical parts 

that may not be changed, adjusted, or 
repaired without an FAA flight check 
to confirm published operations. 

(c) The owner shall make a ground 

check of course accuracy each month 
in accordance with procedures ap-
proved by the FAA at the time of com-
missioning, and shall report the results 
of the checks as provided in § 171.13. 

(d) If the owner desires to modify the 

facility, he must submit the proposal 
to the FAA and may not allow any 
modifications to be made without spe-
cific approval. 

(e) The owner’s maintenance per-

sonnel must participate in initial in-
spections made by the FAA. In the case 
of subsequent inspections, the owner or 
his representative shall participate. 

(f) Whenever it is required by the 

FAA, the owner shall incorporate im-
provements in VOR maintenance 
brought about by progress in the state 
of the art. In addition, he shall provide 
a stock of spare parts, including vacu-
um tubes, of such a quantity to make 
possible the prompt replacement of 
components that fail or deteriorate in 
service. 

(g) The owner shall provide all ap-

proved test instruments needed for 
maintenance of the facility. 

(h) The owner shall close the facility 

upon receiving two successive pilot re-
ports of its malfunctioning. 

[Doc. No. 5034, 29 FR 11337, Aug. 6, 1964, as 
amended by Amdt. 171–2, 31 FR 5408, Apr. 6, 
1966]