Section 171.325

14 CFR Ch. I (1-1-19 Edition)

operation if the primary power fails. A
trickle charge must be supplied to recharge the batteries during the period
of available primary power. Upon loss
and subsequent restoration of power,
the battery must be restored to full
charge within 24 hours. When primary
power is applied, the state of the battery charge must not affect the operation of the MLS ground station. The
battery must allow continuation of
normal operation of the MLS facility
for at least 2 hours without the use of
additional sources of power. When the
system is operating from the battery
supply without prime power, the radome deicers and the environmental
system need not operate. The equipment must meet all specification requirements with or without batteries
installed.
(h) There must be a means for determining, from the ground, the performance of the system including antenna,
both initially and periodically.
(i) The facility must have, or be supplemented by, ground, air, or landline
communications services. At facilities
within or immediately adjacent to controlled airspace, that are intended for
use as instrument approach aids for an
airport, there must be ground air communications or reliable communications (at least a landline telephone)
from the airport to the nearest FAA
air traffic control or communication
facility. Compliance with this paragraph need not be shown 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 factor, the requirements of this paragraph
may be reduced to reliable communications from the airport to the nearest
FAA air traffic control or communications facility. If the adjacent FAA facility can communicate with aircraft
during the proposed instrument approach procedure down to the airport
surface or at least down to the minimum en route altitude, this would require at least a landline telephone.

(j) The location of the phase center
for all antennas must be clearly
marked on the antenna enclosures.
(k) The latitude, longitude and mean
sea level elevation of all MLS antennas, runway threshold and runway stop
end must be determined by survey with
an accuracy of Section3 meters (Section10 feet) laterally and Section0.3 meter (Section1.0 foot)
vertically. The relative lateral and
vertical offsets of all antenna phase
centers, and both runway ends must be
determined with an accuracy of Section0.3
meter (Section1.0 foot) laterally and Section0.03
meter (Section0.1 foot) vertically. The owner
must bear all costs of the survey. The
results of this survey must be included
in the  - operations and maintenance - 
manual required by section 171.325 of
this subpart and will be noted on FAA
Form 198 required by Section 171.327.
[Doc. No. 20669, 51 FR 33177, Sept. 18, 1986, as
amended by Amdt. 171-16, 56 FR 65665, Dec.
17, 1991]

Section 171.325 Maintenance and operations
requirements.
(a) The owner of the facility must establish an adequate maintenance system and provide MLS qualified maintenance personnel to maintain the facility at the level attained at the time it
was commissioned. Each person who
maintains a facility must meet the
FCC licensing requirements and demonstrate that he has the special knowledge and skills needed to maintain an
MLS facility, including proficiency in
maintenance procedures and the use of
specialized test equipment.
(b) In the event of out-of-tolerance
conditions or malfunctions, as evidenced by receiving two successive
pilot reports, the owner must close the
facility by encasing radiation, and
issue a  - Notice to Airmen -  (NOTAM)
that the facility is out of service.
(c) The owner must prepare, and obtain approval of, an operations and
maintenance manual that sets forth
mandatory procedures for operations,
periodic maintenance, and emergency
maintenance, including instructions on
each of the following:
(1) Physical security of the facility.
(2) Maintenance and operations by
authorized persons.
(3) FCC licensing requirements for
operations and maintenance personnel.

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