890
14 CFR Ch. I (1–1–24 Edition)
§ 171.321
(4) There is an error in the time divi-
sion multiplex synchronization of a
particular elevation function such that
the requirement specified in § 171.311(e)
is not satisfied and this condition per-
sists for more than one second.
(5) A failure of the monitor is de-
tected.
(b) The period during which erro-
neous guidance information is radiated
must not exceed the periods specified
in § 171.319(a). If the fault is not cleared
within the time allowed, radiation
shall cease. After shutdown, no at-
tempt must be made to restore service
until a period of 20 seconds has elapsed.
§ 171.321 DME and marker beacon per-
formance requirements.
(a) The DME equipment must meet
the performance requirements pre-
scribed in subpart G of the part. This
subpart imposes requirements that per-
formance features must comply with
International Standards and Rec-
ommended Practices, Aeronautical
Telecommunications, Vol. I of Annex
10 to ICAO. It is available from ICAO,
Aviation Building, 1080 University
Street, Montreal 101, Quebec, Canada,
Attention: Distribution Officer and
also available for inspection at the Na-
tional Archives and Records Adminis-
tration (NARA). For information on
the availability of this material at
NARA, call 202–741–6030, or go to:
http://
www.archives.gov/federal
_
register/
code
_
of
_
federal
_
regulations/ibr
_
loca-
tions.html.
(b) MLS marker beacon equipment
must meet the performance require-
ments prescribed in subpart H of this
part. This subpart imposes require-
ments that performance features must
comply with International Standards
and Recommended Practices, Aero-
nautical Telecommuncations, Vol. I of
Annex 10 to ICAO.
[Doc. No. 5034, 29 FR 11337, Aug. 6, 1964, as
amended at 69 FR 18803, Apr. 9, 2004]
§ 171.323 Fabrication and installation
requirements.
(a) The MLS facility must be perma-
nent and must be located, constructed,
and installed in accordance with best
commercial engineering practices,
using applicable electric and safety
codes and Federal Communications
Commission (FCC) licensing require-
ments and siting requirements of
§§ 171.313(b) and 171.317(b).
(b) The MLS facility components
must utilize solid state technology ex-
cept that traveling wave tube ampli-
fiers (TWTA) may be used. A maximum
level of common modularity must be
provided along with diagnostics to fa-
cilitate maintenance and trouble-
shooting.
(c) An approved monitoring capa-
bility must be provided which indicates
the status of the equipment at the site
and at a remotely located maintenance
area, with monitor capability that pro-
vides pre-alarm of impending system
failures. This monitoring feature must
be capable of transmitting the status
and pre-alarm over standard phone
lines to a remote section. In the event
the sponsor requests the FAA to as-
sume ownership of the facility, the
monitoring feature must also be capa-
ble of interfacing with FAA remote
monitoring requirements. This require-
ment may be complied with by the ad-
dition of optional software and/or hard-
ware in space provided in the original
equipment.
(d) The mean corrective maintenance
time of the MLS equipment must be
equal to or less than 0.5 hours with a
maximum corrective maintenance time
not to exceed 1.5 hours. This measure
applies to correction of unscheduled
failures of the monitor, transmitter
and associated antenna assemblies,
limited to unscheduled outage and out
of tolerance conditions.
(e) The mean-time-between-failures
of the MLS angle system must not be
less than 1,500 hours. This measure ap-
plies to unscheduled outage, out-of-tol-
erance conditions, and failures of the
monitor, transmitter, and associated
antenna assemblies.
(f) The MLS facility must have a reli-
able source of suitable primary power,
either from a power distribution sys-
tem or locally generated. Adequate
power capacity must be provided for
the operation of the MLS as well as the
test and working equipment of the
MLS.
(g) The MLS facility must have a
continuously engaged or floating bat-
tery power source for the continued
normal operation of the ground station