840
14 CFR Ch. I (1–1–24 Edition)
§ 171.213
(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 methods of station identification,
whether by Morse Code or recorded
voice announcement, and the time
spacing of the identification.
(c) If the owner desires to modify the
facility, he shall submit the proposal
to the Federal Aviation Administra-
tion and meet applicable requirements
of the Federal Communications Com-
mission, and must not allow any modi-
fication to be made without specific
approval by the Federal Aviation Ad-
ministration.
(d) The owner’s maintenance per-
sonnel shall participate in initial in-
spections made by the Federal Avia-
tion Administration. In the case of sub-
sequent inspections, the owner or his
representative shall participate.
(e) The owner shall provide a stock of
spare parts, of such a quantity to make
possible the prompt replacement of
components that fail or deteriorate in
service.
(f) The owner shall shut down the fa-
cility by ceasing radiation, and shall
issue a ‘‘Notice to Airmen’’ that the fa-
cility is out of service (except that pri-
vate use facilities may omit ‘‘Notices
to Airmen’’) upon receiving two succes-
sive pilot reports of its malfunctioning.
§ 171.213 Reports.
The owner of each facility to which
this subpart applies shall make the fol-
lowing reports, at the times indicated,
to the Federal Aviation Administra-
tion Regional Office for the area in
which the facility is located:
(a) Record of meter readings and ad-
justments (Form FAA–198). To be filled
out by the owner or his maintenance
representative with the equipment ad-
justments and meter readings as of the
time of commissioning, with one copy
to be kept in the permanent records of
the facility and two copies to the ap-
propriate Regional Office of the Fed-
eral Aviation Administration. The
owner must revise the form after any
major repair, modification, or re-
tuning, to reflect an accurate record of
facility operation and adjustment.
(b) Facility maintenance log (FAA
Form 6030–1). This form is a permanent
record of all equipment malfunctioning
met in maintaining the facility, in-
cluding information on the kind of
work and adjustments made, equip-
ment failures, causes (if determined),
and corrective action taken. The owner
shall keep the original of each report
at the facility and send a copy to the
appropriate Regional Office of the Fed-
eral Aviation Administration at the
end of the month in which it is pre-
pared.
(c) Radio equipment operation record
(Form FAA–418), containing a complete
record of meter readings, recorded on
each scheduled visit to the facility.
The owner shall keep the original of
each month’s record at the facility and
send a copy of it to the appropriate Re-
gional Office of the Federal Aviation
Administration.
[Doc. No. 10116, 35 FR 12716, Aug. 11, 1970, as
amended by Amdt. 171–10, 40 FR 36110, Aug.
19, 1975]
Subpart I—Interim Standard
Microwave Landing System
(ISMLS)
S
OURCE
: Docket No. 14120, 40 FR 36110, Aug.
19, 1975, unless otherwise noted.
§ 171.251 Scope.
This subpart sets forth minimum re-
quirements for the approval and oper-
ation of non-Federal Interim Standard
Microwave Landing System (ISMLS)
facilities that are to be involved in the
approval of instrument flight rules and
air traffic control procedures related to
those facilities.
§ 171.253 Definitions.
As used in this subpart:
Angular displacement sensitivity
(Glide
Slope) means the ratio of measured
DDM to the corresponding angular dis-
placement from the appropriate ref-
erence line.
Collocated ground station
means the
type of ground station which transmits
841
Federal Aviation Administration, DOT
§ 171.253
two or more guidance signals simulta-
neously from a common location.
Course line
means the locus of points
nearest to the runway centerline in
any horizontal plane at which the DDM
is zero.
Course sector (full)
means a sector in a
horizontal plane containing the course
line and limited by the loci of points
nearest to the course line at which the
DDM is 0.155.
Course sector (half)
means the sector
in a horizontal plane containing the
course line and limited by the loci of
points nearest to the course line at
which DDM is 0.0775.
DDM
means difference in depth of
modulation. The percentage modula-
tion depth of the larger signal minus
the percentage modulation depth of the
smaller signal, divided by 100.
Displacement sensitivity
(Localizer)
means the ratio of measured DDM to
the corresponding lateral displacement
from the appropriate reference line.
Facility Performance Category I—
ISMLS
means an ISMLS which provides
guidance information from the cov-
erage limit of the ISMLS to the point
at which the localizer course line inter-
sects the ISMLS glide path at a height
of 200 feet or less above the horizontal
plane containing the threshold.
Glide path
means that locus of points
in the vertical plane containing the
runway center line at which the DDM
is zero, which, of all such loci, is the
closest to the horizontal plane.
Glide path angle
(
q
) means the angle
between a straight line which rep-
resents the mean of the ISMLS glide
path and the horizontal.
Glide path sector (full)
means the sec-
tor in the vertical plane containing the
ISMLS glide path and limited by the
loci of points nearest to the glide path
at which the DDM is 0.175. The ISMLS
glide path sector is located in the
vertical plane containing the runway
centerline, and is divided by the radi-
ated glide path in two parts called
upper sector and lower sector, referring
respectively to the sectors above and
below the glide path.
Glide path sector (half)
means the sec-
tor in the vertical plane containing the
ISMLS glide path and limited by the
loci of points nearest to the glide path
at which the DDM is 0.0875.
ISMLS Point ‘A’
means an imaginary
point on the glide path/localizer course
measured along the runway centerline
extended, in the approach direction,
four nautical miles from the runway
threshold.
ISMLS Point ‘B’
means an imaginary
point on the glide path/localizer course
measured along the runway centerline
extended, in the approach direction,
3500 feet from the runway threshold.
ISMLS Point ‘C’
means a point
through which the downward extended
straight portion of the glide path (at
the commissioned angle) passes at a
height of 100 feet above the horizontal
plane containing the runway threshold.
Interim standard microwave landing
system
(ISMLS) means a ground station
which transmits azimuth and elevation
angle information which, when decoded
and processed by the airborne unit,
provides signal performance capable of
supporting approach minima for V/
STOL and CTOL operations and oper-
ates with the signal format and toler-
ances specified in §§ 171.259, 171.261,
171.263, 171.265, and 171.267.
Integrity
means that quality which
relates to the trust which can be placed
in the correctness of the information
supplied by the facility.
Mean corrective time
means the aver-
age time required to correct an equip-
ment failure over a given period, after
a service man reaches the facility.
Mean time between failures
means the
average time between equipment fail-
ure over a given period.
Reference datum
means a point at a
specified height located vertically
above the intersection of the runway
centerline and the threshold and
through which the downward extended
straight portion of the ISMLS glide
path passes.
Split type ground station
means the
type of ground station in which the
electronic components for the azimuth
and elevation guidance are contained
in separate housings or shelters at dif-
ferent locations, with the azimuth por-
tion of the ground station located at
the stop end of the runway, and the
elevation guidance near the approach
end of the runway.