曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
..........
.....
.....
.....
.....
.....
..... .....
.....
NOTE: Civil ALSF-2 may be
operated as SSALR during
favorable weather conditions.
ALSF-2
Omnidirectional
Flashing
Light
ODALS
Flashing
Light
Flashing
Light
Flashing
Light . Steady
Burning
Light
.. Steady
Burning
Light
.. Steady
Burning
Light
SSALR
ALSF-1 MALSR
... ... ..... ... ...
. Steady
Burning
Light ................ .......... ................
MALSF
Flashing
Light
..........
..........
..........
..........
..........
.......... 15° 10° 10° 15°
LANDING
APPROACH
REIL
AIM 2/19/04
2−1−2 Airport Lighting Aids
2−1−2. Visual Glideslope Indicators
a. Visual Approach Slope Indicator (VASI)
1. The VASI is a system of lights so arranged to
provide visual descent guidance information during
the approach to a runway. These lights are visible
from 3−5 miles during the day and up to 20 miles or
more at night. The visual glide path of the VASI
provides safe obstruction clearance within plus or
minus 10 degrees of the extended runway centerline
and to 4 NM from the runway threshold. Descent,
using the VASI, should not be initiated until the
aircraft is visually aligned with the runway. Lateral
course guidance is provided by the runway or runway
lights.
2. VASI installations may consist of either 2, 4,
6, 12, or 16 light units arranged in bars referred to as
near, middle, and far bars. Most VASI installations
consist of 2 bars, near and far, and may consist of 2,
4, or 12 light units. Some VASIs consist of three bars,
near, middle, and far, which provide an additional
visual glide path to accommodate high cockpit
aircraft. This installation may consist of either 6 or
16 light units. VASI installations consisting of 2, 4, or
6 light units are located on one side of the runway,
usually the left. Where the installation consists of
12 or 16 light units, the units are located on both sides
of the runway.
3. Two-bar VASI installations provide one
visual glide path which is normally set at 3 degrees.
Three-bar VASI installations provide two visual glide
paths. The lower glide path is provided by the near
and middle bars and is normally set at 3 degrees while
the upper glide path, provided by the middle and far
bars, is normally 1/4 degree higher. This higher glide
path is intended for use only by high cockpit aircraft
to provide a sufficient threshold crossing height.
Although normal glide path angles are three degrees,
angles at some locations may be as high as 4.5 degrees
to give proper obstacle clearance. Pilots of high
performance aircraft are cautioned that use of VASI
angles in excess of 3.5 degrees may cause an increase
in runway length required for landing and rollout.
4. The basic principle of the VASI is that of color
differentiation between red and white. Each light unit
projects a beam of light having a white segment in the
upper part of the beam and red segment in the lower
part of the beam. The light units are arranged so that
the pilot using the VASIs during an approach will see
the combination of lights shown below.
5. For 2-bar VASI (4 light units) see FIG 2−1−2.
FIG 2−1−2
2-Bar VASI
Far Bar
= Red
Near Bar = White
Below Glide Path On Glide Path Above Glide Path
2/19/04 AIM
Airport Lighting Aids 2−1−3
6. For 3-bar VASI (6 light units) see FIG 2−1−3.
FIG 2−1−3
3-Bar VASI
Far Bar
Middle Bar
Near Bar
Below Both
Glide Paths
On Lower
Glide Path
On Upper
Glide Path
Above Both
Glide Paths
7. For other VASI configurations see FIG 2−1−4.
FIG 2−1−4
VASI Variations
2 Bar
2 Light Units
On Glide Path
2 Bar
12 Light Units
On Glide Path
3 Bar
16 Light Units
on Lower Glide Path
AIM 2/19/04
2−1−4 Airport Lighting Aids
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
AIM航空信息手册2004上(57)
