motors or ac induction motors to provide drive
lights mounted so they are clearly visible to the
operation. The 28-volt ac is provided by an
LSO. Installations of the approach lights vary
with aircraft. Older aircraft have them in the port
autotransformer located within each light
assembly. In the retracted position, movable lights
wing leading edge. Modern aircraft, such as the
are flush with the undersurface of the wing. In
F-14 (fig. 4-7) and F/A-18, have the approach
some aircraft, you can install a landing light in
lights on the nose landing gear door. Most jet
the nosewheel fairing door. Other aircraft have
aircraft have a three-lamp approach light assembly
a fixed landing light, mounted in the leading edge
connected to the angle-of-attack indicator. The
of the wing.
approach light control is by cam-actuated switches
in the angle-of-attack indicator. The lights operate
As you read this section, refer to figure 4-6.
with landing gear completely down, with aircraft
You are going to learn about the operating
principles of a typical retractable landing light.
off the gear, and arresting gear extended.
The three lights in the approach light assembly
The landing light switch on the pilot's lighting
are red, amber, and green. When the red light is
panel controls the landing light motor. When the
on, it shows that the angle of attack of the aircraft
switch is in either the EXTEND or RETRACT
is low. When the green light is on, it shows that
position, power goes simultaneously to the
magnetic brake (releasing the brake) and the drive
the angle of attack of the aircraft is high. When
motor. Limit switches open the motor circuit
the amber light is on, the angle of attack is prefect
for the landing approach.
when the light has reached its limit of travel in
The approach lights work in conjunction with
either direction (extended or retracted position).
This light can be put in any position between its
the cockpit angle-of-attack indexer lights (fig.
4-7), which give the pilot angle-of-attack
travel limits by turning the switch off. When the
information. These lights mount in the cockpit
power to the motor is off, the gear train holds
on either side of the windshield. They are clearly
the light in that position.
visible to the pilot, but don't obstruct vision.
The lamp illuminates by a sliding contact after
the light assembly travels downward about 10
The indexer lights operate by cam-operated
degrees. Illumination continues until the lamp
switches in the angle-of-attack indicator. At very
low angles of attack, a red-colored inverted V
again reaches the 10-degree position when
illuminates. This warns the pilot to increase the
traveling in the upward direction. The lamp will
remain lighted in any extended position past the
aircraft angle of attack. At slightly low angles of
10-degree position, regardless of power appli-
attack, both the inverted V and circular symbol
(doughnut) illuminate. At desired angles of attack,
cation to the control motor. The pilot can adjust
the amber-colored doughnut illuminates. At
the angle of the light beam to fit the operation.
A switch lets you turn the lamp off while the light
slightly high angles of attack, both the V and
is in any position, as shown in figure 4-6, view B.
doughnut illuminate. At very high angles of
The landing light assembly design lets you
attack, a green-colored V symbol illuminates,
warning the pilot to decrease the aircraft angle
adjust the maximum extended position for each
particular aircraft installation. The light opens to
of attack. The indexer information corresponds
an extended position of 73 degrees, 3 degrees,
to the approach lights assembly information
from the retracted position. The light assembly
displayed to the LSO.
is capable of being extended to positions ranging
Approach lights show the LSO three things--
from 50 degrees to 85 degrees from the retracted
(1) aircraft angle of attack, (2) landing gear is
down and locked, and (3) arresting gear extension.
position.
When you ground-test landing lights, don't let
A limit switch in the arresting gear circuit operates
when an unsafe condition exists, causing the lights
them overheat or be damaged by extending them
against ground support equipment. You should
to flash.
An arresting gear (tailhook) override switch
NEVER look directly at an illuminated landing
light because it can cause permanent eye damage.
allows bypass of the tailhook circuit for carrier
landing practice at airfields. The override switch
Approach Lights
is of the momentary ON type. When in the ON
position, the arresting gear switch bypass relay
The carrier aircraft approach light systems give
energizes. The approach lights operate only in
conjunction with landing gear, since the arresting
the pilot and landing safety officer (LSO) positive
gear is up. When the circuit de-energizes, it
indication of safe or unsafe landing configura-
automatically reverts to its normal condition
tions. All shipboard naval aircraft have approach
