both manually and automatically, with the con-
When this switch is raised to the ON position, its
trols and instrumentation installed. For example,
mating green pilot light is illuminated and engine
if exhaust stack temperatures in excess of a preset
master relay is energized. Power is then available
temperature are experienced during afterburner
at the 28-volt engine control switch, having
operation, the afterburner is automatically cut off
arrived by way of the closed contacts of a
by a latching relay. When this occurs, the after-
normally open relay.
burner cannot be relit until safe temperature
conditions prevail and the relay is reset. Provisions
NOTE: All ON and OFF switches installed
have been made for manually overriding the
on the control board are positioned so that
exhaust stack temperature control system should
their respective ON positions in relation to
it fail or otherwise prove inadequate.
the lower edge of the applicable panel are
established with the toggle raised.
The principle of automatic safety control is
a built-in characteristic of test equipment. An
Control point No. 1 consists of a CO2 pressure
interlock system has been provided for automatic
switch and mating green pilot light. The switch
engine shutdown or prevention of engine start
is a manual reset switch, remotely located at
when the following conditions prevail:
the connector panel in the test cell, and is
programmed to seek the OFF position whenever
1. Inadequate water pressure to maintain
the test cell of the CO2 fire-extinguishing system
exhaust gas cooling, except when bypassed by the
is energized manually or automatically. If the
WATER-FUEL INTERLOCK switch.
pressure switch contacts are broken, they must be
2. Thrust bed not locked and interlocked in
manually reset to the ON position before the
height position.
interlock system circuit can be completed.
3. Front door key not in control panel lock,
Control point No. 2 consists of a front door
or door unlocked without utilization of front door
key-operated switch and two mating pilot lights.
bypass switch and rear door key not inserted in
The key that operates the switch is the key locking
control panel lock.
the front door of the test cell; this key cannot be
4. Primary air supply fire curtain not open.
removed from the door lock mechanism until the
5. CO2 fire-extinguishing system energized,
door is locked.
either manually or automatically.
Before the interlock system can be energized
6. Electric power failure.
by the switch, the key from the front door must
7. System-wide loss of compressed air supply.
be removed and brought to the control room for
use with the switch. The two mating pilot lights
The exhaust augmenter system consists of two
indicate the key switch position--green for
stages. Both stages are adjustable to meet specific
CLOSED and red for OPEN.
engine exhaust conditions.
Control point No. 3 consists of a front door
bypass switch and mating red pilot light. This
The first-stage exhaust augmenter is located
switch is provided to permit removal of the front
in the forward test cell wall of the spray room.
door key from the switch at control point No. 2.
The horizontal center line of the first-stage and
The key cannot be removed without placing the
the second-stage exhaust augmenter is approx-
switch in the OPEN position, so that the key may
imately 5 feet above the test cell floor. The first-
be used to open the front door when it is necessary
stage augmenter receives the exhaust discharge of
for authorized personnel to attend to the engine
the test engine and by venturi action tends to draw
or test equipment during periods of engine
such exhaust to the second-stage augmenter in the
operation.
spray room. The first-stage augmenter spray ring,
which is controlled manually from the control
Exhaust Augmenter Assembly and Exhaust
board, is included in the first stage.
Gas Cooling System Assembly
The size of the first-stage augmenter orifice
The exhaust augmenter assembly (augmenter)
and the distance from the plane of the engine
and the exhaust gas cooling system assembly
exhaust exit nozzle to the mount of the insert
(exhaust cooling system) are provided to ensure
should be correlated for each engine model to
proper disposition of engine exhaust by con-
obtain true engine performance and proper
trolling exhaust gas, flow characteristics, and
control of secondary airflow. Improper sizing and
temperature. These factors can be monitored,
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