redmoddata/lines_train_2M · Datasets at Hugging Face

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delay “Gas Generator.” The Quickmatch ignites the delay, which in turn fires a Secondary
Expulsion charge. This charge functions as the first, producing pressure that shears another set of
12 pins, evenly spaced around the circumference of the flare. Once again the pressure provides an
acceleration/deceleration force to the Drogue Housing and the Candle & Parachute Assembly.
Attached to the Pusher Plate is the cord for the Pilot Chute. As the Pilot Chute deploys, it pulls
the Main Chute assembly out of its housing (Parachute Insert) for Main Chute deployment.
Attached to the Main Chute support cable is a Lanyard that runs through an internal raceway in
the Candle and is attached to the Slider assembly in the Igniter assembly. As the main chute is
deployed, it pulls the Lanyard with a minimum force of 40 pounds. This force shears a shear pin
and moves the slider assembly into the firing position, cocks and releases the firing hammer and
fires the ignition primer. During launch of the Rocket, acceleration forces of at least 17 G for
duration of approximately one second withdrew the weight assembly of the “Zig-Zag” ignition
safe/arm mechanism from its saving position in the slider assembly, allowing Slider movement.
The output of the ignition primer is directed into a cavity containing boron pellets. The fire from
the boron pellets is directed on the forward face of the flare’s illuminant Candle and also on a
small propellant wafer which acts as an ignition booster. The Candle produces light in the near IR
spectrum for about 180 seconds. The main parachute allows for a descent rate of approximately
13 feet per second.
Tabulated data:
M257 Illumination Flare w/ M442 Fuze
Operating temperature limits: -25 oF to +140 oF
(-31.35 oC to +59.40 oC)
Candle composition: Magnesium Sodium Nitrate
Candle weight: 5.44 lb (2.47 kg)
Illumination intensity, visible: 817.19 CP (avg.)
infrared: 250.02 watts/sr (avg.)
Illumination duration: 197.38 sec (avg.)
Function time: 14.23 sec (avg.)
Shipping and storage data:
Storage class/SCG: 1.2 G
DOT shipping class: A
DOT designation: Rocket Ammunition with Illuminating Projectile
Field Storage: Group D
NSN: 1340-01-268-7175
DODIC: H183
UNO Serial No.
M278 IR Flare w/ M442 Fuze
DODIC: H154
UNO Serial No.
the 7-tube launcher continues to use a laminated stack.
experiences from the fire control is 0.06 seconds.
minimize the heat signature of the launcher after rocket firings.
RMS Display Unit RMS Operations Unit
The M138 Rocket Management Subsystem (RMS) is a pilot-operated subsystem that
interfaces with the wing stores subsystem in the helicopter. The RMS operates from power
supplied by the aircraft and consists of one Display Unit and four Operations Units. The RMS
enables the aircraft pilot to select and launch MK 40 or MK 66 rocket motors with the desired
warhead/fuze combination from two or four 7- or 19-tube launchers mounted under the aircraft
stub wings. The RMS automatically senses the quantity and type of launcher installed and
automatically sets its firing sequence to agree with the tube numbering of the launcher on board.
Should one or more launchers be disabled, the RMS will cause the corresponding launcher on the
opposite side of the fuselage to become inactive to maintain in-flight stability by equalizing the
load of unfired rockets.
Rockets are loaded according to type (warhead/fuze) in up to five loading zones, and the types
loaded in each zone are indicated by manually setting five 12-position thumb wheel switches on
the Display Unit panel. The switch positions are marked with two- or three-letter descriptors that
represent the available warhead/fuze configurations. When power is applied to the RMS, it
automatically inventories the rounds loaded in each zone and provides the pilot with a numeric
display of the quantities available for launching from each zone. By setting switches on the face
of the Display Unit, the pilot can select the rocket types to be launched, set the fuzes according to
the tactical situation, and determine the quantities of rockets to be launched in each volley.
Rockets are then launched when the pilot or copilot/gunner squeezes the trigger switch on the
cyclic stick. Should the trigger switch be released before the entire volley has been launched, the
numeric display on the face of the Display Unit is immediately updated to continuously reflect the
quantities of rockets remaining in each loading zone. Refer to TM 9-1090-207-13&P for
additional information pertaining to RMS components.
The primary objectives of the remotely settable fuze concept were to use very inexpensive
components in the fuze itself, eliminate any battery required to run the electronics during the fuze
run time, and accomplish the accuracy goals throughout the total environmental range. The
solution was to select a resistance-capacitance technique wherein relatively inexpensive, broad-
tolerance (+/- 20 percent) components could be used for high-volume production of relatively
inexpensive electronic fuzes. To accurately set the capacitance-charged fuzes for the desired run
time throughout the environmental range requires a compensating setter located in the aircraft.
The setter, immediately prior to launching a rocket, determines the amount of energy required by
the fuze timing capacitor for the component variations existing along with temperature effects to
run the fuze timing circuitry for the range selected. The setter then charges the timing capacitor
and the storage capacitor used as both the power source to run the electronics and the power
source to initiate the pyrotechnic train through initiation of the electric detonator in the fuze
safeing and arming device. The setter must be capable of compensating for 20 percent variations
in component value and for variations in fuze run time due to temperature effects on individual
fuzes. Since each fuze is unique, each fuze must receive a different amount of energy in its timing
sequence, whether it be singles, pairs, or quads, fuzes must therefore receive different amounts of
energy to accomplish the same set time. Therefore, just prior to firing, the individual fuze and its
setter compose an integral subsystem which must perform its function accurately across the entire
environmental spectrum, compensating for inherent errors in individual fuzes.
The Display Unit is a cockpit-mounted line-replaceable unit that presents the pilot with
controls and displays for inventorying and controlling the launching of aerial rockets. It also
contains the power supply and other common circuits necessary for the RMS components to
operate as a subsystem. The Display Unit transmits the electrical command signals selected by the
pilot to the Operations Units. One Operations Unit is used for each launcher and contains the
circuitry that sets the fuzes and the circuitry that provides the rocket motor squib firing pulses for
the rockets loaded into the associated launcher.
Additional description of the RMS is contained in enclosure 1. This is an early system
description as taken from material used for training (extraneous pages have been extracted) of
what eventually became the M138 RMS. It was originally fitted into the AH-1S model of the
Cobra helicopter. The weight of the display unit is 6 pounds and of the operations unit is 2
pounds each. The NSN for the M138 RMS is 1090-01-077-8939. A variation of this system
known as the Armament Management System was fitted into the AH-1G model of the Cobra
helicopter. It uses two zones and was intended as an interim solution for an eventual upgrade to
the M138 RMS.

delay “Gas Generator.” The Quickmatch ignites the delay, which in turn fires a Secondary

Expulsion charge. This charge functions as the first, producing pressure that shears another set of

12 pins, evenly spaced around the circumference of the flare. Once again the pressure provides an

acceleration/deceleration force to the Drogue Housing and the Candle & Parachute Assembly.

Attached to the Pusher Plate is the cord for the Pilot Chute. As the Pilot Chute deploys, it pulls

the Main Chute assembly out of its housing (Parachute Insert) for Main Chute deployment.

Attached to the Main Chute support cable is a Lanyard that runs through an internal raceway in

the Candle and is attached to the Slider assembly in the Igniter assembly. As the main chute is

deployed, it pulls the Lanyard with a minimum force of 40 pounds. This force shears a shear pin

and moves the slider assembly into the firing position, cocks and releases the firing hammer and

fires the ignition primer. During launch of the Rocket, acceleration forces of at least 17 G for

duration of approximately one second withdrew the weight assembly of the “Zig-Zag” ignition

safe/arm mechanism from its saving position in the slider assembly, allowing Slider movement.

The output of the ignition primer is directed into a cavity containing boron pellets. The fire from

the boron pellets is directed on the forward face of the flare’s illuminant Candle and also on a

small propellant wafer which acts as an ignition booster. The Candle produces light in the near IR

spectrum for about 180 seconds. The main parachute allows for a descent rate of approximately

13 feet per second.

Tabulated data:

M257 Illumination Flare w/ M442 Fuze

Operating temperature limits: -25 oF to +140 oF

(-31.35 oC to +59.40 oC)

Candle composition: Magnesium Sodium Nitrate

Candle weight: 5.44 lb (2.47 kg)

Illumination intensity, visible: 817.19 CP (avg.)

infrared: 250.02 watts/sr (avg.)

Illumination duration: 197.38 sec (avg.)

Function time: 14.23 sec (avg.)

Shipping and storage data:

Storage class/SCG: 1.2 G

DOT shipping class: A

DOT designation: Rocket Ammunition with Illuminating Projectile

Field Storage: Group D

NSN: 1340-01-268-7175

DODIC: H183

UNO Serial No.

M278 IR Flare w/ M442 Fuze

DODIC: H154

UNO Serial No.

the 7-tube launcher continues to use a laminated stack.

experiences from the fire control is 0.06 seconds.

minimize the heat signature of the launcher after rocket firings.

RMS Display Unit RMS Operations Unit

The M138 Rocket Management Subsystem (RMS) is a pilot-operated subsystem that

interfaces with the wing stores subsystem in the helicopter. The RMS operates from power

supplied by the aircraft and consists of one Display Unit and four Operations Units. The RMS

enables the aircraft pilot to select and launch MK 40 or MK 66 rocket motors with the desired

warhead/fuze combination from two or four 7- or 19-tube launchers mounted under the aircraft

stub wings. The RMS automatically senses the quantity and type of launcher installed and

automatically sets its firing sequence to agree with the tube numbering of the launcher on board.

Should one or more launchers be disabled, the RMS will cause the corresponding launcher on the

opposite side of the fuselage to become inactive to maintain in-flight stability by equalizing the

load of unfired rockets.

Rockets are loaded according to type (warhead/fuze) in up to five loading zones, and the types

loaded in each zone are indicated by manually setting five 12-position thumb wheel switches on

the Display Unit panel. The switch positions are marked with two- or three-letter descriptors that

represent the available warhead/fuze configurations. When power is applied to the RMS, it

automatically inventories the rounds loaded in each zone and provides the pilot with a numeric

display of the quantities available for launching from each zone. By setting switches on the face

of the Display Unit, the pilot can select the rocket types to be launched, set the fuzes according to

the tactical situation, and determine the quantities of rockets to be launched in each volley.

Rockets are then launched when the pilot or copilot/gunner squeezes the trigger switch on the

cyclic stick. Should the trigger switch be released before the entire volley has been launched, the

numeric display on the face of the Display Unit is immediately updated to continuously reflect the

quantities of rockets remaining in each loading zone. Refer to TM 9-1090-207-13&P for

additional information pertaining to RMS components.

The primary objectives of the remotely settable fuze concept were to use very inexpensive

components in the fuze itself, eliminate any battery required to run the electronics during the fuze

run time, and accomplish the accuracy goals throughout the total environmental range. The

solution was to select a resistance-capacitance technique wherein relatively inexpensive, broad-

tolerance (+/- 20 percent) components could be used for high-volume production of relatively

inexpensive electronic fuzes. To accurately set the capacitance-charged fuzes for the desired run

time throughout the environmental range requires a compensating setter located in the aircraft.

The setter, immediately prior to launching a rocket, determines the amount of energy required by

the fuze timing capacitor for the component variations existing along with temperature effects to

run the fuze timing circuitry for the range selected. The setter then charges the timing capacitor

and the storage capacitor used as both the power source to run the electronics and the power

source to initiate the pyrotechnic train through initiation of the electric detonator in the fuze

safeing and arming device. The setter must be capable of compensating for 20 percent variations

in component value and for variations in fuze run time due to temperature effects on individual

fuzes. Since each fuze is unique, each fuze must receive a different amount of energy in its timing

sequence, whether it be singles, pairs, or quads, fuzes must therefore receive different amounts of

energy to accomplish the same set time. Therefore, just prior to firing, the individual fuze and its

setter compose an integral subsystem which must perform its function accurately across the entire

environmental spectrum, compensating for inherent errors in individual fuzes.

The Display Unit is a cockpit-mounted line-replaceable unit that presents the pilot with

controls and displays for inventorying and controlling the launching of aerial rockets. It also

contains the power supply and other common circuits necessary for the RMS components to

operate as a subsystem. The Display Unit transmits the electrical command signals selected by the

pilot to the Operations Units. One Operations Unit is used for each launcher and contains the

circuitry that sets the fuzes and the circuitry that provides the rocket motor squib firing pulses for

the rockets loaded into the associated launcher.

Additional description of the RMS is contained in enclosure 1. This is an early system

description as taken from material used for training (extraneous pages have been extracted) of

what eventually became the M138 RMS. It was originally fitted into the AH-1S model of the

Cobra helicopter. The weight of the display unit is 6 pounds and of the operations unit is 2

pounds each. The NSN for the M138 RMS is 1090-01-077-8939. A variation of this system

known as the Armament Management System was fitted into the AH-1G model of the Cobra

helicopter. It uses two zones and was intended as an interim solution for an eventual upgrade to

the M138 RMS.