Annex A Flashcards
The ______ collects, processes and sends appropriate signal to the traverse drive assembly, the elevation actuator and the ______
Gun Turret Drive Electronics (GTDE), Control Display assembly.
Fine lay is the _____ position; the turret moves 10 mils for every _______ of the hand wheel
Upper Most, Full Rotation.
_____ is the lower position, the turret moves _____ for every full rotation of the hand wheel.
Coarse Lay, 60 Mils
The upper drive assembly provides the final traverse drive gear reduction and engages the ____ on the turret support bearing
442 gear teeth
The Arm/Safe switch is a ___ position toggle switch that controls the _______ and safing of the weapon systems
2, electrical arming
The Low Ammo Indicators light red if the indicated ammunition supply is low (approx ____ rounds of ___ ammunition, ___ of rounds of ____ ammunition, or ____ rounds of coax ammunition.
37, AP 31, HE 100
The ELRF/DVO is equipped with an ____ magnification direct view optic
8x
_____ updates the thermal system to denote _____ in the scene.
TMI, movement
STARE is best utilized if the vehicle is ______- traversing or elevation the turret will cause video ______ to be seen in the display.
stationary, smearing
_______ must have a ______ understanding of the procedures and the _____ involved witht eh operation of the LAV-25A2 turret equipment in order to effectively utilize the equipment.
Crewman, fundamental, theory
Describe “Weapon Power Circuit Breaker”
applies power to the weapons and to the vent blower.
What is the description of the Range Button (RNG)
When depressed, it will electronically activate the ELRF and update the ballistic solution.
The ______ and ______ knobs adjust the position of the ballistic sight reticle to allow zeroing of the sight to the weapon.
Deflection, Elevation
When ____ are active, the STAB AZ indicator light and the STAB EL indicator light will make a series of flashes to form a two-digit _____
Faults, Fault codes
To engage the auto LOS Drift Compensation, ensure the STAB AZ and EL indicators do not flash a _____. Depress the palm switch for ____ seconds without any Hand Control deflection. Release the _____
fault sequence, 10, palm switch
The ______ located between the gunner and commander provides turret crew with controls and annunciators for the fire control system.
control display assembly
The _______ comprises of _______ that will illuminate to notify the crew of problems or _______ in the turret drive system and the main gun.
warning group, 3 indicator lights, malfunction
The______ flashes to indicate the battery voltage has fallen below ____ volts
Low Battery Indicator, 19.5
The _______ consists of _______ and one indicator light that controls use of the M257 smoke grenade launchers.
Grenade Launch Group, 3 switches
The Reticle Switch selects either ____ or _____ fire control nodes.
NORMAL, STADIA
The _____ will identify a fault condition by flashing the ____ indicator light.
CDA, TEMP/FAULT
The Traverse Drive Assembly is comprised of what 3 components
lower drive assembly, upper drive assembly and manual drive assembly
The test or inspection is a step you take or you follow to _____ the ____ and recheck all the steps once corrected.
Isolate, malfunction
Describe “Overspill”
The laser beam is large enough to hit the desired target and an object behind it.
Describe “Underspill”
There is an obstruction between the laser and the target
The _____ collects and processes signals and sends the appropriate signal to the motor controller and to the control display assembly.
Gun Turret Drive Electronics (GTDE)
The Elevation Knob adjusts the ______ position of the ballistic sight _____ to allow zeroing of the sight to the weapon.
vertical, reticle
The commanders override switch affects what functions
Contrast, Field of View, polarity and focus
The _________ controls and monitors main gun operation, ammunition selections, and ________ using imputs from the commanders or gunners hand control and the Control Display Assembly.
Gun Control Assembly (GCA), rate of fire
When set to LACE the system operates in a ______ mode with _________________________
Normal, Local Area Contrast Enhancement
The commanders daysight pattern is centered in the commanders daysight field of view, and is designed to provide a visual referance for target range and _________
deflection
The position of the NFOV reticle is determinded by the fire control system. The lead and wind offsets applied to the NFOV reticle are ______ when the palm grip on the hand control is released.
removed
For proper LEAD input to the fire control calculation, the operator needs to place and hold the laser aim point on the target for at least how many seconds prior to firing the laser?
1.5 seconds
In writing, list the components of the Commanders Sight Assembly (DIM 36). What is it coupled to and what is it protected by?
visible window, unity window, head mirror unit that is mechanically coupled to the gun sight linkage, which are protected by the ballistic shield
In Writing, describe the purpose of the Eye-safe Laser Range Finder (ELRF)?
provides the gunner with a direct view optic (DVO) and a range estimate for far target location (FTL) and fire control computation (FCC) using an eye safe laser
In writing, describe the purpose of the DC power booster.
stores energy to maintain the input voltage for the north finding module (NFM) above 21 volts for brief periods during vehicle power transient. it also provides power to the electronic head mirror unit.
In writing, describe the purpose of the Power Filter Unit (PFU)
provides power filtering for the thermal sights, north finding module, eye safe laser range finder and the electronic head mirror unit.
In the gunners BDU, the stadia reticle pattern is centered in the bi-ocular display unit when the ______ switch is set to ______
reticle, stadia
At what ranges can the ELRF calculate distance?
240 meters-9995 meters
When will multiple returns be received by the ELRF
When the laser beam strikes more tha one object before the beam reaches the desired target.
What is NOT an internal test that can be run on the ELRF/DVO
general built in test
What is the internal test that can be run on the electric drive motor turret system?
Drive power up built in test (BIT)
In writing, describe the purpose of the Sensor Unit
contains the scanner assembly Infrared imaging optics that focus the energy on the detector array. Infrared detector/ dewar closed cycle cooler assembly and the signal processing electronics.
In writing, describe the purpose of the sight linkage
The sight linkage is comprised of commander DIM 36 sight and gunners primary sight linkage assembly. The sight linkage synchronizes and transfers rotor motion to the sight assemblies. This allows the two sights to remain aligned with turret weapons.
In writing, describe the purpose of the North Finding Module (NFM)
This module provides heading and vehicle location. The NFM uses information from the eye safe laser range finder (ELRF) to determine far target location The NFM communicates with the Defense Advanced GPS Receiver to determine more accurate vehicle postion.
In writing, describe the purpose of the crosswind sensor
This sensor measures the crosswind velocity for the fire control computation.
In writing, describe the purpose of the Defense Advanced GPS Receiver (DAGR)
Determines vehicle position for global positioning system. NFM communicates directly with the Defense Advanced GPS Receiver (DAGR).
What will not cause the ELRF to receive multiple returns?
Thermal Crossover
When is a Power Up Built in Test initiated on the ELRF/ DVO
Upon start up of the ITSS
The PBIT and IBIT are the only internal tests for the electric drive system. (TRUE/ FALSE)
FALSE
What is time to rate
.15 seconds. The time from when the gun receives the signal to start until mechanical action begins to start.
What is time to stop?
.12 seconds. The time from when the gun receives the signal to stop until mechanical action begins to stop.
The ribbed barrel has two types internal finishes,______ and ______.
Chrome and Nitride
What are the features of the enhanced receiver?
Larger breech assembly, longer recoil, triple spring sprocket assembly, bit ready gun drive motor
what are the features of the enhanced feeder?
quick detachable link chutes and a built in test ready feed select solenoid
What are the components of the forward feed section?
forward feed assembly, upper feed sprocket assembly, lower feed sprocket assembly, round position-er feed assembly, ejection chute
What strips HE rounds from the links and places them in the feeder assembly rotor
lower feed sprocket assembly
What is the purpose of the round position-er assembly
round postioner assembly guides and positions the round during transfer from the sprocket assembles to the feeder assembly rotor
What are the sub-assemblies of the reciever assembly
barrel support assembly, recoil mechanism, breech assembly, sear, sear catch assembly, sear retractor assembly, mechanical interlock, direct current motor, handle pin, electrical sear solenoid, riveted receiver
What are the components of the electrical system
1.0 HP 24 VDC motor, electrical sear solenoid, electrical feed select solenoid, index drive cable assembly
The interlock crank, rocker assembly and the sear push rod are components of what?
mechanical interlock system
List the components of the forward feed section
forward feed assembly, upper feed sprocket assembly, lower feed sprocket assembly, round positioner assembly, ejection chute, feeder assembly rotor
What is the second purpose of sear?
locate receiver components for proper timing of the feeder and receiver during assembly
__________ accounts for the last 15-20% of the bolts stopping action, in a normally functioning gun.
The sear assembly
If a case remains stuck in the breech, how much overlap will there be to prevent a new round from being fed into the breech? How much overlap for a failed cartridge rim?
12.7mm/ 2.5 mm of a failed cartridge
For the M242 to continue to function, normal gun function must occur within what amount of time?
30 milliseconds
in a malfunctioning gun, (when experiencing a misfire), the ______, provides 100% of the guns stopping power by stopping the roller assembly________
sear assembly, chain safety link
how much coverage does the positive t slot extractors provide
30 degrees on top, 75 degrees on bottom, 105 degrees total
what is the primary purpose of sear
to positively position the roller assembly chain master link at the end of the firing point, thereby orientng the gun components for feed selection
how much recoil does the recoil mechanism absorb?
85% approximately
what volt range does the m242 electrical system operate on?
18-24 VDC
What is the dispersion for the m242
.5 mils (1m at 1000m)
sear assembly accounts for _____ of the guns stopping power in a normally functioning gun
15-20%
Rapid rate for M240
200 rounds per min (2-3 sec pause between bursts)
what is the m242 power transmission system comprised of
1.0 HP 24VDC motor, feeder drive assembly, chain and bolt drive
Sustained rate for M240
100 rounds per min (4-5 sec pause between bursts)
State the Theory of Operation for all models of the M240 series machine gun
- Gas Operated.
- positive locking of bolt body
- Fires from open bolt position
State the Theory of Operation for all models of the M240 series machine gun?
- Gas Operated.
- positive locking of bolt body
- Fires from open bolt position
8 major components of the M240 Machine Gun
- trigger housing assembly
- cover assembly
- feed tray
- bolt and operating rod assembly
- barrel assembly
- buffer assembly
- driving spring rod assembly
- receiver assembly
What should you always keep in mind while doing unit PMCS?
Warnings
The ______ provides enery for the returning the bolt and operating rod assembly to the firing position
Driving Spring Rod Assembly
What is the cyclic rate of fire for the M240B with hydraulic buffer
550-650 rounds per min (approx)
What is the chamber pressure for the M240 series machine gun?
52,940 psi
What is the muzzle velocity for the M240 series machine gun
2750 psi
When more then 1/3 of the exterior finish is worn off, where will you send the M240
Send to Depot for overhaul
What is the description of the driving spring rod assembly
provides energy for returning the bolt an operating rod back to the firing position
What is the description of the feed tray
serves as a guide for positioning cartridges to assist in chambering
What is the description of the receiver assembly
serves as a support for all major components, houses action of the weapon and through a series of cam ways, controls the functioning of the weapon.
When compressed air is used for cleaning purposes it shall not exceed what
30 PSI
When reporting errors and recommending improvements what for should be used?
NAVMC 10772
If you identify a corrosion problem, what would you use to report it and what key words would you use?
SF 368. Keywords: corrosion, rust deterioration, cracking.
The ______ provides energy for the returning the bolt and operating rod assembly to the firing position
Driving Spring Rod Assembly
what is the purpose of the handle pin?
applies spring tension to lock the feeder handle on one side and provides a lock on the opposite side
What TM should you refer to concerning the destruction o the M242 25mm automatic gun
TM 750-244-7
What TM covers the M242 25mm automatic gun?
TM 08672A-23&P/1
The ______ keeps the roller assembly chain from rebounding backwards during firing recoil
sear catch assembly
