FCS
What are the five reasons that cause loss of effectiveness of the ELRF?
Internal ELRF failure
Vehicle failure
Environmental conditions
Man-made or battlefield obscurants
Multiple returns from a target smaller than the LRF beam width with obstructions to the front and rear of the target
Inside the bore evacuator the gun tube has how many evacuator holes and at what angle are these holes?
Five bore evacuator holes spaced apart and drilled into the gun tube at a 30 degree angle towards the muzzle
What is the purpose of check 6?
Muzzle Reference System (MRS) check determines whether MRS can correct an artificial boresight loss.
List the reasons for MBD loss of Collimation:
Loose collimation screws
Stripped collimation screws
Mishandling of MBD
Inoperative MBD
Tube Wear
Name the six AAC checks.
Check 1- Main gun mount
Check 2- Elevation cylinder
Check 3- Prepare solution board for use
Check 4- Special inputs
Check 5- Ballistic solution
Check 6- MRS
What are the pulse rates of the ELRF?
Continuous-(one pulse per second for a maximum of 120 seconds of 10 minutes cool down time.)
Rapid- (one burst per second for no more than 4 seconds with 4 seconds off time) rapid refers to air mode
A cool down period of 10 minutes is required after 63 bursts
What is the purpose of Zone 2?
The transition between the chamber and the bore which guides the projectile into the bore and compresses the obturator on the projectile resulting in forward obturation in zone 3
What is the purpose of check 5?
Ballistic solution check verifies FCS is correctly implementing ballistic solutions in all main gun channels.
Define cone stabilization.
A cone shaped projection at the base of the projectile to induce drag, thus destabilizing the projectile at slower velocities.
What is the purpose of the Ballistic Computer Subsystem?
Is an accurate digital system that continuously calculates and provides command signals to control the angle between the GPS reticle, the CITV reticle, and the Main gun.
What is the Delta P?
A transducer detects flow rate and direction, sends a feedback signal along with the 3rd stage LVDT to the FCEU
What is muzzle bulge?
The deformation of the muzzle end of the bore caused by a pressure spike when the exiting round is impleaded by dirt or foreign debris.
What is the purpose of check 3?
Prepare solution board for use is to ensure proper setup of the solution boards reducing angular errors, elimination false failures or masking actually system failures.
Define Ballistics.
Everything that happens to the projectile from the point of initial detonation of the round until the sub-projectile comes to a complete stop.
How does the ELRF work?
Works on the principle of transmitting an energy (laser) pulse that reflects off a target. The time required for the laser pulse to travel to and return from the target is converted to distance (range) which is sent to the MPU's for ballistic solution calculation.
Explain how the tank compensates for Dynamic CANT.
The POS/NAV gyros sense pitch and roll of the tank. The HTPS determines the position of the turret in relation to the hull. These two signals are sent to the TMPU to determine dynamic cant
What are the four main purposes of a recoil system?
To absorb recoil energy
To provide a fixed length of recoil through all angles of elevation
To return the gun to battery through all angles of elevation
To hold the gun in battery through all angles of elevation
What is the purpose of check 2?
Elevation cylinder check ensures that main gum elevation cylinder is capable of maintaining the lay of the gun of the distance aiming point.
Define Parallax.
The apparent movement, or difference in apparent direction, of an object as seen from two different points not on a straight line with that object.
What are the three purposes of the replinisher?
Allows the crew to monitor the fluid level in the recoil system
Allows the crew to add or drain fluid as needed
Replenishes the recoil system during firing
What is the Hull/Turret position sensor (HRPS)
An electro/optical device that monitors hull to turret position and rotation which is then sent to the FCEU to be used for ballistics solution calculation and turret position display on the GCDP and the CDU
What are the borescope inspection criteria?
Every 150 EFC round interval after the first 300 EFC have been firing
Within 180 days prior to firing
When troubleshooting indicates you should
Anytime a cannon tube is installed, even if new
If you are uncertain whether or not a tube has been inspected
What is the purpose of AAC's
Helps to ensure that the fire control system is fully operational and verifies that special inputs to the ballistic solutions are implemented properly for the fire control components and all main gun ammunition. They also verify that the MRS can correct an artificially induced induced boresight loss.
What is Mean Jump?
The average difference between the actual impact of a group of rounds fired over many occations and the intended strike of those rounds, given that all inputs to the FCS are correct or within tolerance.
Define Variable Bias Errors.
Errors whose value remains nearly constant when firing one type of ammunition at a particular target at a given range, but can change considerably from one engagement to the next.