STUDENT HANDOUT TITLE: AH-64D AERIAL ROCKET SYSTEM (LOT 11) FILE NUMBER:

Transcription

1 UNITED STATES ARMY AVIATION CENTER OF EXCELLENCE FORT RUCKER, ALABAMA April 2009 STUDENT HANDOUT TITLE: AH-64D AERIAL ROCKET SYSTEM (LOT 11) FILE NUMBER: Proponent For This Student Handout Is: COMMANDER, 110 TH AVIATION BRIGADE ATTN: ATZQ-ATB-AD Fort Rucker, Alabama FOREIGN DISCLOSURE STATEMENT: (FD6) This product/publication has been reviewed by the product developers in coordination with the USAACE Foreign Disclosure Authority. This product is releasable to students from foreign countries who have purchased the AH-64D model, but the IETM is not releasable.

2 TERMINAL LEARNING OBJECTIVE: NOTE: Inform students of the following Terminal Learning Objective requirements. At the completion of this lesson, you (the student) will: ACTION: Identify components, controls, procedures, inhibits, and ballistics factors of the AH-64D Aerial Rocket System (ARS). CONDITIONS: In a classroom environment, given an AH-64D Operator's Manual (TM ),Aircrew Training Manual (TC 1-251), and Helicopter Gunnery (FM (FM 1-140)).. STANDARD: Identify the components, controls, procedures, inhibits, and ballistics factors of the AH-64D Aerial Rocket System (ARS) and receive a Go by answering 7 of 10 questions on scoreable unit 2 of criterion referenced test IAW the SEP. D-2

3 A. ENABLING LEARNING OBJECTIVE 1 After this lesson, you will: ACTION: Identify the components of the ARS. CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In accordance with TM and TC Learning Step/Activity 1 Identify the components of the ARS. Figure 1. Aerial Rocket System (ARS). a. M140 ARS (1) The M140 ARS provides AH-64D pilots with the capability to remotely select: (a) (b) (c) (d) Rocket type Warhead Fuze Quantity desired (2) The ARS can fire the 2.75-inch/70mm Folding Fin Aerial Rockets (FFAR) in two firing modes: (a) (b) Independently Pilot (PLT) or Copilot/Gunner (CPG) controlled Cooperative (simultaneously PLT/CPG controlled) D-3

4 Figure 2. Pylons. b. ARS components (1) Pylons. The pylons are mounted on the underside of the wings and provide mounting for the following: (a) (b) (c) The ejector rack contains attaching lugs for securing the store to the pylon and the explosive ejector for stores jettison. The Pylon Interface Unit (PIU) provides interface between the Weapons Processor (WP) and the pylon discrete signals. The pylon actuator articulates the pylon in elevation by applying hydraulic power in response to pointing commands from the WP. 1) Ground stow a) The Ground Stow mode commands the pylons to the stow position ( 5 ) so that the wing stores are parallel to the ground (level terrain). b) The Ground Stow mode is automatically commanded when the Squat switch indicates GROUND when a rocket launcher or a hellfire launcher is present. The pylons can be manually ground stowed while in flight via the Weapon Utility (WPN UTIL) page. 2) Flight stow a) The Flight mode commands the pylons to a single fixed position (+4 ). D-4

5 (d) b) The Flight mode is automatically commanded on at takeoff when the squat switch indicates airborne for more than 5 seconds. 3) In flight, the pylons remain in the Flight mode until missiles or rockets are actioned. Pylons are independently articulated through a range from +4.9 to 15 in elevation. The pylons are equipped with hydraulic and electrical quickdisconnect provisions and contain electrical aircraft interfaces for the 2.75-inch ARS, auxiliary fuel tanks, Hellfire Modular Missile System, and servo control of rack positions. Figure 3. Pylon Interface Unit (PIU). (2) PIU (a) (b) (c) (d) The PIU is a remote processor that communicates with the WP and provides interface to the M261 rocket launchers and pylon actuators. The PIUs perform rocket fuzing and squib ignition. PIUs are solid state Remote Terminal (RT) Line Replaceable Units (LRUs). Each PIU provides the necessary Input/Output (I/O) and processing capability to control up to nineteen 2.75-inch FFAR. D-5

6 Figure 4. M261 Rocker Launcher. (3) M261 rocket launchers (a) (b) (c) (d) (e) The M261 rocket launcher carries and launches the 2.75-inch (70mm) FFAR within the operating environment of the AH-64D helicopter. The rocket pod weighs approximately 86.8 pounds. The pods are 65 inches long. The pods have a diameter of 16 inches. Each rocket launcher has 19 individual rocket tubes. (f) Up to four rocket launchers (one per pylon), for a total of 76 rockets can be loaded on the AH-64D helicopter. (g) (h) Two top mounted suspension lugs allow attachment to the wing pylon. Two electrical connectors on the top of the launcher provide fuzing and firing interface. 1) The forward connector provides the fuzing. 2) The aft connector provides the firing circuit. D-6

7 (i) Rocket pods can be jettisoned individually or all at once from either crewstation. Figure 5. STORES JETTISON (JETT) Panel. (4) STORES JETTISON (JETT) panel (a) (b) (c) (d) (e) The STORES JETTISON panel is located on the left console in the pilot and CPG crewstations. The STORES JETTISON panel provides the pilot or CPG with the capability to jettison individual wing stores. Pressing one or more of the pushbuttons on the STORES JETTISON panel will illuminate the selected pushbutton(s) in both crewstations to indicate that the Stores Jettison function at the selected station is now in the ARM mode. Pressing an illuminated pushbutton a second time will cause that pushbutton light to be extinguished, indicating that stores jettison at that station is no longer in the ARM mode. Pressing the recessed JETT pushbutton will cause stores to be jettisoned from all stations in the ARM mode. Only that crewstation arming the STORES JETTISON panel can de-arm it. Once armed, either crewstation can activate the Stores Jettison function. D-7

8 Figure 6. Emergency Stores Jettison (JETT) Switch. (5) Emergency Stores Jettison switch (a) (b) (c) Located on the flight section of the collective grip. Provides the pilot or CPG with the capability to jettison all external wing stores at the same time. Pressing the guarded JETT switch will cause all external stores to be jettisoned from the aircraft at the same time. D-8

9 Figure 7. LOAD / MAINTENANCE PANEL (LMP). (6) LOAD / MAINTENANCE PANEL (LMP) (a) (b) Located in the right aft avionics bay. Provides the ground crew with the capability to manually enter and display rocket weapon data and position pylons for loading wing stores. 1) Display and specify rocket type associated with each rocket zone. 2) Position the pylons (PYLON POS) for Maintenance Operational Checks (MOCs) with a range of UP +4 to DOWN 5. 3) Override the Squat switch (AIR/GND mode) setting to simulate airborne conditions for troubleshooting and testing on the ground. CAUTION There is no indication in the cockpit when the SQUAT ORIDE switch is in the AIR position. The possibility exists that the Area Weapon System (AWS) could inadvertently be driven into the ground. D-9

10 (c) The LMP provides the capability to check/verify rocket type within each of the rocket zones on pre-flight. (d) The WPN UTIL LOAD page is provided on the Multipurpose Display (MPD) to permit aircrews to modify (override) the LMP zone inventory in the event an entry error is made by the load crew during munition loading or an LMP failure occurs. NOTE: At aircraft power-up, the WP will read the rocket zone inventory from the LMP. D-10

11 CHECK ON LEARNING 1. Pylons are independently controlled through a range of in elevation. ANSWER: 2. The provides the interface between the weapons processor and the pylon discrete signals. ANSWER: 3. The flight mode is automatically commanded on takeoff when the squat switch indicates airborne for more than seconds. ANSWER: 4. The STORES JETTISON panel allows for jettison of wing stores while the emergency JETT pushbutton will jettison all stores. ANSWER: 5. The pylons are positioned to ground stow (WPN UTIL Page) which commands the pylons to degrees. ANSWER: D-11

12 ACTION: CONDITIONS: ENABLING LEARNING OBJECTIVE 2 Identify the controls and displays of the ARS. Given a written test without the use of student notes or references. STANDARD: In accordance with TM , TC 1-251, and FM (FM 1-140). 2. Learning Step/Activity 1 Identify the controls and displays of the ARS. Figure 8. ARMAMENT Panel. a. ARS controls and displays (1) ARMAMENT panels (a) (b) The crewstation ARMAMENT panels provide pushbuttons used for arming and safing the aircraft armament as well as overriding the aircraft Squat switch when the aircraft is on the ground. The ARMAMENT panel is located on the Instrument panel in each crewstation. It provides two pushbuttons to activate switches. 1) The ARM/SAFE indicator is a momentary-action, illuminated pushbutton. This is an aircraft common switch. The aircraft is either armed or safe in both D-12

13 crewstations, regardless of who activated the switch. a) The ARM legend is illuminated Night Vision Imaging System (NVIS) yellow. b) The SAFE legend is illuminated NVIS green. 2) The GND ORIDE (ground override) indicator is a momentary-action, illuminated pushbutton illuminated NVIS green ON. 3) Upon application of aircraft power, the System Processor (SP) establishes the aircraft state as SAFE. Figure 9. Weapon Page Rocket Format. (2) Weapon (WPN) page Rocket (RKT) format. Rocket moding is controlled from the Weapons page, with the rocket format displayed. (a) (b) (c) Selecting the RKT button on the WPN page or actioning the rockets with the Weapons Action Switch (WAS), will cause the rocket icons to become inverse video and rocket moding controls to be displayed. If the RKT selections are not initialized with preloaded data, the firing quantity, penetration distances, and warhead/fuze options are initialized with default values. Rocket icons and indicators D-13

14 1) Rocket icons will be displayed respective to their location on the wing stations. 2) Rocket type will be displayed within the rocket icon, when a rocket type selection has been made from the inventory grouped option. 3) The rocket type will be selected automatically if only one type of rocket is inventoried. Figure 10. Weapon Page Rocket Format DEGR Icon. (d) RKT launcher Degraded (DEGR) or FAIL icons. The ARS can detect Degraded or Failed modes through Built-In-Test (BIT) processing. 1) DEGR a) A degraded rocket launcher is considered to be one where the PIU can select certain rockets for firing, but cannot select all the rockets in that launcher for firing; that is, one or more rocket launcher tubes is not available for firing, or warhead fuzing capability is lost. b) When a station is in DEGR mode, a yellow DEGR icon is displayed around the rocket launcher icon. D-14

15 Figure 11. Weapon Page Rocket Format FAIL Icon. 2) FAIL a) A failed rocket launcher indicates that no rockets can be fired from a particular station for one reason or another, such as a failed PIU. b) When a system failure renders a station unavailable, a yellow FAIL icon is displayed around the rocket launcher icon. c) Additional indications of system failure are provided by the Data Management System (DMS). D-15

16 Figure 12. Weapon Page Rocket Format Rocket Inventory. (e) Rocket inventory 1) Rocket INVENTORY buttons are used to select the desired rocket warhead and type. 2) The Option buttons include a warhead/rocket motor-type label and the total number of rounds available. These values are loaded at the LMP but can be updated on the LOAD page. 3) The number of rounds shown in the Option buttons will decrease in real time to reflect the number of rounds remaining as the rockets are fired. When all rockets of the selected type have been fired, the selected Rocket Warhead Option button will blank and the label will be removed from the icon. 4) Another Rocket Warhead Option button (if available) must be selected to resume rocket firing, unless it is the last type/warhead remaining. 5) Rocket inventory selections are independent in each crewstation. D-16

17 Figure 13. Weapon Rocket Quantity Format. (f) Rocket quantity 1) The Rocket Quantity (QTY) button, on the WPN RKT (Weapon Rocket) page, is used to select the number of rockets to be fired: 1, 2, 4, 8, 12, 24, and ALL; the default quantity is 2. 2) Selecting one of the QTY selections will set that as the quantity and return to the Weapons page rocket format. The selection will be displayed under the QTY button label. 3) Rocket quantity selections are independent in each crewstation, except in the Cooperative mode where the QTY and TYPE will default to the CPG, (then, the last-select logic applies). 4) Quantities greater than one will be fired in pairs, one-half of each quantity setting from the left wing store and one-half from the right wing store. D-17

18 Figure 14. Weapon Rocket Penetration Format. (g) The Rocket Penetration (PEN) button on the WPN RKT page is used to select the desired warhead fuze penetration setting. These selections are independent in each crewstation. 1) The PEN button is displayed only when warheads requiring a penetration selection, such as those with M433 Fuze, are loaded. 2) Selecting the PEN button calls up the following options: a) 10 Detonate 10 meters after jungle canopy contact. b) 15 Detonate 15 meters after jungle canopy contact. c) 20 Detonate 20 meters after jungle canopy contact. d) 25 Detonate 25 meters after jungle canopy contact. e) 30 Detonate 30 meters after jungle canopy contact. f) 35 Detonate 35 meters after jungle canopy contact. g) 40 Detonate 40 meters after jungle canopy contact. D-18

19 h) 45 Detonate 45 meters after jungle canopy contact. i) BNK Set to defeat bunkers up to 3 meters (9.84 feet) thick. j) SPQ Set to detonate when fuze makes contact with any object. Figure 15. TOTAL ROCKETS Status Window. (h) TOTAL ROCKETS status window 1) The TOTAL ROCKETS status window is displayed when there is a difference between the number of rockets available for firing and the number of rockets actually of the selected type. The status window and messages are displayed in white. 2) An example for displaying this status window would be if rocket fuzing failed and the rockets did not fire. In this case, the SP would inventory the total rockets at each trigger pull but decrement the failed rockets from the displayed INVENTORY. When a rocket misfire occurs, the misfired rocket is no longer available for firing. 3) The total rockets available for firing (of the selected type) will be displayed in the INVENTORY Grouped Option buttons. 4) The total of all rockets (including failed or misfired) will be displayed in the TOTAL ROCKETS status window. D-19

20 5) Due to safety considerations, the ARS cannot be cycled off and on to reinventory the rockets while in the air. This prevents a double fuzing pulse to remote set-type-rockets, which may result in unreliable fuze settings. Once on the ground, the RKT system can be cycled on the WPN UTIL page to reinventory the rockets. Figure 16. UTIL LOAD Page. (i) Rocket Inventory (INV) options 1) The RKT INV bracket on the WPN LOAD page will display the five ZONE buttons possible for selecting the desired rocket type loaded into that particular tube location. 2) A zone selection will be highlighted in white with a question mark when rocket inventory data is not valid. 3) Selecting one of these multi-state buttons within the RKT INV group will call up the rocket ZONE status window and inventory options. D-20

21 Figure 17. Rocket Launcher Inventory. (j) The rocket launcher zone selection is based on the number of launchers available. 1) Zone E is available if any rocket pods are installed on any wing store. 2) Zones C and D are available if inboard pods are installed. 3) Zones A and B are available if outboard pods are installed. 4) The RKT INV zone (A, B, C, D, and E) selections located on the LOAD page are used to select the desired rocket type and warhead for a particular zone. 5) When a ZONE selection is made, the LOAD page will display that selected zone with the rocket type selections available. CAUTION: Due to the possibility of surging the engines, do not fire rockets from the inboard stations. Fire no more than pairs with two outboard launchers every three seconds, or fire with only one outboard launcher installed without restrictions (ripples permitted). These are the only conditions permitted. NOTE: The cautions and notes in Chapter 4 of the -10 covers several parameters for rocket operation and configuration that must be addressed before firing. D-21

22 Figure 18. Rocket Inventory and Zone Options. Figure 19. Common Rocket Types. D-22

23 6) The inventory selections may include the following rocket types: a) MK-66 Rocket Motor/Warheads 1 6PD Point detonation, high explosive (a)m151 Warhead HE is antipersonnel, anti-material and referred to as the 10 pounder. The body is olive drab with a yellow band and yellow or black markings. This warhead contains 2.3 pounds of composition B with a bursting radius of 10 meters and a lethality radius of more than 50 meters. The compatible fuze for this warhead setting (6PD) is the M423, which will arm in flight approximately 52 to 110 meters. (b)m229 Warhead is HE antipersonnel, anti-material and referred to as the 17 pounder. This warhead is an elongated version of the M151. The body is olive drab with yellow markings. This warhead contains 4.8 pounds of composition B with a bursting radius of +14 meters and a lethality radius of more than 75 meters. The compatible fuze for this warhead setting (6PD) is the M423, which will arm in flight approximately 52 to 110 meters. There is no ballistic solution for the M229 warhead. (c)m274 Warhead is the smoke signature training rocket, which will match the ballistic settings of the M151 warhead. The body of the warhead is blue with a brown band. Contains 2 ounces of potassium perchlorate with aluminum powder, this will produce a flash bang smoke signature. The compatible fuze for this warhead setting (6PD) is a modified M423. D-23

24 2 6RC Penetration, high explosive The M151 and M229 warheads will accept the M433 fuze (6RC), which uses the PEN settings for penetration. The M433 arms at approximately 143 meters downrange. There is an increased risk of premature fuze function. 3 6MP Time, multi-purpose submunition (MPSM) (a)m261 Warhead provides improved lethality against light armor, wheeled vehicles, material, and personnel. The body of the warhead is olive drab with yellow markings and band. This warhead contains 9 M73 SM s with the M230 omnidirectional fuze with a M55 detonator is used on each SM and functions regardless of impact. Each SM contains 3.2 ounces of composition B, internally scored steel body to optimize fragments against personnel and material. The SM arms when the ram air decelerator (RAD) deploys. The RAD stops forward velocity and stabilizes the descent. Upon detonation the SM body explodes into high-velocity fragments (about 195 at 10 grains each up to 5,000 feet per second that can penetrate more than 4 inches of armor) to defeat soft targets. A SM will land 5 degrees off center 66% of the time, which has a 90% probability of producing casualties against prone exposed personnel within a 20 meter radius. A SM will land 30 degrees off center 33% of the time, which has a 90% probability of producing casualties against prone exposed personnel within a 5 meter radius. The compatible fuze for this warhead setting (6MP) is the M439, which will arm in flight approximately 96 to 126 meters. D-24

25 (b)m267 Smoke signature Training rocket, which will match the ballistic settings of the M261 (MPSM). The body of the warhead is blue with a brown band and while markings. This warhead contains 3 M75 practice (1 ounce of pyrotechnic powder) and six inert SM to replicate the M261. The compatible fuze for this warhead setting (6MP) is M IL Time, illumination (a)m257 was designed for battlefield illumination. The body of the warhead is olive drab with white markings. M257 contains 5.4 pounds of magnesium sodium nitrate. The candle descends 15 feet per second and provides one million candlepower for seconds. Preset to deploy approximately 3500 meters down range. It can illuminate approximately one square kilometer. The compatible fuze (6IL) is the M442 (9 second fuze), which will arm 150 meters from the launcher. (b)m278 Infrared Illumination Warhead is designed for target illumination using NVG s. The body of the warhead is black with white markings. The M278 puts out an equivalent of million candlepower of IR illumination. Preset to deploy approximately 3500 meters down range. The IR flare will provide IR light for approximately 180 seconds. The compatible fuze is the M442 (6IL). 5 6SK Time, smoke. M264 red phosphorus (RP) is a smoke-screen warhead. The body of the warhead is light green with a brown band and black markings. The warhead contains 72 RP wedges that are air-burst D-25

26 ejected over the intended target area. The smoke generated by 14 rockets will obscure a 300 to 400 meter front, in less than 60 seconds for 5 minutes. The smoke generated by the RP will block the entire visual spectrum as well as much of the IR spectrum. The effective range is 1000 to 6000 meters. The compatible fuze is the M439 (6SK). 6 6FL Flechette. M255 rocket is equivalent to the tanker s canister round. The warhead body is olive drab cylinder with white diamonds and white markings. This rocket contains 1, grain steel flechettes. They are packed in a red pigment powder that can alert the crew to the point of payload deployment. The flechette warhead detonates 150 meters before the range set at launch. The flechette cloud is a cylinder of about 49.7 feet in diameter. The compatible fuze is the M439 (6FL). b) CRV7 Rocket Motor/Warheads (Not currently used) 1 PD7 Point detonation, high explosive 2 RA7 Armor piercing, high explosive 3 IL7 Time, illumination 4 SK7 Time, smoke 5 MP7 Time, multi-purpose submunition 6 FL7 Flechette 7) The available rocket inventory options are presented on both sides of the display. CRV7 warhead types are shown in the L1 L6 Multi-State Option buttons. Similarly, the MK-66 warhead types are shown in the R1 R6 Multi-State buttons. Selecting an inventory option will change the inventory for that zone and return to the LOAD page. The type selections will be displayed on the left side of the WPN page when the rocket system is selected. (k) The M433 (PEN) allows the pilot to set the fuse for bunker penetration and M439 resistance capacitance fuze allows for the pilot to remotely set the fuze for airburst. D-26

27 1) The fuze has no internal battery; the required voltage is supplied to the capacitor by the aircraft through an umbilical assembly. 2) If a selected rocket fails to launch, the WP will not allow the operator to fire the selected rocket again until the rocket system is re-inventoried (on the Squat switch). 3) This procedure precludes the possibility of overcharging the delay circuit and premature explosion. 4) In the AH-64D, the voltage sent to the capacitor is measured for the proper amount before allowing the rocket to fire. This will ensure a far more accurate fuze detonation at the set range. Figure 20. Weapons Action Switch (WAS). (3) Weapons Action Switch (WAS) (a) (b) (c) (d) The WAS is a five-position, momentary contact switch that actions the selected weapon. The actioned weapon may be deselected by re-actioning the same weapon or by actioning another weapon. The WAS is mounted on the PLT/CPG cyclic and on the TEDAC Left Handgrip (LHG). Weapons selection (action) is as follows: G (12 o clock position on the WAS): Actions the M230 30mm automatic gun. R (9 o clock position on the WAS): Actions the ARS. D-27

28 (e) (f) M (3 o clock position on the WAS): Actions the Hellfire missile system. A (6 o clock position on the WAS): Is a growth function for Air- To-Air (ATA) missiles. Figure 21. Trigger Switches. (4) Trigger switches (a) (b) The Trigger switch is a three-position, guarded switch used to fire the selected weapon. It is mounted on the forward portion of the pilot and CPG cyclics and on the forward portion of the TEDAC LHG. 1) Pressing the trigger to the first detent will fire a weapon if no inhibits exist. 2) Pressing the trigger to the second detent will override the weapons performance inhibits and fire the weapon. Safety constraints can never be overridden. D-28

29 Figure 22. Rocket Steering Cursors. (5) Rocket steering cursors (a) The rocket steering cursor is a dynamic I-beam symbol that indicates the delivery mode and how to point the aircraft for rocket delivery. The I-beam represents the articulation range of the pylons. 1) If the pilot or CPG actions the rockets from the cyclic, then the ARS will be fired in the independent mode and the rocket steering cursor is only displayed on the crewmember that WAS the rockets. 2) When the CPG actions rockets from the TEDAC, the rocket steering cursor is presented in both pilot and CPG formats for cooperative engagements. 3) When the rocket fixed mode is selected, the rocket system is actioned, pylons containing available rockets of the selected type are positioned to degrees, and a unique continuously computed impact point (CCIP) constraint symbol is presented. The CCIP symbol reflects the point in space in which the rockets will pass and the operator simply maneuvers the aircraft to align the symbol over the intended target prior to initiating launch. The pylon elevation angle for fixed rocket mode will permit firing of the rockets in the event of an invalid IHADSS LOS. D-29

30 (b) (c) The cursor moves about the format to indicate the azimuth and elevation position of the aircraft in relation to the selected Line Of Sight (LOS) to provide a steering cue to the crewmember. The rocket steering cursor is displayed six ways: 1) Stowed rocket performance/safety inhibited steering cursor 2) Stowed in-constraints rocket steering cursor 3) Normal rocket performance/safety inhibited steering cursor 4) Normal in-constraints rocket steering 5) Inhibited cursor training 6) Articulated cursor training 7) Inhibit fixed cursor 8) Fixed cursor D-30

31 CHECK ON LEARNING 1. The processor establishes the aircraft state as SAFE upon aircraft power-up. ANSWER: 2. The M151 warhead has a bursting radius of meters and a lethality radius of meters. ANSWER: 3. The TOTAL ROCKETS status window is displayed when there is a difference between the number of rockets available for firing and. ANSWER: 4. The PEN button will display when the fuze is loaded which can defeat bunkers up to meters thick. ANSWER: 5. The M261 (MPSM) warhead contains M73 submunitions that will produce 195 (10 grain) high velocity fragments that travel up to 5000 feet per second and can penetrate more than inches of armor. ANSWER: 6. Due to the possibility of surging engines, do not fire rockets from the stations. Fire no more than with two outboard launchers every seconds, or fire with only one outboard launcher installed without restrictions. ANSWER: D-31

32 Enabling Learning Objective 3 ACTION: Identify the ARS Safety and Performance Inhibits. CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In accordance with TM and TC Learning Step/Activity 1 Identify the ARS Safety and Performance Inhibits. a. Rocket constraints are organized into safety and performance inhibits. SAFETY PERFORMANCE GENERIC ACCEL LIMIT PYLON LIMIT (AIR) SAFE ALT LAUNCH GUN OBSTRUCT TXX TRAINING LOS INVALID PYLON ERROR PYLON LIMIT (GROUND) TYPE SELECT Figure 23. Rocket Inhibits. (1) Rocket system safety inhibits. The WP will abort the remainder of the rocket launch event if a safety inhibit is detected during the launch event. (a) (b) (c) (d) ACCEL LIMIT: Indicates that the vertical acceleration is less than 0.5 G s and may cause the main rotor blades to obstruct the trajectory of the rockets.. ALT LAUNCH: Indicates that a Hellfire launch is in progress GUN OBSTRUCT: Indicates that rockets resident on inboard launchers are inhibited from launch because the gun is out of coincidence and may obstruct the trajectory of the rockets. LOS INVALID: Indicates that the selected LOS is either failed or invalid, also no valid FCR Next To-Shoot (NTS) target will cause this safety inhibit D-32

33 (e) (f) (g) (h) PYLON ERROR: Indicates that the pylon elevation position is not equal to the commanded position. The WP will inhibit rocket firing for pylon position errors as follows: 1) If the selected sight is Target Acquisition Designation Sight (TADS) or FCR, and the pylon position error is greater than ) Integrated Helmet And Display Sight System (IHADSS) is the selected sight, and the pylon position error is greater than 1.5 PYLON LIMIT: Indicates that the commanded pylon position exceed the pylon articulation limits of +4 to -5 on the ground TYPE SELECT: Indicates that no rocket type is selected.( multiple rocket types are available) If the Sight mode has changed since trigger pull was initiated, the WP will inhibit launch from all pylons until the trigger is released. (2) Rocket Performance inhibits: If a performance criteria is not met, the 2 nd detent of the weapons trigger switch may be used to override the performance inhibit. PYLON LIMIT: Indicates that the commanded pylon position exceed the pylon articulation limits of +4 to -15 in the air. (a) (3) GENERIC inhibits (a) (b) (c) The WP will inhibit rocket firing for pylon position errors as follows: SAFE: Indicates the weapon system is not been armed through the Armament Control Panel. TXX: Displayed for 4 seconds to indicate the file address in which the coordinate data has been stored. (TADS/FCR target store switch on LHG) TRAINING: Indicates the weapon training mode is active, or the TESS is enabled, and the armament control is in the ARM state and a weapon is actioned in either crew station. (4) The selected range source is beyond the rocket type maximum range (MK-66 = 7500 m, CRV-7 greater than 9000 m). There are no ballistic calculations for the MK40 rockets. D-33

34 CHECK ON LEARNING 1. The two types of rocket inhibits are and. ANSWER: 2. What does an ALT LAUNCH message indicate? ANSWER: 3. What message will display when the actioning crewmember s selected sight is Fire ControlRadar (FCR), and there is no Next-To-Shoot (NTS) target? ANSWER: 4. What is the maximum range for MK-66 and CRV-7? ANSWER: D-34

35 B. ENABLING LEARNING OBJECTIVE 4 ACTION: Identify the procedures for operation of the ARS. CONDITIONS: Given a written test without the use of student notes or references. STANDARD: In accordance with TM and TC Learning Step/Activity 1 Identify the procedures for operation of the ARS. a. Procedures for ARS operation. The ARS can be operated by either crewmember independently or collectively in the Cooperative mode. (1) Independent mode (a) (b) (2) Cooperative mode (a) (b) (c) (d) (3) Training mode (a) (b) When Independent moding is used, only the actioning crewmember trigger is active and the ballistics calculation is based on their LOS and range source. The WP calculates a ballistic solution based on the selected LOS and associated range source data, aircraft inertial data from the Embedded Global Positioning Inertial Navigation System (EGI) units, air data from the Helicopter Air Data System (HADS), and the selected warhead type. The Cooperative mode is active whenever the rocket system is actioned via the TEDAC left handgrip and pilot cyclic WAS. When the Cooperative mode is in use, the CPG acquires and tracks the target and the pilot aligns the aircraft for launch using the rocket steering cursor. In the Cooperative mode, both weapon triggers are active and the CPG LOS and range source are used for the ballistics calculations. When this mode is used, the rocket inventory and quantity will default to the CPG selection but can be changed based on the crewmember s last choice. The Weapons Training mode is an emulation of weapons system operation. All controls and displays will appear to function as they would during normal operation. The TRAIN button is used to activate and deactivate the Training mode. 1) The TRAIN button is not displayed when the Tactical Engagement Simulation System (TESS) is enabled. 2) When the Armament control is in the ARM mode, or when a Weapon system is actioned, the TRAIN button is displayed with a barrier. D-35

36 (c) (d) (e) HMD and TEDAC displays show different symbology in the Training mode. 1) The rocket steering cursor is displayed with a boxed T. 2) TRAINING is displayed on the High Action Display (HAD) while in the weapon inhibit field unless a valid weapon inhibit is displayed. Sound effects indicate each firing event, and the simulated RKT INV (19 rockets per M260 launcher installed) is decreased accordingly. 1) There are six sound effects that represent 1, 2, 4, 8, 12, 24, or 38 rockets fired. 2) Rocket sound effects will cease after 120 milliseconds for each pair of rockets. 3) All sound effects cease when the trigger is released, or all of the rockets have been fired. TESS is an interactive simulation system that allows aircrew training for all of the AH-64D Sight and Weapons systems. NOTE: A data entry change to the gun rounds count or the use of rocket "spoofing" devices will adversely impact gross vehicle weight. (4) Targeting data. The ARS accommodates use of the FCR NTS, TADS, Integrated Data Modem (IDM) handover, and IHADSS LOS inputs. D-36

37 CHECK ON LEARNING 1. When the Independent mode is used, only the crewmember s trigger is active. ANSWER: 2. In the Cooperative mode, the acquires and tracks the target, and the aligns the aircraft for launch using the rocket steering cursor. ANSWER: 3. The rocket INVENTORY and QTY selection defaults to the selections during cooperative engagements. ANSWER: 4. The Cooperative mode is active whenever the rocket system is actioned via the: ANSWER: 5. In the Cooperative mode, both weapon triggers are active and the Line Of Sight (LOS) and range source are used for the ballistics calculations. ANSWER: D-37

38 ACTION: CONDITIONS: STANDARD: C. ENABLING LEARNING OBJECTIVE 5 Identify the ballistic factors that affect rocket firing. Given a written test without the use of student notes or references. In accordance with TM , TC 1-251, and FM (FM1-140). 1. Learning Step/Activity 1 Identify the ballistic factors that affect rocket firing. a. Ballistics (1) Ballistics is the science of the motion of projectiles and the conditions that influence that motion. (2) The four types of ballistics influencing helicopter-fired weapons are: (a) (b) (c) (d) Interior Exterior Aerial Terminal (3) Each type produces dispersion, which is the degree that projectiles vary in range and deflection about a target. (4) Interior ballistics. Interior ballistics deals with characteristics that affect projectile motion inside the gun barrel or rocket tube. It includes effects of propellant charges and rocket motor combustion. Aircrews cannot compensate for these characteristics when firing free-flight projectiles. (a) (b) Propellant charges 1) Production variances can cause differences in muzzle velocity and projectile trajectory. 2) Temperature and moisture in the storage environment can also affect the way propellants burn. 3) Propellant burn variations, as a function of ambient temperature, are also a significant contributor to muzzle velocity variations and are addressed in the aforementioned muzzle velocity temperature compensation. Launch tube alignment 1) The AH-64D aircraft employs a PIU in each pylon assembly for launch positioning of the pylons based on its independent error sources as measured with the Captive Boresight Harmonization Kit (CBHK). 2) A further consideration associated with alignment accuracy is related to the M261 rocket launcher. Specifically, the launcher deflects appreciably when rocket motors initially ignite and the launcher D-38

39 (c) holdback mechanism is not yet overcome. This phenomenon is most pronounced when rockets are launched from the periphery tubes of the launcher (outer ring). 3) Finally, the mechanical misalignment of the launcher tubes pales in comparison to the inherent round-to-round dispersion of the MK66 rocket, which approaches 10 milliradians (mr). 4) As such, any attempt to precisely align the rocket launcher beyond current guidelines represents diminishing returns. Thrust misalignment 1) A perfectly thrust-aligned, free-flight rocket has thrust control that passes directly through its center of gravity during motor burn. In reality, free-flight rockets have an inherent thrust misalignment, which is the greatest cause of error in free flight. Spinning the rocket during motor burn reduces the effect of thrust misalignment. 2) Firing rockets at a forward airspeed above Effective Transitional Lift (ETL) provides a favorable relative wind, which helps to counteract thrust misalignment. When a rocket is fired from a hovering helicopter, the favorable relative wind is replaced by an unfavorable and turbulent wind caused by rotor downwash. This unfavorable relative wind results in a maximum thrust misalignment and a larger dispersion of rockets. (5) Exterior ballistics. Exterior ballistics deals with characteristics that influence the motion of the projectile as it moves along its trajectory. The trajectory is the path of the projectile as it flies from the muzzle of the weapon to the point of impact. Aerial-fired weapons have all the exterior ballistic characteristics associated with ground-fired weapons. They also have other characteristics unique to helicopters. (a) Air resistance 1) Air resistance, or drag, is caused by friction between the air and the projectile. 2) Drag is proportional to the cross-section area of the projectile and its velocity. 3) The bigger and faster a projectile is, the more drag it produces. 4) The AH-64D ballistics calculation factors air density ratio, based on the data from the High Integrated Air Data Computer (HIADC), in the gun and rocket time-of-flight calculations, which ultimately impacts the aimpoint. D-39

40 5) Projectile time-of-flight increases in denser air masses. The opposite is true in thin air. 6) Any increase in the munitions time of flight equates to a larger ballistic correction due to the effects of gravitational drop. Figure 24. Gravity. (b) (c) Gravity Yaw 1) The projectile loss of altitude because of gravity is directly related to range. As range increases, the amount of gravity drop increases. 2) This drop is proportional to time-of-flight (distance) and inversely proportional to the velocity of the projectile. 3) The appreciable decay in projectile velocity is the root cause of increased time-of-flight and associated gravitational drop. 4) The MK66 rocket achieves maximum velocity at approximately 400 meters from launch and, like the 30mm round, decays rapidly thereafter. 5) The AH-64D algorithms, and associated rocket and gun coefficients, automatically address gravitational drop as a function of time of flight. 1) Yaw is the angle between the centerline of the projectile and the trajectory. D-40

41 (d) (e) 2) Yaw causes the projectile trajectory to change and drag to increase. 3) The direction of the yaw constantly changes in a spinning projectile. 4) Yaw maximizes near the muzzle and gradually subsides as the projectile stabilizes. 5) Unlike other exterior ballistics, yaw cannot be quantified or compensated for. 6) Spin-stabilized projectiles help minimize yaw error. 7) Yaw error is largest at muzzle exit due to tip-off, not because of lack of spin stabilization. 8) In the case with the rockets, the MK66 motor flutes impart a high spin rate (in excess of 30 revolutions/second) during the boost phase of motor burn (approximately 1 second). 9) Thereafter, the folding fins reverse the roll and sustain the spin stabilization for the remainder of the munitions free-flight profile. Projectile drift 1) When viewed from the rear, most projectiles spin in a clockwise direction. 2) Spinning projectiles act like a gyroscope and exhibit gyroscopic precession. This effect causes the projectile to move to the right, which is called the horizontal plane gyroscopic effect. 3) As the range to the target increases, projectile drift increases. The amount of projectile drift is proportional to the spin rate of the projectile, which varies throughout the flight profile. 4) The AH-64D ballistic algorithms compensate for this phenomenon and no adjustments are required. Wind drift 1) The effect of wind on a projectile in flight is called wind drift. 2) The amount of drift depends on the projectile time of flight and the wind speed acting on the crosssectional area of the projectile. 3) Time of flight depends on the range to the target and the average velocity of the projectile. 4) When firing into a crosswind, the gunner must aim upwind so that the wind drifts the projectile back to the target. 5) Firing into the wind or downwind requires no compensation in azimuth but will require range adjustment. D-41

42 6) In the AH-64D, wind drift is compensated automatically by the WP. Important wind compensation considerations: a) Munition sensitivity 1 Rockets weathervane into the wind vector during the motor boost phase and drift with the air mass during the motor coast phase. 2 The 30mm round drifts with the air mass throughout its free-flight trajectory. 3 The amount of projectile drift attributed to wind effects is directly proportional to munitions time-of-flight, which accounts for air density ratio, wind vector (angle), and wind magnitude. b) Wind compensation characteristics 1 Longitudinal and lateral wind data received from the aircraft Air Data System is translated by the WP to the predicted LOS (where the target will be at termination of munitions free flight). 2 Since the air mass characteristics are measured locally, the ballistics applies wind sensitivity adjustments to the aimpoint as if the munition flies directly to the target, and the measured winds are constant from ownship to target. 3 However, as a function of increased range and gravitational effects dictate that the munitions be aimed well above the target to achieve intercept, and the wind characteristics at these altitudes or target ranges do not reflect those measured locally by the aircraft, appreciable error can occur. 4 For example, MPSM (6MP) and illumination (6IL) rockets the submunition payloads are deployed between 600 and 1900 feet above the target and exhibit high wind drift sensitivity due to their slow descent rates. Clearly, the potential for large wind variations exists under certain conditions. D-42

43 (6) Aerial ballistics. Common characteristics of aerial-fired weapons depend on whether the projectiles are spin-stabilized and whether they are fired from the Fixed mode or the Flexible mode. Figure 25. Rotor Downwash Error (a) Rotor downwash error 1) Rotor downwash acts on the projectile as it leaves the barrel or launcher. This downwash causes the projectile's trajectory to change. 2) Although rotor downwash influences the accuracy of all weapon systems, it most affects the rockets. 3) Delivery error is largest while hovering In Ground Effect (IGE), because it is harder to characterize and compensate for due to blade impulses and the random nature of induced flow pattern. In essence, IGE launch yields greater dispersion, because the aircraft cannot apply appropriate downwash compensation. Note that the real reason rockets pitch up in hover, whether IGE or OGE apply, is weathervaning. 4) As stated previously, rockets turn into the relative wind source during boost. The rotor downwash magnitude of the Longbow Apache (LBA) varies appreciably as a function of aircraft gross weight. At 18,000 pounds, the downwash magnitude is nominally 21 meters/second or 40 Kts in stabilized hover. This wind source imparts a significant angular error (pitch axis) dependent upon exposure D-43

44 time. At approximately 33 Kts forward airspeed (indicated), the rotor disk is pitched forward such that the influence vector is moved just aft of the rocket launcher front bulkhead, thus reducing downwash to zero. 5) When transitioning to rearward flight, downwash magnitude initially increases since the rotor disk is pitched aft and the rockets spend more time in the influence vector. 6) Note that the LBA ballistics algorithms automatically compute rotor downwash compensation for rockets based on aircraft dynamic gross weight, air density ratio, and longitudinal true airspeed. However, this compensation assumes rocket launch is initiated at OGE altitudes. Downwash compensation is not applied for the gun due to the position of the muzzle with regard to the rotor disk and the short exposure time of the 30mm projectiles. 7) When initiating rocket launch in crosswinds, the aircraft should be temporarily leveled for munitions release, presuming that terrain permits doing so. Automatic roll compensation of the rocket aimpoint (and pylon position angle) will not be implemented with any degree of effectiveness. (b) Figure 26. Angular rate error Angular Rate Error. 1) The motion of the helicopter causes angular rate error as the projectile leaves the weapon. 2) For example, a pilot using the running-fire delivery technique to engage a target with rockets at 4500 D-44

45 (c) meters may have to pitch the nose of the helicopter up to place the reticle on the target. When the weapon is fired, the movement of the helicopter imparts an upward motion to the rocket. The amount of error induced depends on the range to the target, the rate of motion, and the airspeed of the helicopter when the weapon is fired. Most of this motion is compensated for by the pylons by articulating up to 10 per second. 3) Angular rate error also occurs when aircrews fire rockets from a hover using the pitch-up delivery technique. Anytime a pitch-down motion is required to achieve the desired sight picture, the effect of angular rate error causes the projectile to land short of the target. Fin-stabilized projectiles 1) The exterior ballistic characteristics affecting finstabilized projectiles are very important. The AH- 64D ballistics algorithms automatically compensate for weathervaning during the boost phase of rocket motor burn. 2) Relative wind effect a) When a helicopter is flown out of trim, either horizontally, vertically, or both, the change in the crosswind component deflects the rocket as it leaves the launcher. b) Because the rocket is accelerating as it leaves the launcher, the force acting upon the fins causes the nose to turn into the wind. (7) Terminal ballistics. Terminal ballistics describes the characteristics and effects of the projectiles at the target. These include projectile functioning, including blast, heat, and fragmentation. (a) Penetration fuzes (impact fuzes) 1) Penetration fuzes (6RC M433) activate surface and subsurface bursts of the warhead. 2) The type of target engaged and its protective cover determine the best fuze for the engagement. 3) Engage targets on open terrain with a superquick fuze that causes the warhead to detonate upon contact. D-45

46 Figure 27. Fuze. (b) 4) Engage targets with overhead protection, such as fortified positions or heavy vegetation, with either a delay or forest penetration fuze. These fuzes detonate the warhead after it penetrates the protective cover. Fixed time-base fuzes and airburst fuzes. Fixed time-base fuzes detonate and release their payloads at a fixed time after rocket launch. 1) Fixed time-base fuzes are employed in the 6IL and IL7 (CRV7) illumination rockets with the associated function time of 9.0 seconds after motor burnout. 2) Fixed timed fuzes produce airbursts and are most effective against targets with no overhead protection. 3) Optimum release range is established as 3.5 km for the 6IL and approximately 4.0 km for the IL7 (due to increased motor velocity). 4) Airburst fuzes (M439) permit the host aircraft to establish a variable time of function from 0.95 to seconds. 5) The ballistic algorithms define the optimum fuze time-of-function value based on conventional ballistics compensation, use of prescribed range and height offset associated with the payload, and submunition free-flight characteristics. 6) M439 fuzes are employed in the following rockets: a) 6FL MK66 motor, flechette warhead b) 6SK MK66 motor, smoke warhead c) 6MP MK66 motor, Multi-Purpose Submunition (MPSM) warhead D-46

47 d) MP7 CRV7 motor, MPSM warhead e) SK7 CRV7 motor, smoke warhead Figure 28. Wall-In-Space Concept. (c) Wall-in-space concept 1) The MPSM (M439 fuze with M261/M267 warheads) provides a large increase in target effectiveness over standard unitary warheads. 2) The MPSM warhead helps to eliminate range-totarget errors because of variations in launcher/helicopter pitch angles during launch. 3) The timing cycle begins immediately after termination of the fuze charging cycle. The warhead Safe/Arm device simply isolates the charging line and connects the firing capacitor to the detonator at the first instance of motion. 4) At the computer-determined time (a point slightly before and above the target area), the M439 fuze initiates the expulsion charge. 5) The submunitions eject, and each Ram Air Decelerator (RAD) inflates. Inflation of the RAD separates the submunitions, starts the arming sequence, and causes each submunition to enter a near-vertical descent into the target area. D-47

48 (d) Figure 29. Dispersion Dispersion Pattern. 1) Dispersion and accuracy are functions of slant range. 2) This is directly attributed to high projectile velocity (flat trajectory) wherein a small miss distance above the target yields a significant downrange error. 3) As range increases dispersion decreases. 4) Longer engagement ranges do not necessarily equate to improved accuracy for aerial rockets. 5) Firing at extended ranges reduces linear (range) dispersion but increases cross-range dispersion. This specific problem is best addressed by using airburst (M439 fuze) rockets whenever possible. D-48