student handout title: ah-64d aerial rocket system (lot 11...

UNITED STATES ARMY AVIATION CENTER OF EXCELLENCE

FORT RUCKER, ALABAMA

April 2009

STUDENT HANDOUT

TITLE: AH-64D AERIAL ROCKET SYSTEM

(LOT 11)

FILE NUMBER: 011-0922-3.5

Proponent For This Student Handout Is:

COMMANDER, 110TH

AVIATION BRIGADE

ATTN: ATZQ-ATB-AD

Fort Rucker, Alabama 36362-5000

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.

D-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 1-

1520-251-10),Aircrew Training Manual (TC 1-251), and Helicopter Gunnery

(FM 3-04.140 (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 011-1081

IAW the SEP.

D-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 1-1520-251-10 and TC 1-251.

1. 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) Rocket type

(b) Warhead

(c) Fuze

(d) Quantity desired

(2) The ARS can fire the 2.75-inch/70mm Folding Fin Aerial Rockets

(FFAR) in two firing modes:

(a) Independently Pilot (PLT) or Copilot/Gunner (CPG) controlled

(b) Cooperative (simultaneously PLT/CPG controlled)

D-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) The ejector rack contains attaching lugs for securing the store

to the pylon and the explosive ejector for stores jettison.

(b) The Pylon Interface Unit (PIU) provides interface between the

Weapons Processor (WP) and the pylon discrete signals.

(c) 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-5

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.

(d) The pylons are equipped with hydraulic and electrical quick-

disconnect 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) The PIU is a remote processor that communicates with the WP

and provides interface to the M261 rocket launchers and pylon

actuators.

(b) The PIUs perform rocket fuzing and squib ignition.

(c) PIUs are solid state Remote Terminal (RT) Line Replaceable

Units (LRUs).

(d) Each PIU provides the necessary Input/Output (I/O) and

processing capability to control up to nineteen 2.75-inch FFAR.

D-6

Figure 4. M261 Rocker Launcher.

(3) M261 rocket launchers

(a) The M261 rocket launcher carries and launches the 2.75-inch

(70mm) FFAR within the operating environment of the AH-64D

helicopter.

(b) The rocket pod weighs approximately 86.8 pounds.

(c) The pods are 65 inches long.

(d) The pods have a diameter of 16 inches.

(e) 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) Two top mounted suspension lugs allow attachment to the

wing pylon.

(h) 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-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) 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.

(b) 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.

(c) 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.

(d) Pressing the recessed JETT pushbutton will cause stores to

be jettisoned from all stations in the ARM mode.

(e) Only that crewstation arming the STORES JETTISON panel

can de-arm it. Once armed, either crewstation can activate the

Stores Jettison function.

D-8

Figure 6. Emergency Stores Jettison (JETT) Switch.

(5) Emergency Stores Jettison switch

(a) Located on the flight section of the collective grip.

(b) Provides the pilot or CPG with the capability to jettison all

external wing stores at the same time.

(c) Pressing the guarded JETT switch will cause all external

stores to be jettisoned from the aircraft at the same time.

D-9

Figure 7. LOAD / MAINTENANCE PANEL (LMP).

(6) LOAD / MAINTENANCE PANEL (LMP)

(a) Located in the right aft avionics bay.

(b) 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-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-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-12

ENABLING LEARNING OBJECTIVE 2

ACTION: Identify the controls and displays of the ARS.


STANDARD: In accordance with TM 1-1520-251-10, TC 1-251, and FM 3-04.140(FM 1-

140).


Identify the controls and displays of the ARS.

Figure 8. ARMAMENT Panel.

a. ARS controls and displays

(1) ARMAMENT panels

(a) 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.

(b) 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-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) 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.

(b) If the RKT selections are not initialized with preloaded data,

the firing quantity, penetration distances, and warhead/fuze

options are initialized with default values.

(c) Rocket icons and indicators

D-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-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-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-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-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-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-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-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-22

Figure 18. Rocket Inventory and Zone Options.

Figure 19. Common Rocket Types.

D-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 anti-

personnel, 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 anti-

personnel, 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-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-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

M439.

4 6IL—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 100-120

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-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

1,179 60 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-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) 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.

(b) The WAS is mounted on the PLT/CPG cyclic and on the

TEDAC Left Handgrip (LHG). Weapons selection (action) is as

follows:

(c) G (12 o’clock position on the WAS): Actions the M230 30mm

automatic gun.

(d) R (9 o’clock position on the WAS): Actions the ARS.

D-28

(e) M (3 o’clock position on the WAS): Actions the Hellfire missile

system.

(f) 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) The Trigger switch is a three-position, guarded switch used to

fire the selected weapon.

(b) 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-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 +3.48

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-30

(b) 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.

(c) 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-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-32

Enabling Learning Objective 3

ACTION: Identify the ARS Safety and Performance Inhibits.




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 TXX

GUN OBSTRUCT 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) 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..

(b) ALT LAUNCH: Indicates that a Hellfire launch is in progress

(c) 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.

(d) 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-33

(e) 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 0.5.

2) Integrated Helmet And Display Sight System

(IHADSS) is the selected sight, and the pylon

position error is greater than 1.5

(f) PYLON LIMIT: Indicates that the commanded pylon position

exceed the pylon articulation limits of +4 to -5 on the ground

(g) TYPE SELECT: Indicates that no rocket type is selected.(

multiple rocket types are available)

(h) 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

2nd

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) The WP will inhibit rocket firing for pylon position errors as

follows:

(3) GENERIC inhibits

(a) SAFE: Indicates the weapon system is not been armed

through the Armament Control Panel.

(b) 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)

(c) 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-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-35

B. ENABLING LEARNING OBJECTIVE 4

ACTION: Identify the procedures for operation of the ARS.




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) When Independent moding is used, only the actioning

crewmember trigger is active and the ballistics calculation is

based on their LOS and range source.

(b) 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.

(2) Cooperative mode

(a) The Cooperative mode is active whenever the rocket system is

actioned via the TEDAC left handgrip and pilot cyclic WAS.

(b) 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.

(c) In the Cooperative mode, both weapon triggers are active and

the CPG LOS and range source are used for the ballistics

calculations.

(d) 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.

(3) Training mode

(a) 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.

(b) 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-36

(c) 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.

(d) 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.

(e) 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-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-38

C. ENABLING LEARNING OBJECTIVE 5

ACTION: Identify the ballistic factors that affect rocket firing.


STANDARD: In accordance with TM 1-1520-251-10, TC 1-251, and FM 3-04.140(FM1-

140).


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) Interior

(b) Exterior

(c) Aerial

(d) 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) 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.

(b) 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-39

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.

(c) 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-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) Gravity

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.

(c) Yaw

1) Yaw is the angle between the centerline of the

projectile and the trajectory.

D-41

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.

(d) 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.

(e) 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 cross-

sectional 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-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-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-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.

Figure 26. Angular Rate Error.

(b) 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-45

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.

(c) Fin-stabilized projectiles

1) The exterior ballistic characteristics affecting fin-

stabilized 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-46

Figure 27. Fuze.

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.

(b) 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

25.575 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-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-to-

target 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-48

Figure 29. Dispersion Pattern.

(d) Dispersion

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-49

CHECK ON LEARNING

1. What are the four types of ballistics influencing helicopter-fired weapons?

ANSWER: __________________________________________________________________

_________________________________________________________________

2. Which type of ballistics best describes the characteristics and effects of the projectiles at

the target?

ANSWER: __________________________________________________________________

_________________________________________________________________

3. Thrust misalignment is a characteristic of ________ ballistics.

ANSWER: __________________________________________________________________

_________________________________________________________________

4. Interior ballistics deals with characteristics that affect projectile motion inside the:

ANSWER: __________________________________________________________________

_________________________________________________________________

5. The pilot may have to pitch the nose of the aircraft up when firing rockets beyond

________ meters. The pylons will articulate up to _________ degrees per second to

compensate for this motion.

ANSWER: __________________________________________________________________

_________________________________________________________________

student handout title: ah-64d aerial rocket system (lot 11...

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