Purpose of guided missiles

The purpose of a guided missile is to reach and destroy or damage a target. The type of target involved influences the characteristics of the missile; however, each missile must meet the following basic requirements;

(2) It must be maneuverable in flight to correct its flight path as required to intercept the target.

(3) It must be capable of inflicting a satisfactory degree of damage to the target on intercept.

(4) It must have an acceptable operating envelope (range/altitude) within which it is effective.

(5) The missile and its components must be safe to handle, store, and load.

Classification
Guided missiles are classified according to their range, speed, launch environment, mission, and vehicle type.
(1) Range
(2) Long-range guided missiles are usually capable of traveling a distance of at least 100 miles.
(3) Short range guided missiles often do not exceed the range capabilities of long-range guns.
(4) The Navy has air-launched guided missiles that function within these ranges. They are medium-range (MR) or extended-range (ER) missiles which are normally upgraded variants of existing missiles.

Speed
(1) The speed capability of guided missiles is expressed in Mach numbers.
(2) A Mach number is the ratio of the speed of an object to the speed of sound in the medium through which the object is moving.
(3) Under standard atmospheric conditions, sonic speed is about 766 miles per hour (Mach 1.0).

Guided missiles are classified according to their speed.
(1) Subsonic-Up to Mach 0.8
(2) Transonic-Mach 0.8 to Mach 1.2
(3) Supersonic-Mach 1.2 to Mach 5.0
(4) Hypersonic-Above Mach 5.0

When considering the speed of an air-launched guided missile.
(1) The speed of the launching aircraft is added to the speed of the missile.
(2) Example, if a missile's speed, is Mach 2.5 and the aircraft's speed, at the time of missile launch, is Mach 2.0, the missile's speed is Mach 4.5

Missile Theory of Flight

Three phases of flight.

(a) Launch- Initial power up to independent flight.

(b) Mid-course- Major corrections towards target.

(c) Terminal- Final maneuvers/TDD or fuzing activation.

Type
Guided missiles are divided into two types -service missile and nonservice missiles.

(1) Service missiles - generally referred to as tactical missiles. Service missiles are fully operational and fully explosive loaded rounds, designed for service use in time of war.


(2) Nonservice missiles - all types of missiles other than service or tactical. They are subdivided as practice (or exercise) missiles, training (or inert operational) missiles, and dummy (or shape) missiles.

Guided missiles used in naval aviation include air-to-air and air-to-ground missiles. Air-to-air guided missiles are fired by one aircraft against another aircraft. Air-to-ground guided missiles are fired from an aircraft against a target on the land or water surface.

Designation

The Department of Defense (DOD) established a missile designation sequence. The basic designation of every guided missile are letters, which are in sequence.
(1) First Letter: the environment from which the vehicle is launched.

(2) Second Letter: the primary mission of the missile.

(3) Third Letter: the type of vehicle.

Examples of guided missile designators common to the Aviation Ordnanceman are as follows:


Basic Designator Meaning
AGM Airlaunched ground-attack guided missile
AIM Air-launched intercept-aerial guided missile
ATM Air-launched training guided missile
RIM Ship-launched intercept-aerial guided missile

The basic designator is followed by a design number. In turn, the number may be followed by consecutive letters showing a modification. For example, the designation of AIM-54C means:
(1) A = Air launched
(2) I = Intercept
(3) M = Missile
(4) 54 = Missile Design
(5) C = Modification

Most guided missiles are given popular names such as Sparrow, Sidewinder, Harpoon, Maverick, etc.

Identification
There are three significant color codes used on guided missiles and their components:


(1) Yellow - identifies high explosives which indicates the presence of explosive, either, sufficient to cause the ammunition to function as a high explosive, or, particularly hazardous to the user.

(2) Brown - identifies rocket motors, indicates the presence of explosive, either, sufficient to cause the ammunition to function as a low explosive, or particularly hazardous to the user.

(3) Blue - identifies ammunition used for training or firing practice.
NOTE: The colored band around a component, will identify a explosive hazard. If the components are painted blue on a practice missile and have a yellow or brown band painted on them, the component has explosive hazard.

Each component of the missile is identifiable by lettering stenciled on the exterior surface of the component.
(1) Mark and Mod
(2) Type and weight of explosive filler
(3) Loading activity symbol and date of loading
(4) Temperature range restrictions
(5) Unit serial number

All missiles used in naval aviation are assigned missile serial numbers. These numbers are shipped with the missile's logbook.
(1) The missile serial number is normally the serial number of the leading component of the missile.
(2) Used to track the missile from assembly to firing.

Components
Guided missiles are made up of a series of sections: guidance, control, armament (warhead and fuzing), and propulsion.

The sections are carefully joined and connected to each other, they form the ALL UP ROUND (AUR) that is currently used in the Navy.

Guidance section: is the BRAIN of the missile. It directs the missile toward the target. Air launched guided missiles currently in use are of the homing-type. They use radar or infrared
 homing systems. A homing guidance system is one in which the missile seeks out the target, guided by some physical indication from the target itself. There are three types of homing guidance: Active, Semiactive, and Passive.
 (1) Active homing system, target illumination is supplied by a component in the missile, such as a radar transmitter.
(2) Semiactive homing system, the missile gets its target illumination from an external source, such as a transmitter carried in the launching aircraft.
(3) Passive homing system, the directing intelligence is received from the target. (i.e., INFRARED RADIATION, RADAR SIGNALS)

Other Forms of Guidance Include:

1 Laser Guided homing system, the missile is directed by a laser beam to the target, which can be either supplied by ground personnel, another aircraft, or the aircraft carrying the missile.

2 TV/Data Link/Pre-programs, which enables weapons to be directed to target by video link, data link, and Global Positioning Satellites(GPS).


In all types of homing, the target signal is continually processed to: Relative position, bearing, range, speed, and correct angle of attack.

Control Section - Actuates the movement of the wings and fins from a signal received from the guidance section.


Armament/Warhead section contains the payload (explosives), fuzing, safety and arming (S&A) devices, and target-detecting devices (TDD's).
Warheads used in air-to-air guided missiles contain a rather small explosive charge of 10 to 18 pounds of H-6, HBX, or PBX high explosives. It is common in air-to-surface guided missiles to have warheads ranging up to 450 pounds of Comp B and H-6 high explosives.

 Fuzing - The fuzing and firing system is normally located in or next to the missile's warhead section. It includes: Fuze, Safe and arming device (S&A), Target-detecting device (TDD). There are two general types of fuzes:

Contact fuze - In the contact fuze, the force of impact closes a firing switch within the fuze to complete the firing circuit, detonating the warhead.


Proximity fuze - When proximity fuzing is used, the firing action is very similar to the action of proximity fuzes used with bombs and rockets.


Safety and Arming (S&A) Devices- S&A devices are electromechanical explosive control devices. They maintain the explosive train of a fuzing system in a safe (unaligned) condition until certain requirements of acceleration are met after the missile is fired.

Target-Detecting Devices (TDD)- TDD's are electronic detecting devices similar to the detecting systems in VT fuzes.

Air-to-Air guided missiles are normally fuzed for proximity burst using a TDD with a S&A device.

Air-to-Surface guided missile fuzing consists of influence (proximity) and/or contact fuzes.

Propulsion section provides the force (thrust) that propels the missile.
There are two basic types of jet propulsion power plants used in missile propulsion systems:


Turbo-jet propulsion system depends on the atmosphere to supply the oxygen to start and sustain burning.(Harpoon and SLAM).


Thermal jet propulsion which consists of a solid propellant, providing it's own oxygen supply and is used in the majority of all air launched missiles.(Sidewinder, Sparrow, and AMRAAM).