Combat Aircraft Survivability

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COMBAT AIRCRAFT SURVIVABILITY

PRESENTED BY:

MOHD AFNAN BIN MOHD SANI 0432107

MUHAMMAD FAIRUZI BIN MOHD YUSOF 0432803

MOHD ZAIME BIN MISRI 0435635

Video of an aircraft (MIG-21) that was attacked by missile

Aircraft combat survivability (ACS) is defined as the capability of an aircraft to avoid or withstand a man-made hostile environment including both man-made and naturally occurring environments, such as lightning strikes, mid-air collisions, and crashes

It can be measured by the probability the aircraft survives an encounter (combat) with the environment

The traditional discipline known as system safety attempts to minimize those conditions known as hazards that can lead to a mishap in environments that are not made hostile by man

Thus, together, the system safety and survivability disciplines attempt to maintain safe operation and maximize the survival of aircraft in all environments in both peacetime and wartime.

The survivability of an aircraft is related to the aircraft's killability, or susceptibility and vulnerability, by the equation

PS = 1 - PK

= 1 - PHPK|H

Survivability = 1 – Killability

= 1 Susceptibility • Vulnerability

Thus, an aircraft's combat survivability is enhanced when it's killability is reduced.

The killability of an aircraft is reduced when the susceptibility and the vulnerability of the aircraft are reduced

What is aircraft susceptibility?

Susceptibility is the inability of an aircraft to avoid

 Guns

 Missiles

 Air interceptors

 Radars

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 The important susceptibility measures is probability of detection by the enemy

 Its strongly dependant upon the size of the signature of the aircraft

Aircraft signature

 radar signature

 visual signature

 infrared signature

 aural signature

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Radar signature

When the signal passes over the aircraft

 A portion of the incident power absorbed as heat

 Another portion pass completely through parts of the aircraft

 The remainder is radiated or scattered in many different directions

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Various scattering surfaces on an airplane

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Typical radar sparkle points on a helicopter

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IR signature

General sources of IR signature are radiation emitted by

• airframe and propulsion system

• exhaust gas and plume from the engine typical major IR sources

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Two IR seekers (+) tracking flares

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IR image of a Dauphin helicopter at night

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Visual signature o The visual detect ability of an aircraft is dependent the difference between the background and the aircraft.

o Aircraft detection occur when the aircraft luminance is too low compared with its background

Camouflage of fighter aircraft

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Aural signature

 Aircraft are often heard before seen by ground observer

 Primarily as a result of engine or rotor blade noise

Example

Low-flying helicopters sound can heard as 30s before they become visible because of rotor blade noise

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Design for Low Susceptibility

5 susceptibility reduction concepts

 Signature reduction

 Threat warning

 Radar deception

 Expendables

 Weapons and tactics, flight performance and crew training

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Reduction of radar signature

Reflection of the radar signal away from the receiving antenna a. shaping and orienting conducting surface b. aligning all edges in few direction

 Absorption radar signal using special Radar

Absorbent Materials RAM) or Radar

Absorbent Structures called RAS

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Reduction of infrared signature (IR)

 Reduce the temperature of the hot parts

 Reduce the surface emissivity of the hot parts

 Reduce the temperature of the exhaust

 Reduce or mask the observable surface radiating area

 For reflecting surfaces reduce the surface reflectivity

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Example on how to reduce IR signature from engine

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Threat warning

The system has been build to warn the pilot if they are being targeted by enemy

Example

Radar Warning Receivers (RWR)

Missile Approach and Warning System (MWS)

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Radar deception

Deception system consists of those electronic techniques that present false target information to the radar

General approaches for deception

 To provide incorrect target bearing, range, or velocity information to the radar

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Expendables

Material or devices to be ejected from an aircraft for the purpose of denying or deceiving threat tracking system for limited period

Example

 Chaff (confuse radar)

 Aerosols

 Flares (IR decoy)

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• IR flares to decoy an infrared (IR) guided missile

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Weapons and tactics, flight performance and crew training and proficiency

This last concept is somewhat of a catch all concept. It combines all of the operational aspects

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Vulnerability

Aircraft vulnerability refers to the inability of the aircraft to withstand the damage caused by the man made hostile environment, to its liability to serious damage or destruction when hit by enemy fire. Aircraft that are more vulnerable are softer, where as those are less vulnerable are harder.

Type of aircraft kill

1. Attrition kill category

Kill level

KK

Definition

Aircraft destroyed immediately after being hit

K

A

B

C

Aircraft fall out of control within 30 seconds after being hit

Aircraft fall out of control within 5 minutes after being hit

Aircraft fall out of control within 30 minutes after being hit

Aircraft fall out of control before completion of the mission objectives.

2. Mission abort kill category

 prevents an aircraft from completing its designated mission and minimum flying qualities remains after the hit

3. Mission denial kill category

 aircraft is hit and the pilot unable to control the aircraft, and aborts the mission because of the aircraft damage.

(Mission objectives does not achieved)

4. Landing kill category

 Carrier base aircraft are able to return to the carrier but cannot land because of the damage to the tail hook.

5. Forced landing category

 It is helicopter kill category in which damage to the helicopter causes the pilot to land (powered or unpowered) because of receiving the indication of component damage.

Critical components kill modes.

1. Component dysfunction, damage, failure or kill

 The inability of a component to provide the function it was designed

2. Components kill modes.

 failure modes and damage modes

3. System kill modes

4. Loss-of-function kill modes

 Loss of essential functions

5. Cascading-damage kill modes.

 When a damage component that can kill other critical component

Vulnerability reduction concepts

1. Component redundancy

 total redundancy and partially redundancy

 dual electrical generators where a single generator only powers some of the aircraft systems

 dual power control hydraulic subsystems

2. Component location

 positioning critical components that can reduce the probability of lethal damage

3. Passive damage suppression

 providing redundant load path in critical structural elements such as multispar wings

4. Active damage suppression

 fire detection and extinguishing system that uses a detector to sense an ignition source of high temperature area

5. Component shielding

 Providing armor material to the critical components as a shields

6. Component elimination or replacement

 replacing a fuel-feed boost pump with a fuel-feed suction device

• Speed and altitude

Some Survivability Enhancement

•Maneuverability/agility

•Chaff and flares

•Fighter escort

•Self-repairing flight controls

•No fuel adjacent to air inlets

•Self defense missiles and guns

•Good target acquisition capability

•Night-time capability

•Crew situational awareness & Tactics

•Threat warning system

•More than one engine – separated

•Low signatures

•Antiradiation weapons

•Nonflammable hydraulic fluid

CONCLUSION

The survivability community must apply lessons learned from combat and tests to improve future system design, performance capability, and survivability against anticipated lethal and nonlethal threats. So, to increase the survivability of combat aircraft we have to decrease the susceptibility and vulnerability of the aircraft.

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