COMBAT AIRCRAFT SURVIVABILITY
PRESENTED BY:
MOHD AFNAN BIN MOHD SANI 0432107
MUHAMMAD FAIRUZI BIN MOHD YUSOF 0432803
MOHD ZAIME BIN MISRI 0435635
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|HSurvivability = 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
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What is aircraft susceptibility?
Susceptibility is the inability of an aircraft to avoid
GunsMissilesAir interceptorsRadars
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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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IR signatureGeneral 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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Visual signatureo 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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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
ExampleChaff (confuse radar)Aerosols Flares (IR decoy)
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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
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 Definition
KK Aircraft destroyed immediately after being hit
K Aircraft fall out of control within 30 seconds after being hit
A Aircraft fall out of control within 5 minutes after being hit
B Aircraft fall out of control within 30 minutes after being hit
C 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 modes4. 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
Some Survivability Enhancement • Speed and altitude
•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
CONCLUSIONThe 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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