Wednesday, January 6, 2010
EO MISSILE APPROACH WARNING
1. The greatest threat to aircraft and 1. The greatest threat to aircraft and helicopters comes from IR missiles. As these are not normally associated with radar guidance, aircrew get no warning of the impending danger unless they are lucky enough to either see the weapon being launched or in flight. The proliferation of IR missiles is high, if we look only at shoulder launched ‘Manpad’ systems the most numerous is the SA-7 with many hundreds of thousands having been produced. The US Stinger has been sold in numbers approaching 50,000 while the French Mistraal numbers 12,000 to 18 different countries. The following examples give an indication as to the success of passively guided IR weapons:
a. During 1977 to 1985 905 of all loses were to IR guided weapons. 4.4% were to radar guided weapons.
b. During the Gulf War 78% of all loses were to IR weapons.
c. Over the last 20 years only 10% of aircraft have been shot down by radar guided weapons.
2. IR weapons can be defeated by the use of flares and manoeuvring or by the use of IR jammers or Lasers. We shall look at these techniques in later lessons and here concentrate on the piece of equipment that can provide warning of incoming missiles and thus automatically fire the flare or other EOCM techniques. Missile Warning Systems (MWS) or Missile Approach Warner (MAW) as they are also known as, detect the EO signal given off by the approaching weapon. This can be either IR or UV and both types of equipment have been developed.
3. MWS were originally developed for helicopters and large transport aircraft. The equipment was large and heavy but it was thought that the threat to fast jets was very low. With hindsight we now know this was the completely wrong assumption. With a maximum missile flight time of 10 seconds all types of aircraft are vulnerable and a quick warning is required. There must be no false alarms and the system must be capable of detecting the time of impact, as this is important in the correct use of the countermeasures.