A flare (or decoy flare) is a countermeasure used by planes and helicopters to counter an infrared homing (heat-seeking) missile. These flares deploy and burn at thousands of degrees, which is much hotter than the exhaust of a jet engine. They cause the missile to make incorrect steering decisions, because the missile seeks out the hotter flame of the flare believing it to be an aircraft's engine exhaust or an aircraft in afterburner. In order for countermeasure flares to be effective, the aircraft must be equipped with very advanced radar systems that are able to detect very fast, small objects (the missiles). These countermeasure flares are ineffective against some modern missiles.
