There have been much lower helicopter loss rates compared to Vietnam, due in large part to more survivable designs. Even so, helicopter loss rates are still high relative to fixed wing aircraft. Future conflicts, which might be conducted against nation state opponents, however, present an entirely different picture. This is due to the proliferation of advanced short-range air defence weapons, which are highly lethal against helicopters.
Of all modern aircraft, helicopters are the least survivable due to their low altitude and relatively low speed flight profiles compared with jet aircraft, and their high acoustic and radar signatures. These are inherent limitations of rotary wing aircraft, which cannot be easily or affordably designed out.
Formal survivability analysis is centred on two components: the first being susceptibility analysis that aims to measure the probability of an aircraft being hit; and the second vulnerability analysis, which aims to measure the probability of a hit with a given weapon inflicting fatal damage to the aircraft.
Central to discussion of helicopter survivability is the threat environment in which the aircraft must operate.
During the invasion of Iraq in 2003 and the subsequent counter-insurgency campaign the US Army experimented with a range of tactics, including the use of the AH-64D Longbow Apache to directly attack targets in the manner fighter aircraft would do, but suffered heavy losses in airframes due to concentrated gunfire.
The insurgents in Iraq had an abundant supply of Soviet supplied SA-7 SAMs and Chinese clones, and there are claims that newer Russian SA-16 and SA-18s may have been used. These have generally proven less than effective since much of the coalition helicopter fleet was equipped with infrared exhaust suppressors, active infrared jammers and flare dispensers. Many larger helicopters were also equipped with missile approach warning systems to cue countermeasures deployment. The most prominent kills achieved by MANPADS were transport aircraft, spurring the deployment of infrared jammers across coalition fleets.