Editing Self-propelled anti-aircraft weapon (section)

===Cold War and later===
{{Unreferenced section|date=November 2024}}[[File:Brno, Řečkovice, transportér Praga V33 II.JPG|thumb|Czechoslovak self-propelled anti-aircraft gun [[M53/59 Praga]] developed in the late 1950s.]]
[[File:Gepard 1a2 overview.jpg|thumb|[[Flakpanzer Gepard]], combining radars, fire control and two 35&nbsp;mm guns in a new turret mounted on a  Leopard chassis.]]
[[File:2008 Moscow Victory Day Parade - 9K22 Tunguska.jpg|thumb|right|Typical of more modern designs, the [[Tunguska-M1]] mounts both missiles and cannons.]]The introduction of [[jet engine]]s and the subsequent rough doubling of aircraft speeds greatly reduced the effectiveness of the SPAAG against attack aircraft.{{dubious | date=July 2014}} A typical SPAAG round might have a muzzle velocity on the order of {{convert|1000|m/s|foot/s}} and might take as long as two to three seconds to reach a target at its maximum range. An aircraft flying at {{convert|1000|km/h|mph}} is moving at a rate of about {{convert|280|m/s|foot/s}}. This means the aircraft will have moved hundreds of meters during the flight time of the shells, greatly complicating the aiming problem to the point where close passes were essentially impossible to aim using manual gunsights. This speed also allowed the aircraft to rapidly fly out of range of the guns; even if the aircraft passes directly over the SPAAG, it would be within its firing radius for under 30 seconds.

SPAAG development continued through the early 1950s with ever-larger guns, improving the range and allowing the engagement to take place at longer distances where the crossing angle was smaller and aiming was easier. Examples including the 40&nbsp;mm U.S. [[M42 Duster]] and the 57&nbsp;mm Soviet [[ZSU-57-2]]. However, both were essentially obsolete before they entered service, and found employment solely in the ground-support role. The M42 was introduced to the [[Vietnam War]] to counter an expected North Vietnamese air offensive, but when this failed to materialize it was used as an effective direct-fire weapon. The ZSU-57 found similar use in the [[Yugoslav Wars]], where its high-angle fire was useful in the mountainous terrain.

By the late 1950s, the US Army had given up on the SPAAG concept, considering all gun-based weapons to be useless against modern aircraft. This belief was generally held by many forces, and the anti-aircraft role turned almost exclusively to missile systems. The Soviet Union remained an outlier, beginning the development of a new SPAAG in 1957, which emerged as the [[ZSU-23-4]] in 1965. This system included search-and-track radars, fire control, and automatic gun-laying, greatly increasing its effectiveness against modern targets. The ZSU-23 proved very effective when used in concert with SAMs; the presence of SAMs forced aircraft to fly low to avoid their radars, placing them within range of the ZSUs.

The success of the ZSU-23 led to a resurgence of SPAAG development. This was also prompted by the introduction of [[attack helicopter]]s in the 1970s, which could hide behind terrain and then "pop up" for an attack lasting only a few tens of seconds; missiles were ineffective at low altitudes, while the helicopters would often be within range of the guns for a rapid counterattack. Notable among these later systems is the German [[Flugabwehrkanonenpanzer Gepard|Gepard]], the first western SPAAG to offer performance equal to or better than the ZSU. This system was widely copied in various [[NATO]] forces.

SPAAG development continues, with many modern examples often combining both guns and short-range missiles. Examples include the Soviet/Russian [[Tunguska-M1]], which supplanted the ZSU-23 in service, the newer versions of the Gepard, the Chinese [[Type 95 SPAAA]], and the British [[Marksman anti-aircraft system|Marksman turret]], which can be used on a wide variety of platforms. Some forces, like the [[United States Army|US Army]] and [[United States Marine Corps|USMC]] have mostly forgone self-propelled guns in favor of systems with short-range infrared-guided surface-to-air missiles in the [[AN/TWQ-1 Avenger]] and [[Bradley Fighting Vehicle#M6 Linebacker|M6 Linebacker]], which do not require radar to be accurate and are generally more reliable and cost-effective to field, though their ability to provide ground support is more limited. The U.S. Army did use the [[M163 VADS]] and developed the prototype design of the [[M247 Sergeant York]].