One of the 80 new Chinese Z-19 helicopter gunships in service was recently seen equipped with a mast mounted radar, as in the American AH-64D. Actually the Z-19 is a heavily armed scout helicopter, a 4.5 ton, two seater armed with a 23mm autocannon and up to half a ton of munitions (missiles, usually). The AH-64D weighs twice as much. Cruising speed is 245 kilometers an hour and range is 700 kilometers, the Z-19 is basically an upgraded Z-9W (armed transport helicopter, a license-built version of the French AS365).
The AH-64D features the Longbow radar based fire control system. This enables the crew to spot armored vehicles, or stationary targets, in any weather, up to ten kilometers away, and destroy them with Hellfire missiles (max range, eight kilometers). Introduced in the late 1990s, this was a late Cold War development, the perfect weapon to destroying enemy tanks at long range.
The AH-64D got some use during the 2003 Iraq invasion, but since then, the Longbow radar has been more of a liability. The radar system has not been much use for firing Hellfires at targets in residential areas, where you usually want to get a visual, not radar, picture of the target. Moreover, the radar system weighs 227 kg (500 pounds, about three percent of the weight of a fully loaded AH-64D). Such a system would be seven percent of the Z-19s weight meaning if the Z-19 used a similar radar it would probably have to drop the 23mm cannon and carry no more than six Hellfire type missiles.
In Afghanistan, where the AH-64s fly at high altitudes, where the thin air means less lift, the Longbow system was often removed. Losing three percent of your weight made a difference in performance. In Iraq, the high heat, and abundant dust, makes the Longbow electronics more prone to breakdown.