The US Army's ill-fated Division Air Defense Gun, known commonly as the DIVAD or Sergeant York, was intended to protect ground forces, both armored columns and formations of troops in the field. The new weapon was needed to counter two different threats: increasingly potent missile-carrying helicopters that can hug the terrain of the battlefield to evade existing antiaircraft gun radars, and modern, computer-guided jet aircraft whose low attack altitudes and high speeds render current weapons ineffective.
Ford Aerospace & Communications Corporation won the competition to develop the DIVAD gun system in 1980. Ford's concept was a 30 mile per hour, tank-like vehicle that could keep up with rapidly-moving armored units on today's fast-paced battlefields.
The vehicle would carry two 40 millimeter antiaircraft guns with a range of 21/2 miles. To locate and track targets, DIVAD was designed to use both radar and a laser range finder.
The diesel powered vehicle was designed to be operated by a crew of three.
The DIVAD experienced problems almost from the beginning of its test cycle. The radar proved unable to reliably track even slow-moving helicopters at low altitudes.
The gun jammed often and malfunctions occured repeatedly, even during several well-publicized demonstrations for congressional observers and the press.