Defense Media Network

DIVAD Wasn’t a ‘Cure All,’ After All

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At the height of the Cold War in the late 1970s, the U.S. Army wanted a self-propelled anti-aircraft gun (SPAAG) to guard American armor and infantry from Soviet air threats – aircraft, helicopters and missiles.

Of special concern was the “pop-up” aerial menace posed by the Soviet Mil Mi-24 “Hind” helicopter that could briefly expose itself above terrain and launch a 9 K114 Shturm (AT-6 “Spiral”) air-to-ground missile.

The cure-all seemed to be the M247 Sgt. York Division Air Defense (DIVAD) gun system. A tracked vehicle on a tank chassis mounting a formidable twin Bofors 40 mm cannon armament, DIVAD would protect U.S. ground forces from any and all air threats. The system drew its name from Sgt. Alvin C. York, the sharpshooter who was one of the most decorated American soldiers of the Great War of 1914-1918.

 

Promising Portent

It looked good, it sounded good, but in the end it turned out to be a brilliant mistake. The comparable Soviet ZSU-23-4 Shilka system (named for a river) was effective and widely used by Warsaw Pact forces. DIVAD was neither. DIVAD couldn’t do the job it was created to do and became an open-ended drain for tax dollars.

M163 Vulcan

Soldiers of the 1st Battalion, 3rd Armored Cavalry Regiment, drive an M-163 20 mm Vulcan self-propelled anti-aircraft gun system to a refueling area during Operation Desert Shield. Although the M247 Sergeant York was designed to replace the Vulcan, the Vulcan outlived the M247 by nine years. U.S. Army photo

The DIVAD system was to be a replacement for the geriatric M163 Vulcan SPAAG, which was viewed as slow, clunky, vulnerable to standoff weapons, and virtually useless on a modern battlefield where everything happened in large numbers at high speed. DIVAD was expected to track up to 48 aerial objects in rapid motion, determine which were hostile, and shoot at them in priority, firing first at the closest, shooting it down, and proceeding to the next, all in the midst of a fast, mobile air-ground battle. High-tech was very much in favor in the early 1980s when the Reagan administration was building up U.S. forces: The Army planned to buy 618 units, considered enough for effective division air defense on the plains of Europe and in Korea, where massive air-ground battles were a constant possibility.

Because the Pentagon was already heavily invested in its “Big 5″ procurement programs (M1 Abrams tank, Bradley infantry fighting vehicle, AH-64 Apache attack helicopter, Black Hawk utility helicopter, and Patriot air defense system), its ground rules for the DIVAD program called for using as much off-the-shelf technology as possible. This meant that the new SPAAG would be built using the chassis of the M48A5 Patton 48-ton medium tank. In the competition for a DIVAD source selection, officials narrowed their prospects down to two designs, one from General Dynamics using twin 35 mm Oerlikon cannon, and the other from Ford Aerospace and Communications Corporation which utilized twin 40 mm L/70 Bofors guns.

M247 DIVAD TN

An M247 Sgt. York Division Air Defense Gun (DIVAD), on display in Jamestown, Tenn. Photo by Mark Holloway

In May 1981 the Ford entry was selected and designated M247 Sergeant York, featuring the twin 40 mm guns mounted in a new box-like armored turret with both tracking and surveillance radar fitted atop. The gunner was provided with a roof-mounted sight incorporating a laser rangefinder, the commander having a panoramic roof-mounted periscope and fixed periscopes. The radar was a modified version of the Westinghouse APG-66 system introduced in the F-16 Fighting Falcon.

Deliveries began in 1983, before operational testing had reached its planned mid-point. It was now a SPAAG, but the M247 Sergeant York still looked and handled like a tank, albeit with antennas sticking out in all directions. Its weight had increased to 62 tons, with the new turret alone topping 20 tons. The vehicle had a crew of three, consisting of commander, gunner and driver.

 

Posing Problems

One soldier said that the chassis was flawless and the turret useless. The turret traverse was too slow to track a fast-moving target. The Sgt. York, this soldier said, would be able to defeat a target only by driving over the top of it. In fact, the chassis had been out of production for decades, existing examples hadn’t been maintained in good order, and some in the DIVAD fleet had mechanical problems.

The fire control system was unable to live up to the hype with which DIVAD was introduced to the world. The APG-66 pulse Doppler radar was neither designed, nor adapted, to cope with ground clutter, nor could it stand up to the extremes of heat, vibration, and other conditions encountered aboard an armored vehicle on a battlefield. Moreover, the radar was poorly positioned, with the guns directly in its field of view. Except for the radar, most components worked more or less as intended, but did not function well as an integrated whole: one veteran remembers “shortcuts and shoddy work on parts.”

After early tests in 1984, Rep. Dennis Smith (R-Oregon) complained about the exorbitant cost of the tests themselves and of the growing price tag of the DIVAD system. Smith accused the Army of faking the results of some tests – including tests in which target drones were fitted with radar reflectors.

Seeking to placate Congress and the Pentagon’s newly founded Operational Test and Evaluation Office (OT&E), a further series of tests was undertaken. By now, Congress had decreed that DIVAD could move ahead only if the Pentagon certified that the system “meets or exceeds the performance specifications of its contract.”

M247 Sergeant York

An M247 Sgt. York undergoing testing at Aberdeen Proving Ground, Md. DoD photo

The OT&E concluded that the reliability of the system was inadequate and could not be improved. In a new round of tests in the American southwest, an M247 assigned to shoot down a fast-flying target drone instead locked onto a nearby latrine fan, the system apparently classifying it as a slow-moving target.

Tests against slow-flying drones were no more successful. Even against a helicopter drone hovering still in mid-air, the Sgt. York missed its target. Subsequently, during a demonstration for important visitors, an M247 swung its guns toward an audience that included Smith and other congressmen, causing several minor injuries as dignitaries scrambled for cover.

On Aug. 27, 1985, unhappily, Secretary of Defense Caspar Weinberger cancelled the program after about 50 vehicles had been produced.

In retrospect, it appears the Army would have gotten a better, cheaper system had it purchased one from scratch, rather than throwing together a hodgepodge of existing components. The Army’s need for a DIVADS-type defense system was not met until years later, when a system employing the Stinger surface-to-air missile was successful. Some supporters of the man after whom DIVAD was named have argued that the Sgt. York appellation should have been transferred to a more successful weapon.

Most M247s ended up being targets on Air Force bombing ranges. Surviving M247s are in several military storage locations, museums and parks, including the Sgt. Alvin C. York State Historic Park in Pall Mall, Tenn.

By

Robert F. Dorr is an author, U.S. Air Force veteran, and retired American diplomat who...