The US M247 Sergeant York DIVAD SPAAG

SPAAG History

The fast paced development over the last few decades with which helicopters and their Anti-Tank Missiles has progressed, has proven difficult to match in terms of the development of an effective land based vehicle capable of matching the quick engagement times of these tank hunter helicopters. This has been highlighted for some time by the US’s Combined Arms Team (CAT).

These ATM’s have progressively increased in their range and their guidance systems, which has reduced the exposure time of the helicopters and narrows the window with which a SAM system could detect and engage them successfully.

For this reason a Self-Propelled Anti-Aircraft Gun system is better suited as it can react quicker, thou their effective range is limited by the calibre of the guns they use and these were all problems that faced the US from the 1950’s onwards.

The earlier Duster lacked effective sighting and tracker equipment. And was retired within 10yrs of it entering US service. A number of other vehicles were proposed as a replacement such as the Vigilante, but were not adopted. Other vehicles that were, such as the Vulcan simply further highlighted the CAT’s concerns.

The DIVision Air Defense program aka DIVAD

On the 18th of May 1977, US Colonel Parker addressed a meeting of industry representatives on the DIVision Air Defense program, which was set up to meet the requirement for a new SPAAG turret which was to be mounted on a M48A5 tank chassis so that it could keep up with the CAT operated tanks in combat.

The gunners sights had to have a FLIR (thermal imaging) channel and laser range finder to acquire a target and start firing within five seconds (later extended to eight) of it becoming visible or coming into its 3000m range, and had to have a 50% chance of hitting the target with a 30 round burst.

From the competing companies designs, both General Dynamics and Ford were selected in 1978 to each provide a working prototype. These were bothered tested during phase one trials against engaging a number of remote controlled helicopters, planes and drones.

Ford won on the 7th of May 1981 the fixed-price $6.97 billion development and initial production contract. The system was officially named M247 Sergeant York when the contract was awarded.

During later trials a number of problems with the prototype were  discovered:

1. The tracking radar had problems with ground clutter and was unable to distinguish between helicopters and trees.

2. When the guns were pointed upward to fire on high-angle targets, the barrels projected into the radar’s line of sight and further confused the system.

3. The reaction time was far too slow; against hovering helicopters it was 10 to 11 seconds.

4. The turret proved to have too slow a traverse to track fast moving targets.

5. The used guns taken from U.S. Army stock were in twisted condition due to careless warehousing (the vehicle was to use the stored 20mm Bofors from the older Duster).

6. The turret weighed 20 tonne’s and the M48’s couldn’t keep up with what was at the time the new Abrams Main Battle Tank.

A case of misidentification!

In February 1982, at a demonstration for U.S. and British officers at Fort Bliss, the turret immediately swung towards the reviewing stands upon activation of its computer causing the audience to scramble thinking they were going to be shot at.

After technicians worked on the system, the target was again presented and the gun blasted the ground in front of it 300 yards out. It never successfully engaged the targets that day and this was not the last incident where this kind of thing happened.

The DIVAD Project is cancelled

The system went on to be further tested in battlefield condition testing. The testing concluded that the gun could perform the mission as originally specified, but also showed that the system had considerable reliability problems, many as the result of trying to adapt a radar system developed for aircraft to the ground role.

Initial production tests run from December 1984 to May 1985 turned up a continued variety of problems, failing 22 of 163 contract requirements, and 22 serious failures in operational readiness.

On the 27th of August 1985, Secretary of Defense Caspar Weinberger killed the project after about 50 vehicles had been produced. He said, “the tests demonstrated that while there are marginal improvements that can be made in the York gun, they are not worth the additional cost-so we will not invest any more funds in the system.”

Most of the production M247 vehicles ended up as targets on air force bombing ranges. However, one is on display at the Sgt. Alvin C. York State Historic Park in Pall Mall, TN where its namesake hailed from and another is located at the AAF Museum in Danville, VA.