In 1982 I participated in both cooperative and non-cooperative tests at Aberdeen Proving Grounds in Maryland, flying an Air Force CH-3E helicopter against a Sergeant York. I would have been dead many times over had it been shooting live rounds at us instead of just video.The Sergeant York was the front-runner in a program intended to provide the Army with a sorely needed “division air defense” (DIVAD) weapon system. It was based on a novel concept: re-purposing M48 Patton tank chassis’ with a new turret incorporating twin Swedish Bofors 40mm cannons and two radar systems — one for area surveillance (the rectangular antenna) and one for targeting (the conical antenna, an off-the-shelf application of the F-16′s radar).A firing control system integrated the two radars, with on-board software prioritizing targets based on the threat they were assessed to pose to the system itself. (For the late ’70s /early ’80s, this was cosmic.) If the operator elected to allow the system to engage targets hands-off, it would slew the turret around at a nauseatingly rapid rate, taking on each in turn automatically.On the next-to-last day of the test, my aircraft was joined by an Army AH-1 Cobra and OH-58 Kiowa and two Air Force A-10s. My H-3 was part of the test profile because its radar signature was essentially the same as that of an Mi-24 HIND assault helicopter of the day, which was heavily armed with both anti-tank missiles and rockets. We all converged on it simultaneously from about 6000 meters. My aircraft was the first to die, followed by the two A-10s, then the Cobra, and finally the Kiowa. It took less than 15 seconds to put plenty of hypothetical rounds into each of us.I spent a depressing amount of that week watching myself get tracked and killed on video. Trying to “mask” behind anything other than rising terrain simply didn’t work; the DIVAD radar got a nice Doppler return off my rotor system if any part of it was within its line of sight, and it burned right through trees just fine. I couldn’t outrun or out-maneuver it laterally; when I moved, it tracked me. I left feeling pretty convinced that it was the Next Big Thing, especially since I’d come into the test pretty cocky thanks to having had a lot of (successful) exercise experience against current Army air defense systems.So, what happened to the program itself? I think it was a combination of factors. First, the off-the-shelf concept was cool as far as it went, but the Patton design already was a quarter-century old; the DIVAD was awfully slow compared with the M1 Abrams tanks it was supposed to protect. It would have had a lot of trouble keeping up with the pack.Second, The Atlantic Monthly published a really nasty article (bordering on a hatchet job) purporting to show the program was a complete failure and a ruinous waste of money. One of its most impressive bits of propaganda was an anecdote about a test where the system — on full automatic — took aim at a nearby trailer full of monitoring equipment. Paraphrasing, “It tracked and killed an exhaust fan,” chortled the author. (See The Gun That Shoots Fans for a recounting of this.)Yeah, it did. It was designed to look for things that rotate (like helicopter main rotor systems) and prioritize them for prompt destruction. If any bad guys were on the battlefield in vehicles with unshrouded exhaust fans, they might have been blown away rather comprehensively. (My understanding at the time was that said fan was part of a rest room in one of the support vehicles and not a “latrine,” but why mess up a good narrative, right?)To my knowledge, neither ventilated latrines nor RVs full of recording devices are part of a typical Army unit’s table of allowance, so I really doubt there was much of a fratricide threat there. However, the bottom line was that this particular piece of partisan reporting beat the crap out of a program that I believe the Army needed, but already was facing a few developmental issues, and helped hasten its cancellation.(The New York Times opinion piece linked to above was equally laden with innuendo and assumptions. It made a fair point about possible anti-radiation attacks it might have invited… but there are radars on every battlefield, and there are means of controlling emissions. It compared a late-Fifties era Soviet system — the ZSU-23–4 — with one fully twenty years newer in design. It asserted that it couldn’t hit fixed-wing aircraft, which to my mind and personal observation was arrant nonsense. The only issue it raised that I agree with was possible NATO compatibility problems with the unique 40mm caliber shells the Sergeant York’s guns fired. Funny — the Times pontificated that it wouldn’t be cancelled, too. Oops.)Third, the hydraulics that were used in the prototype were a 3000 psi system that really couldn’t handle the weight of the turret in its Awesome Hosing Things mode. One of the only times I actually got a score on the system was when I cheated; I deliberately exploited that vulnerability. I flew straight toward the system (which would have blown us out of the sky about twenty times over had I tried to do so for real) until directly over it, then tried to defeat the system from above.If memory serves, the system specifications called for the guns to elevate to more than 85 degrees if something was coming up and over; it then would lower them quickly, slew the turret 180 degrees around, and raise the guns again to re-engage. It was supposed to be able to do that in perhaps ten seconds (but I’m here to tell you it did it a lot faster than that). So, I had my flight engineer tell me the moment the guns dropped, at which point I did a course reversal maneuver to try to catch it pointed the wrong way. What the video later showed was:Helicopter flies over.Traverse/re-acquire movement starts.Helicopter initiated hammerhead turn (gorgeous, if I say so myself).Guns started to elevate to re-engage.Clunk. Guns fall helplessly down; DIVAD crew uses bad language.The hydraulics hadn’t been able to support the multiple close-on, consecutive demands of movement in multiple axes and failed. Like I said, I cheated. The Army and the contractors already knew about this problem and were going to fit out production models with a 5000 psi system. That might have had some survivability issues of its own, but the Army was perfectly happy that we’d done what we did — it proved the test wasn’t rigged and underscored the need for the production change.Finally, the Army itself honestly appraised the system based on its progress (and lack of progress) versus their requirements. Wikipedia provides a passage that encapsulates this end-game well: “The M247 OT&E Director, Jack Krings, stated the tests showed, ‘...the SGT YORK was not operationally effective in adequately protecting friendly forces during simulated combat, even though its inherent capabilities provided improvement over the current [General Electric] Vulcan gun system. The SGT YORK was not operationally suitable because of its low availability during the tests.’ ”I guess I’m forced to conclude that the Sergeant York was a really good concept with some definite developmental flaws — some recognized and being dealt with, perhaps one or two that would have made it less than fully effective in its intended role — that was expensive enough for bad PR to help bring it down before it fully matured. The Army was under a lot of political pressure to get it fielded, but to their credit they decided not to potentially throw good money after bad.On balance, a lot of the contemporaneous criticisms mounted against the M247 really don’t hold up very well over time. Short-range air defense currently is provided by the latest generation of the AN/MPQ-64F1 Improved Sentinel system. Radar emitting on the battlefield? Check. Target prioritization capabilities? Check. Towed (which equals “slow”) versus self-propelled? Check.I’m glad we never wound up in the position of needing it but not having it. My personal judgment was and is that it probably could have wound up a heck of a lot more capable and useful than its developmental history might suggest, but its cancellation probably was justified given other acquisition priorities at the time.Bottom line: I repeatedly flew a helicopter against it over the course of many hours of testing, including coming at it as unpredictably as I knew how, and it cleaned my clock pretty much every time.