Alpha’s First Blow Down
By Al Garrett
Every HAWK Battery Assembly Section takes great pride in preventing “Blow Downs”. What is a Blow Down, you ask? Quite simply it is something that happens when the electronic signal gets to the circuit that arms the missile’s Electrical Power Unit (EPU) and activates the Hydraulic Fluid Bladder as well. In a perfect world, the EPU and Hydraulic Bladder are always activated simultaneously. No one knows why, but that is not always true with your classic Blow Down.Only HAWK Missile and Launcher technicians will know what a Blow Down is. And if they have never been around one, their concept will be vague. Alpha battery had been operational “on site” for about a year before we experienced our first Blow Down. I am proud to state that I was there and saw the whole thing. Here’s what happened:We had just prepared a missile for check out (We thought). Our Section Chief activated the Missile Test Shop and power would normally be provided to the missile under test by the Test Shop. In this instance the missile did not sound right. One of the technicians noticed that part of the wiring harness that goes to a jack on the gimbal ring was hanging down, not connected to anything. So he dutifully reached down and tried to plug the cable into the jack without really seeing what he was doing. Just then there was a tiny “pop”, not quite as loud as a cap pistol would make. And a tiny wisp of gray smoke was coming out of the EPU exhaust port on the bottom of the missile, just forward of the warhead. Someone exclaimed, “Shit, our first Blow Down!” The section chief argued that it was not really burning like it should (The EPU fuel stick burned like a cigar, from one end to the other). The gasses it produced turned a tiny armature through a magnetic field, thereby producing the missile’s in flight power supply. It did not have to burn for a long time, just long enough for the missile to close on the target and kill it.
I was unusually quiet (for me) when this started and I leaned on the guidance section of the missile wondering who would get to fill out the Report of Survey.All of a sudden, that little wisp of smoke turned into an orange flame about 14 inches long. It sounded like a train coming through. And we cleared that test area quick. I was in a position that to get out of the tent I had to go behind the test shop and leave though the back of the tent. But because of the winter weather, we had that sealed pretty well. In fact we had sand bags holding down the canvas of the tent. I had a helluva time getting out of that tent and I started to laugh at myself, my fellow technicians, and the absurdity of my situation. That thing burned for about three minutes. More smoke than one could imagine.Once everyone got out we assembled in a spot between the Assembly Area and the Ready Shack. The Gate Guard had noticed the large amount of smoke coming from the Assembly Area and had alerted the rest of the Battery. So we were stuck having to tell the truth right away. Sooner or later we would have had to deadline that missile because they only get one shot at electronic and hydraulic arming.At this point I want to switch to a new subject. Annual Service Practice. The Army spent a lot of money seeing to it that every Missile Air Defense Battery had an opportunity, on an annual basis, to fire a missile with their own equipment. The point was to be sure that the men involved in a sometimes slow and boring daily mission, got to participate in an actual live firing exercise. This provided everyone involved with confidence in their ability to do the job, as well as confidence in the complete system. In my career I participated in all aspects of ASP. I can tell you that there is nothing more difficult to pull off without a hitch as a “scheduled” missile firing. And no one wanted the result of all of the hard work and preparation to end with a Blow Down. The HAWK Launcher had some built in features which would preclude firing a missile in the wrong direction. It was called the Launcher “Cut out Circuits”. Most folks barely understood it. I will try to explain it here. First, there were the cut out clips that were placed under the superstructure of the launcher and therefore were out of sight. In an ASP firing application, the firing fan was extremely narrow so there were lots of cut out clips to be checked. There was an electronic way to check whether the cut out clips were properly installed. Then there was the Cut Out Override Switch. This switch allowed the crew to over ride the cut out clip ABOVE the elevation indicated on the switch. Normally, the launcher “setting of the Day” was 200 mils elevation and straight down the primary target line (PTL) in azimuth.The targets used in 1966, the year I was assigned as the Senior Launcher and Missile Technician, were small air breathing drones. These target drones would react quickly and dramatically to changes in wind direction. The computers on the Illuminator Radar, were constantly calculating (and displaying) the “Lead Angle and Super Elevation” data. Another expression for “Kentucky Windage”. The problem was that a missile could be forced into a cut out zone by the Illuminator Radar lead angle calculation. In this case, although everything is perfect, you get a Blow Down. And everybody walks around with a long face. As the Senior Launcher Technician I would be with the crew during final arming. By this point I was no longer “evaluating” them, I was part of the team. I would take one last look at the Firing Over Ride switch and pull it down to zero. Therefore, the cut out clips were overridden and there would be no Blow Down. As soon as the missile was fired I would stroll out to the launcher and reposition the Firing Override Switch to its correct position. No one ever was the wiser. And I did that forty times that year.In closing, let me tell you who have been to the Eighth Army Special Sea Range something I bet you didn’t know: All over the US Army, and probably the Air Force too, duty in Korea was described as “the Best Kept Secret in the Army”. Do you remember the large sign in the shape of an arc over the main gate? It said “Eighth Army Special Sea Range” in English. Just below those words were a series of Korean signs/letters which when translated, said “The Best Kept Secret in Korea”. 