2.75” Rocket Range
submitted by: Alva Leon Matheson
There wasn’t much for the US FACs to do except VR and VR and VR a lot. In fact we even wrote the ‘Tum FAC Song’, which mainly tells about our ability to VR and VR and VR a lot.
On one of these endless VR missions, I decided to find out how far a 2.75-inch rocket would fly if fired at a 45-degree angle. Since Binh Dinh province was right on the coast, I figured the place to do it would be over the South China Sea since I wouldn’t have to worry about accidentally hitting anything on the ground.
I started flying east following the 090 radial off the Phu Cat AB TACAN. Just as I was about to go ‘feet wet,’ I rolled inverted, lowered the nose to build up some airspeed, and then rolled upright and raised the nose to 45 degrees and hosed off a rocket. At the same time I hacked my watch so I could measure the rocket’s time of flight (TOF), and noted my DME (distance) from Phu Cat.
I then continued flying east watching for the plume of white smoke in the ocean. Visibility was good but not great (perhaps three miles), with a lot of haze over the water. I kept pressing east and finally saw the plume of smoke billow up in the distance (TOF = 95 seconds). As I headed towards the smoke to overfly it and measure the rocket’s range, I started to make out the silhouette of a US Navy destroyer in the haze. As I got closer, I saw that my rocket had landed about 1⁄4 of a mile or so from the destroyer.
I immediately decided that I didn’t need to overfly the rocket’s impact point or the destroyer and did an immediate 180 and headed back towards Phu Cat AB, all the time wondering how much trouble I was going to be in for launching a rocket at a Navy destroyer.
Fortunately, when I landed, there was no committee waiting for me on the ramp, and I never heard anything about it. But I’ve always wondered if in some USN archive somewhere there is a destroyer’s logbook from early 1970 reporting taking enemy fire while sailing off the coast of Vietnam. Perhaps some destroyer captain got a Bronze Star because of me.
In a couple of weeks I got up enough courage to try my experiment again. Only this time I first flew out the 090 radial for about ten miles and checked for ships before coming back to the coast to fire the rocket.
Results: A 2.75-inch rocket fired from 1,000’ AGL at a launch angle of 45 degrees has a range of seven miles and a TOF of 95 seconds.
Cheers,
Gary Dikkers