Launch Report Spring WELD, April 13-14, 2013

We enjoyed great weather this weekend, and a spring WELD without drenching rains and high winds is a rare event, indeed.? The temperatures on Saturday were in the low ?60s, with winds out of the west and northwest at a brisk speed, but pushing everything out over the emptiest part of the field.? Sunday was even warmer, even calmer, and totally without clouds until we had finally packed the trailer.? Just a few words about the origin of the name WELD for our semi-annual Tripoli Research weekend event:? WELD stands for Whitakers Experimental Launch Days, and these were originally 2-day Experimental events held annually, usually in the spring of the year.? The Whitakers field, and the Tripoli North Carolina, Tripoli East NC, and Tripoli East Virginia clubs that flew there, was the first venue east of the Mississippi to support TRA Experimental launches when the parent club first began to sanction that activity back in the 1990?s.? The original events, called SmallBALLS in imitation of the big daddy of all amateur Experimental rocketry launches, held on Black Rock Desert in Northern Nevada every year, was extremely popular and drew flyers from all over the eastern half of the United States.? The SmallBALLS events were really, REALLY big deals, and it was just such an event that was my first exposure to high-power, back in the autumn of 1997.? In the early 2000?s, Dennis Hill, Jeff Taylor, Kelly Mercer and I went to a twice-a-year schedule and changed the name to recognize our own field.? For those of us who actively engaged in Experimental rocketry (or ?Research? rocketry, as I should be calling it) Whitakers will always occupy a special place in our hearts, not only because of the monumental flights we saw there, but because of the people we met there who changed our lives, people like Jim Mitchell, Mark Lloyd, and Ben Russell.

After the motor use summary, we will discuss a few individual flights.

The big event of the weekend was the flight of Jim Livingston?s Viper, which had been equipped with three 4? diameter side pods in which were housed 3 x 3? diameter L motors.? The central motor was a 5-grain 115mm diameter N motor, and all 4 motors were mixed up from Jim?s white-smoke propellant and they were all lit on the ground.? The combination produced 26,466 N.s of total power, and so this flight is classified as the lone O motor flight of the weekend. ??The whole package weighed 156 lbs on the pad, and achieved a Vmax of 953 feet per second at 4.7 seconds into the burn and coasted on up to 8500 feet before recovering perfectly.? It was a magnificent performance!

Jim Livingston’s Viper launch, photo copyright (c) E.E. Schnegelberger

Eric Fadely was also on the scene this weekend and made a number of flights with his own white-smoke propellant, which has unusually fast burn characteristics.? He flew his Scratch Built twice on this formula, once on a 38mm motor and again on a 54mm.

Mike Collier brought back a beautiful scratch-built rocket called Double Diamondback with an ornate set of fins in a double diamond pattern.? Unfortunately, there were some problems with the main parachute and the assembly landed hard enough to break a fin.? It looked fixable, to me, so I have every expectation of seeing it again at another launch soon.? It really is a lovely rocket.

Ray Bryant was bringing sugar motors to the pad as fast as he could prep them, and he experienced zero CATOs!? He?s really getting good at this sugar-motor thing.? With the aid of the flight cards, I recall very successful flights using 5 grain 29mm, 6 grain 38mm, 4 grain 54mm and 3 grain 76mm motors, all of which used sorbitol.? There was another, less successful flight of the Orange Crush using a 2 grain 54mm motor made from potassium nitrate and dextrose.? This motor produced a ton of smoke, crawled lethargically to the end of the launch rail, and completely lost oomph about 18 inches off of the rod.? Fortunately, it didn?t have far to fall.

Scott Schnegelberger has been flying his Thing One at Bayboro and Orangeburg for a few years now, and it has become an accomplished work-horse.? On Saturday, one of Scott?s altimeters suffered some manner of serious malfunction during a flight on one of the Cesaroni J425 Blue Streaks, and there was a lot of damage to the airframe.? Once again, the damage looked repairable, and I will bet that we see that one again, also. [Update from Scott: no altimers malfunctioned or even fired any charges — the J425 is ‘strong’ enough off the pad that I should have put the heavier nose cone on it. It started turning sideways about 0.2s before motor burnout and basically sheared apart, zippering 2/3 of the upper tube and dumping out the main parachute. I repaired it a week later and flew it again at Bayboro on April 27, so it’s earned its name back!]

Chuck Hall, Charlie Goble, and Eddie Haith were also present and flying a lot of rockets in the G through K range.

Sunday was a lot more relaxed, only 3 people flying rockets and Jim Livingston running the show.? Ray Bryant made 3 flights, 2 sugar motor flights described previously and a small Patriot on 2 E20?s.? I (Alan Whitmore) flew my Stealth Blue on a homemade 3-grain 76mm small L to 9056 feet.? This flight had a Raven on board that reported 1080 feet per second Vmax, so the next flight, on a 4-grain full L, has a good chance of going through the sound barrier.? [Historical note:? Only people older than a certain age refer to Mach 1 ? the speed of sound at sea level ? as ?the sound barrier?, because we are the only people who remember when that is exactly what it was, a real barrier, one that could not be penetrated with the available airframe construction techniques and propulsion technology.? In the 1980s and 1990s, a few airlines flew the SST around the world, offering well-heeled customers the opportunity to fly to London or Tokyo or Sydney faster than the speed of sound, but in the 1940s, transonic manned flight was a BIG DEAL.]

Eric Fadeley flew his 5.5? diameter Scratch Built on a homemade 76mm L motor made from the ?Tiger Tail? formula.? This was a very impressive flight and was recovered perfectly.? This rocket has flown several times at Bayboro and at Price, MD, and it?s about time for this one to get both a paint job and a decent name.

I finished the day off with a flight of my semi-new Extended Irene on a new homemade 29mm H motor using the Black Velvet propellant.? The adjective ?semi-new? comes from the fact that the fin section of this rocket was last flown at LDRS 19 in 2000.? It sat over behind my desk at home, getting in the way, until I decided to do something with it in early 2013.? At that time it flew as a ?parachute at apogee? device on single-use F and G motors, so I built a new forward section and electronics bay for 2-stage recovery and flights on H motors.? Then I made a new 4-grain 29mm homemade H motor and flew it to 1442 feet for its first flight.? A larger 6-grain motor is being made now.

I?ll see you all for the last launch of the season on the weekend of April 27-28 at Bayboro.

Alan Whitmore

Prefect, Tripoli East NC