Sunday, May 11, 2008

5-10 launch report

This was a small FAA notification launch. This is a central CT field, about 125 acres filled with trees and wetlands including a substantial stream. The weather conditions for the day were predicted to be: 30% chance of rain, cloudy, with winds 10 - 20 mph. The actual conditions were a bit different: winds were gusty and lower at ground level, around 5 - 15 mph, but seemed to be a constant 10 - 15 mph at altitude. There was significant flooding from previous rain, the field was loaded with water (but that was not a huge problem and provided a few comical "splashdown landings".) Around 1:00, the sun came out and it was suddenly a perfect day with somewhat reduced wind even. I was able to fly three rockets, burning a total of 5 motors (out of 7 attempted). All rockets came back in one piece, so that is the most important result. No hardware was lost or damaged. The first three flights - E11J in the SNP, F39T in the LOC Graduator, and D15T in the SNP again were perfect. The final flight for the day, a 4xD12 cluster in the Viper did not go exactly as planned, but the rocket was fine.

This is my SNP discussed previously, ready to go on an E11J-4. What a perfect flight! This motor was very old (5 years maybe?) and had some irregularities in the burn, but overall it was the perfect slow, graceful flight. I have one left, and three F12Js... and cant wait to use them again.

The LOC graduator here is ready for a nice flight on an F39T-4. This was a concern for me for several reasons. First, this rocket is getting old (20 - 30 flights over 9 years) and also getting very heavy. I was worried that the F39, essentially an E39 with a bit of extra power, wouldnt quite cut it. Also, the launch lug and rod didnt seem to get along for some reason. I had this problem on my viper as well, clearly I need to sand or even replace the lugs on these rockets... along with lots of other changes I need to make to upgrade my hardware for next time. In any event, with some sanding, the flight was great. Nice and low, but perfectly safe with great recovery. I will continue to fly this combo in the future.

This is a general view of the launch pads - this was a small event with 15 "pads" on 3 racks. The inner two are low and mid power, the outer pads are for higher power - 1/4th inch and up, and a rail.

Here is the motor block on the attempted 4XD12 flight. Not only was the launch lug too tight for the 1/4th rod (I was lucky enough to be given a 3/16ths, a pretty risky allowance I have to say!), but as you can see only two motors lit. My igniter setup was a bit sloppy, I will admit, and though it worked last time for 5 motors, this time it didnt work out. Next time I will have to do a better job, clearly. In any event, one motor lit right off, and the rocket was getting tossed off the rod to basically crash land. Around the end of the rod, the 2nd motor lit, and was just enough to launch the rocket to between 50 and 200 feet (yeah I was that nervous). The 3 sec. delay saved the rocket, and the chute ejected with a matter of feet to spare. The rocket was safe, but the two unused motors got wet and had to be destroyed. A small price to pay. But this is a good lesson, next time I will do a better job.

Overall, a great launch. Good to be back. I may attend a launch next month, check back for more updates.