BLUE MOUNTAIN ROCKETEERS DISCUSSION FORUM

Saturday, October 24th, Heppner Oregon:

Considering all the building I've been doing since August, I wanted to get just a FEW more flights in before winter really got nasty. I *would* have headed for Mansfield this weekend but....Darrell was busy and I wasn't looking forward to camping in 30-35 degree weather, or getting rained on neither. So....

One of my customers (Mark Wunderlich) manages a very large stretch of hay bottom along Willow Creek; approximately from the Heppner reservoir (just east of town), 15 miles up the creek to the Umatilla National Forest boundary. The Wilkinsons also own thousands of acres north and south of the creek, and there are no other major land owners for some miles in any direction. I'd mentioned to Mark about a year ago that I was looking for a place to fly some of my bigger projects, and he was quite enthusiastic about it; as long as I took reasonable precautions to avoid fire danger, he was perfectly willing to host launches.

We tooled around up and down the canyon Thursday, and finally decided that the hay field east of his house was the best spot; it's about 3600 ft between his place and a house he rents to his neighbor up the creek, with perfectly flat ground about 500-700 ft wide most of that length. Farther to the east, there is another 3000-5000 ft. of valley bottom. The county road is about 1000 ft north of the creek bottom, with a 14KV power line in between. The county road is normally empty, but this is the tail end of bird season so there was a little more traffic than usual. LOTS of space beyond the road north, as well as south of the creek, and all owned by the same people. In other words, an almost ideal launch area for anything up to about the FAR 101/Class 1 limit.

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I got everything prepped ( I thought ) Friday night and headed out for the ranch about 8:30 AM. This was strictly an private launch; Mark and one of his hired guys were the only people on the field (recovery crew!), and a few more of his crew and a friend of mine from town parked up along the road to watch; roughly a dozen people at most. Wind was pretty consistently about 10 mph out of the west, so it was more or less blowing straight up the canyon toward the neighbor's place.

I set up three launch pads: an 1/8", 3 ft rod for the models, a 1/4", 4 ft rod for mid-power, and a 4ft rail (Thanks Tim!) on a heavy tripod for my big rockets. Then I strung out the 100+ ft of cable for the launch system from the pads back to the car. After some battery fun, I was ready to go.

1. First, to see how far the wind was blowing stuff, I sent up my 1.6x upscale Sprint on a D12-5. Nice and straight, good deploy, and it landed in the middle of a horse pasture at the end of the hay field, about 1200 ft east of the pad. Ah well, if nothing goes farther than that....

2. I attempted to fly an F40W in my new scratch-built Weasel; the motor had failed to light at Rolling Thunder in September. I'd taken it apart Friday night, sanded on the slot inside the grain a little, and put it back together, but.... No go. The igniter chuffed once again and failed to light the motor. Ah well.

3. The rebuilt Hod Carrier 4, on an H123W. Mark and his hired man were somewhat familiar with models, but this was a new experience for them, heh-heh. It's always nice to watch a newcomer's mouth drop open and slowly mumble out 'Holy Sh....'. Glad I didn't leave this one til last!
I'd forgot the altimeter sled at home, so this was strictly an integrity flight. LOUD hard boost off the rail, perfectly straight up, perfect deployment. I'd put a 36" chute in it, but without the altimeter hardware the rocket only weight about 2 lbs. The wind was had kicked up a bit, and the rocket ended up about 3/4 of a mile up the creek in another hay field. No damage, no problem, everything intact.

4. After that, it was time for the real 'research'. Next I wanted to do some altimeter flights (the PerfectFlite Alt15K) in my '18skin II'. Loaded up an A8-3, and lit it off. Everything worked, streamer out OK. Altimeter beeped out 207 ft; and considering my simulation was 209 ft, I was pleased.

5. Same rocket, this time with a B6-4. Good lift off, but the motor ejected out the back (broken retention bolt) and the rocket came down seperated, but without the streamer out. Landed on the nice thick grass, luckily, and the altimeter was still beeping happily: 662 ft, considerably over my sim of 614.
Some of that may have been extra altitude produced by the kick from the ejected motor, but this still implies a C.d (coefficient of drag) of about .45-.50 for this rocket. After a repair job, maybe I can fly this on some bigger stuff.

6. I wanted to fly some more BP motors with an altimeter, but... I'd forgotten to attach launch lugs to my well-worn HCX-13, a BT-50 sized model a little bigger than the 18skin. On to the next thing, then...

7. The 24skin, using the new 24/60 Aerotech casing. The only load for this right now is the F35W, and I'd rolled one (11 second delay) the night before. Loaded up the Alt15K, and boom! F35W's are VERY loud for their size, comparable to the F40 and G64. Good straight boost again, good streamer deploy. Wind was now blowing across the canyon a little, so it landed about 20ft on the other side of the county road. No damage, no problem. Altimeter beeped out 3182 ft, compared to a sim of 3502.

8. Repointed the launch pad, reloaded the 24skin with an E28-7W. Another load snarl off the pad, another good straight boost. This time, it drifted down in between the creek and the 500ft hill to the south, and landed about 200 ft from the car. Easy! Altimeter indicated 2377 ft, once again quite a bit under the 2611 in the sim.
These results imply a C.d of about 0.9, which is certainly different from the 18mm rocket above. Finish and fin contour must have a lot more effect then you'd think; this rocket is much 'rougher' on the tail end than the smaller one.

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I wound up about noon; my hosts were gone to ranch business and I'd only obtained permission for the morning. But generally the weather was excellent, wind not too bad; a great launch site if I can just get anything to land on it.

- Pat Struthers