Flight Log for 1 September 1997, 60 Acres Park, Redmond, WA


Thudershowers in the early morning gave way to scattered altocumulus and high cumulostratus, wind 2-5 and variable. We flew an informal Spot Landing contest, but the early bad weather limited attendance. Michael Park, of Seattle Rocket Works, was present shooting video tape for an upcoming Cable Access program.
Model Flt
#
Recovery Type Motor Comments
Bertha-24 16 12" plastic parasheet with spill and vents Estes B6-4 This was my first Spot Landing event flight -- after careful pad adjustment, off it went on the usual reliable Bertha flight, to land exactly 50 feet from the spot for the first score of the day.
Bertha-24 17 12" plastic parasheet with spill and vents Estes B6-4 Second try, with a tiny wind shift and small adjustment to the pad, was even better -- after boost, weathercock, coast, and drift on the parachute, the rocket landed 38 feet, 1 inch from the spot -- eventually good enough for second place.
Super Firefly B/G 3 Glide with 18" streamer in pod Estes 1/2A3-2T With a completely redesigned latch between the pod and the glider, this time it stayed together during boost. Unfortunately, there was too much decalage, leading to looping during coast. Separation was clean, but part of the wadding caught on the glider's stabilizer, leading to a Red Baron.
Super Firefly B/G 4 Glide, with 18" streamer in pod Estes 1/2A3-2T After retrimming the glider to use much less decalage and correspondingly reduced nose weight and wingtip weight (for turn), hand glides were good; again, the glider stayed together on boost, indicating that problem is solved, but again there was some looping during coast (though less than previously -- adjustments helped). This time, there was no interference with the glider, and it settled into a slow, floating glide on the bare edge of stalling: exactly what's wanted for best duration, as I understand it. Turn was acceptable, with about a fifty foot turning circle, and there was no damage on either flight. Further refinement is simply a matter of adjusting for the absolute minimum of decalage to minimize looping at the high speeds of boosted and coasting flight, before separation. I may also need to add a small amount of clay to the pod nose cone to help this, but the concept of the paper covered, framed wing for 1/2A boost glider seems (to me, prior to a lot of flying) to be proven -- at the least, this can yield a good looking glider with good performance at a minimum of effort, comparable to that needed to cut and sand a solid wing.
Fat Fat Boy 3 18" plastic parasheet Estes C6-5 + 2x Quest C6-0 For this flight, I loaded two of the outboard tubes with booster motors, and put an adapter in the core motor mount to accomodate an 18mm motor there as well. After carefully prepping (to maintain cluster compatibility, I used Estes igniters in all motors), I tested continuity in each igniter separately before twisting the leads together and putting the rocket on the pad. On ignition one motor ignited late, and the resulting unbalanced thrust caused the rocket to gyrate wildly until both outboards were past their thrust peaks. Unfortunately, when the rocket settled down to stable, straight flight, it was pointed about ten degrees above horizontal and approximately southwest, toward another group flying rockets in that corner of the park.

The rocket impacted the ground before ejection, and fortunately fell about fifty feet away from the other rocket group; the only damage was a single fin stripped off clean at the surface of the body tube, and the nose weight shaken loose inside the nose cone. Both outboard motors ejected on burnout, as I expected they would, and both casings were recovered, allowing me to verify that all three motors did light; the fact that one outboard was recovered near the pad, and the other near the impact point of the rocket, serves as proof of late ignition of one motor, rather than simply an unstable rocket (my VCP calculations indicate that this rocket could be flown with 4x18mm C mootrs and remain stable with the one ounce of nose weight I have in it).

Cherokee-D(2) 4 12" plastic parasheet Estes B6-4 Another low, relaxed flight on the Cherokee-D -- if I can keep from losing it, this could become another "old reliable" like the Bertha-24.
Cherokee-D(2) 5 12" plastic parasheet Estes B6-4 This was the last flght of the day; the glider guiders were starting to get antsy about us using "their" part of the field (even though we set up in the last drops of the thundershowers, and they didn't start to apppear until almost noon). I assured them that I'd launch this last flight, and then leave. The flight was one more perfect flight to chalk up to the Cherokee-D -- a design that was impossibly cool when I was in rocketry the first time, in the early 1970s, and still is.



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