Test Flying in Russia

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sgilkey
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Joined: Mon Mar 19, 2001 8:26 am

Test Flying in Russia

Post by sgilkey »

I’ve already posted about our experience at the Samara combat meet on the Debrief forum. I thought I would post some stuff here about our experiences with test flying, and seeing the workshops of our hosts.

The day we arrived in Samara, we dropped our stuff off at our hosts’ house, got settled a bit, and headed out to the flying field. Mike and Brian had brought their own planes and we wanted to try flying them if they were competitive. We had standard RCCA Open B planes, but in Mike’s case he had installed a Webra .32 engine, which added considerable speed and pulling power.
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For Brian’s planes, we had originally planned to bring his standard AVENGER 1072+ planes, but just before we left we learned that there are size restrictions on checked baggage which would make this impossible. It turned out that we had to clip the wings to 64 inches span so that they would fit in the box that Mike built for us- this box was to the maximum dimensions allowable. We had installed an OS .37 heli engine in one of Brian’s planes, and an OS .32 engine in the other.
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We brought our own radio gear on US frequencies (Russians fly on another band), and Mike brought a scanner so we could (hopefully) confirm our frequencies were clear. I brought Tx modules and crystals for every frequency we have, just in case.

We arrived at the field and promptly started reassembling the planes (we had to pull engines, batteries, fuel systems, etc. off when they were packed). This did not take too long before we were ready to fly. In the meantime, the Russians had been flying some of their planes. Here's what I would call a "nice rack!"
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When we watched them for the first time, I think the collective thud of our jaws hitting the ground registered on some seismographs in the Samara area. We had expected their planes to be faster, and maybe more maneuverable, and they were. WAY more maneuverable and WAY WAY faster! But we thought the toughness of our planes might be an advantage that would offset this.

The frequency scanner looked clear, so Brian took off for the first test flight. His plane was flying well and the OS .37 was pulling strong. However, now that we had more direct visual comparison of ours in the air compared to theirs, it was pretty obvious that ours would not be competitive. Their planes are EXTREMELY fast and maneuverable, capable of amazingly tight turns both inside and outside. They are mostly of a flying wing design (though some use a very close-coupled separate elevator) weighing about 1 kg (a little over 2 pounds). They are allowed up to 8cc (around .50) displacement but most that we saw today were running 5-6.5cc (.30-.40). There were a few OS .32SX and MVVS .28 engines, but these had been modified with custom heads which accept the Nelson glow plug.
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These mods really work- trust me, this plane was WAY faster than Brians which had a 32SX with MCP. Note they also rework the stock MA props (or use custom-made ones). They use the Nelson plug because it is more durable and reliable. Many engines are custom-built and all that we saw use either ¼-wave or full-length tuned pipes which they custom-design and build themselves. We did not see any tach checks but were told that typical front-line 5cc (.30) engines are spinning a prop of about 5 inches pitch at over 27k rpm. The wing span is about 1.2m (around 40 inches). Unlike the RCCA, they are not allowed to use sticky stuff on their wing leading edges, but they can and do use sandpaper. This is only allowed on the first meter of span. Their wings are of broad chord and their wing area is probably almost as big as our planes. They do not use longer span because of issues with roll authority and aileron flutter (again, their planes are WAY faster than ours). They typically use dual HS85 servos on the elevons and HS81 for throttle, with a 700 mah NiMh AAA 4-cell pack for Rx power. The planes are designed for rapid field repair/replacement of modular assemblies/movement of gear from one plane to the next. It is not uncommon for them to go through many planes in a contest. Our host told us they had built over 60 planes in preparation for this season!

The upshot of this technology is that the Russian planes are probably about 20-40% faster than ours. They also turn much tighter and more violently. They use a flying style that uses as much negative g turning as positive g, with extremely rapid changes between the two, a style not well suited to our planes. Based on the practice rounds we saw, the combat style is constant furball, with competitors taking jabs at each other as they swirl almost continuously. It did not appear that they engage in any form of pursuit flying- they tend to use fast, slashing attacks.

A heavy rain shower came in, forcing us to stop flying for about 1 ½ hours. After this, we continued testing and prop swapping. Mike also got his plane airborne. Unfortunately he was immediately hit by interference but managed to nurse his plane back. Once in the pits he checked the scanner and sure enough, his channel had been hit (which had not been happening previously!). Fortunately I had brought the spare crystals and a Tx module which I gave to him so he could switch to a clear channel. His plane flew fine after that. The Webra .32 which he had purchased only one week ago was pulling like crazy, and his plane was turning very tightly. At any RCCA meet his plane would have been a top-notch performer. But still, compared to the Russian planes, it was really no match.

The Russian fliers were very helpful and friendly. They work on a team system- one guy (the lucky one) flies, while there is an airframe builder, an engine builder/modifier, and a pit man whom they call the “mechanic.â€
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boiler
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Post by boiler »

Beautiful report Scott. Thanks[:D]
drewjet
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Post by drewjet »

Great reports Scott. I think you guys made a fantastic representation of the US. I feel much better about my addiction now after seeing how many wings are in their shop. WOW!
CStein
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Post by CStein »

Great pictures and sharing of your trip !!!! Thanks Scott
Hey whats the wing span on those planes ? root and cord measurements ?

Thanks Corey
sgilkey
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Post by sgilkey »

i did not get dimensions. their newer planes seem to have more area than the ones we flew. their chord is a bit broader and mostly constant (ailerons are tapered for flutter resistance) than ours so despite the shorter span their area is probably not much smaller than ours. coupled with the much lighter weight their wing area is much lower.
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Ed Kettler
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Post by Ed Kettler »

Outstanding write up Scott! This one needs to be 'packaged' and put on the web site so it doesn't get lost.
lyoha
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Post by lyoha »

If you want i posted or upload CAD drawing (laser cut templates and montage scheme) with "Yellow Vzhik" combat planes. Mike and brian seen this plane as a basic combat weapon of "Pilotage" team from Moscow. Dimension of drawing is metric (mm).
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