Wednesday, August 31, 2016

Comparing Free Flight and RC Sailplane Contests

I enjoy both outdoor free flight and radio control sailplane competition, in both types of competition you must have your model aircraft flying in rising thermal air currents. The rules and the nature of the aircraft differ between the two types of model aircraft competition.

Winch Launch RC Sailplane
Altitude Electric RC Sailplane Contest

In RC soaring contests you are required to launch at your specified time to fly. The height of the launch is pretty close for everyone. If it is an altitude limited contest by using an altitude sensing device in an electric powered sailplane all launch heights should be close to the same. If launched by winch the height can vary based on the zoom obtained after releasing from the winch line.

Glow Powered Free Flight Launch

Free flight airplanes are normally limited by the engine or motor run; be it glow engine or electric motor. Rubber powered free flight can have limitations on the amount of rubber used to power the airplane. Unless it is FAI free flight competition which uses a series of rounds in which you must fly once within the round and wait until next round starts before making another flight; you are free to launch any time you want.

Free Flight Discus Gliders in Thermal

 Discus launch height in both radio control and free flight is whatever height the pilot is able to throw his sailplane to.

RC soaring scores are normally adjusted based on a factor of the best flight time for the pilots flying at the same time.  

In free flight you are pretty limited where you can launch your model. With RC sailplanes you are limited where you launch but after launch the sailplane can be flown anywhere to search for thermal lift.

FF Glider Launched Within Glider Pen Area

What does this all mean as far as strategy of the contestants in either event? Basically in free flight you try predict as closely as possible when strong thermal is passing through your immediate area and launch, hoping the airplane will continue to circle in the thermal for a max flight.  In RC soaring you launch when required and direct your sailplane to find the thermal lift often a fair distance away from launch.  The signs you look for are often other sailplanes or birds climbing in lift or the blowing of tree leaves in the distance. Free flight contestants often use a variety of tools to measure temperature and wind speed as well as using Mylar streamers and blowing soap bubbles. They watch other airplanes as well often resulting in a bunch of airplanes in the air at once.

Wind Speed and Temperature

Both types of model competition are challenging and fun for the contestants.

Bill Kuhl

My Related Videos Nats 2016 Free Flight  Electric Sailplane Introduction   RC Sailplane Electric Winch Launching

Monday, August 22, 2016

Too Wimpy for Competition

After my poor contest standings in a local radio control soaring contest yesterday and in free flight contests before that I have to admit my not taking chances might be one excuse I could use.  In the RC soaring contest it appeared that the longest flights were by those that flew downwind after launch while I was trying to find lift upwind. An experienced pilot told me the thermals were coming across the field and shearing off at the tree line behind us. 

With sailplanes that have better glide ratios and penetration than my Sig Riser 100, going far downwind is normal for a Supra but pilots with lesser performing sailplanes were doing it too. After crashing into the low branches of a tree with my Gentle Lady a couple of years ago I seem to have become more timid about going downwind off the field.  I watched in amazement yesterday as Ali and John S. flew over the trees for extended periods. 

In the free flight contest flying I have done recently I have no backup airplanes so if I lose one I am done for that event. In addition I have no tracker system. On my P30 airplane that has put in respectable flights I have not worked with the viscus DT system enough to be able to set it for a flight time over 2 minutes. My airplane is using stab DT which I understand is not always adequate for strong thermals to bring the airplane down. As far as finding the thermals I do not have the patience or experience yet.

NJAPF P30 Free Flight

Yes, I have plenty of excuses and could come up with more. More importantly I am having fun and learning all the time.  If it was too easy that would not be fun either, I remember flying in a lesser RC pylon racing event for a time in which I won every race for a time. That wasn’t much fun and I switched back to the more competitive event. Flying so many different aspects of model aviation no doubt lessens my focus on a particular aspect but I enjoy the variety.  

For the last two flights I switched to a different glider that turns and penetrates slightly better. On the last flight I caught some lift off launch and then went downwind over the trees.  My timer said I thought you were going to have to land two minutes ago; I came down at 4:57.  I was happy with my performance on that flight. 

Almost as much as participating in model aviation, I enjoy writing about it and sharing the success of others.  As I meet more people in model aviation they tell me they enjoy reading my blog posts. Thank you, that keeps me going.

Bill Kuhl

Tuesday, August 16, 2016

Minnesota Free Flight Contest near North Branch MN

This past Sunday I made the trip to a monthly contest of the MMAC free flight club at their flying site near North Branch Minnesota. I had been there once before several years ago but believe they were flying from a different section. There is a lot of area but besides sod there are crops as well. My flights never made it into the crop area. For me this is over a two hour drive one way and there was a big detour that extended the time. Earlier this year I was planning on going but the weather was bad on contest day.

When I arrived I made some test flights of my Pearl e202 after doing repairs on the stab after the Nats, flights were pretty good but I think I need adjustments yet on the power phase of the flight. This was their mostly silent meet so there was a lot of rubber models, gliders, and a couple of glow powered airplanes. I flew P30, scale, and HL glider. 

It appeared that there was some lift in the morning but it was more consistent in the afternoon.  My last P30 flight was made in the afternoon and it landed fairly close to the edge of the grass area of the field. I was well satisfied as I do not have a tracker. Dave Edmondson had his P30 land a couple of miles away and it was found by using the tracker.

I spent a great deal of time flying at this contest but didn’t get as much time to spend on taking pictures and video as I would have liked.  One person I met has corresponded with me through the Internet. Steve had a beautiful Korda rubber model that uses the rubber band burning DT system.  It looked like a good combination of old tech and new tech. Gary Oakins had a really nice power flight that had people wondering if the DT was going trip, see flight in video link.

Bill Kuhl

Videos from the Flying

Dave Edmondson Hustler 750  -

Embryo Take Off -

Long Glow Flight -

Wednesday, August 10, 2016

Nats 2016 Flying Part II

Besides E36, I flew in three other categories; catapult glider, HL glider, and P30. Catapult was a last minute decision, I just put a hook on the front of a hand launch glider I had. The glider had no DT and I was afraid of losing it on a test flight right before the contest. My first contest launch went straight up and straight down crashing in the glider pen but no damage. For the rest of the flights I used a Vartarian glider. I didn’t wait very long for what might be good thermal air and flights were pretty short.

Catapult Glider Flyers

After my official flights I tried the first glider again. Several not so good flights and then it connected with a thermal. The glider circled and drifted down the field, I took up chase in a golf cart. I was beginning to think the glider would be lost forever as it was getting rather high; but it started a downward spiral to the ground.

HL Glider Event

HL Glider which is mainly a discus launch event had some stiff competition but at least I had a glider with a fair amount of flying on it but always with short DT set. During the time period I made my official flights the sky was overcast, probably not great thermal conditions. Some of my launches were pretty good, others not so good. When I try to launch really hard my coordination seems to suffer, at least I had one flight of a minute.

My Dynomite 

The designer of the Dynomite glider I was flying Stan Buddenbohm was there as well as other top notch competitors such as Tim Batiuk and Jan Langelius . Just from a quick glance, Stan noticed my stab had a warp in it. When I stopped by later I noticed several gliders circling in a thermal, what a cool thing that was to see.

Stan Launching

Gliders in a Thermal

P30 Rubber Event

Friday which was the final day was the P30 event and the weather was really nice. Several years ago I had built the Al Lidberg beginners P30 NJAPF but just this year I added the DT and flew it with several hundred turns on the rubber motor. I flew from small fields and set the DT for no more than 30 seconds to keep it on the field. Before going to the Nats I was busy with College for Kids class and did not have a chance to test the DT for a two minute flight.  I wound the DT up much farther than I had before but this resulted in the DT deploying at just over a minute bringing my plane down too soon where at least one flight might have been a max. Still I was happy how well it flew and was worried I might lose it with a stab DT and no tracker.

My NJAPF P30 Model

Bill Kuhl

Monday, August 8, 2016

Flying my E36 at 2016 Nats

Although we (Dave Edmondson and myself) arrived on Saturday evening, first flights at the 2016 Free Flight Nats were on Sunday morning. My first flights were with my tip launched glider Dynomite; flights were pretty short but the trim appeared to be good. There were a couple of people in the immediate area flying E36 models. Jack Murphy parked right next to us and graciously helped with getting some short flights on my Pearl E202. He placed a washin wedge the right wing panel. The power pattern seemed pretty good but the wind was increasing so I put the model away before the end of the flying day.

My Pearl E202 E36 Model

Tuesday afternoon I spent some time trying get in some short flights. If the launch was to the left the transition appeared to be better than to the right. Flying to the right the glide would become too steep resulting in a hard landing. On one flight just as I started the motor the propeller came off, I gave up searching in the grass after several minutes.

Hank Nystrom found me the next day and was able to produce the correct size folding propeller by switching some blades and hubs. Later in the day Dohrman Crawford who I had only known through the Internet helped me fly my E36.  As he looked at my model he noticed some warps so he borrowed a heat gun and we found a spot with electricity near the runway in the middle of the field. Dohrm twisted the wing and I used the heat gun, it got rather hot for Dohrm holding the wing. 

Dohrman Crawford E36 in Flight

Jim and Dohrm Retrieving my E36

I did not have the DT rigged properly so the stab was only going up maybe 35 degrees. After only 8 second motor run the airplane with a real short DT my plane started a really tight circle that was obviously in a thermal. It kept going up, after a couple of minutes I was worried that I might never see it again but then it started to come slowly down. Dohrm and Jim Jennings were ready to chase after it with a motorcycle but it came down just before the road next to a bean field. When we returned Dohrm and Jim re-did the DG system on my model.

With Jim Jennings and Dohrman Crawford

The next day after Dawn Unlimited event I made more flights with Dohrm’s help and worked up to a 15 second motor run and 30 second glide. To flatten out the glide the battery was moved way rearward. However my flight attempts later in the day resulted again in too steep of glide and damage to the airplane. I noticed the metal stab adjustment screw appeared to have changed; I now have a nylon bolt. The nut in front of the motor housing was loose so maybe the vibration had changed the incidence setting.

At home while repairing the minor damage to the wing, I decided to inspect the entire airplane over and found several breaks in the stab structure after removing the covering. As the stab has been warped up towards the tips for awhile, no doubt the breaks did not just happen in the last hard landing. No doubt this might explain some of the trouble I have had in getting consistent flights. I have much to learn but enjoy the challenge of it.  Flying a faster power model is much different than a rubber model like my P30. I saw several other electric models crash over the week.

Someone Had a Crash Worse Than Any of Mine

Bill Kuhl

Related Websites

Texas Timers - Supplier for Electric Components

Pearl Free Flight

Friday, August 5, 2016

Competitor and Writer at Free Flight Nats 2016

Last week I spent a wonderful week in Muncie Indiana at the national headquarters of the Academy of Model Aeronautics. I flew in a few events and also was recruited at the last second to take pictures and write short articles for a daily publication published during the Nats known as “Nats News”.  I toured the museum and had the chance to meet Bill Pritchett education director in person. The weather really was great for the end of July and I never had to stop flying because of weather conditions. I had the chance to meet several people that I had only known through the Internet previously including; Hank Sperzel, Hank Nystrom, Dohrman Crawford, Jack Murphy, Norman Furtutani, Joe Mekina, and George Bredehoft. Several people mentioned they had read of my foam airplanes or my science activities.

I will be writing in more detail about the week and flying in different events. Below are links to picture albums and a few short video clips I took.

Sample of Nats News :
This is pretty much all the pictures and a good share of the video from Nats 2016    Old Gas Models    FAI    Large Glow Models    HL & Catapult    Rise Off Water   AMA Museum    Jetex   Electric Free Flight  Towline Glider   AMA Administration Building

Video Clips   Rise Off Water Rubber Model    Denny Dock’s payload model   Dawn Unlimited 36 Pearl    Large Glow Model entire flight   F1C Folder Flapper   Rise Off Water Gas Model Crash  Ruth Bane Launching Jim O Rielly Test Flight

Added 8-16-2016  Large Glow Free Flight Breaks Wing Dan Berry Payload Flight   Bob's Flight  Flasher on Dawn Unlimited  Jack Murphy Test Flight

Bill Kuhl