# A day at the Airfield



## jharkin (Nov 11, 2012)

With some warm late fall weather this weekend I took advantage of the time for some late fall flying at our local model airfield.

This is what I do when Im not burning or working on the house  


I only had my "small" fleet out flying... The big guns got left at home 







It doesn't exactly show in the photos but we had a pretty good crowd for a late fall day...






And the heli guys where out...







Of course the sun decides to come out right when I had to head home...












Packed up to go...


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## yooperdave (Nov 11, 2012)

Sure would enjoy seeing those in action.  Is the grey shed in the second pic there for a reason???  Like maybe protection??


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## jharkin (Nov 11, 2012)

The Shed is a leanto, we put it up last year for someplace to get out of the sun or a passing thundershower. It has benches inside and a storage rack for our radios.  The side walls swing up like awnings.


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## jharkin (Nov 11, 2012)

To give you an idea of why I say the little fleet... This is me with the "big gun"... Left it home this morning tho...


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## thewoodlands (Nov 11, 2012)

You had a great day for it, not many of them left, storm coming in the week before Thanksgiving.

zap


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## bioman (Nov 11, 2012)

Beautiful weather, Awesome planes, Way Cool !


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## Gasifier (Nov 11, 2012)

Cool hobby you have there J. Thanks for sharing the pics.


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## Eatonpcat (Nov 12, 2012)

That's cool. we have a little airfield down the road that has a setup for the remote planes.


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## Tramontana (Nov 12, 2012)

Pretty neat, thanks for sharing.  I've wanted to try RC, but I CANNOT have another hobby.

Cheers!


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## jharkin (Nov 12, 2012)

Definitely don't try R/C if you cant afford another hobby ($ or time wise)  its as addictive as crack.  Im on something like 25 planes in a dozen years... and I'm not considered one of the crazy ones he he he


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## Gasifier (Nov 12, 2012)

jharkin said:


> Definitely don't try R/C if you cant afford another hobby ($ or time wise)  its as addictive as crack. Im on something like 25 planes in a dozen years... and I'm not considered one of the crazy ones he he he


 
That is good harkin. Because when you belong to Scotty's "club" you *may* be considered one of the crazy ones here.  So at least your not on "the list" for both of your hobbies!


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## MasterMech (Nov 14, 2012)

jharkin said:


> Definitely don't try R/C if you cant afford another hobby ($ or time wise)  its as addictive as crack. Im on something like 25 planes in a dozen years... and I'm not considered one of the crazy ones he he he


 http://www.rcdon.com

He's one of the crazy ones, lol.  I've been following him for years.  He appears to have moved on from planes and pursue other, equally interesting projects, but I still love to watch a video or two of his planes in action.  My brother was into RC for awhile, but quickly decided flying full-scale aircraft was more his speed. (He wasn't even out of high-school yet!)


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## jharkin (Nov 14, 2012)

Yeah there is a lot of crazy out there... Ive seen RC Dons page before, his plane collection is actually quite tame compared to those jet engine projects (nutz!) he did. 

more craziness...

The guy with the Heli in my photos is an electrical engineer form MIT. designed his own on board charging system for the heli that runs an alternator of the gas engine - no batteries to worry about. He also has a plane that he and one of his colleagues setup with there own design video and telemetry link. Its got on board camera and a GPS that send a video downlink to his base station that displays all the GPS derived flight data (speed/altitude/etc) as a heads up display on the screen. the GPS also works with an autopilot that he can plan a flight path into, and they build a tracking system to steed the ground antenna to follow the plane for better reception. In theory they can fly it a couple miles beyond our visual sight, although our safety rules don't allow us to try it.

At the giant scale aerobatic meets it used to be that a 1/3 scale airplane was a big deal. Now the Pros fly 40% and even 50% scale (airplanes up to 45+lb, wingspans in the 10ft + range) and there was one guy down in Texas who built a 75% scale Extra 300.... weighed something like 300+ lb and flew on an Ultralight aircraft engine.  Ive heard of the jet guys going even bigger - there was a fellow in the UK who built a scale B-52 bomber with 4 turbine engines and a wingspan something like 50 ft. 

It had a spectacular crash however.

The big event for the big planes is the Joe Nall fly in in South Carolina. Its kind of a bucket list event for r/c  flyers. If anyone is in SC and wants to see some flying insanity the event is open to the public.

Me, I'm a little less crazy.  Ive just got my aerobatic planes and have a couple big projects lined up that should fill up my spare time for the next 10 years or so - a 1/4 Scale WWI German Albatros D.Va (like this) and a 1/5 scale P-51 Mustang (like this)


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## Gasifier (Nov 14, 2012)

That is a cool hobby you have there jharkin. Very interesting. Thanks for sharing. Now you have to add a pic or two of that VC Encore 2550 and/or those fireplaces throwing some heat.


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## Beer Belly (Nov 14, 2012)

My Dad who recently passed was into the R/C planes for as long as I can remember (I'm 52)....we grew up with airplnes hanging on the walls instead of pictures (really !).....my brother and I also flew with him for a while. The past few years (10 or so) he got into the big stuff....bought a van just to haul it. When he passed, we realized just how deep he was into it....he had close to 30 kits, which each Grandkid, or sibling grabbed, about 5 ready to fly....countless parts and Engines. We sold a few that were half built, and have a couple left over......a Stutka comes to mind that is too beautiful to fly...display piece for sure.


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## charly (Nov 14, 2012)

Flying is my passion as well. Took paragliding lessons 4 years ago, then switched to a back pack paramotor, then decided wheels would be easier. This is my instructor test flying my Green Eagle 4 stroke trike. 5 gallons of fuel gets you about 3 plus hours of flight time with plenty of reserve. Generac engine, 3000 hr engine life. Ashton from Texas has been building these going on four years with zero engine outs. Can't beat the dependability of a 4 stroke over a 2 stroke. Quieter too. Taking cross over lessons to the Green Eagle if we get some descent winter weather or I'll wait until spring. I'm going to fly right from my farm, have a 1400 ft long field.


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## Beer Belly (Nov 14, 2012)

I've got a G5 Flight Simulator left from my Dad.....gotta tell ya, it's a lot easier flyin' that.....if you crash, just hit the reset button


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## jharkin (Nov 15, 2012)

charly said:


> Flying is my passion as well. Took paragliding lessons 4 years ago, then switched to a back pack paramotor, then decided wheels would be easier. This is my instructor test flying my Green Eagle 4 stroke trike. 5 gallons of fuel gets you about 3 plus hours of flight time with plenty of reserve. Generac engine, 3000 hr engine life. Ashton from Texas has been building these going on four years with zero engine outs. Can't beat the dependability of a 4 stroke over a 2 stroke. Quieter too. Taking cross over lessons to the Green Eagle if we get some descent winter weather or I'll wait until spring. I'm going to fly right from my farm, have a 1400 ft long field.


 


That is COOL! Do you give rides?  I like the collision alarm, and then when he takes his phone out to snap a photo I'm thinking "don't drop it dude!"

I always wanted to fly full scale but its so expensive...For a while i was flying at a field we shared with Ultralites but never looked into it that much (my wife is terrified of me getting hurt if I tried one).


I didn't realize they had moved to 4 stroke on the paragliders even. I just love 4 stroke, even a large percentage of our model engines are 4 stroke now. The small alchohol burning engines have been avalable in 4 stroke since the 80s (singles, twins even some model raidals, etc) and now we are even starting to see some 4 stroke gasoline for the big scale planes.

My favorite model engines are these, made by Saito in Japan. From as small as 0.30ci (5cc) single up to a 57cc twin and 70+ cc radial.


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## charly (Nov 15, 2012)

jharkin said:


> That is COOL! Do you give rides?  I like the collision alarm, and then when he takes his phone out to snap a photo I'm thinking "don't drop it dude!"
> 
> I always wanted to fly full scale but its so expensive...For a while i was flying at a field we shared with Ultralites but never looked into it that much (my wife is terrified of me getting hurt if I tried one).
> 
> ...


Those are nice looking motors.. That opposed twin has to be one smooth motor. Fuel useage wise they are probably good as well. I always loved the radial engines. Got to fly with a guy Randy Brooks in a stearman Bi plane. Also a B17 ride as well. Nothing beats four radials. Sorry no rides on the Green Eagle. A single seater, Part 103 FAA says one person and no more then 5 gallons of fuel to be legal and a max empty weight of 254 lbs. No license needed just training. Cheapest way to fly.


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## jharkin (Nov 15, 2012)

The small 4 strokes are pretty good on fuel. For example the biplane up above has a 50 in wingspan and weighs about 6lb. It has a Saito 1.0 cu in 4 stroke engine, that tuns a 15x6in propeller about 9,200 rpm on the ground (for just under 10lb static thrust, or a 1.5 power to weight ratio ) . It carries a 12oz tank of fuel that is good for a 15minute flight with about 1/4 tank reserve.

Similar 2 stroke power would be around .75 cu in but Id need 15 or 20oz of gas on board. That makes a huge difference over time at the $25 a gallon model airplane fuel costs these days (The fuel mix is 15% nitromethane/65% methanol/20% oil)

Overall though, the small alcohol burning hobby engines are dying out these days. Pretty much everything bigger than 10lb is going over to gasoline. That big plane Ive got weighs 16.5lb and flies on a Desert Aircraft 50cc 2 stroke gas motor. It turns a 23x8in prop at 6900rpm for 28lb thrust. And I get 20minutes on 16oz of regular unleaded 2 stroke mix ($0.50 a flight vs over $2 a flight on the smaller plane)

And all the small planes are steadily moving to electric. With lithium Ion batteries and brushless DC motors we can do electric setups with similar power output as gas (just more $ upfront).


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## charly (Nov 15, 2012)

jharkin said:


> The small 4 strokes are pretty good on fuel. For example the biplane up above has a 50 in wingspan and weighs about 6lb. It has a Saito 1.0 cu in 4 stroke engine, that tuns a 15x6in propeller about 9,200 rpm on the ground (for just under 10lb static thrust, or a 1.5 power to weight ratio ) . It carries a 12oz tank of fuel that is good for a 15minute flight with about 1/4 tank reserve.
> 
> Similar 2 stroke power would be around .75 cu in but Id need 15 or 20oz of gas on board. That makes a huge difference over time at the $25 a gallon model airplane fuel costs these days (The fuel mix is 15% nitromethane/65% methanol/20% oil)
> 
> ...


4 strokes have to be a little quieter too, except for blade tip speed. And maybe a little less exhaust mess on the fuselage. Thing I don't like about the 2 strokes in the paramotor - ultralight world, is even if you take good care to run good fuel and do good preflights plus letting the motor warm up,,, one small air leak can simply lean out a motor and it's gone! My friend put over 100 hours on his Green Eagle last year with zero problems. Turn the key and fly. How can you beat that. Run some Amsoil synthetic oil, Seafoam or Startron in the fuel and you should have years of trouble free flying. As four strokes become lighter and stronger , I think 2 strokes will be phased out. A friend who snowmobiles said, riding a 2 stroke verses a 4 stroke snowmobile 8000 miles,,,, the 4 stroke will save you 2500 dollars in oil mix. Something to think about.


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## charly (Nov 15, 2012)

Another nice four stroke from Fresh Breeze, a company from Germany.


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## jharkin (Nov 15, 2012)

charly said:


> 4 strokes have to be a little quieter too, except for blade tip speed. And maybe a little less exhaust mess on the fuselage. Thing I don't like about the 2 strokes in the paramotor - ultralight world, is even if you take good care to run good fuel and do good preflights plus letting the motor warm up,,, one small air leak can simply lean out a motor and it's gone! My friend put over 100 hours on his Green Eagle last year with zero problems. Turn the key and fly. How can you beat that. Run some Amsoil synthetic oil, Seafoam or Startron in the fuel and you should have years of trouble free flying. As four strokes become lighter and stronger , I think 2 strokes will be phased out. A friend who snowmobiles said, riding a 2 stroke verses a 4 stroke snowmobile 8000 miles,,,, the 4 stroke will save you 2500 dollars in oil mix. Something to think about.


 
In the alcohol motors, yes the 4 strokes are a LOT quieter. The exhaust note is quiet enough that we can use very small mufflers or no muffler at all and its not much of an issue. The two strokes on the other hand have to use big heavy multi-chamber silencers and still the exhaust note is sometimes louder that prop noise.

The other benefit of model 4 strokes is they generally develop their max power at much lower and more usable RPMs - 7,000-11,000 for typical model 4 strokes vs. the 2 strokes that often need to be run at 12,000-16,000 for max power. You get to turn a larger prop slow which as you noted reduces tip speed. For noise limits we have tables of max rpm per diameter to keep the tip speeds below 0.6 mach, if you go above that you start to get that really annoying "prop rip" My big plane with the 23in prop is actually pushing that limit so I have to be careful about extended full throttle runs.

As far as mess... if you ever had a toy with a little Cox motor you know this things are extremely messy. Wiping down a 1/8in thick layer of oil off the fuselage at the end of the day is typical, and castor oil is particularly sticky stuff  A bottle of simple green and a a roll of paper towels is a must have in the field kit. The alcohol fueled 4 strokes are no better than the alcohol 2 strokes because the small motors rely on ring blow by for bottom end lubrication, so we run the same 20% oil mix.

That's the other big benefit of the gasoline motors. A 2 stroke gas engine running 32/1 or 50/1 is amazingly clean by comparison. I don't even bother to clean the big plane unless I'm at a show and using the on-board smoke system.


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## jharkin (Nov 15, 2012)

A couple more cool shots...

This is my little speed demon. Its a pylon racing plane, we have miniature air races just like the full scale guys at Reno. Ive never raced though as this thing scares the (#*$&% out of me every time I fly it. Its about 4 lb, runs a 0.46 cu in 2 stroke motor turning a 9in prop at 16,500 rpm. Never clocked it but we figure it probably hits 120mph.

And that wouldn't be competitive in the races. They have classes that go over 150mph and some of the jets can do 250.


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## jharkin (Nov 15, 2012)

Some folks might like to see how they all go together... here are some of the big plane when I was building it. Its a 30% scale model of an Edge 540 aerobatic plane like you might see in the Red Bull Air races


This is the real thing





And this is mine halfway though construction... 85 inch wingspan, and about 16-17 lb. Just like the models of old this is mosly Balsa and plywood, but now we use a lot of foam, fibergalss and carbon fiber to reinforce critical parts. Some planes are even factory built entire from composits now.

This is 6 or 7 years ago in my old bachelor pad before I got married. (Mrs. J: "_How much did that cos_t??")






The engine setup. Its a 50cc gasoline 2 stroke made in the US by a company called Desert Aircraft. The carb is an off the shelf Walbro but everything else is custom cast and CNC'd for models. The silver box is an electronic auto-advance battery powered ignition. No magnetos. The motor is very light, the entire setup sans muffler only weighs 3lb and it will develop 5 hp.






The muffler side. The two hoses - one is the fuel line to the carb, the other is the smoke system. We carry a second tank on board with smoke oil and there is an electric pump that pushes it into a spray bar in the muffler (controlled remotely). Same setup that full size air show pilots used, just miniaturized.

Oh and the black firewall is a special aerspoace composite of end grain balsa sandwhiched between 2 sheets of carbon fiber. Expensive but I had a major nose weitght problem and had to get rid of the heavy 3/8in aircraft plywood piece. The prop spinner is also carbon.





The heart of the plane. To the left are the fuel and smoke tanks and smoke pump. In the middle is the rudder servo with cables running back to the tail, on the right are the radio receiver (9 channel) and an electronic remote kill switch for the motor.

One other interesting tidbit – these airplanes all disassemble for transport. See the cardboard tube that runs between the wings below? There is a 4ft long carbon tube that slips onto it –then the wings slip on to that (there are similar tubes glued into the spar structure) and wooden down pins and a couple large plastic breakaway bolts lock it in place and prevent it from rotating. The horizontal tail/elevators are detachable in a similar manner. I can fit this into a hatchback.







All done.


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## jharkin (Nov 15, 2012)

charly said:


> Another nice four stroke from Fresh Breeze, a company from Germany.


 
"Without propeller the trike is without sense..."

That's too cool... Makes a neat go cart doesn't it. And goes together faster than some complex scale models Ive seen. The one thing that would be a little nerve racking though is the thought that your life depends on those 2 carabiners not breaking. I think I 'd want backups.

Question - looks like a lot of these are water cooled.  Any reason why they go that route vs. sticking to lighter and simpler air cooled setups?


I'll have to remember do a victory dance the  next time I start an engine


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## Beer Belly (Nov 15, 2012)

Nice work Jeremy....how does it fly ???.....my dads club sometimes would have a challenge....send up a few planes...send up a few Helium Ballons, and see who pops the most.....lot of planes got cut in half when they chased the same ballon


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## Gasifier (Nov 15, 2012)

jharkin said:


> "Without propeller the trike is without sense..."
> 
> That's too cool... Makes a neat go cart doesn't it. And goes together faster than some complex scale models Ive seen. The one thing that would be a little nerve racking though is the thought that your life depends on those 2 carabiners not breaking. I think I 'd want backups.
> 
> ...


 
If we were meant to fly we would have wings already. I have flown many, many times over the years. From puddle jumpers to the biggest ones, for different jobs I have had. But I think I will take my chances on the ground from now on. Even with what the statistics say.  I have not flown in years now, probably 6 years anyway. Just plan ahead for a longer trip and drive it. I like the "getting there" part of it as much as the destination part.


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## jharkin (Nov 15, 2012)

Beer Belly said:


> Nice work Jeremy....how does it fly ???.....my dads club sometimes would have a challenge....send up a few planes...send up a few Helium Ballons, and see who pops the most.....lot of planes got cut in half when they chased the same ballon


 
The gas plane is a blast to fly. With the excess power you have the ability to do things no full scale aircraft can do. I can takeoff, pull vertical and then stop in midair with the plane just hanging off the prop like a helicopter (hover). Then punch the throttle and it will actually accelerate vertical from a dead stop.

The larger size than the small models lets us fly on breezy days that the small stuff cant handle. 10-15mph winds are no big deal so long as its not gusting. The larger size presents better in the air, its easier to see farther away and at the same speed it appears to be moving slower than the small models so the maneuvers are less frantic - more like an airshow and less like a bumblebee zipping around. The greater mass and weight also lets a plane this size do inertial maneuvers that full scale airplanes can do (like tumbles and lomcevaks) that are hard to do with the really light small models.


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## firefighterjake (Nov 16, 2012)

So JHarkin . .. does the Mrs. still let you work on your plane on the kitchen table?  

Also, the "pilot" in the Red Bull model plane . . . is that a likeness of you?


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## jharkin (Nov 16, 2012)

Mostly it was built in my basement shop.  In the old apartment I had to move it upstairs to the dining room table to put the wings on in and balance because I didn't have room in the shop.  In our house I have enough room to do that stuff in the basement now


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