althepal

After lots of work to rework the Great Planes Tiger Moth, in order to give it a little more svale look, the day wad arrived... We ahd a streak of rainy days, and finaly a break in the rainy weather was on the horizon. Arriving at the field, it was very windy...what am I gonna do? Well, the planes looks good, let's put it together. Took me over 30 minutes, and there she was, proud, waiting. The sky was darkening again, and for sure, 5 minutes later, it was a good shower...OK, let's dry her up...The club test pilot was on hand, and agreed to fly the Moth when the wind calms down. All gased up, when the time came, the OS 91 surpass was roaring, spinning that 14x6 prop with ease...You know, it is a Tiger Moth, it flies by itself...anyway, with the 8.oz pf lead on the engine mount, it was balanced ok, so, taxi to the runway... Everybody watches, not a word, no other plane in the air...Our hot shot opens the throttle and here she goes, lifting her tail, gaining speed until the weight was transfered from the wheels to the wings... SHE FLIES...and beautifuly at that. A long climb, I expect to hear a reduction of power, but no, the wind is to strong, she barely moves in relation to the ground, but climbs...Comes the forst turn...nothing, the ailerons are on low rates, and she does not dip a wing..ok, high rates flip, and ...that's better, but it is very sluggish...a few circuits around the field, and our test pilot brings her for a beautiful kiss landing...you culd hear the wind in the wires as she approached the treschold...
Wheel landing on the main, 20 feet later the tail comes down.....slow down, 180 turn and here she comes...This is a beautiful airplane BUT...
back to the pits, comments are going around, but it is clear that the power is marginal It flew realistic, yes, but at ful bore all the time so to speak..OK, was windy, so she can handle the wind ok. But the manual says 91 to 120 4 stroke. True, but the manual does not say about the scale finish I did ad, the paint, the bigger whells, the fabric instead of monokote...the T.O weight was around 13lbs, for 71" wingspan, in a biplane that has more drag then a refrigerator flying in formation with a bunch of bricks... At full bore, the surpass, cowled, was running a little hot..
What, said a modeler, you did had half a pound of lead in the front! Yeah. and it seems the norm, even without all the ad ons.
Lets see


an OS surpass 91= 23 oz
a 120 fs=31oz
lead to balance the plane=8oz
23oz+8oz=31oz

So, it flew, it flew well considering the weather and all the handicaps stated above...
Now, I am gonna put a 120 fs in front, with a 16x6, make a baffle for the engine inside the cowl, to force the air around . Put some differencial on the ailerons, and use the rudder a little more also.

The suspension works great, it looks like the real thing.
Now, as soon as we have some nice weather, I will put the plane together and shoot some pictures of it now that it is almost finished. It is not scale, it is not scratch build, how do I define this hybrid? an reworked ARF, a modified mass produced kit...
Would I do it again...probably not. I like building, but I wanted a bipe that looks cool to refresh my flying skills...but one detail leading to another....now, my ARF is overweight.
Was it fun..YES, and that is what this hobby is all about. Everyone does what he likes.
Should I complain about the wrinkled finish that was on it to begin, about the missing roll of wire to make the flying wire, about the rusty bolts and nuts that came in the harware package of this kit, personaly, I would not, and after all the modifications I have done, I honestly can not say that Great Planes issued a bad model with this bipe.
The first time I had the plane together with the flying wires, I took a few pics
since then , it has been wethered slightly, the wheels ahve now the De Havilland emblems
the pilot, handcarved out of balsa and milliput is now properly dressed and dsiplays asilk scarf, flying in the propwash, all the gauges are installed, the front cockpit is detailed...was fun as I said

Al

althepal

Pictures...[img][/img]

swooper

Hi Alain,
Nice!! What a great trim scheme, and your detailing looks great.
I like the idea of starting with an ARF and putting the work into the detailing.
Makes me think about my GP Space Walker, it needs an engine head sticking out the other side of the cowl, at least.

I'm flying the GP Tiger Moth with 1.20 Surpass and it balanced without ballast. Never a need for more than 1/2 throttle
Mine came with a whole lot less incidence in the top wing than the bottom. I dropped the trailing edge of the top wing about 1/4 in. by drilling lower holes in the fuselage for the cabanes, and shortening the rear interplane struts. Now the wings are more parallel. The plane flies OK and never fast.

Thanks for the pics of your beautiful biplane!

althepal

Paul,

I did not change a thing as far as incidence, so I have a difference of angle of incidence between top and bottom wings, the top wing beimg with a negative angle of -1*. This off course lowers the stall speedand increases the top speed, enlarging the flight enveloppe!
If I would have to do it all over , I would BUILD the model, and that's what I will do with the Jungmeister. The pictures are from the plane when it was not detailled yet as far as small details.
Years ago, when I was in flight school, there was a fly-in for RC models in the county, and modelers from all over Georgia, and even Florida showed up. Near the closed runway where the show was held, there was a HUGE RV with a fancy licence plate..SIG 1 !
Hazel Sig and Maxey Hester were there...Maxey was flying a 1/3 Spacewalker with an OS four stroke twin! The real Spacewalker had a four cylinder engine, so Maxey installed two cylinder heads from OS behind the actual engine..Hell, looked like a Pegasus flat four to me, but no, was a Gemini....with two dummy cylinders. Not exactly cheap, but it was looking cool!

Thanks for your input on my Moth
Al

Skribnod

Wow what a nice airplane. I have the GP tiger moth and still have yet to get it to fly right !! I built it exactly to the manual and it wanted to climb and bank hard left on maiden flight. After some trimming it straightened out but still flies badly....wants to mush all over the place and thats with a Super tiger 75 pulling it. I balanced it according to the manual and it needed 10oz in the nose!! I dont have a incedence meter to check the wings but I believe the top wing is making it want to climb and drag badly. I have 3 1/2 inch wheels on and cant get it to stop noseing over on the runway (short grass). Any ideas on what I can do to improve this airplane to make it fly like it does on the simulator? Thanks and any help would be appreciated.