"Tribewt" maiden - Baby Blender monoplane hybrid.

Tribewt monoplane

19^th April was when I finally got out to try a maiden on this plane - sorry no video! I didn't fancy juggling a video camera and flying the plane. Well, my 'Tribewt' – newly named -  just floated off the ground in what looked like a perfect balanced take-off. But no! It was tail heavy - and things soon went wrong. A drooping tail and excessive control throws on the ailerons soon had me beat. After a few wobbles and swoops I nosedived and pranged the propeller. The plane survived relatively unscathed as the foam nose absorbed a fair bit of the shock. Well I should have stopped there, but I put on another prop, adjusted the elevator trim to try and compensate for the heavy tail and took-off again. Well, it flew, sort-of, but (!!! because I didn’t take time to check properly !!!) the last crash had loosened the elevator horn. Soon it had worked loose and I was struggling to get any reaction from the elevator. The plane climbed to a dead stop, did a back flip and plunged straight down for another dirt nap. I wiped out the front end, but the motor and pod survived! I did a field repair, hence the packing tape on the nose, but I couldn't repair the control horn - which was probably just as well - who knows what the next crash would have wrecked!

When I got home I rebuilt the nose, losing some of the fancy detail,

and took the opportunity to shift the wing back about 15mm.

I also fixed and reinforced the control horn,

I know it looks a bit askew but it's screwed through into the lolipop stick underneath so its solid.

Second outing was Sunday 2^nd June. You’ll see from the film that it flew pretty well, though I felt it was still a tiny bit tail heavy.

First flight ended in some kind of brown-out, and the plane did a nasty belly flop. Fortunately nothing was broken. I swapped-in another battery and this time I hand launched. Once it was trimmed-out it was great fun.I was quite happy just looping it around the field. The landing was a bit rough again, but I reckoned with better balance it would come down a lot easier.

I flew it one more time, sorry no video, but stuck on another battery just as an additional balance weight. What a difference! The plane just cruised around - I was stunned how smooth it was. I even tried a bit of inverted flying, but I was on low rates and couldn't keep the nose up. A quick roll got me out of trouble.

I had a battery monitor on the battery and after about ten minutes of very satisfying flying the bleeper went off. As I coasted in for the landing, I had another brown-out/signal failure which lost me the elevator at the last part of the approach. The landing was bumpy but OK, but I think I’ll try another receiver.

So I added more weight, prettied it up, and put in another receiver. What a difference!

Overall I’m very pleased with this plane.My final CG is about 20-22% of the wing chord. If you look at my other recent build which I'll post soon – the Velie Monocoupe, you’ll see I'm having similar problems with finding the CG. Initially I was looking at somewhere between 25-30% of the chord – but again it was tail heavy. I’m concluding that for the Armin wings I’m building I should start with a CG more around the 20% of chord and work from there.

I was thinking about this monoplane fuselage layout and reckon it could be easily adapted to a number of turtledeck variations; cockpit well to the rear, single cockpit, enclosed cockpit, etc.

 The only issue is the access for the servos. A servo hatch would be easy enough. I found that if I stripped the paper from one side of the foamboard it could be coaxed into forming quite a tight curve, with the paper on the outside. 

Some more images after repainting.