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My first "real" airplane, prior to this I only had the "Bilka airplane".
It is also my first design and build, hence it's name :).

It's gone though quite a few revisions... Caused by lets call them landings.
Each rebuild was also a nice opportunity to make some slight modifications.

MK I

Was't finished when an opportunity came for some flying.
Finished gluing it together at the field.
The CG seemed to be too far back. It has launched never the less, as I could not move the battery further forward.

Sure enough it climbed up up and away (way too steeply), instinctively I cut back on the throttle (The "bilka airplane" had no elevator rudder, climb rate was controlled using engine throttle).
A split second later I realized my mistake. I panicked, increased the throttle to 100% and made my second mistake, applying up elevator instead of down.

The plane did't have the engine power to take the abuse and stalled.
Of course by then it had reached height high enough to get badly damaged on landing(impact), but not high enough for me to recover.

Surprisingly the wing survived all the bodies.
Sure the servos got ripped out of it, the rudder surfaces got rebuild quite a number of times but the wing itself remained the same on all 5 bodies.

Motor: Graupner Speed 280 FG 3 gearing, with a Graupner slim prop 9-5"
Battery: 2x 630mAh Li-ION cells (supposed to be used in a cellphone battery)
Wingspan: 70cm.
Takeoff weight: Unknown.

MK II

Moved the battery on top of the motor fixing the GC problem.
Got a few brief flights out of this one.
I had a tendency towards staling it when making sharp turns, at least that's what I thought happened.
Glue and tape became my best friends...

MK III

As it seemed that I had problems controlling my turns (making them too sharp) I decided to reduce the depth of my rudder surfaces. Preventing me from making too violent control trows without using "end point adjust" on my transmitter.
I also decided to try attaching wingtips onto the wing, giving it a dihedral shape making it "self righting".
As the strength of the open box design was quite limited I also reinforced the body.
Additional strength was gained by applying tape to the depron foam, making it much stronger. Caused bu concern over the possible current drawn from the Li-ION batteries, I also experimented with a small NiMH battery pack.
Last but no least I extended the nose section to allow the battery to be located behind the motor.

The extra wing area did however make the airplane feel even more underpowered.
The dihedral in combination with the reduced rudder area also made it quite hard to turn against the wind.
On the second flight one of the tips touched the ground and got damaged internally.

After this I removed them all together and restored the rudder surfaces to there previous glory.
I got a quite a lot more flight time out of MK III than MK I+II, caused mainly by the increase in flight experience and to some degree the increase in sturdiness.

Some of the crashes may be explained by the fact, that I thought the receiver was full range (1km) but in reality it only had a range of 300m.
This wasn't' discovered until way into the lifespan of MK V, and most of the crashes should be attributed to pilot error :)

The transparent construction of the wingtips was mostly a "it would be cool if they were transparent" thing.
It did however make them quite a bit weaker and it did't seem to be much lighter.
The plastic material btw. was ordinary gift wrapping plastic (PE as far as I remember), I later discovered that it too shrinks when heated, if I had tightened it the wing tips would probably have been much stronger (and better airfoils)...

Motor: Graupner Speed 280 FG 3 gearing, with a Graupner slim prop 9-5"
Battery: 2x 630mAh Li-ION cells or 6x 600mAh NiHM cells
Wingspan: 70cm (approx. 140cm with tips).
Takeoff weight: 216g without tips (243g with tips).

MK IV

To be written

Motor: BM2410-09 brushless motor , with a GWS EP-1047 prop
Battery: 2x 1300mAh LiPo cells
Wingspan: 70cm.
Takeoff weight: 268g.

MK V

To be written

Motor: BM2410-09 brushless motor , with a GWS EP-1047 prop
Battery: 2x 1300mAh LiPo cells
Wingspan: 70cm.
Takeoff weight: 299g.