FAIREY FIREFLY MARK 5, 1:4 SCALE

[Karl mander]

SHEDOLOGY SUCCESS!

Yes ,maiden flight undertaken today, all 42kg hauled into the air.

I had ground run it, then taxied it with no signs of overheating.
I was suspect about the balance point on the plan and was proved right as it flew tail heavy. I'll remove some of the 1 kg of lead in the rear.
As normal I'm unable to upload pictures, however the below link is to the you tube video, unfortunately Steve Vodrey was cameraman thus the lovely sky shots.
Link-

https://youtu.be/ilVaRRx15fQ

[Karl mander]

I forgot to state that it flew woefully over propped, thus under powered. It's currently got a 37 x 14 so some experimentation is required.

[David Brown]

Nice one Karl, I look forward to seeing it in the flesh. I am too busy at present to get out to fly. I am running a 40 X 22 SEP wooden prop on mine at 3150 rpm (6300 on the engine) with a 2 - 1 ratio drive, the prices are very good for what you get. I have had a local fabricator knock up a stand for test running my engine, I bet if I took off the hand brake it would pull the van along .

[Karl mander]

Now that's my kind of engine test bed, love it, great idea.
A 40 x 22 prop,! Christ it's not far off full size.

[Euan Galloway]

karl,
Well done big question what next ?
cheers Euan.

[Karl mander]

After the crank snapped on the inline twin zenoah in my tempest I always knew that the inline triple in the firefly was on borrowed time.
Although I'd beefed up the prop driver with additional 6mm bolts it failed in flight at the weekend.
the firefly suffered damage when it almost made it back to the strip.
Even if the prop driver hadn't failed upon inspecting the engine I noticed that the crankcase had cracked around one of the reduction drive attachments( I had braced the other)
A lesson learnt, don't expect longevity out of components when you put through them three times the power they're designed for.