The Sig Akrobat was my step up in control line flying after having wrung the Jetco Shark 15 out fairly well with most of the standard stunt pattern. I never was able to pull off a recognizable clover leaf, so I figured the Sig Akrobat with a Fox .35 engine should do the job. At the ripe old age of about 15, I set forth to build my dream airplane. The bedroom floor was my workshop at the time, and a piece of that old black fiber board that used to be used as sheathing on the side of houses under the asbestos shingles was my building board (it held straight pins fairly well). Anyway, in-between interruptions like school and a paper route, I enthusiastically cut, glued, whittled and sanded for weeks. The finish was Silkspan with Sig butyrate dope, done up in scale colors to look just like the box cover. Too bad that I don't have any pictures of it.
The Fox .35 was the biggest engine I had ever had, and if memory serves me correctly, it seemed a bit foreboding with the high compress pressure against the equally large propeller. I loved it, though. Unfortunately, my engine starting equipment had not progressed much beyond the Cox .049 days, so the ritual of endless flipping of the prop due to a crappy battery and no electric starter ensued. The Fox .35 brought with it a surprise that I had never experienced before - it liked to pop and then catch on fire! On more than one occasion I realized it was aflame and had to pick it up and swing it around in the air to put out the fire. That'll get your attention for sure. Well, the engine had finally reached the recommended amount of break-in time, so my flying buddy, Jerry Flynn, and I set off for Klinken's Field at the edge of our neighborhood of Holly Hill Harbor, in Mayo, Maryland.
OK, there we are at the field, lines stretched out, controls checked, fill the tank, start the engine, hold the plane nose-up to adjust the engine, set the Akrobat back on the ground, and run out to the center of the circle and pick up the handle. I give the thumbs up to Jerry to release the bird. He lets go and in just a few feet my Sig Akrobat is airborne. A few laps around the circle and I'm ready to see what she's made of. A wingover blows me away (that's what we said in the early 1970s), so I do a loop. Awesome. A horizontal figure-eight. More awesome. The force on the handle is unbelievable to some one who has flown only Cox .049 and Fox .15 power. Next on the list is sustained inverted flight. I had always been a little shaky there, but had developed an emergency pull-up reaction in case I panicked too close to the ground while inverted... or at least that's what I thought. Yep, I must have had a brain fart, forgot that up was down, and somewhere around the second inverted lap I buried my beautiful Sig Akrobat. Actually, I more than buried it, I demolished it... beyond repair.
The Fox .35 lived to run again, but the next of kin had to be notified for the airplane. I think I might have gone into catatonic shock because I'm told I just stood there for a long time. If school kids were being routinely drugged by doctors in those days as they are now, I certainly would have been a candidate at that point. Somehow, though, got past the devastation and lived to fly another day. At some point I bought a Sterling Ringmaster and mounted the Fox .35 to it. Oddly enough, I have no recollection of its ultimate demise. Jerry Flynn -- if you're out there, do you remember?
In 2007, I spend a little time and money into acquiring kits some of the models and engines that I had as youngster. Of course the Sig Akrobat was high on my list. eBay proved to be a good venue for finding most of what I was looking for. Sometimes the bid prices can get very outrageously high, so I skip those auctions and wait patiently for the next one in hopes that others will be asleep at the switch. At the bottom of the page are some screen captures from eBay auctions at the ends of the bidding periods. Prices typically, as of January 2008, end up around $110 to $150.
Wingspan = 51" Engine = .29 to .40
To the right above are photos of the Sig Akrobat kit that I snagged on eBay around the middle of 2007. It's funny how seeing something after so many years can instantly seem so familiar. One look at the plans and my mind was instantly taken back to 1973 (or was it 1974?) with the smell of Duco Cement and Sig dope. Oh, and for the record, Sig dope was the only kind of dope I ever used. My hair was long like all my peers of the day, but I never touched a single illegal substance.