We have liftoff, the 2 Bits Bipe has flown. Now with pictures.

This morning, I loaded it up in the van and headed up to Gordy's house. Carl Shoup was visiting, and both of them, Norm Whittle, and Jimmy Rhoades were going to be flying at the park near gordy's house.

I had checked the balance at home, and it appeared to be about right without the need to add balancing weight. It also appeared to hang straight from the leadouts, making me believe that the vertical CG was at least close.

I put up 2 flights on the bipe. Talk about a bundle of nerves though. We had to hand launch due to the thick grass, and I was suprized at how nicely the plane handled a hand launch.

Level flight seemed good, no tendency to hunt was observed. it did seem to have the outboard wing low though. I had short tanked the plane so because of nerves, and not wanting to have the plane shut off somewhere I didn't want it to, I just did some climbs, a shallow wing over or three, high flight, and an inside loop.

The Stalker .61RE had good power, but a little more might be needed if I really try to nail a pattern. Lap times were 5.0 on a APC 12X6 prop.

The biggest suprize was when the power shut off. I expected the plane to drop like a rock, as I've seen other biplanes do. This one glides. it glides as good as some of the mono wings I've flown. I don't know yet, but suspect that there's a combination of weight, and clean design, that allows it to penetrate in the glide.

It didn't like the grass for landing though. It tried to roll over on the top wing, but didn't get that far, coming back to rest on the gear like a proper lady.

Carl offered a CF copy of the APC 13X7 electric prop to try for the second flight. It's a beautiful, well made CF copy, and the engine spooled it up as fast on the ground as the previous prop. In the air, the engine settled into a deeper 4 cycle, and the lap time dropped to 5.9. This was a bit slow, and I wasn't real sure the plane would perform at this altitude, (4,600 ft ASL) especially with the temp going up as it was.

The flight went about the same as the first, though I could feel the planes weight more, due to the slow flight, I did more climbs, high flight, shallow wing overs, and loops. Finally, I went inverted. Scared me as the plane rolled in slightly, and for a second, I had little or no line tension. The tension came back a bit, but the plane was flying with the outboard wing high. The engine seemed to have about the same sound-speed, so after only one lap, I did an outside to bring it around to upright.

All other events were about the same as the first flight, including the landing.

A third flight was attempted, but apparently something, possibly a bit of crud, made the engine balky and not wanting to start.

So, I'll remove the engine, and check out the fuel system. I'll also need to tweak the flap horn, as the inboard flap is slightly lower than the outboard, which is what caused the uneven wings and rolling upright to inverted.

My feelings at this time allow me to surmise that the plane has a lot of possibillities. It will fly and do round manuevers on the current power, but an increase should make it much better, especially for the square manuevers. I might be able to upgrade to the Stalker .66 rather than the .81. The .81 would have all the power needed and then some, but would require adding balancing weight, whereas the .66 essentially weighs the same as what's in there.

All in all, I'm pretty happy with it all so far.

Carl took several in-flight photos, and he'll be sending them to me after he gets home tonight.

Good News . The 76 is the same fit as the 66 , but about 1/4 in higher .Going to try the bigger intake on the 66 to see if itl get ' bouncey ' rather than the current tractor like powerband .

Maybe a .310 intake and 5 1/2 to 6 pitch ? .

It did fly.
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WOW! That plane is huge! The plane looks GREAT!

Definately Far Out , good to see someone getting away from square aeroplanes

>The Stalker .61RE had good power, but a little more might be
>needed if I really try to nail a pattern. Lap times were 5.0
>on a APC 12X6 prop.

Hi John...
Or you could switch to a "real engine" like a PA 65 and have lots more power!


Great looking airplane Buddy!


Randy Cuberly

John,

Admirable work!

Martin

John,

Continued nice work.

Allen Brickhaus

Thanks guys, I thought I would post a few pictures of the plane, ready to fly. The first, prior to the first flight, and the second, after the second flight.

I've had the plane apart, and checked all connections. I took the engine out, and checked it out as well. It's all back together now, and ready for the coming weekend's flights.

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We took the Bipe out this past Sunday morning for more flights. I still am having problems getting the wings level, upright, and inverted. It was better than last week, so I did a couple of laps inverted. Other than the engine speeding up, because I need to adjust the uniflow, it was uneventful. It seemed to groove well, and had no tendency to hunt, either upright or inverted.

Inside loops were fine, and easy to make round, but because of the wing situation, I opted out of outside loops, other than the half loop used to return to upright flight. These were bigger loops, but I believe I did it because of the planes atitude, (Banked in towards me) not giving me a huge amount of confidence.

After the engine quit, I once agian enjoyed the glide, going well over a lap after the power was off. Upon landing, the plane nosed over in the tall thick grass, and a sharp crack was heard by all. I looked the plane over, and all seemed OK, so it went up for another flight after I had tweaked the flaps to try and get the wings level.

Most notable on this flight was that I had tweaked the flaps too far, and the plane now flew upright banked into the circle. I did try a square loop though. First turn was good, and it hit the vertical line rather well, it hit the inverted line well, as well as the downward vertical line. The last turn was slightly sluggish, and it didn't turn at the same speed, so I came out slightly nose down, and had to make a correction to level the plan. To those watching, it looked like the plane might have stalled on the last corner, but it was showing it's weight in the last turn, but wasn't stalled.

Again, the glide after the engine quit, and another nose over on landing.

I was getting ready for a third flight, taking some of the tweak out of the flaps, when I looked at the gear leg. Then I knew what had made that loud cracking sound on the first landing. The Ply-CF hybred gear had twisted, and one of the laminations had let go. The gear had bent back far enough afterr that, that the rear of the wheel pant dented the lower wing sheeting. I was done for the day.

So, I'm making up a new gear, and plan on testing it well, before deciding whether I'll go to standard CF gear. I've also been looking over the controls, I believe I may take the time to re-center the flaps and elevators, as right now, the flaps are slightly down, when the elevators are level.

I hope I can make all the needed adjustments and fixes so I can take it out again next weekend.

I will say, it looks great out on the end of the lines.

Glad the "Crack" was just the gear and not something, well, more critical. Looking good.
Pete

Something different and it looks great. Best luck with new bird. I like colors and nice photos.
Cheers,Dan

Due to the problems with the home made ply-CF gear de-laminating on several landings, I've been unable to put up more than 4 flights total. It was obvious that I needed to address the problem before going much further. I believe the problem comes from trying to use regular hobby type 30 minute epoxy, which just doesn't seem strong enough to work in this instance. It might work better if I'd used a professional grade laminating epoxy, but none was available to me at the time. This was brought home to me when the new set of gear I made failed when I tested it, knowing, from experience now, what kind of stress was occurring.

So, I decided to install a set of commercial CF gear. It took some searching, but I finally found a company that supplied gear that was almost a perfect match for my needs, just being a little bit taller, which won't hurt at all, what with the tall grass I have to try and fly off, and onto.

Since I was waiting for the gear to arrive, I took the plane over to Gordy's, and we put the gauges and meters to it. I suspected that some alignment may be off. The meters showed that the flaps on the lower wing were aligned with the elevator, both showing 0-0 at neutral, but the top wing was off, showing a 5 degree droop when the lower wing is at 0-0. After making adjustments, every thing is within a fraction of a degree to each other.

The new gear is installed, so I checked the vertical CG in case the differences in weights may have moved it. I hung the plane from the leadouts and set a torpedo level on the fuselage flat spot between the wings. It appears that I will have to move the leadouts down about 1/2". Turning the level 90 degrees shows the nose hanging slightly down, which agrees with my assessment regarding line tension on my last flights.

Now, with the new gear, which should allow a lot more flights during a session, I should be able to quickly get the wings level, and adjust the uniflow for equal lap times upright and inverted. After that I should be soon flying the pattern.

>I was getting ready for a third flight, taking some of the
>tweak out of the flaps, when I looked at the gear leg. Then I
>knew what had made that loud cracking sound on the first
>landing. The Ply-CF hybred gear had twisted, and one of the
>laminations had let go. The gear had bent back far enough
>afterr that, that the rear of the wheel pant dented the lower
>wing sheeting. I was done for the day.
>
>So, I'm making up a new gear, and plan on testing it well,
>before deciding whether I'll go to standard CF gear. I've also
>been looking over the controls, I believe I may take the time
>to re-center the flaps and elevators, as right now, the flaps
>are slightly down, when the elevators are level.
>
>I hope I can make all the needed adjustments and fixes so I
>can take it out again next weekend.
>
>I will say, it looks great out on the end of the lines.

Dare I suggest that if you are testing this model over a grassed field that you lose the wheel pants?

They are known to catch the grass and probably caused the above problem.

Other than that, I love it!

It's been a couple of weeks since the last flights on this airframe, mostly due to poor weather problems on the weekends.

Today, we met at the field, and put up some more trimming flights.

I'm still working on getting the wings level, but they are pretty close now. I was suprized to find that I needed to raise the leadouts. I referenced to the wings this time rather than the fuse sides.

Today I did some consecutive loops. They were nice and round, with entry, and exits at the same altitude. They tracked true which makes doing them much easier.

Level flight was good, and also tracked true, upright, and inverted.

Then, I tried some inside squares. This is where the extra weight showed up. Turns 1,2,and 3, were good, with a nice and sharp snap to the verticle or horizontal lines, until the last, number 4 turn. That last turn showed a stall, unless I eased up on the turn. Even eased up, it still showed a tendency to stall.

So, here's the cure we came up with.

I want to try and get rid of some weight, and add some area, to get a better wing loading. Here's where I'm glad I can easily remove and replace parts.

I believe I can get rid of several ounces by building a new top wing as a one piece structure. That's half of the solution, the rest is to increase the chord slightly, and add some span to that top wing, to increase the area.

I figure to have the new wing ready soon.

Now, my impression is that if I can keep the first 3 turns in a square manuever, and match those with the last turn, this just may wind up being a very nice stunter.

Stay tuned