Stratos 5 Maiden

[Frank S]

A few months ago, Dieter at ShredAir put on the hard sell (actually he just sent pictures) and sold me a new Stratos 5. Apparently, I may have the only one currently flying in the US, so I think it's worth a thread.

The Stratos 5 is the latest from the builder of the Stratos SL, Stratos SR, and Tsunami. It's a fully molded F3B plane, with an X-Tail, full-flying stab, two piece wings, and a 3.2 meter wingspan.

You can get more info on the plane from ShredAir's news page: http://www.shredair.com/news/2004.html (scroll down), or from the manufacturer at http://f3b.cz/produkty/str5-f3b.php3

Here's a picture of my Stratos 5 with all the major parts stuck together.

[Frank S]

With a pre-installed wiring harness, building the plane was very easy. The first piece of work was routing out the keel to fit battery, switch, elevator and rudder servos.

[Frank S]

The only tricky part was getting the linkages right for the bottom hinged, top-actuated flaps. I wanted to minimize the amount of cutting that I'd have to do in the wing. The photo below shows the flap wiper and the hole for the linkage as it comes from the factory. Without modification, it allowed for almost zero flap travel.

[Frank S]

I cut out the top skin a little bit, opened up the hole through the trailing edge spar, relieved the flap wiper, and ground the clevis. This next photo shows those changes.

[Frank S]

All the small changes combined to give me about 70 degrees of flap travel, which is plenty.

[Frank S]

I glued the wing servos (flap servo shown here) directly to the top skin with epoxy and microballoons. The microballoons make it brittle, so the servo pops out on a hard landing.

[Frank S]

I had originally hoped to maiden the plane at the slope, but once I had the plane done, the wind stopped blowing. Eventually, I decided to maiden it in my neighbor's field on the winch. Sorry I don't have any in-flight pictures.

My neighbor's field is small and surrounded by trees, so flaps are mandatory. That makes my first few flights tense until I get elevator-crow compensation dialed. I don't really think about much other than getting the plane down in one piece for those first flights.

In addition to lack of wind, there's been an inversion in our valley almost every day, so lift was minimal on all three days that I've flown the plane. This may have been a blessing in disguise, as it motivated me to be very methodical about setting up the plane.

The rest of my flights on the first day were spent working on the CG. I didn't have a recommended CG to start with, so I started out very conservative. I then crept it back very slowly. At the end of day one, my CG was still too far forward, but I was already feeling very good about the plane, with very solid launches and landings.

I've flown my Stratos 5 a couple more times since its maiden. I have tried to be very systematic about setting it up. It's the best job I've ever done setting up a plane, so it's hard to say how much is the plane and how much is the pilot, but so far I'm thrilled with its performance.

Based on some LoLo data, it seems to be launching about 7% higher for me than my F3J Nyx, and at least that much higher than my Zenith, as well. It definitely pulls very hard, as I broke my winch line several times launching into a headwind that was no more than 5 mph. Launches are rock solid without a hint of trouble.

Dead air hang times seem very good, although I don't have any reliable data to compare them with. The plane seemed to telegraph and work what little lift I found very well. It's not as floaty as the Zenith, and requires more pilot attention as well, but so far I think it's going to be easier to thermal than my Nyx. It's hard to say how much of that is plane, how much is setup, and how much is from improvements to my own skill level.

Landings are exceptional. With my other planes, I'd say I managed to get about 30% of my landings within 1-2 meters of a target. I've been very consistently landing within 1-2 meters of a target with the Stratos 5 - probably 90% or better. Once again, it's hard to say how much is plane, how much is setup, and how much is pilot, but the plane sure seems to be flying well for me.

My CG is currently at 105 mm. That's close to neutral, but I might move it back another mm or two when I get it to the slope. I haven't measured any of my throws yet, because they're not really tuned. I will say that I'm not using a whole lot of camber - maybe a couple of millimeters of trailing edge droop at most. AUW is 80.5 ounces.

I'm still waiting for the ballast kit, so I can't say how it performs with more weight. I'm really looking forward to flying it on the slope. I'll probably post again in the slope forum when I do.

[dhauch]

Hey Frank,
Great info !
I had a chance to buy this plane before you, but I really wanted white.
Been waiting to see how it flies.

Looks like you could remove more of the wiper in front of your flap horn so the clevis doesn't hit, and should give you more throw then.
I did this on my X-21 and worked great.

You plaining on any running any f3b task with this plane ?

dave hauch

[Frank S]

Dave,

There's really not much more flap wiper to be removed without compromising the integrity of the flap control horn. I've got plenty of flap travel, anyway.

I programmed crow so that I get all of my flap travel at about three-quarters of the stick movement, and then the ailerons start to go up for the last quarter. I leave the ailerons neutral during the first three-quarters, but I understand that some people camber them for part of the stick travel, before switching. However you do it, the method gives you some extra precision in controlling your glidepath. You can slow it down with the flaps, then control your sink rate with the "spoileron."

I don't know if I'll ever get a chance to try F3B. I don't exactly live in a soaring hotbed, so I'd have to travel to even get a chance to practice. I go to CA from time to time, and so I might give one of their F3F races a shot someday.

Frank

[dhauch]

I hear you on removing the wiper.
But, if you have a good puddle of milled glass and epoxy around your horn, that will hold the horn just fine without that little bit of wiper removed.

Anyway, how do you like your Zenith ?
Been thinking of getting one for those light thermal days with no wind.
All I have right now are all f3b planes, (Tragi, Icon, & X-21).

You can PM me at djunruh@qtm.net so we don't get off topic on your post.
Plus your post takes for ever to pull up on my PC with all the pics.

Thanks,
dave hauch

[ShredAir]

There are more details on this plane here: http://www.rcgroups.com/forums/showthread.php?t=276295
Dave, with the Euro rising, you sure missed an unique opportunity just because it was yellow... : )
Frank, I'm working on the ballast...

Dieter Mahlein, ShredAir

[dhauch]

Hey Dieter, from wanting a white gliders, I also need ballast for my planes! :-)

dh