Shark .45's First Test Flights

Guys,

Put two test flights on the new Shark .45 after work on Fri evening. Second flight was full pattern. Squares were very good, about equal to my Intrepid X/L but didn't have as much nose in tendency with a slightly shorter prop. The trimming changes needed were observed as:

1. move leadouts slightly forward to eliminate slight yaw out angel.

2. lower fuel tank 1/64 to eliminate slightly leaner run inverted.

3. Increase cooling vent outlet area to help cool engine while still on the ground. It's fine in the air though.

4. tweek trim tab to raise inboard wing 1" in level flight.

5. Tracking good

6. Turn rate inside and outside equal.

7. No tendency to hunt, but control handle set up slightly too sensitive; will decrease spacing.

So far so good. Made the corrections and found that:

1. Tank height is now perfect.

2. Needs leadouts slightly more forward.

3. About another 2 degrees on the trim tab position.

4. Another slight decrease in handle sensitivity on down line.

5. Take 0.2" pitch off the Bolly 3 Blade.

A few more trimming refinements and this will be one slick
flying plane! Corners better than my Intrepid and has very
good to excellent line tension everywhere, even in moderate
to high wind conditions.

I don't know about other Shark .45's, but this one I believe could easily make a top 20 in open and with some exceptionally
skillful flying (not mine of course) could be a contender for
the top 5.

After I finish the paint job on it, then it's on to practicing.

Jim --

Good details. Wish more people would take the time to explain trimming changes they made and why. Oh yeah, what did you observe that caused you to change the prop pitch? Lap times?

I wish I knew enough to know what and where to apply trim adjustments. If I knew that, I would tell some one what to do.
Hi Jim. Sorry we didn't get to visit with you and Janet when we came through Huntsville last Friday evening and night. The phone # I had was not good and I couldn't find you in the local directory.

Very late I got hold of another modeler there I think he said he was flying a Sky Dancer ??? Any way, we had to roll out early Sat morn to get back home. Maybe we will get to see you and Janet another time.
Bigiron

I sure am glad your Shark flys well Jim, it keeps me thinking it will be worth it when I FINALLY get finished sanding mine! I started to build an adjustable trim tab into my wing, but when I talked to Dan Winship he told me he had some eighth inch tweakable horns, so I went that route instead. They are VERY nice units btw! I hope you can come through here when you come to Oregon, maybe by then you can help me trim mine

Marvin,

Sorry I missed you! You seem to have talked to Curtis Comer.
He is the designer of the Skydancer. My new phone number is
256-885-0530. I'm sorry that I hadn't gotten that to you. An
oversight on my part.

The Skydancer was featured in Model Aviation in 1994, and is Curtis's own design circa 1960. Another modeler here in
N. Alabama John Simpson is the designer of the Cavalier. Plans
for the Cavalier are available from PAMPA products, and Plans for
the Skydancer are available from the MA plans service.

Is you E-Mail still [email protected]? I sent you some E-Mail
just yesterday and it came back saying it was undeliverable.

Regards,

Jim & Janet Pollock

Larry,

No it wasn't necessarily lap times. It was the speed at which the engine was running that is causing me to decrease the pitch.
Lap times are 5.42 upright and 5.34 inverted on 66' eyelet to
eyelet lines. Tension is just what I want, what I am trying to
do is increase the engine RPM slightly and keep the same lap times. This will put the engine directly in the middle of it's
highest tourque value. That's what I'm shooting for not to change the lap times. Since line tension is excellent at the line length I have, I don't want to increase that variable.

Regards,

Nope Jim , my new one is [email protected] It should be in my profile.
Bigiron