Monday, March 12, 2012

Extra 3.25





First heard about the design as a Model Airplane News plan, designed by Rich Uravitch. Then found the Lanier kit version on EBay, got it for Christmas in 2010 together with a used OS FS 26. Unclear how old that engine is. It looks a bit more gummed up than my other 10-year old OS 26.

The Lanier kit has very nice laser-cut pieces which I wanted to preserve, since it's getting harder to find nice kits. So this plane was built by copying the pieces of the kit.
Everything came together quickly until it was time to assemble the middle section for which the kit provides a vacuum formed clear plastic part. Created a plaster mold, but failed to duplicate it because it was hard to get a suitably large sheet of clear plastic. Ordered a canopy from Tower for a 60-sized cup that appeared similar, but that piece arrived broken. So ended up creating the center section from scratch out of balsa.
The kit also includes a cowling which I didn't want to remove from the kit, either. Tried to copy it in fiberglass, which turned into a big mess. Then ordered a replacement fiberglass cowling from Fiberglass Specialities, but have not put it on because it's much easier to reach the engine without a cowling. The only part on this plane that came from the kit is the aluminum landing gear.

The kit suggests a weight of 3.5 to 4.5 lbs, but my plane came out just under 3 lbs! It appeared front-heavy, had to move the receiver battery into the back of the fuse to balance. Servos are 3 normal sized ones and a small one for throttle. One servo with bell-cranks for ailerons, no "flap" mixing option.

Wingspan 120 cm
Length 87 cm
Area 23.4 dm2
Weight 1330 g
Loading 56.8 g/dm2
Airfoil Semi-Symmetrical
Engine OS FS 26
Tank120 cc

First flight was on the 2012/03/12. Engine runs fine, solid put-put-put, no screamer. The plane has a tank that only uses a third of the front section, and I don't know how long it will run, but after 4 minutes it's still 3/4 full.The plane feels very light and can fly quite slow. very easy to fly, like a trainer except maybe a faster roll rate.