The Hobbico Classic Biplane has a 20" wingspan and resembles the old Beech Model 17 Staggerwing. It is a relatively easy project to convert this $15 classic scale electric free-flight plane to R/C using the Cirrus Micro Joule Flight pack.

After gutting the stock power system, it weighed in at 1.4oz.

 The wings weighed 0.7oz together and the empty fuselage was 1.1oz.

For a light power system that draws less than an amp, the Astro Flight Firefly is a good choice. I have used this power system on other 3oz applications.
 

The combination of my new power system and Cirrus MJ receiver and two servos weighed a total of 1.4oz. This matched the stock electric free-flight power system weight.

Mounting the MJ servos was easy. I simply cut slots into the side of the fuselage and press fit the 0.1 servo in place. No glue was needed.

The linkages were made from Dubro micro control horns, carbon rod, thin solid wire, and shrink tubing.

I replaced the cut out foam with a few balsa pieces; one to hold the 2-cell Kokam 145mAh pack and the other as a press-fit hatch.

My Hobbico Classic Bipe is RTF R/C at 3.6oz. To finish up, I added the decals and painted the prop tips red.

Hobbico Classic Bipe Video (5meg)

This is the maiden voyage of my converted Hobbico Classic Bipe using the Cirrus MJ Flight Pack and Astro Flight Firefly motor on a 2-cell Kokam 145 pack. This model resembles the old Beech Model 17 Staggerwing and flew great!