Sam Barros’ Model Airplanes Hobby

I currently own two radio-controlled model airplanes. One is a PT-40 trainer with 1M52 wingspan and a 1M33 long body, weighting about 3kG. This plane is powered by a 7.5cc (.40 Cu.In) Irvine two-cycle engine. It took me about 8 months to build it (it was an after-school thing, so I couldn’t devote too much time to it each day). This plane is an extremely stable flier, which can recover from stalls by itself (due to wing dihedral and washout, and also a slightly positive elevator setting) and, because of its low wing loading, it gracefully glides through the air. It’s a real pleasure to fly and I highly recommend it to anyone who is learning RF flight… It’s easy to fly, sturdy enough to take any rough landings or light crashes, and yet fast and agile for maneuvers once you are comfortable flying. Plus, when you are done with it, you should be able to master any other medium difficulty plane, such as my second choice; the 1.3 meter long, 1.2 meter wing span F-15 Eagle powered by an O.S. Engines .46Cu In with a resonant exhaust.


 Here are some photos and specs of my PT-40:

PT-40 Side ViewHolding the plane for scale Wingspan: 60 in (1520mm)
Wing Area: 672 sq in (43.3 sq dm)
Weight: 6 lb (2800g)
Wing Loading: 21 oz/sq ft (64 g/sq dm)
Fuselage Length: 52.5 in (1335mm)
Power plant: 2-stroke .40 cu in (7.5cc) Irvine Engine.


PT-40 Front View





Top viewPicture showing the fuel tank and the servo bay from above.










 PT-40 under construction

  I took this photo before I finished covering the top of the wings. I think it looks cool because it shows why those planes are so light: Most of their inner space is hollow, and they make use of a special interlocking balsa wood structure to achieve structural strength. Both planes are covered with Monokote�. Some kind of shrink wrap plastic (not sure what) that, despite only being a 10th of a mm thick, is nearly impossible to break by pulling (it cuts easy though).

 F-15 Eagle:

 Here is my newest plane: it is a 1:6 scale F-15 Eagle. It is powered by an OS.F-15 perspective MAX FX .46Cu. In. (8.2cc) two stroke engine with a resonant exhaust built into the fuselage (30% extra horsepower, more aerodynamics, and less noise!). The plane is slightly smaller than the PT-40, at 1M33 length, and 1.1M wingspan, but it is also heavier, at over 3kilograms, and higher powered. It took me 5 months to build (I had part of the Christmas holidays to work on it). The power plant provides it with over 2 horsepower and can spin a 10 X 7 propeller at 18000RPM!
The powerful engine/resonant exhaust system and sleek aerodynamics of this plane make it a *VERY* fast flyer:
It can take off vertically and reach as much as 150Km/h in flight. It is NOT easy to fly though, and the landings are very fast. Flying this plane is a lot like flying a brick: it goes where you want it to go, how you want it to go, but not the way you expect it to go: When the throttle is high it doesn’t seem to care if it’s sideways, upside down, or tilted, it will fly either way… It’s quite odd for someone who is used to a more glider-like plane such as the PT-40. It is also not much affected by wind, which is a good thing.

F-15 and me Here you see a picture of me and my plane on my house’s garden (in Holland). It gives you a rough idea of the plane’s size… Since this is a rather old picture, the plane didn’t have the OS engine and resonant exhaust system yet (I was using the Irvine engine for test flight, it wasn’t all that great).

 Here are it’s specs:

 Wingspan: 47 in (1190 mm)
Wing Area: 615 sq in (40 sq dm)
Weight: 6.5 lb (3000g)
Length: 52.5 in (1335 mm)
Power Plant: 2-stroke .46 (8.2cc) OS MAX FX engine with resonant exhaust.

My Flight Box containing everything I need to start, fly, and repair the planesHere you can see my field box, which contains everything I needed to start, fly and refuel the planes, as well as materials for some small field repairs. Some of the inventory includes my Futaba F-15 remote control (4 channels), a liter of methanol/castor oil mix with 5% nitro methane added for extra engine power (I make my own fuel), a spare propeller, an X-Acto knife with a full set of blades, a pen flashlight, a full set of small screwdrivers (regular and Phillips), two larger screwdrivers, a large Swiss army knife, two pliers, spare nuts and bolts, sandpaper, scotch tape, spare glow plugs and others… The box contains a 12V battery (in front of the remote) which powers the fuel pump, starter and glow plug through a power panel (next to the battery).
Answering some questions I received: A plane flies on average 10 – 15 minutes on a full tank. These planes have 250 and 350ml tanks respectively)

 Both of these planes are manufactured by Great Planes.