L-19 “Bird Dog”

Some have asked me how the Bird Dog came to be…

So, to help answer that question, I give you the following little bit of history.

The Bird Dog was created for the sole purpose of helping the ‘New Guys’ in our Club get in more quality stick time. In my opinion, there are very few, if any, truly great Trainers available today that are designed to be easy to fly, inexpensive……..and, EASY to build. Because of this perceived need in our own Club, we devoted part of one of our regular monthly meetings to a discussion of what the Members themselves felt they wanted in a “True Trainer”. The list that came out of that meeting is presented below. I then took all that input, and, in the end, cranked out, what I feel, is a neat looking flat foamie version of the famous L-19 “Bird Dog” that has proven to be an easy to build, inexpensive, and most of all, a really great flying airplane……….just ask any of our members that have built one.

The Ideal Trainer

  • The airplane should be a very stable aircraft, capable of sustained, straight-and-level flight, all by itself.
  • Hands off, it should fly straight away from the launch, as if it were on rails. It should be stable enough so that more than the average amounts of control inputs are required to get the airplane to turn, climb, or dive.
  • Power on to power off, the airplane should require no trim changes.
  • It should be a ‘large’ airplane, easily seen, slow in flight, with a light wing loading and a low power loading.

Includes

  • Large size – 54″ wingspan, with 400 sq. in. of wing area.
  • Low wing loading – glider like flight performance.
  • Low power loading – just enough power for scale-like flight.
  • Low cost motor and ESC.
  • Front end nose triplers for front end stiffness and strength ( read that ~ “Crash Resistance”).
  • 1/4″ square fuselage stiffeners and tail stiffeners.
  • Fuselage stiffeners become stab mount doublers.
  • A 20% CG location for ultra stability ( usually 25% to 30%).
  • The use of 7 degrees of decalage (the usual is 2-1/2 to 5 degrees) for stability and drag.
  • The use of 15 degrees of dihedral for ultra stable, free-flight “Fly-On-A Rail” feature.
  • Airfoiled wing for higher lift, higher drag and added strength.
  • Low-cost wing spar made from an inexpensive 48” wooden dowel, with a music wire joiner.
  • Steerable tail wheel to enable controlled, “Rise-Off-Ground” flying.
  • Large rudder with small throw will provide low sensitivity, positive steering.
  • The use of drag links in both the rudder and elevator pushrods to provide pushrod support and throw adjustments, yet have the use of the full torque from the servo.
  • Torsion main gear for durability, shock absorption, and airframe protection.
  • Wide stance mail gear for excellent ground handling.
  • Dry weight, without flight battery, should be less than 16oz.
  • Scale appearance…the final design should LOOK like a real airplane.