| Flying scale model airplanes is perhaps the dream of | | | | aerodynamic design should be considered. This |
| every model airplane hobbyist. Almost or many RC | | | | phenomenon is known as The Scale Effect. |
| airplane enthusiast dream of having their favorite full | | | | You can’t scale down the air molecules & |
| size replica to bore holes in the sky. But it will not be | | | | the viscosity of air. The behavior will be different. The |
| easy just to copy the exact dimension of the full size | | | | wing location & wing area, horizontal and vertical |
| airplane and then scale it down to what ever you | | | | stabilizer area & location, airfoil design, plays a |
| desire, like for example 1/8 scale, ¼ scale so forth | | | | major role on its stability. Redesigning the airplane is |
| and so on. Even though you know how to use CAD | | | | essential. The model has to be redesigned based on |
| software to design and draw the airplane, without | | | | the lift and drag coefficients and Reynolds number on |
| considering the aerodynamic principles, you | | | | its miniature dimensions to achieve stability. This is why |
| won’t have a stable airplane. So this is the first | | | | some Almost Ready to Fly, Ready to Fly or Kits have |
| step on how to fly scale model airplanes. It will be | | | | 30% or 40% scale specification. Meaning only 30% |
| impossible to fly your scale model airplane without | | | | was copied from the full size airplane. Possibly the |
| considering the aerodynamic design. Again, before you | | | | horizontal stabilizer area was modified or vertical |
| attempt to build & fly your very first scale model, | | | | stabilizer. Changed the airfoil type or wing area. In order |
| you should have already build your skill to at least an | | | | to achieve stability. The closer its size to the full size |
| intermediate level. Meaning, flying a non-scale shoulder | | | | airplane, the more you can copy the exact dimension |
| wing design type of model airplane. Then choose the | | | | and behavior. This is why ¼ scale model airplanes |
| trainer type full-scale model airplane like the Cessna | | | | are popular to those really serious on RC airplane |
| 150 or J3 Piper Cub. At least those airplanes have a | | | | modeling. Considering the cost and set-up, danger to |
| built-in stability design. The wings constant chord and | | | | life and property, it will only be possible for those who |
| rectangular (for J3 Piper Cub). High wing location, | | | | were well to do. Imagine how many gallons of fuel it |
| meaning the wings is above the fuselage, which have | | | | will consume! You will also need bigger flying field. |
| pendulum stability. Landing gear is tricycle type (for | | | | Good thing that gas or petroleum engines (chainsaw |
| Cessna 150). But wait, does this mean the stability is | | | | engines) are fit to use in those monsters which |
| the same when you scale down those airplanes? The | | | | reduces the cost of fuel. Unlike using methanol, castor |
| answer is No. Those airplanes will fly terrible when you | | | | oil and nitromethane for fuel on glow engines. So |
| scale it down and copy the exact dimensions. Like | | | | before having any expectations on acquiring one, first |
| what I’ve mentioned previously, the | | | | consider those facts. |