RC helicopters are split into two distinct groups – scale models and pod-and-boom, or sports grade. The latter are most often associated with RTF electric helicopters, and if you’ve bought a beginners RC it will probably be one of these.
All micro co-axials are pod and boom construction, as are most of the 4 and 6 channel electric helicopters. All choppers designed for 3D and sports flying are of this type. Scale models are relatively rare in the RC electric helicopters world.
Pod and boom helicopters are like the real thing in terms of flight dynamics – but there the resemblance ends. They are nothing like a real helicopter in appearance. The smaller single rotor designs, in particular, act more like an angry insect, all long tail and high pitched buzz! It is part of their charm, and their names reflect this: Dragonfly, Honeybee etc.
With a pod and boom FP/CP helicopter, the main mechanics are contained in a pod at the front and this is balanced by a tail boom with a rotor at the end. The long tail is necessary to balance the two different weights, with the centre of gravity being midway between them.
In co-axial electric helicopters, the weight is far more centrally placed. This allows more freedom with the design. The nose can be lengthened and the tail stem shortened. This gives them a more realistic appearance and is the reason they are used in scale model design (see below).
Scale model RC helicopters are exact replicas of the full-size versions and are named accordingly. Owners pride themselves on the detail and authenticity of their craft, which is why they are more likely to be found in kit-built and nitro powered collections. However, there are a few RTF scale model electric helicopters in existence gaining in popularity. Walkera, for example, make authentic copies of the Airwolf, Comanche and Chinook military helicopters.
All of the above are co-axial 4 channel electric helicopters (apart from the Chinook, which is twin-rotor). However, strip away the fancy fuselage and underneath they are just standard pod and boom models!