Variable pitch propellers blade are manufactured from a mix of wood construction. The blade roots are made of high compressed beech wood specially produced for aviation applications, taper bonded to blade body made of light wood, Spruce / Cedar by means of special joints. The entire blade surface is composite coated with two or more composite layers. The leading edge protection is applied in the same way as on the fixed pitch propellers. High resistance lacquers are applied. The blade root retainer is bonded to a special inner conical thread by way of an aluminium or steel bush.

HUB ASSEMBLY

The hub  is made of machined aluminum  using latest CNC-machineries. The external surface and internal parts are anodized to prevent corrosion.
The hub is installed on engine flange with six bolts. The electric motor installed on the top of the hub mooves an internal threaded cam joined to special fork for pitch selection. The pitch change range is limited by mechanical and electronic stops. The electric current for the pitch change is transfeared from a brush block via sliprings to the motor. The brush block housing is made of plastic material and contains two carbon brushes and RPM pickup.The corresponding blade angle can be adjusted when the propeller is installed on the aircraft. The blade lodging is made of steel. Several GT blades models can be easily installed. Presently two electric hub models are available. Some new hydraulic controlled hubs are in progress. 

THE SPINNER

The spinner dome is a one-piece part made of composite,fibre or carbon extremely crack resistant and light. The bulkheads are made from spinformed or forging pressed aluminum. The dome is attached to the bulkhead with stainless steel spinner screws. Three spinner models are  available for GT variable propellers

THE GOVERNOR

Two different automatic pitch governors units are available for electric actuated Propellers. One governor model available for hydraulic actuated propellers.

THE ADVANTAGES OF VARIABLE PITCH PROPELLERS

Increases all levels of flight performance both on take off and cruise. Improved fuel economy extending distance range. Noise reduction . Low vibration and smoother engine running. Stress reduction on engine parts , frames and instruments. Low polar moment of inertia. More confortable flights. No blade fatigue over time. Higher blades safe factor. All weather durable. Easy blades replacing. Low maintenance costs.

TERM GLOSSARY