Main Rotor Drive System

You have invested (or you are giving it a lot of serious thought about investing) a lot of money, time, and effort to build your rotorcraft and experience the thrill of vertical flight. Now you can enhance the pleasure of that flying experience and provide enhanced peace of mind by improved safety by installing and using the PRO-DRIVE'S MAIN ROTOR DRIVE SYSTEM for your Rotorway helicopter.

This system represents the greatest improvement in RotorWay technology in 25 years. The smoother, quieter, safer ride in your Rotorway helicopter is provided by the first retro-fittable main rotor drive conversion system available only from
PRO-DRIVE, INC.Main Rotor Drive Kit

Expressly developed for all "Exec Series" rotorcraft, this system solves a number of nagging problems and gives new meaning to the words "reliability and low-maintenance," and will provide many hundreds of hours of quieter, smoother and worry free flight.

If you have grown weary with constant need to clean up the power compartment, replace oil saturated drive belts, the vibration, the noise and that hundred hour replacement; then you owe it to yourself to have a serious look at the new main rotorshaft conversion kit from PRO-DRIVE, INC..

Specicially created by PRO-DRIVE for the RotorWay series of light helicopters, this patented drive system comes in a complete "kit" form with detailed installation instructions, and can be completed by the average builder/pilot on a weekend with the same tools and skills you used to build your "dream machine."

Rotorway has created an excellent flying machine, with good performance, responsive controls and great flight characteristics - an almost perfect machine - were it not for that abominable chain!

There are more than 300 of these kits sold!

PRO-DRIVE has taken a good design and made it even better by getting rid of that chain and giving you over 20 pounds of increased load in the bargain!

Below are listed the highlights, or salient points, that make PRO-DRIVE'S MAIN ROTOR DRIVE SYSTEM the only way to go:


                               Installed Main Rotor Drive Kit


  • The Main Rotor Drive is based upon KEVLAR high strength cog belt technology. Since there is no chain, there is no oil bath needed. It is this belt concept that reduces noise, vibration, and no oil being slung all over the place.
  • RotorWay's maintenance schedule recommends changing the chain drive components every 100 hours. A PRO-DRIVE Main Rotor Belt Drive system has been operating in a RotorWay aircraft for 325 hours without showing any signs of significant wear and tear (Yes, it is inspected regularly).
  • As a matter of fact, we have in our possession a Main Rotor Cog Belt Drive System that was involved in rollover. The blades broke, the main drive shaft bent, and the pilot (thank God!) walked away from it. But, the cog belt drive was intact. There is no apparent damage to the system as can be seen by visual inspection. (And believe me, there have been a lot of knowledgeable and experienced eyeballs looking at it}.


  • Now don't forget that your aircraft is 22 pounds lighter with this kit installed.


  • Reduced water and oil temperature(up to 25 degrees F)


  • Up to 50 degrees F. lower secondary bearing temperature


  • Improved viewing of engine compartment, allowing safer pre- and postflight inspection


  • NO OIL BATH! Therefore, you have oil free drive belts, exhaust manifold, radiator, and engine compartment!


  • Reduced and easier aircraft maintenance


  • Reduced friction in the drive system provides improved auto rotation


  • Improved power coefficient for hover and forward flight





John Spurling, Pres.
Route 3, Box 12 C
Cleveland, OK 74020, USA
Tel. (918) 243-7635
Fax: (918) 243-7882