Pro-Drive Secondary

The Problem

RotorWay Engineering Report #1

RotorWay Engineering Report #2

RotorWay's Sport Helicopter Article

Questions Posed to RotorWay

Answers to Some of Your Questions

Check Out This Recent Article about Secondary Shafts

Detailed Engineering Analysis

The Warranty:

If the Pro-Drive Secondary breaks during the life of the helicopter (2000 hours),

Pro-Drive will replace the shaft!


Pro-Drive 35mm Secondary disassembled after 85 Hours!

Compare that to the 35mm shafts shown below!

Check out these photos of unbroken, disassembled secondary shafts.

Click on picture to see a larger view.

     33 Hours, 35 mm       280 Hours, 30 mm           25 Hours, 35 mm    100 Hours, 35 mm


To check this shaft the 40mm bearing had to be cut off, look at the difference between the inner races of a Pro-Drive 40mm bearing and a RotorWay 35mm Bearing!

Pro-Drive 40 mm bearing after 85 Hours       Vs.     RotorWay 35mm bearing after 35 Hours

Did you know that all of the Pro-Drive Secondary Shafts are X-rayed to ensure the highest quality?


Pro 162 SF (Secondary Fix) is back from Sun-n-Fun!

Pro 162 SF takes Best of Type with the Pro-Drive Secondary Shaft


Click on pictures for larger image

This setup originally had 135 F bearing temperatures.  This installation is now running at 110 F!


Pro-Drive and its affiliates have repeatedly tried to work with RotorWay to develop an improved secondary shaft.  RotorWay says "why experiment with a design change in the shaft?"  Pro-Drive feels that the number and cause of failures is a serious concern and must be addressed.  Therefore, Pro-Drive will manufacture, and make available for sale, a secondary shaft that addresses the cause of secondary shaft failures.




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