INSTALLATION ON LANCAIR O-235

 This Lancair has been flying for 8 years with the 3 bladed Airmaster variable pitch propeller. Because the 3 bladed propeller produced a very quiet installation it was decided to install the 2 bladed and investigate the noise level and vibration characteristics throughout the operating rpm range of both 2 and 3 bladed propeller. Chadwick vibration analysis equipment was used and both propellers were dynamically balanced at 1400 rpm. The best balance which could be obtained with the 3 bladed propeller was .18 IPS (acceptable limit is .20 IPS). The 2 bladed propeller was installed 30º out of phase with crankshaft horizontal plane and balancing at 1400 rpm produced .06 IPS vibration level.

Aerotek Propeller

Airmaster Propeller