Re: Contra-rotating propellers

Date:         05 Jan 98 23:43:06 
From:         Arthur Utay <>
Organization: AT&T
References:   1
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  or MIME structure wrote:
> I flew on a BAe Jetstream 4100 aircraft the other day, and I noticed that the
> two propellors turned in opposite directions.

Yup, TPE331-14GR/HR engines (GR's rotate CW from pilots seat, HR's CCW)
The purpose is to minimize engine out control effects, as some other
people have stated.

> But I suppose then separate sets of spare engines - both
> "clockwise" and "anti-clockwise" have to be kept in store since the engines
> can not be inter-changed.

The engine is modular. Primarily, all that has to be changed to convert
from a GR to an HR is the front gearbox, which resides inside the

> Which other aircraft also use this kind of arrangement?

No other aircraft use HR engines. The GR's have been certified recently
on the Antonov AN-38

A. W. Utay
C180 N180Y