ADV: Quiet Pawnees

The silent sport of soaring can risk an unfortunate reputation with
community neighbors by operating loud towplanes. Mile High Gliding,
Inc., a commercial glider operator in Boulder, Colorado, now offers a
solution. They have acquired an STC for fitting a smaller diameter
four-blade propeller to many existing towplanes, which removes most
propeller noise, the main reason for over-flight complaints. The
difference is dramatic, making a 260HP Pawnee less noticeable than a
Citabria, proven with thousands of Boulder tows not to mention years
of European data. The Boulder gliderport provides a stringent test
case, located as it is next to a University town with an
environmentalist sensibility, and community noise activists have
proffered compliments on the change. The FAA approved alteration is a
simple bolt-on replacement for an OEM McCauley two-blade metal
propeller. Climb rate is virtually the same and the smaller, lighter,
wooden propeller is an improvement in other respects: better ground
clearance, better cooling, easier starts, less vibration, lower
gyroscopic effects, faster descent. The STC SA2515NM is applicable to
all PA-25 variants, certificated both Normal and Restricted Category.
Mile High Gliding, Inc. will not only be happy to sell permission for
its use, they are also a dealer for the product itself, the HO
2/27BHM-185 series from Hoffman Propeller GmbH & Co. KG. Contact
David Campbell at 5534 Independence Rd., Boulder, CO 80033.
(877)527-1122. .

Doh! A couple of typos slipped out before I could stop them. First
of all, the subject was supposed to say (USA) -- these Hoffman
4-bladers have been in widespread use in the UK, Germany etc. for a
long time. The big news is that there is now a multi-use STC for easy
installation in the USA. Second, the product name itself had a slip!
It's the HO 4/27BHM-185. Also, the zip code in Boulder is 80301.
Hope that's all.

just when we were changing out our exhaust to a more "throaty" roar..

had to change the pipe anyway... and a little more power out of it..

don't worry about the noise.. the nearest house to the airport is about 7
miles..

BT

"David Campbell" wrote in message
om...
The silent sport of soaring can risk an unfortunate reputation with
community neighbors by operating loud towplanes. Mile High Gliding,
Inc., a commercial glider operator in Boulder, Colorado, now offers a
solution. They have acquired an STC for fitting a smaller diameter
four-blade propeller to many existing towplanes, which removes most
propeller noise, the main reason for over-flight complaints. The
difference is dramatic, making a 260HP Pawnee less noticeable than a
Citabria, proven with thousands of Boulder tows not to mention years
of European data. The Boulder gliderport provides a stringent test
case, located as it is next to a University town with an
environmentalist sensibility, and community noise activists have
proffered compliments on the change. The FAA approved alteration is a
simple bolt-on replacement for an OEM McCauley two-blade metal
propeller. Climb rate is virtually the same and the smaller, lighter,
wooden propeller is an improvement in other respects: better ground
clearance, better cooling, easier starts, less vibration, lower
gyroscopic effects, faster descent. The STC SA2515NM is applicable to
all PA-25 variants, certificated both Normal and Restricted Category.
Mile High Gliding, Inc. will not only be happy to sell permission for
its use, they are also a dealer for the product itself, the HO
2/27BHM-185 series from Hoffman Propeller GmbH & Co. KG. Contact
David Campbell at 5534 Independence Rd., Boulder, CO 80033.
(877)527-1122. .