2-1/4” Panel Mount
Magnetic Compasses
Unlighted ...............Cat. No. A-027-100............................... $74.50
Lighted...................Cat. No. A-085-100 ............................... $84.95
3-1/8” Sensitive Altimeter
0-20,000’............. Cat. No. A-064-000 ............................. $239.00
3-1/8” Low Range Airspeeds
0-120 .................. Cat. No. A-066-000 ............................. $109.50
0-150 .................. Cat. No. A-065-000 ............................. $109.50
2-1/4” CHT/EGT 18mm Kit
Unlighted. Includes, gauge,thermocouple &
probe w/leads. .......Cat. No. A-152-008 .............................. $94.75
3-1/8’ Rate of Climb
0-2,000’............... Cat. No. A-067-000 ............................. $124.00
2-1/4” Inclinometer
10/10 Scale......... Cat. No. A-012-000 ............................... $42.25
A-027-100
A-064-000
A-066-000
A-067-000 A-012-000
1-800-558-6868
SHOP AT onlinecatalog.wagaero.com
Non-TSO’d Instruments Imported for
WAG-AERO
A-152-008
S/A62
Automated Engine
Monitoring...
..of up to 29 parameters with
62 alarms. From RPM to
peak-detection leaning, the
EIS does it all. Includes
graphical and digital displays,
customizable screens, and
alarms with external warning
light. Models for all engines
up to 9-cylinders. Find out
why the EIS is the choice of
thousands of pilots.
All-cylinder EGT/CH T analyzer
functions for 4, 6 or 9 cylinder engines.
Actual Size 6"W x 2. 75"H x 2. 5"D
$995
$553
$473
4-cylinder
2-cyl 4-stroke
2-stroke
Prices include probes.
www.GRTAVIONICS.com
Grand Rapids Technologies, Inc.
616 245-7700 Fax 616 245-7707
3133 Madison Ave SE, Grand Rapids, MI 49548
FAA STCs available for: A1 Husky Cessna 172D-P, R, S Cessna 182A-P, A185E, F Cessna T210M-P, P210N, R Cessna 336 / 337A-F Cessna 340, 340A, 414+RAM Lake LA-4-200 Mooney M20E, F, J, K, L Pitts S2A, S2B Piper PA-28-R201T Piper PA-28-RT201T Piper PA-46-310P, 350P iper PA-60-600, PA-60-601 Shorts SC- 7 and many more... www.mt-propeller.comMT-Propeller USA, Inc., Florida Phone: (386) 736-7762 Fax: (386) 736-7696 info@mt-propellerusa.com MT-Propeller Headquarters, Germany Phone: +49-9429-94090 Fax: +49-9429-8432 sales@mt-propeller.com Cirrus SR22 STC #SA02924CH
Beech Baron STC #ST02819NY
HANDS ON
RETRO FIT
The Top Prop program has been designing,
testing, and marketing improved propellers
to fill niche markets in retrofitting general
aviation aircraft.
Hartzell does not claim specific increases in takeoff, climb, or
cruise with its Top Prop conversions, because quantifying those
improvements would be on a case by case basis. “Every airplane is
different, and whether it’s 1 knot or 5 knots [faster in cruise] is
hard to measure accurately,” said Trudeau. And often there are
other modifications that are performed at the same time the propeller is changed out, so it’s impossible to attribute with certainty
where each incremental improvement in performance came from.
Trudeau also cautioned against taking too much from some
propeller specifications, such as static thrust measurements. He
said a propeller could measure very strong thrust pulling against
a static tester, but its pulling power could dissipate significantly
at around 40 knots of airspeed. “We had a prop blade design here
at Hartzell that did exactly that. Measured very well in static
tests but didn’t work out so well in the real world,” he said, somewhat ruefully.
Hartzell’s best Top Prop customers are usually those who are
facing issues with an existing prop. “It usually begins with a
need,” said Trudeau. It might not be a full overhaul, but maybe a
blade needs to be replaced, or some other major work. The list
price of each Top Prop kit is about 30 percent less than the combined price for all the parts, said Trudeau. He cites this typical
scenario—an aircraft owner is faced with a $6,000 prop overhaul.
He can purchase the Top Prop kit for, say, $9,000, then sell off the
core blades from the old prop for about $1,500. “So now the delta
is only about $1,500 to have something brand new—and better,”
said Trudeau.
Now owned by Tailwind Technologies, Piqua, Ohio-based
Hartzell has been making propellers since 1917, when an air-minded Robert Hartzell branched out from the family lumber
business to supply a propeller for Orville Wright. (The company
even designed and built two aircraft models of its own during the
aviation heyday following Lindbergh’s New York to Paris flight in
1927.) Today, the propeller division of the company is one of its
cornerstones, and the Top Prop program has been designing, testing, and marketing improved propellers to fill niche markets in
retrofitting general aviation aircraft. Close to 19,000 Top Prop kits
have been sold throughout the world over the past two decades,
with annual sales varying from highs of around 1,200—to 750-to-
800 over the past few lean years. “We expect there’ll be a party
around here when we hit 20,000,” said Trudeau.
Mark Phelps, EAA 139610, is an aviation writer living in New Jersey. He is the
former editor of EAA’s Vintage Airplane magazine, and owner-pilot of a 1954
Beechcraft Bonanza.
