AOPA Pilot Magazine - May 2013 - 64

Like other modern ag airplanes,
the Thrush is capable of carrying
more payload than its empty weight.
This lightly loaded 510G is climbing
about 1,500 fpm at around 100 mph
as I reduce engine power, pull the
prop back to 1,900 rpm, and take
in the view from pattern
altitude.
Forward visibility is
helicopter-like because
of the low instrument
panel and the sharply
downward slope of the
preposterously long,
thin cowl. The propeller
is about 20 feet in front of
the cockpit, and it looks
as though it could be in
another time zone.
The strange perspective of the downsloping
nose tricks me into
climbing when the airplane appears to be in
level flight. When the cowl is level with the
horizon, the airplane is in a 10-degree climb.

components hooked up again. The
change is intended to radically
reduce the amount of downtime
required for engine changes.
Thrush officials say the H80 typically burns about 50 gallons of fuel
per hour, roughly the same amount
as a similar-sized PT6A34AG at the low altitudes
where ag aircraft normally
work. For high-flying airplanes, GE officials say
the H80 offers a quicker
climb to altitude because
of its high horsepower, and
potentially faster cruise
speeds.

HIGH COMMODITY prices

have made for boom
times at Thrush
Aircraft (above), where
the company set records
in production and revenue
last year. In addition to
agricultural flying, the
Thrush can serve as a fire
bomber, dropping
hundreds of gallons of
water from a door at the
bottom of the fuselage
(right).

CZECH ENGINE. Development of the H80
engine began soon after GE bought Walter
Motors in 2008. Walter had been making
engines for 60 years in the Czech Republic,
and one of the most popular was a PT6 clone
known as the M601 that was used throughout
the Eastern Bloc.
Walter turboprops were flown from Siberia to
Africa on many Transport-category and military
aircraft, and the engines earned a reputation for ruggedness and operational simplicity during more than
17 million flight hours. The H80 is based on the M601
and has the same external dimensions. But better
materials and design improvements allow the H80 to
put out 800 horsepower while the M601 is rated at 650.
A GE factory near Prague manufactures the
engines and sends them in individual containers
(which look remarkably like GE refrigerator boxes)
to Thrush Aircraft for installation. The H80 weighs
382 pounds and is lighter than a PT6A-34AG, so the
Thrush 510G had its Pinocchio-like nose extended
another 14 inches to accommodate the new engine.
The change also allowed Thrush to remove ballast
from the Pratt & Whitney-powered aircraft, so a GE
Thrush is more than 200 pounds lighter.
Wiring for all H80 electronic engine controls and
sensors are routed through two cannon plugs. When
an H80 engine is replaced in the field, technicians need
only reconnect the two plugs to get all the electronic
64 | AOPA PILOT May 2013

STAYING LOW. I’m tempted
to climb to learn more
about the engine’s climb
performance and fuel consumption, but a slate gray
overcast at 4,000 feet makes that impossible in
this VFR-only aircraft. (A few Thrush aircraft,
including those made for special missions, are

AOPA Pilot Magazine - May 2013

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