In the US and Europe, agricultural aircraft are typically small, simple, and rugged. Most have spraying systems attached to the trailing edges of their wings, and pumps are usually driven by wind turbines. In places where farms are larger, such as
New Zealand,
Australia, the former
Warsaw Pact nations, and parts of the developing world, larger and more powerful aircraft have been used, including turboprop powered aircraft such as the
PAC Cresco, twin engined types such as the
Lockheed Lodestar and the
WSK-Mielec M-15 Belphegor – a
turbofan-powered
biplane. All tend to be of simple, rugged
STOL design. Sometimes a
ram air turbine is used as an auxiliary power source for the pumping machinery instead of taking power directly from the engine (because this can be installed without any modifications of the airplane's mechanical systems). In places where dedicated use as an agricultural aircraft is uneconomic, utility types such as the
Antonov An-2 biplane and
De Havilland Canada DHC-2 Beaver have been used. In the case of
helicopters, tanks are placed on or outside the body of the aircraft, while a spray rig, extending outward to the sides, is attached well below the main rotor blades. Hydroseeding is often done by helicopters using tanks and drop systems much like those used for
aerial firefighting. ==Techniques==