"Gyroplane" is an official term
designated by the Federal Aviation Administration (FAA) describing an aircraft
that gets lift from a freely turning rotary wing (rotor blades), and which
derives its thrust from an engine-driven propeller. Historically, this type of
aircraft has been known as the autogiro and the gyrocopter. The early names and
variants were filed as trademarks.
Gyroplanes derive lift from freely turning rotor blades tilted back to catch the
air. The rushing air spins the rotor as the aircraft is thrust forward by an
engine-driven propeller. Early gyroplanes were powered by engines in a tractor
(pulling) configuration and were relatively heavy. Modern gyroplanes use a
pusher propeller and are light and maneuverable. With the engine in the rear,
the gyroplane has unobstructed visibility.
A Gyroplane can fly more slowly than airplanes and will not stall. They can fly
faster than helicopters but cannot hover. Since the rotor blades on the
gyroplane are powered only by the air (autorotation), much like a windmill,
there is no need for a tail rotor for anti-torque. The gyroplane is a stable
flying platform. This is not so with helicopters, which pull the air down
through engine-powered rotor blades making it possible to hover, but also making
the aircraft very complicated and expensive to fly. Due to their inherent
simplicity, gyroplanes are easier to operate and less expensive to maintain than
helicopters.
Gyroplanes in flight are always in autorotation. If power fails in a gyroplane
the autorotation continues, and the aircraft settles softly to the ground from
any altitude. The procedure to land after a power failure is the same procedure
as a normal landing, which requires no landing roll. Thus the gyroplane is a
safer aircraft for low and slow flight, as compared with both helicopters and
airplanes. The ability of gyroplanes to fly faster than helicopters and slower
than airplanes makes it something of a hybrid, having the good qualities of the
other two types of aircraft with little of the bad.
The single attraction of helicopters over gyroplanes is their ability to hover,
which is necessary in some situations such as rescue or in sling load work. In
air surveillance and point-to-point flying, not being able to hover is not a
disadvantage because many gyroplanes, such as the Groen Brothers Hawks, take off
and land vertically without having to hover. Helicopters at low altitude out of
ground effect avoid hovering whenever possible. It is too dangerous. To fix
surveillance on one spot, proper procedure for all rotorcraft is to circle in a
slow orbit.