ELECTRIC PREROTATOR
The electric prerotator found on gyroplanes uses an automotive type starter with a bendix and ring gear mounted at the rotor head to impart torque to the rotor system. [Figure 18-5] This system has the advantage of simplicity and ease of operation, but is dependent on having electrical power available. Using a “soft start” device can alleviate the problems associated with the high starting torque initially required to get the rotor system turning. This device delivers electrical pulses to the starter for approximately 10 seconds before connecting uninterrupted voltage.
 
TIP JETS Jets located at the rotor blade tips have been used in several applications for prerotation, as well as for hover flight. This system has no requirement for a transmission or clutches. It also has the advantage of not imparting torque to the airframe, allowing the rotor to be powered in flight to give increased climb rates and even the ability to hover. The major disadvantage is the noise generated by the jets. Fortunately, tip jets may be shut down while operating in the autorotative gyroplane mode. 
 

INSTRUMENTATION
The instrumentation required for flight is generally related to the complexity of the gyroplane. Some gyroplanes using air-cooled and fuel/oil-lubricated engines may have limited instrumentation.
ENGINE INSTRUMENTS
All but the most basic engines require monitoring instrumentation for safe operation. Coolant temperature, cylinder head temperatures, oil temperature, oil pressure, carburetor air temperature, and exhaust gas temperature are all direct indications of engine operation and may be displayed. Engine power is normally indicated by engine r.p.m., or by manifold pressure on gyroplanes with a constant speed propeller.
 
 

ROTOR TACHOMETER
Most gyroplanes are equipped with a rotor r.p.m. indicator. Because the pilot does not normally have direct control of rotor r.p.m. in flight, this instrument is most useful on the takeoff roll to determine when there is sufficient rotor speed for liftoff. On gyroplanes not equipped with a rotor tachometer, additional piloting skills are required to sense rotor r.p.m. prior to takeoff.
 

Certain gyroplane maneuvers require you to know precisely the speed of the rotor system. Performing a jump takeoff in a gyroplane with collective control is one example, as sufficient rotor energy must be available for the successful outcome of the maneuver. When variable collective and a rotor tachometer are used, more efficient rotor operation may be accomplished by using the lowest practical rotor r.p.m. [Figure 18-6]
 
SLIP/SKID INDICATOR
A yaw string attached to the nose of the aircraft and a conventional inclinometer are often used in gyroplanes to assist in maintaining coordinated flight. [Figure 18-7]
 
AIRSPEED INDICATOR
Airspeed knowledge is essential and is most easily obtained by an airspeed indicator that is designed for accuracy at low airspeeds. Wind speed indicators have been adapted to many gyroplanes. When no airspeed indicator is used, as in some very basic amateur-built machines, you must have a very acute sense of “q” (impact air pressure against your body).