Quick turns with short turn radii place high loads on the wings as well as the pilot. One g is the force acting on the airplane in level flight imposed by the gravitational pull of the earth. Five g in a maneuver exerts 5 times teh gravitational force of the earth. The purpose for flight testing is to gather data about the flight characteristics of an airplane and its subsystems for subsequent analysis on the ground. This data gathering process starts with sensors or transducers which have been mounted throughout the airplane.
Transducers are devices which convert mechanical measurements into electrical signals.
Different kinds of transducers are used to measure control positions, pressures, temperatures or loads. The electrical signal from each transducer is routed through special instrumentation wiring to a central location in the airplane where it is connected to signal conditioning equipment. The resulting organized stream of data is then transferred to an on-board tape recorder and also to a telemetry transmitter. The tape recorder records the data on magnetic tape in much the same way that music is recorded on a tape cassette. The telemetry transmitter transmits the same data stream from the airplane to a ground station on a selected radio frequency, in much the same way as a commercial radio station broadcasts music to our homes.