A method for the measurement of incremental structural Loads on complex aircraft surfaces without previous knowledge of load distribution is presented. The judicious location of electric strain gages and a suitable electric circuit with a single channel output to a recording mechanism are the means of effecting the measurement. Since the output of the strain-gage circuit is generally fed into an amplifier and then to a recorder, equations for a bridge looking into a high impedance are developed for measuring loads in a complex surface, and application of the equations is illustrated. Both design and experimental data are shown. The electrical equipment used is described. An approach similar to the one presented can be used for other types of strain-gage circuits. Static test calibrations using the method have indicated a maximum error of 3.7 per cent in a complex surface, such as a horizontal stabilizer of a fighter airplane.