An onboard system for use in measuring, computing and displaying the gross weight and location/relocation of the center of gravity, for aircraft (1). Temperature and pressure transmitters and transducers (49, 53) are mounted in relation to each of the landing gear struts (8). Transmit those temperature and pressure signals to an onboard micro-computer/controller with redundancy for accuracy and failure protection. The system also incorporates a software correction program to correct and compensate for physical changes to strut components due to temperature fluctuations, O-ring seal (11) drag and hysteresis within modern day 'shock absorbing' aircraft landing gear struts. The computer makes adjustments for internal temperature changes and drag; converts sustained pressures to the weight supported by each strut, and computes the aircraft's current gross weight and center of gravity. The computer also is pre-programmed to illuminate a 'Hard Landing Indicator Light' mounted on the display (29), when pre-programmed individual strut pressure limits are exceeded and sensed during landing. These pressure readings are stored in the computer memory and can be utilized when the aircraft is inspected and serviced.