The B747 was the first Lufthansa aircraft originally equipped with an electronic strain gage weight & balance system. This system determines electronically with axle mounted strain gage transducers the Take-Off Gross Weight (TOGW) in kg and the Center of Gravity (CG) in % MAC. The basic purpose of the system was to achieve confidence in the load and trim data sheet data. This confidence is obtained by comparison of the independent weight & balance indication with the load and trim sheet data, which is calculated with statistical standard weights.
After the first period where we experienced a good system performance we started an investigation with the target to operate the weight & balance system in primary mode. The advantage of the primary operation would be the deletion of load and trim sheet with several corresponding economical and operational benefits. In addition this would result in a safety increase by higher accuracy of the weight & balance data and prevention of load and trim sheet calculation errors and loading errors.
To achieve the approval from the German Airworthiness Authority for primary operation, LH demonstrated with an extended evaluation program that system accuracy, reliability and self test capability is sufficient.
LH received the authority approval and will start primary operation of the B747 Weight & Balance System beginning in 1979.