🛩️ Aviation History – 1950s: The Transponder & Secondary Radar Era During the 1950s, aviation entered a new age of safety and precision. The invention of the transponder allowed radar systems to identify individual aircraft and display their altitude. The 1950s marked the true beginning of modern radar-based ATC. #AviationHistory #ATC #Radar #Transponder #SSR #AviationSafety #AvelFlightSchool #PilotTraining #AvGeek #HistoryOfAviation #education #🤔 Unknown Facts