Detailed mapping of karstic aquifers is of prime importance for water resources management. To achieve these surveys objectives, airborne measurements are the only methods which allow both large and dense coverage. Electromagnetic induction methods such as time-domain electromagnetic (TDEM) help to map conductors like clayey accumulations surrounding karstic conduits. Fixed-wing TDEM systems using light aircrafts do not exist on the market, despite being able to offer higher cost effectiveness and performance close to that reached with helicopter-borne EM systems in hydrogeological surveys. A sensitivity analysis of key acquisition parameters is undertaken to evaluate the capabilities of this kind of system for mapping karstic environments. Despite a flight altitude of 50m, higher than the average altitude of 30m reached with helicopter-borne systems, the results are encouraging and indicate a good capacity for investigation from 10m to about 150m depth.