When considering economic aspects, recent work has shown that 100% hydrogen fueled airplanes will not be feasible for at least several decades. This paper analyzes some of the technological topics involved in the use of hydrogen as additional fuel in conventional kerosene fueled aircrafts. The addition of limited quantities of hydrogen does not require modifying aircraft shape or volume, and therefore, since it has no impact on its aerodynamics, could represent a starting point and smooth transition to 100% hydrogen use situation. An estimate of both engine and aircraft performances has been carried out in order to evaluate the benefits of this technological option. The addition of small quantities of hydrogen to a kerosene fueled gas turbine decreases its specific fuel consumption, no matter what the engine thrust. This decrease in specific fuel consumption will change the performance characteristics such as range, payload, operating empty weight (OEW) and fuel weight for a similar maximum take-off weight (MTOW) of the aircraft.