I'm not sure how you will package the hydrogen for use on an airliner. You have two choices, liquid hydrogen at near absolute zero (which first you must liquify, and then you must add enormous amounts of heat to turn back into a gas --- very inefficient) or you can store hydrogen as a gas at very high pressures in heavy steel tubes/cylinders. Neither system would work well for an airplane as far as I can tell. What might work is what is already being done in some cases. Turn organic matter (ie, sawdust, yard waste, etc) into biofuels which can be used in the airplanes we already have with almost zero changes. Again, not very efficient, but it is doable and does not require fossil fuels.