Is this reasonable for Arabs to fund aircraft that
do not use fossil fuel?

It certainly is. Because oil is not an infinite resource, it only
represents wealth to the oil producing countries so long as it is available.
It will end someday, as will their income.

That makes it reasonable to fund alternative fuels for a number of sound
reasons. It will postpone the date when their oil is depleted. At the same
time, it will provide a new source of energy, which would make it more
likely that the free-enterprise system would be useful to resolve the energy
demands and less the liklihood that control of the energy source is by non
free-enterprise methods. And, finally, if the oil countries control the
techology of the alternate fuel and use their wealth to control new energy
production, they will have multiplied their wealth.

In addition to the financial advantages, there may be a bit of public
relations in such an adventure. Consider the cost of such an investment
compared to the total oil income.

But, once we get some sort of lift in our gliders, we are also solar
powered, simply using energy created by the sun.

Colin N12HS