One of my most favorite and certainly timeley is from one of the true
aviation pioneers, Otto Lilienthal. I shortened and changed it for my
own use:

"With each advent of spring when the air is alive with innumerable
happy creatures... a certain desire takes possession of John. He longs
to soar upward and to glide, free as the bird, over hot deserts,
smiling fields, leafy woods, mountain peaks, and mirror-like lakes, and
so enjoy the varying landscape as fully as only a bird can do."

I don't think Otto would mind my theft of his words. Can you imagine
his joy at seeing, feeling and flying our beautiful sailplanes? The
actual quote is:

"With each advent of spring, when the air is alive with innumerable
happy creatures; when the storks on their arrival at their old northern
resorts fold up the imposing flying apparatus which has carried them
thousands of miles, lay back their heads and announce their arrival by
joyously rattling their beaks; when the swallows have made their entry
and hurry through our streets and pass our windows in sailing flight;
when the lark appears as a dot in the ether and manifests its joy of
existence by its song; then a certain desire takes possession of man.
He longs to soar upward and to glide, free as the bird, over smiling
fields, leafy woods and mirror-like lakes, and so enjoy the varying
landscape as fully as only a bird can do."
Otto Lilienthal

or how about:

To invent an airplane is nothing. To build one is something. But to fly
is everything.
Otto Lilienthal