So I was just about to fall asleep when the most glorious thought occurred to me. Some folks like to rid themselves of babies and children whenever possible, as they are resource-sucking tantrum-bombs waiting to go off and have a penchant for creating incredibly useless artifacts because you can't steer them towards awesome professions. This has been largely achieved via burrows and unfortunate magma incidents. The idea that my semi-dozing brain came up with is pretty simple: add a [FLIER] tag to the raws of babies and children. When you have a good number of terrible lazy useless wastes of perfectly good plump helmets cadets in your experimental flight program, you may remove the tag. The wise cadets will have stayed close to the ground, as this is where every good Dwarf should be. The foolish cadets will fail out of the program in a spectacular fashion. Best to have the adults go inside before this happens.
Also, this is potentially weaponizable, as you can have your cadet squadron go on maneuvers during a siege before you give the order for a strafing run. Come to think of it, you could add the tag to any number of critters if your goal was an air force. There's nothing quite like a cavy boar plummeting toward a goblin siege at terminal velocity.
Now, I don't know if any of this would actually work, but I thought I'd pass along the idea for any enterprising raw-tinkerers who want to do something fun with their fort's littlest citizens.