What it actually looks like: https://fonts.google.com/specimen/B612
replies(6):
Legability means you have to be able to differenciate words and letters. With a font specialized for aerospace use that probably also mean it has to retain that quality when printed on panels.
A special requirement I would think of is legability while in motion. Try taking your favourite, perfectly kerned font and reading it while shaking your head wildly in poor light conditions, then you get a hint of why this font isn't optimized for looks.