Europeans are mobilizing a massive aviation assistance effort for Ukraine.

As Kay Wolf and Stephan Sahling watched the news of Moscow's full-scale invasion of Ukraine unfold on February 24, the two German IT security professionals reacted instantly.

The long-time friends share many interests, but it was their mutual love of aviation — Sahling is a pilot with over 15 years of experience and Wolf is an enthusiast — that prompted them to concoct a plan on the spot.

They planned to use....