I wish organizations like this would just come out and say, "We want free help" and then explain why they can't afford to pay. I get there's lot of events that can't afford what a professional would charge, and that's fine. But just be up front about it.
It's a very good cause and is well worth someone's best effort. The pilots are donating time, aircraft and significant expenses. From the current responses on Facebook it looks like they have what they need. As long as the photographer doesn't mind trying to wade through the iPhones, iPads and such it'll be a good day.