Money
Member ledger
The running account of everything a member owes and has paid: flight charges, dues, reserves, credits, and payments, in order.
In practice
A real ledger answers the only two questions that matter - what is my balance, and why - without anyone rebuilding math in a spreadsheet. Every flight posts as a charge with its meter reading; every payment posts against open charges (oldest first, in Resyrv's case); every line explains itself. When a member disputes a bill, the answer is already on the page.
Get started
See it with your own aircraft.
Add your aircraft and your rates, then see the schedule, the squawks, and the ledger all work off one record. No card required.