Airborne hours
Airborne hours is the duration the aircraft was off the ground — block time minus the taxi time at both ends. Some syndicates bill on airborne hours rather than block time because it reflects actual flight time more precisely.
Syndik8 computes airborne time from a usage log’s block times and the configured taxi minutes. The formula: block time − (2 × taxi minutes), floored at zero. The doubling is because the taxi-minutes setting represents a single one-way taxi; it is subtracted at start and at end.
Airborne hours are only used for billing when the syndicate’s billing basis is airborne. On engine-meter or block bases, the configured taxi minutes have no effect on charges.