Per-airdrop-type tunables. All optional in config; code supplies defaults.
alert sent to the caller when the plane reaches the drop ("" = none)
bombing payload
crate payload: ms for the parachuted crate to fall
keep the plane at cruise altitude instead of dipping to the drop
ms for the plane to cross the whole flight path
Per-airdrop-type tunables. All optional in config; code supplies defaults.