Here are the required airports as they currently stand (completed airports in red).
Requirements
Full stop landing at each airport
Two stops below 40S Latitude 500 nm apart
Two stops above 60N Latitude 500 nm apart
Bonus airports 1 hour each
Requirements
Full stop landing at each airport
UT65
SLCB
FMSF
LGZA
UOOO
NWWK
SLCB
FMSF
LGZA
UOOO
NWWK
Two stops below 40S Latitude 500 nm apart
Two stops above 60N Latitude 500 nm apart
Bonus airports 1 hour each
SABA (better have some scenery installed)
VNKT
FACT
RORY
VNKT
FACT
RORY