There are three basic types of commercial real estate leases. These leases are organized around two rent calculation methods: net and gross.. The gross lease typically means a tenant pays one lump sum for rent, from which the landlord pays his expenses. The net lease has a smaller base rent, with other expenses paid for by the tenant. The modified gross lease is a happy marriage between the two.
The Transportation Security Administration agrees with it, but airlines don't. For instance, American Airlines advises passengers to be at the airport two hours before flight time for international departures and 90 minutes for domestic flights. Also, there's an exception for flights to certain overseas destinations, which require that you check in earlier.
The airlines have a cut-off time of 30 minutes prior to flight time in order to check in (we almost missd it once). To be safe, for domestic flights, we arrive at the airport between 1 hour to 1.5 hours prior flight time, which gives enough time to check in, and get through security lines. For an international flight, I would arrive 2 hours before flight time.