Perhaps for the narrow body fleet, we could codify something like an ADL (for average daily landings) to be some thing like 2.5. Then a four day trip could look like 4-3-2-1 or any combination of daily landings to come under 2.5. Then further limit duty day with ADDP (for average daily duty period) to something like 9. Then a four day could look like 10-9-8-7, 12-6-10-8 or any combination to come under 9 hours.

Maybe having better rigs would accomplish the same thing. Not sure. Please feel free to chime in.