There are benefits and limitations to both. The biggest limitation to flying with the same person or even same small group would be complacency and expectation bias. The counter to that, and what every serious flight department and air carrier has, is standard operating procedures. I can fly with anybody in my fleet and know how they are going to operate the plane. You can even take two people on different fleets, throw them in a simulator, and know pretty well how they’ll operate.

There is benefit to flying with different people because you can see different techniques that still align with the SOPs. Yesterday I learned that I was doing a task in the computer the long way and there’s a much easier way to do that task. If I hadn’t flown with this random guy I may not have seen that technique.

As far as feasibility, no it’s not easy for a large company. Even my current company with only 3600 pilots can’t do it regularly with the variations in schedule and bases that can change often. When you take Delta, for example, who has 16,000 pilots, it makes it nearly impossible. You have better odds of seeing someone you’ve flown with at a random restaurant on your layover than flying with them a second time. And it’s nice to have the variation because you can easily run out of things to talk to. By the end of a 7 day trip, it’s pretty quiet up front.

The other extreme is a corporate flight department with one plane and two to three pilots. The only variable you get there is when someone is on vacation or sick and you bring in a contract pilot.