If you want to geek out on this: https://nmb.gov/NMB_Application/wp-c...anual-2019.pdf See 19.501

https://nmb.gov/NMB_Application/inde...eterminations/

Search year by year and click on the page cite to read the determination. Bottom line is there's little consistency case by case.

Here's the unsuccessful case between World Airways and North American in 2013: https://nmb.gov/NMB_Application/wp-c.../10/40n012.pdf

QUOTE=FXLAX;3164908]Yes, I got that. Operational control is not the right term to use. My comment to Johnnyjetprop was to add that it does require common decision making, for lack of a better term.[/QUOTE]