With a post 1970 pod, get the US government ( perhaps due to the oil shock, etc) to force through law, all the US major airlines to merge into just 2 companies.
Bonus points if you can get each company to use only Boeing or McD aircraft ( I'm presuming McD design and build a 767 & 777 type aircraft to go head to head with Boeing) for their entire fleet.
Triple points if you can get both airlines to be marketed under the Pan-Am and TWA corporate colours.
Regards filers.