For the life of me I still don't understand the TWA/Pan Am route swap of 1975. I have always been under the impression that Pan Am gave up access to southern european points (such as Madrid, Paris and Rome) while TWA gave up access to points such as Frankfurt. Looking at timetables from early 1978 for both airlines PA in fact did serve Rome from New York as did TWA (TWA also flew nonstop to Rome from Boston) , did fly to Madrid albeit from Miami instead of New York and Boston where TWA flew from, and to Paris from London on a connector flight wihich allowed PA passengers bound for Heathrow to connect to Paris. TWA flew from Paris nonstop to New York, Chicago, Boston and Washington. TWA did fly to Frankfurt from Boston, while PA continued to serve the Boston-Heathrow route I though they had given up in the route swap. I did notice that cities such as Istanbul, Ankara, Tehran, Damasucus and Delhi were exclusive Pan Am cities while Cairo, Casbalanca, Athens and Milan were exclusive TWA cities. They both served Bombay and Bahrain, again something I though was not permitted under the 1975 deal.
Also, was their a similar unwritten arragement between Pan Am and Braniff for Latin American routes? PA and Braniff served almost enitrely an different set of cities in Latin America from primary gateways in Miami and New York.