15. MSPeconomist correctly answered PSA with regard to all coach B727-200 service being operated between SFO and LAX. I believe the other air carrier with all coach 72S service on the route at this time was United and the class of service was designated as K.
BTW, when I was quite a bit younger, I flew PSA a number of times between SFO and LAX on board the stretch 727. And I always noticed how beautiful most of the young lady flight attendants were! Talk about California girls!