By 1971, the Federal Communications Commission (FCC) introduced the Prime Time Access Rule, which freed local network affiliates in the top 50 markets (in practice, the entire network) to take a half hour of prime time from the networks on Mondays through Saturdays and one full hour on Sundays. Because nearly all affiliates found production costs for the FCC's intended goal of increased public affairs programming very high and the ratings (thus advertising revenues) low, making it mostly unprofitable, the FCC created an exception for network-authored news and public affairs. After a six-month hiatus in late 1971, CBS thus found a prime place for 60 Minutes in a portion of that displaced time, 6–7 p.m. (Eastern time; 5–6 Central) on Sundays, in January 1972. This proved somewhat less than satisfactory, however, because in order to accommodate CBS' telecasts of late afternoon National Football League games, 60 Minutes went on hiatus during the fall from 1972 to 1975 (and the summer of 1972). This took place because football telecasts were protected contractually from interruptions in the wake of the infamous ""Heidi Game"" incident (as previously mentioned) on NBC in November 1968.