This American Airlines fare just appeared for San Francisco to Frankfurt $463 round trip. At least I did not notice an hour ago when I wrote up SFO-Zurich on AA for $414 round trip. This fare is available for departures from September through mid-December, then January into April 2017. Low fare is available about 85% of weekdays.
Minimum stay for low fare is first Sunday after departure date.
Update: Low fares in $400s to Frankfurt and Zurich are available from most United hubs: SFO, DEN, IAH, CLE, EWR, IAD.
American Airlines San Francisco SFO – Charlotte CLT – Frankfurt FRA
$463.36 Thu Sep 15 – Wed Sep 21
Take note that this one-stop itinerary SFO-FRA is one flight number in each direction. I have not flown one of these kinds of flights in quite some time. Is it still the case that this flight calculates AAdvantage miles as SFO-FRA rather than SFO-CLT-FRA? The mileage for SFO-FRA round trip is 11,399 flight miles vs. SFO-CLT-FRA at 13,387. That is a lot of missing miles, if the single flight number is calculated that way.
An alternative is to find an itinerary with different flight numbers.
American Airlines San Francisco SFO – Dallas DFW – Frankfurt FRA – Charlotte CLT – San Francisco SFO
$470.86 Tue Sep 13 – Sun Sep 18
SFO-DFW-FRA-CLT-SFO = 13,301 flight miles.
Loyalty Traveler – Hotel Promotions Guide.