Flights for UA1521 These are not all the flights that UA1521 has taken, just some of them that have flown in or out of SFO

UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on July 05, 2015. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 21, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 10, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 06, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 13, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 20, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (DEN-SFO)
This United Airlines flight traveled from Denver International Airport to San Francisco International Airport, on June 28, 2013. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (EWR-SFO)
This United Airlines flight traveled from Newark International Airport to San Francisco International Airport, on February 06, 2014. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (EWR-SFO)
This United Airlines flight traveled from Newark International Airport to San Francisco International Airport, on February 18, 2014. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (EWR-SFO)
This United Airlines flight traveled from Newark International Airport to San Francisco International Airport, on February 10, 2014. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.
UAL1521 (EWR-SFO)
This United Airlines flight traveled from Newark International Airport to San Francisco International Airport, on March 05, 2014. Passengers were flying aboard a Boeing 737-800. See all the flights for UA1521.
UAL1521 (EWR-SFO)
This United Airlines flight traveled from Newark International Airport to San Francisco International Airport, on January 29, 2014. Passengers were flying aboard a Boeing 737-900. See all the flights for UA1521.

All these flight data are available as openly licensed data on the sfomuseum-data GitHub account. If you'd like to read more about our efforts to archive flight data at SFO Museum have a look a the Mills Field weblog posts tagged "flightdata".