Turkish airlines seems to serve this city pair 5 times a week in 2010 with a Boeing 777-300ER.
They have also used their Airbus A330-200 on this route in June 2010.
Turkish airlines links these 2 cities on a daily basis with an Airbus A340-300 in 2009.
Departure in Istanbul is at 11:45 pm and arrival in Beijing is at 2:00 pm.
After arrival in Beijing this flight (TK 20) continues to Shanghai Pudong (PVG) with the A340-300. Departure in Beijing is at 3:15 pm and arrival in Shanghai is at 5:25 pm after a 2 h 15 min flight with the Turkish Airlines A340-300.
The return flight (TK 21) leaves Shanghai Pudong (PVG) at 10:20 pm. It arrives in Beijing at 10:45 pm. There it leaves for Istanbul at 11:55 pm.
Arrival back in Istanbul is at 5:30 am after a 10 h 35 minutes flight.