Something I have noticed about flight numbers from a U.S. based airline is all pacific flights except one flight is are numbered in the 800's. Example LAX-SYD, 815. SFO-HKG, 805. LAX-NRT, 897. and the only one UAL doesnt have in the 800's is the now suspended UAL flight 1 which was LAX-HKG. that flight had been on and off as around the world which continued on to New Delhi, India, London Heathrow, Washington Dulles or New York Kennedy, Los Angeles. I believe it also would go to Singapore or Bangkok throughout the past years if im not mistaken. Prehaps they opperate in the 800's due to 8 being a luckey number in Asia? I also think European flights for UAL are in the 900's correct? Well Prehaps what I have just said will give you a bit more light on the subject!