Cathay Pacific Asia Miles - Why CX879 Keeps Departing Ontime but Arrive So Late?

Checking through flight stats, I wonder why CX879 is scheduled for a late arrival into HKG (about 51 minutes today) for the 3rd consecutive day when it more or less departed SFO on time:

Apr 1
Departure
Airport: (SFO) SFO International Airport
San Francisco, CA, US
Scheduled: Tue - Apr 01, 2008 1:35 PM
Actual: Tue - Apr 01, 2008 1:29 PM

Arrival
Airport: (HKG) Hong Kong International Airport
Hong Kong, HK
Scheduled: Wed - Apr 02, 2008 6:40 PM
Estimated: Wed - Apr 02, 2008 7:31 PM
Estimated to arrive at gate 51 min later than scheduled

Mar 31
Departure
Airport: (SFO) SFO International Airport
San Francisco, CA, US
Scheduled: Mon - Mar 31, 2008 1:35 PM
Actual: Mon - Mar 31, 2008 1:34 PM

Arrival
Airport: (HKG) Hong Kong International Airport
Hong Kong, HK
Scheduled: Tue - Apr 01, 2008 6:40 PM
Actual: Tue - Apr 01, 2008 7:26 PM

Mar 30
Departure
Airport: (SFO) SFO International Airport
San Francisco, CA, US
Scheduled: Sun - Mar 30, 2008 1:35 PM
Actual: Sun - Mar 30, 2008 1:45 PM

Arrival
Airport: (HKG) Hong Kong International Airport
Hong Kong, HK
Scheduled: Mon - Mar 31, 2008 6:40 PM
Actual: Mon - Mar 31, 2008 7:52 PM

I apologise if someone already knows the answer to this, but it is rather baffling as to why a flight which manages an on time departure time frame can arrive into it's destination so late as shown above. :confused:

I'm taking this flight in June and I hope this won't happen.

Just a guess..The US is using Daylight Savings Time, and I don't believe HKG is. The flight is departing SFO on time, but because 1:35 is one hour later in an absolute sense than during Standard time, the flight's arrival time should be 1 hour later in HKG, which is reflected in all of these times.

I could be wrong, but I don't know that CX adjusted their schedule to the earlier start of Daylight Savings this year (moved up several weeks).

Another possibility is stronger than usual headwinds. A quick check of other airlines' transpac flights would tell whether this is the case. It can happen at this time of year.

The reason is definitely not daylight savings. Airline schedules have definitely factored in daylight savings.

The reason for delay is headwind, because if you look at LAX flights, they are also roughly delayed for 30 minutes to one hour on arrival.

Another factor would probably be long taxi-out holds in San Francisco. I don't know if it is still true, but whenever I fly out of SFO, especially to Hong Kong, the taxi-out time is really long, like around 30 minutes.

Yes, very strong headwind lately. :eek: Most westbound flights are arriving late, while most eastbound flights are arriving early. Not unusual at all this time of the year. ;)

Definitely strong head winds. I believe CX 883 had to make a tech stop in TPE the other day.

How close to the maximum 744 range limit is SFO-HKG? Is it very close or still far from it?

SFO-HKG is definitely the range of a B744. I could probably recall only a few days a year that there is a fuel stop on the SFO-HKG route. But it is definitely cutting close to the limit, especially on westbound flights in winter, since LAX flights, which are only a few hundred miles away, require frequent techstops on many days.