factsonly From Montserrat, joined Aug 2012, 325 posts, RR: 0 Posted (3 months 3 weeks 6 days 14 hours ago) and read 3834 times:
This may be nitpicking but............DL loaded a new Summer 2013 timetable with some very subtle changes in flight timings and equipage, thus breaking the regularity of its daily flight program. Could anyone clarify why they do this?
ATL-AMS-ATL:
Here we have a different aircraft type operating one flight per week, but the flight timings and aircraft type are not consistent on all days.
jbmitt From United States of America, joined Jan 2002, 509 posts, RR: 2 Reply 1, posted (3 months 3 weeks 6 days 14 hours ago) and read 3708 times:
I'm sure they use historical data. Different types of aircraft can cruise at different speeds, and congestion in the skies can impact arrival/departure.
They are trying to maintain on time arrivals and departures.
brilondon From Canada, joined Aug 2005, 3180 posts, RR: 1 Reply 2, posted (3 months 3 weeks 6 days 13 hours ago) and read 3574 times:
They change aircraft usually due to demand and when certain types of aircraft are available on certain days of the week. The time changes are just general estimates as to when they are scheduled and they may need to change due to changes at each airport. Most airlines change and do not let their passengers know if it is just 5, 10 or 15 minute changes, but at least DL has continued the NW policy of coming up with publishing such minute changes, although in the grand scheme of things it really doesn't make a whole lot difference if you arrive 5 or 10 minutes either early or late of their scheduled time. Schedules are not set in stone as they may very due to weather or traffic delays anyway. I have yet to depart and land exactly as they are scheduled.
hOmsAR From United States of America, joined Jan 2010, 804 posts, RR: 0 Reply 3, posted (3 months 3 weeks 6 days 11 hours ago) and read 3332 times:
If you think that's bad, you should take a look at United's schedules.
Their schedules vary from day to day, and week to week. Just check a domestic hub-hub route such as ORD-SFO, and see how many columns/pages it takes to show the entire schedule over the next month. It's almost impossible to figure out how many flights per day they operate because there are so many variations you can't keep track of them all.
enilria From Canada, joined Feb 2008, 6137 posts, RR: 13 Reply 4, posted (3 months 3 weeks 6 days 9 hours ago) and read 3084 times:
Quoting factsonly (Thread starter): This may be nitpicking but............DL loaded a new Summer 2013 timetable with some very subtle changes in flight timings and equipage, thus breaking the regularity of its daily flight program. Could anyone clarify why they do this?
The actual reason this now happens is that a computer optimizer program is creating the schedule. In the old days a person was doing it and he/she didn't go to the trouble of making such minor changes. Now the software is optimizing it to the minute. Departure and arrival times change connection opportunities among other things.
Viscount724 From Switzerland, joined Oct 2006, 21495 posts, RR: 24 Reply 5, posted (3 months 3 weeks 6 days 8 hours ago) and read 2873 times:
Minor differences from day to day can also be due to problems obtaining consistent daily slot times. Or it could reflect gate availability either at the origin or destination which may vary from day to day when all flights aren't daily.
Many schedules change seasonally due to differences between average summer and winter winds.
PITrules From United States of America, joined Jun 2000, 2691 posts, RR: 3 Reply 6, posted (3 months 3 weeks 6 days 7 hours ago) and read 2783 times:
Another factor is that flight crews largely get paid based on block times. If there is historical data to suggest a flight is a few minutes shorter on a given day of the week, then the airline will take advantage of that considering crews get paid literally by the minute.
FlyDeltaJets From United States of America, joined Feb 2006, 1625 posts, RR: 3 Reply 9, posted (3 months 3 weeks 6 days ago) and read 2279 times:
Quoting hOmsAR (Reply 3): If you think that's bad, you should take a look at United's schedules.
I was just about to mention that, sucks internally because you may think you can make an OT departure but then you double check and the flight leaves 10 min earlier than it did for the entire week.
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