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Precise Timing In US Airline Schedules  
User currently offlineSuperhub From Hong Kong, joined Jan 2006, 478 posts, RR: 0
Posted (8 years 7 months 3 days 20 hours ago) and read 3861 times:

One thing I have noticed about US airlines is that they use very precise times for their schedules. For example:

DL 632 departs SFO at 8:30am and arrives ATL at 3:59pm everyday except Wednesday. On Wednesday, the same flight arrives at 4:02pm.

Another example:
AA1541 departs DFW at 8:49am and arrives SEA at 10:54am everyday.

As you can see, these schedules are very precise...contrast these with other airlines such as CX or BA, which schedule their flights to the nearest 5 minutes.

CX 460 departs HKG at 8:35am and arrives in TPE at 10:15am

BA 307 departs CDG at 10:50m and arrives at LHR at 11:15am


I can see why trains can implement timetables which are very precise... because trains in general departs/arrives at the very precise time (especially in countries like France and Japan). Trains also have less factors to think about when making their timetables...they don't have to think about weather (winds etc)...they just have to think about where other trains are, what speed they are going..how long are they going to dwell at stations etc.

Airlines, however, are very unlikely to arrive at precisely the scheduled arrival time. Other factors play in such as wind, congestion etc which will make the flight arrive earlier/later than the scheduled arrival times.

My question is...why do US airlines have such precise schedules, or why do international airlines round up their times to the nearest five minutes?

So for this example:
DL 632 departs SFO at 8:30am and arrives ATL at 3:59pm everyday except Wednesday. On Wednesday, the same flight arrives at 4:02pm.

Why don't they just say that the flight arrives at 4pm everyday except Wednesday when it will arrive at 4:05pm?


Alternatively:
BA 307 departs CDG at 10:50m and arrives at LHR at 11:15am

Why doesn't BA say that the flight departs at 10:51am and arrive at 11:16am?

30 replies: All unread, showing first 25:
 
User currently offlineTransWorldSTL From United States of America, joined Mar 2006, 568 posts, RR: 1
Reply 1, posted (8 years 7 months 3 days 17 hours ago) and read 3791 times:

I think a long time ago someone told me it was to improve their on time performance. If they give exact times that are a little later than needed, they can arrive/depart while saving their on-time performance record.. I'm probably wrong but I remember hearing that..

User currently offlineSESGDL From United States of America, joined Jan 2001, 3489 posts, RR: 10
Reply 2, posted (8 years 7 months 3 days 17 hours ago) and read 3785 times:

Quoting TransWorldSTL (Reply 1):
I think a long time ago someone told me it was to improve their on time performance. If they give exact times that are a little later than needed, they can arrive/depart while saving their on-time performance record.. I'm probably wrong but I remember hearing that..

That's pretty correct. One reason airlines do it is to increase flight times. For instance, if I fly from MSP-ORD, a flight which is about 50 minutes, instead of a flight being from 12:45pm-1:45pm, airlines schedule it for like 12:45pm-2:16pm, for allowance of more taxi time, etc. Another reason is airlines are now using limited turnaround times. DL, for example uses 45 minute turnarounds for all narrowbody flights domestically when they can. So if a flight arrives at 2:16pm, it will depart again at 3:01pm. I'm gonna stop, because it's too late and I'm explaining it wrong... Sorry...

Jeremy


User currently offlineSuperhub From Hong Kong, joined Jan 2006, 478 posts, RR: 0
Reply 3, posted (8 years 7 months 3 days 17 hours ago) and read 3773 times:

Quoting SESGDL (Reply 2):
One reason airlines do it is to increase flight times. For instance, if I fly from MSP-ORD, a flight which is about 50 minutes, instead of a flight being from 12:45pm-1:45pm, airlines schedule it for like 12:45pm-2:16pm, for allowance of more taxi time, etc

Thanks for the explanations TransWorldSTL and SESGDL.

But making arrival time later than needed does not really mean the times have to be that precise... In your example, they can schedule the flight to arrive at 2:15pm and then do a forty five minute turnaround and the flight will be scheduled to depart at 3:00pm.


User currently offlineLeskova From Germany, joined Oct 2003, 6075 posts, RR: 70
Reply 4, posted (8 years 7 months 3 days 16 hours ago) and read 3749 times:

Those "precise" timings are also a means to get a better listing in CRS displays, since - as usual - most people will prefer a faster connection; so if AA lists it's flight as taking 47 minutes and UA lists it's flight as taking 46 minutes on the same route, UA's flight will be listed first (admittedly, that depends on the CRS and on the type of schedule/availability display being used).

Other than that, I really don't see any sense in it; as you say, the likelihood of the flight ever really hitting the mark of arriving at 2:16pm or 8:32am or whatever is really rather low.

Regards,
Frank



Smile - it confuses people!
User currently offlineBDKLEZ From Ireland, joined Jun 2005, 1735 posts, RR: 10
Reply 5, posted (8 years 7 months 3 days 14 hours ago) and read 3723 times:

As far as I'm aware, it reflects the runway slot that has been booked with the airport for that particular arrival or departure. A runway slot is literally an airline's permission to use the runway at any particular airfield.


Trespassers will be shot; survivors will be shot again!
User currently offlineSuperhub From Hong Kong, joined Jan 2006, 478 posts, RR: 0
Reply 6, posted (8 years 7 months 3 days 14 hours ago) and read 3699 times:

Quoting BDKLEZ (Reply 5):
As far as I'm aware, it reflects the runway slot that has been booked with the airport for that particular arrival or departure. A runway slot is literally an airline's permission to use the runway at any particular airfield.

Then why doesn't BA implement precise-timing in their schedules? Slots are very tight at LHR.


User currently offlineLoneStarMike From United States of America, joined Jul 2000, 3866 posts, RR: 34
Reply 7, posted (8 years 7 months 3 days 13 hours ago) and read 3695 times:

I've always wondered about this, too. Southwest Airlines rounds all their arrival and departure times to the nearest 5 minutes.

Seems like it would make things easier for folks who work in scheduling to deal with five mminute increments, but then again I don't know since that's not my job expertise.

LoneStarMike

User currently offlineBDKLEZ From Ireland, joined Jun 2005, 1735 posts, RR: 10
Reply 8, posted (8 years 7 months 3 days 13 hours ago) and read 3680 times:

Quoting Superhub (Reply 6):
Then why doesn't BA implement precise-timing in their schedules?

Again, as far as I'm aware, it's a US thing. But please feel fre to correct me if anyone knows any different.



Trespassers will be shot; survivors will be shot again!
User currently offlineLeskova From Germany, joined Oct 2003, 6075 posts, RR: 70
Reply 9, posted (8 years 7 months 3 days 13 hours ago) and read 3670 times:

Quoting BDKLEZ (Reply 8):
Again, as far as I'm aware, it's a US thing. But please feel fre to correct me if anyone knows any different.

It's primarily used in the US, that's true... I know that CM also schedules their flights this way, and I think I've seen the occasional other schedule in South America that looked like this; but other than that, the 5-minute-rounding is pretty much standard all over the world.



Smile - it confuses people!
User currently offlineGrimey From Ireland, joined Jun 2005, 459 posts, RR: 5
Reply 10, posted (8 years 7 months 3 days 13 hours ago) and read 3646 times:

And the funny part is, the flights are usually delayed by a few minutes anyway  Big grin

Quoting BDKLEZ (Reply 5):
As far as I'm aware, it reflects the runway slot that has been booked with the airport for that particular arrival or departure. A runway slot is literally an airline's permission to use the runway at any particular airfield.

Yes that is one reason why it is used, it may not show up on a BA ticket/timetable but in LHR in their office they might have that flight listed to an exact minute. For example a BA flight LHR-JFK may be shown to take off a 15:00 but in a LHR office that flight would be known to take off at 15:02.

Grimey


User currently offlineAlexPorter From , joined Dec 1969, posts, RR:
Reply 11, posted (8 years 7 months 3 days 6 hours ago) and read 3525 times:

I have been on flights that depart the gate and arrive at the gate at the exact scheduled times! However, that isn't very often, but they're actually usually quite close.

User currently offlineHawaiian717 From United States of America, joined May 1999, 3208 posts, RR: 7
Reply 12, posted (8 years 7 months 3 days 6 hours ago) and read 3504 times:

Quoting BDKLEZ (Reply 5):
As far as I'm aware, it reflects the runway slot that has been booked with the airport for that particular arrival or departure. A runway slot is literally an airline's permission to use the runway at any particular airfield.

Except that slot time scheduling is somewhat rare in the US. There are only a handful of slot-controlled airports in the US, and most allow a particular landing and takeoff cycle, but don't specify an exact time.


User currently offlineDesertAir From Mexico, joined Jan 2006, 1478 posts, RR: 0
Reply 13, posted (8 years 7 months 3 days 6 hours ago) and read 3484 times:

I have noticed on a number of flights, the time for the flight that the flight attendants give differs from the time given by the pilot/co-pilot. It seems to me that there are the official scheduled times and the real time taking into consideration weather, airport slots....

User currently offlineJcavinato From United States of America, joined Jan 2005, 520 posts, RR: 0
Reply 14, posted (8 years 7 months 3 days 6 hours ago) and read 3464 times:

What I would love to see is a posting of times that luggage starts to come out of the shoot. To me that is the real arrival time of me and my things.

IAH on US from PIT for years would take anywhere from 45-50 minutes for luggage to start coming out. CO was much better. In this way I always thought CO had the better true passenger transit time.


User currently offlineSupa7E7 From , joined Dec 1969, posts, RR:
Reply 15, posted (8 years 7 months 3 days 5 hours ago) and read 3423 times:

Precise schedules help an airline be more efficient.

Of course you can't estimate today's flight to 1 minute. But your ESTIMATE of the flight time (taking past flight data into account) can be very precise, since it's a mathematical construction. Delta knows exactly how much time ATL-MCO needs to achieve a 90% on-time rate. Add one minute, your on-time rate will increase. But they want to avoid wasting minutes too, (expensive), so it's a fine balance. Leaving 5-minute intervals is a convenience for customers but it makes the schedule less optimal.


User currently offlineCentPIT From United States of America, joined Dec 2005, 990 posts, RR: 3
Reply 16, posted (8 years 7 months 3 days ago) and read 3297 times:

Quoting Jcavinato (Reply 14):
IAH on US from PIT for years would take anywhere from 45-50 minutes for luggage to start coming out. CO was much better. In this way I always thought CO had the better true passenger transit time.

US is historically known to take the longest amount of time with luggage in PIT. When flying with Delta in and out of PIT, the luggage is often at the carousel before I arrive. This is weird!



Pittsburgh International: US Airways---160 daily departures! (52 destinations)
User currently offlineJcavinato From United States of America, joined Jan 2005, 520 posts, RR: 0
Reply 17, posted (8 years 7 months 2 days 21 hours ago) and read 3223 times:

Yet there were times on US at PIT when I was inbound late from somewhere and ran and rushed through the underground shuttle and was the last one to board to SCE. Connection from hell. On those trips I always wondered if my luggage made it. It always did.

User currently offlineN200WN From United States of America, joined Feb 2005, 784 posts, RR: 6
Reply 18, posted (8 years 7 months 2 days 17 hours ago) and read 3175 times:

Southwest uses rounded times to the nearest five minutes. You won't find any 10:59 departures or 12:16 arrivals in the schedule. I think it's much easier for the customers to remember rounded times as well.

Quoting DesertAir (Reply 13):
I have noticed on a number of flights, the time for the flight that the flight attendants give differs from the time given by the pilot/co-pilot. It seems to me that there are the official scheduled times and the real time taking into consideration weather, airport slots....

I've noticed this on Southwest. The F/A's will always give the gate to gate time - which is the same as the time listed in the schedule. The pilots always seem to give fly time...wheels up to touchdown.


User currently offlineJohnClipper From Hong Kong, joined Aug 2005, 855 posts, RR: 0
Reply 19, posted (8 years 7 months 2 days 14 hours ago) and read 3120 times:

US airlines will only do this on domestic flights. I've noticed that on international flights, the US airlines follow the "rounded" 5 minute rule too.

User currently offlineCgnnrw From Germany, joined May 2005, 1170 posts, RR: 2
Reply 20, posted (8 years 7 months 2 days 6 hours ago) and read 3024 times:

Quoting Superhub (Thread starter):
On Wednesday, the same flight arrives at 4:02pm.

In the US, Wednesday is called "over the hump day" because it's in the middle of the work week. To get "over" the hump takes an airplane a bit more time. Perfectly logical can't understand why you even asked.  Wink  mischievous 



A330 man.
User currently offlineVV701 From United Kingdom, joined Aug 2005, 7737 posts, RR: 17
Reply 21, posted (8 years 7 months 1 day 20 hours ago) and read 2925 times:

Quoting Superhub (Reply 6):
Then why doesn't BA implement precise-timing in their schedules? Slots are very tight at LHR.



Quoting BDKLEZ (Reply 8):
Again, as far as I'm aware, it's a US thing.



Quoting JohnClipper (Reply 19):
US airlines will only do this on domestic flights. I've noticed that on international flights, the US airlines follow the "rounded" 5 minute rule too.

My observation is that AIRPORTS in the US have timetables to the minute and elsewhere to the 5 minutes. So I believe BA cannot implement precise timing because at LHR it is down to BAA not BA. So yes it is a US thing but I believe not a US airline thing. So when US airlines go international they adoipt the international method because, for example, they can get an 1100, 1105 or 1110 slot at LHR but not an 1104 or 1107 slot.


User currently offline3201 From , joined Dec 1969, posts, RR:
Reply 22, posted (8 years 7 months 1 day 20 hours ago) and read 2905 times:

Quoting Superhub (Thread starter):
Southwest Airlines rounds all their arrival and departure times to the nearest 5 minutes.



Quoting N200WN (Reply 18):
Southwest uses rounded times to the nearest five minutes.

Rumor has it that at least one of the majors will be making this switch later this year. Don't waste bandwidth by quoting and saying "Source?" because I won't say any more -- but I believe this will really happen.

Quoting JohnClipper (Reply 19):
US airlines will only do this on domestic flights. I've noticed that on international flights, the US airlines follow the "rounded" 5 minute rule too.

Only on the non-US side of the flights. For example:

UA900 departs SFO 1:58pm, arrives FRA 9:45am
UA930 departs SFO 1:02pm, arrives LHR 7:10am
UA954 departs SFO 7:12pm, arrives LHR 1:30pm

UA955 departs LHR 10:05am, arrives SFO 12:57pm
UA931 departs LHR 2:15pm, arrives SFO 5:17pm
UA901 departs FRA 1:45pm, arrives SFO 4:12pm


User currently offlineJAFA From United States of America, joined Aug 2003, 782 posts, RR: 4
Reply 23, posted (8 years 7 months 1 day 19 hours ago) and read 2884 times:

My hypothesis is that the non-rounded times allow for a smoother hub operation. Imagine 10 flights pushing back at exactly 7:00am. The another 10 at 7:05, and another 10 at 7:10a.

By staggering the departures you need less push back crews, and have less congestion on the ramp.

Someone already mentioned the main reason, and that is to get preferential listing in the computer systems. It has been shown that flights can make or loose money by adjusting the departure time forward or backward a few minutes. This is most common with multiple carriers on the same route.


User currently offlineFlyDeltaJets From United States of America, joined Feb 2006, 1936 posts, RR: 2
Reply 24, posted (8 years 7 months 1 day 19 hours ago) and read 2872 times:
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At DL we refer to that as Operation CLockwork. It is a ploy to minimize taxi-time and boost on time performance by having an off hour departure time.


The only valid opinions are those based in facts
25 Penguinflies : UA use to have two HNL-LAX flights on two DC-10s leaving at 9:15pm and 9:16pm. Those flights usually left from gates right next to each other (gate 7/
26 ContnlEliteCMH : I think, after more than 250 flights in the past 20 months, the words "precise" "timing" and "airline schedule" should never be used in the same sente
27 FlyDeltaJets : That's not nice. At JFK we strive really hard to get our flights out on time. Any delays we do have are minimal 20 mins at most. Time which can be ea
28 Ckfred : Have you ever noticed during the announcement before the safety briefing that the F/A will give the exact flying time. On my last flight, LAS-ORD, the
29 Post contains links ContnlEliteCMH : It wasn't intended to be nice. Or to be mean. It's merely a fact based at least on the contract of carriage that you offer to your very own customers
30 B741 : This is also a Canadian system too. AC and WS flights are not rounded to the nearest 00.
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