Another Look At Phl Scheduling

[BoeingBoy]

It's been a while since I've done this, so thought I'd update the PHL departure scheduling comparisons. This time I've compared to AMR at ORD, since that's their hub with about the same number of departures per day.

I've also looked at one day vs the whole month's departures - I was concerned that any Sat/Sun schedule differences might be distorting the picture somewhat. So I picked a Wednesday in the middle of the month - the 17th of November in this case (Nov is the latest available from BTS).

One note - AMR is "mainline" only while U includes MDA flights since they operate on the same certificate (the company reports them as "mainline" while the W/O'ed aren't included in the "On Time" BTS database - major carriers only)

OK, one other note in case you don't remember the layout from before. The day is divided into 15 minute blocks, with the flights scheduled to depart within any one block included in a single bar on the chart. So any flight scheduled to depart starting at 1200 thru 1214 will be included in the "12" bar.

The attached chart for PHL shows some improvement over the early summer charts I posted - the valley's have filled in somewhat.



Jim

 

[phllax]

The beginning of February is their target date for completing the transition of PHL from a banked hub to a rolling hub. They started in some ways in the fall.

 

[Art at ISP]

It will be interesting to see how the chart looks after the "rolling" of PHL begins--with the exception of 8AM and 7PM hours, the AA situation looks to be an improvement.

If I am not mistaken, AA has also instituted a dedicated fleet to ORD-keeping the same aircraft connecting through ORD. Combined with the new practice of keeping a crew with the same airplane for a duty shift, perhaps the savings will begin.....thoughts?

 

[BoeingBoy]

Art,

From what I've read, AMR is trying to dedicate a narrow-body aircraft type to each hub as well as trying to keep crews and airplanes together as much as possible. I think both are intended as "schedule preservation" measures more than efficiency measures - attempting to prevent delays from spilling over to other flights and affecting other hubs as much as possible.

Now that we've seen the "macro" view, let's look at the "micro" view of PHL vs ORD. Frankly I hadn't really paid that much attention until it hit me between the eyes a few weeks ago - U schedules all hub departures (maybe all departures) at the even 5-minute times. There's a 7:05 flight to Stumpwater, never a 7:03 or 7:07.

What this means is that there are often (usually?) multiple aircraft scheduled to depart the gate at the hub at the exact same time. At PIT or CLT this is not too much of a problem, but the physical layout of the concourses at PHL is different - only enough room between the concourses for one (two at most) planes to push back at the same time in the same "alley" (the ramp between two concourses). Plus, if an aircraft is pushing back in an alley, it means that an inbound plane can't get to it's gate in that same alley until the outbound flight taxis clear.

So here's the minute by minute schedule for PHL and ORD departures for a one hour period in the middle of the day (the same day as used for the above charts) - 12:00 to 12:59 for ORD and 1:00 to 1:59 for PHL - those periods had the largest number of departures for each airport if you omit the "morning rush" and the evening international departures.

Notice how many times in each hour ORD has more than 1 departure at a specific time vs at PHL....

Jim

[Edit by me - the charts didn't load, let me try again]