Planes May Fly Longer

[tadjr]

I like the delinking idea as well. Our current schedule has both evening flights to PIT (530 and 715) coming from PHL (757s) going back into PIT with a minimum 30 min conx for many of the flights. Anyone want to guess how many times they've been on time so far? How many people are getting their exercise nightly trying to connect in PIT?
This is another example of take a bad idea and make it worse. Not only do both planes COME from PHL but go back into a minimum connecting bank IF they are on time. What are they thinking?
As far as the other situation, depending on what cities they decide to fly point to point, some of the planes outbound from a hub that wouldnt necessarily make good connections back into the same hub could be used as part of the point to point flying during certain times of the day. This would also allow for point to point flying during the day to turn into hubbound flights so the above situation of trying to "force" a plane to make connections wouldnt have the pressure on it during the day.

 

[BoeingBoy]

I wish I could take credit for dreaming this stuff up, but I'm not that bright. Ironically, AMR started both depeaking and delinking in an effort to minimize delays - efficiency wasn't a big part of it. And delinking results in relatively small efficiency gains - it mainly minimizes the spread of delays.

tadjr, your thoughts on tying the delinking into the point-to-point flights is excellent. It hadn't occured to me.

Jim

 

[diogenes]

I know PI delinked DAY as much as possible from the moment DAY opened.

Flights that originated in the northern tier (TOL, CAK,FWA, etc) passed thru DAY to DFW, DCA, LGA, etc. Many of those flights turned around and came back to DAY, enroute to TOL, CAK, etc. Of course, many were rotated out to keep the mx scheds, but we often saw the same birds two or three times a day.

And PI was very reluctant to run hub-to-hub flights - they were concerned about the problems mentioned in this post. Eventually, DAY-CLT flights were put on, but PI made sure a 'virus'would not spread.

Considering the proximity of U hubs, and the fact that one wx system can take two down, I think it would be wise to delink the hubs as much as possible - the overall good would outweigh the costs.

 

[MarkMyWords]

Believe it or not, at one point we did delink our hub flights, especially PHL. Of course this was prior to 9/11. The delinking did work very well and provided much more schedule reliability for hubs like PIT and CLT. It also gave you the ability to recover from delays because you were able to cancel a PHL- ALB-PHL roundtrip and get the line of flying back on time. With the current schedule you will find that most of the flights from PHL-BOS are on B733/734 airplanes and the retunr BOS-PHL are on A319/320 airplanes. Now, when a city like BOS is closed due to a snow storm, in order to recover the airline operation, you end up ferrying more airplanes to get your equipment back into position. For example, lets say airplane 1 (B734) flies PHL-BOS-CLT-MCO and plane 2 (A320) flies CLT-BOS-PHL-TPA. The BOS airport is closed due to a snow storm. If you cancel the BOS landings, you end up cross ferrying 2 airplanes in order to get the airplanes back in position.

Jim - Thanks for the graphs on the depeaking by AA. That is a great visual on how the depeaking of PHL could reduce ATC delays.

 

[mweiss]

It seems much more efficient to make productive use of the extra ASM's generated with the same assets to "grow" the airline - either by adding more flights thru the hubs or doing more point-to-point.

It's not just you that feels that way. And right now that's probably the right approach, given a rising demand. It's less clear if that would have been the right answer in, say 2002.

In any case, I'm certainly a firm believer that one should use increased efficiencies to produce more, not to lay people off. Provided there's sufficient demand to absorb the additional productivity, that's a no-brainer.

As a related note, one of WN's great successes has been dramatically increasing demand by decreasing the price, while still making profits. They've proven that the market is pretty elastic, and that monopolistic pricing isn't necessarily the way to maximize profits. It's a lesson I hope more businesses come to learn.

 

[mweiss]

Yes, I do believe it's bad karma to run an airline with a monopoly mind set, and I believe that it's this attitude that is at the heart of U's problems.

You said a mouthful there. That is, in my opinion, the number one problem facing US Airways. The company is tuned to having a monopoly in the markets it serves, when in fact the market has shifted to an oligopoly in the past decade.

Incidentally, gate control hasn't turned out to be as useful as slot control was, which appears to have led to the market shift. Even PIT has a couple of free gates on the D concourse, which is plenty for WN to come in and make a killing, especially on the PIT-PHL route.

 

[mweiss]

If you cancel the BOS landings, you end up cross ferrying 2 airplanes in order to get the airplanes back in position.

Interesting point. It illustrates yet another subtle advantage that WN's more uniform fleet provides.

 

[GuppyPup]

For anyone interested, here is a graphical depiction of the change in traffic flow at a rolled hub. Pay particular attention to AMR's operation at DFW, since they have been the most aggressive at attacking the hub problem.

**This is an Adobe PDF document - Adobe Acrobat required.

Chart

Jim

http://www.its.berkeley.edu/news/De-Peaking.pdf

Here is the recent study done on depeaking

 

[BoeingBoy]

Thanks, GuppyPup. This is the study that the AWST article I read was based on, except AWST only discussed the ORD part of it.

Jim

 

[tadjr]

Looks like we're prepared to fight in PHL if the May skd is final. TPA-PHL drops to 6 flights a day. Oh, and we are sure flying those planes longer. One of them doesnt go to sleep until 554pm and another one at 728pm and two dont start flying the next day until 930am and 935am. Yep, two more hours a day would put them at what most would consider normal flight day? Hey, looks like someone might get a nice overnight in TPA for the month though! :down: