Rolling Hubs
 

It has been discussed today that MEM will begin a rolling hub schedule next year. Is this going to be expanded to DTW and MSP?

RC

What do you mean by rolling?

- Pat

More on rolling hubs

http://www.flyertalk.com/forum/Forum35/HTML/006546.html

RC

Presumably, abandoning the practice of scheduling heavy "banks" of flights at certain peak points of the day in favor of a more constant number of movements per hour. This irons out the peaks and slack times inherent in bank hubbing.

Pros: less chance of congestion delays; shorter taxi times; fewer waits for occupied gates to free up. Cons: longer layover times; maybe fewer seats departing at high-demand periods like dinnertime.

I am all for them trying it out at MEM to see if it helps things any, though with the reduced schedule this year I haven't had any real delays in/out of DTW/MSP.

Maybe NW will test this in MEM with the possiblity of rolling it out to DTW and MSP. AA, if I remember correctly, planned that they could operate the same number of fligts at ORD with a few fewer aircraft. As mentioned before the connection times may be increased, but how much fun is it to sit at #20 for departure in DTW for a 20 minute flight to LAN/FNT, etc. I believe the previous thread mentions the gap times in MEM. When coming in from the west coast (always early) the place is a f'ing goast town! But I believe that MSP and DTW have too many flight banks to realize any benefit from the "rolling hub" concept.

If anything, MEM does not have enough flights to have a successful rolling hub schedule. A rolling hub would require a lot more flights (not just four per day [if even] to various destinations). MEM does not have enough O&D to have a rolling hub schedule (just like STL for AA).

It might work for MSP & DTW, but it won't for MEM. NW has one intercontinental flight out of MEM. That in itself basically forces the flights to come and go in banks if there were to be any connecting traffic.

Does anyone know if rolling hub scheduling increases or decreases the hours that the a/c crews (i.e. FA's and Pilots)?

If the crews are waiting for another a/c that has been rescheduled (rolled back) then couldn't nwa crews spend many hours waiting for the next trip?

RC

You raise some good points in regards to MEM -- perhaps a combination type system of a rolling hub & banks could be designed -- or they could operate as a rolling hub for most of the day and then operate the last set of flights as a bank, especially since they have the late MEM-AMS flight. They could also setup their other Intl flights for last bank arrival / departures (if appropriate depending on the destination) to allow for better connections.

Despite the current 4 banks, I think they could create a rolling hub system of some type that would work effectively. I think you're right in that it may prove difficult with the lack of flights, but I think with the right approach which could include using a rolling & banking approach depending upon time of day, it could be successful. It also seems more people are returning to the skies, which could aid in the rolling hub approach by adding additional flights since resources including aircraft would be better utilized with a rolling approach.

I should note I don't fly through MEM that often, but when I do, it's typically quite busy. As such, I've never experienced this 'lull' that is talked about between banks. I personally wouldn't mind a somewhat longer connection as there are many times I encounter connecting times too short to grab a bite to eat or do anything other than go from one meal-less flight to the next.

I've never had a MEM connection much longer than 1 hr, other than one time I had a significantly delayed flight. However, MEM stayed busy the entire time (a few hours) I was there, primarily because it seemed most other flights were delayed (major wx problems at MSP that day) and the place was full of people with meal vouchers http://www.flyertalk.com/forum/smile.gif

It was incredible how major WX problems at MSP affected the operations at MEM, despite perfect weather at MEM and DTW. My inbound flight for my connection (that day) was coming in from MKE (also wx affected) but MEM was the most crowded I had ever seen it.

That particular day I was doing a two-hub connect SDF-DTW-MEM-TPA because of the Double Miles MEM & the Turbo Miles promotion last year. I really liked the Turbo Miles promotion - I would love to see that one again as I really racked the miles up.

On rare ocassion I'll run into some long connections, but these primarily occur at DTW when connecting on to destinations which don't have the most frequent service. As an example, I had a 3 1/2 hr connection in DTW to get to SAN earlier this year. For the SAN arrival I wanted, the SDF-DTW and DTW-SAN (afternoon departure) just didn't hook up well. Same thing happens when I want to take NW 40 to AMS. I usually get into DTW around noon and have to wait until 4pm for the departure of NW 40. Otherwise, my average connection runs between 30 mins to an hour. FWIW, my next MEM connection is exactly one hour.

Best,

SDF_Traveler

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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -- Ben Franklin

You raise a great point. The longer the scheduled layover, the less attractive connecting flights in the 150-300-mile range. Why sit around the airport for three hours when you could go get a car and drive to your destination city in the same time? The rolling-hub model might not make Airlink too happy.

I've been on enough irregular ops over the years that I always try to schedule a 2 hour + connection and then enjoy the amenities of the WorldClub (used to be CRC) if the extra time is not needed.

A rolling hub would be fine for us.

Such is the M.O. of 'standard' hub operations: it's either feast or famine. So-called 'rolling hubs' dismantle flight banks and elongate connection times to create a more constant (and efficient) flow of traffic.

[This message has been edited by ExtrAAordinaire (edited 07-12-2003).]

No.

I don't think you understand the concept of rolling hubs (which is surprising considering you started this topic).

The point of a rolling hub schedule is to get an aircraft to turn as efficiently (read: quickly) as possible at both the hub and the spoke station. The point is to have aircraft in the air more and less ground time. Therefore, there's no 'rolling back' of any flights.

--

Another point against a MEM rolling hub is that MEM is in a good location to serve the Southeast US. On AA, if rolling hub schedules don't work (i.e. 2.5-3 hr waits), then one can still go through STL (or even ORD, MIA) without too much of a detour. With MEM, the alternate hub is not there. If someone wants to fly say from AUS to TPA, and the connection through MEM 2.5-3 hours, then chances are the passenger will fly someone else (via DFW, IAH, ATL, etc).

As a former AA analyst, I thoroughly studied the implementation of rolling hubs in the early 90's. (It was abandoned at that time because we needed short connection times to get good display in the travel agent's reservation systems.)

Truly, you can only implement rolling hubs in the busiest hubs -- that are near peak capacity. Otherwise, your connecting times will be much too long. For example, even with AA's saturation at DFW, connecting times for mid-day connections from San Antonio to Seattle are as long as 2.5 hours -- a bit long for my tastes.

Rolling hubs do require fewer aircraft and also improve crew utilization -- by minimizing downtime of aircraft and crew. For example, rather than waiting at a "spoke" station for 2 hours for the next bank of flights at the hub, the aircraft will return to the hub immediately (after a 50-55 minute turnaround time).

In some sense, rolling hubs are how Southwest has "connections". They just schedule a lot of flights into a city (say Las Vegas, Phoenix, Baltimore, Houston Hobby, Chicago Midway, Nashville, St. Louis, Kansas City, Dallas Love, etc.) and connections tend to "naturally occur".

One caveat is that rolling hubs cause the airport to be moderately crowded for long periods of time. In the early 90's, before DFW was remodeled, we were literally simulating unusually long lines for the restrooms and restaurants!

[QUOTE]Originally posted by keithguy:
[B] No.

I don't think you understand the concept of rolling hubs (which is surprising considering you started this topic).

The point of a rolling hub schedule is to get an aircraft to turn as efficiently (read: quickly) as possible at both the hub and the spoke station. The point is to have aircraft in the air more and less ground time. Therefore, there's no 'rolling back' of any flights.

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Keithguy,

I think you misunderstood what I was asking, my question was if crews (FA's/Pilots) would end up with longer work days after rolling hubs were implemented because they might arrive on one a/c and have to wait a longer time for the next a/c (2-3 hours?)compared to the current "banked flight scheduling" and ultimately have a longer day/trip.

RC

RC,

Rolling hubs are supposed to be more efficient for aircraft and crew. The aircraft at DFW (for example) continue to leave every 55 minutes all day long. The crews will leave immediately on the same or other aircraft.

On the other hand, the passenger may experience a longer connection due to the "smoothing out" of the banks of flights.

By the way, another term for rolling hubs is continuous hubbing (if that helps anyone).