Chuska wrote:FlyingElvii wrote:32andBelow wrote:Agreeing to triangle routings can also get you more daily flights but many don’t like doing this. 12 seems like a sweet spot.
In the past, tag flights had short ground times at the mid stations.
10 minutes for 19 seaters, with the right engine running, 15 minutes for the 30 seaters, etc.
Now you see these intermediate stops scheduled at 30 minutes, 45, or even longer.
I think that is due to hub congestion and ATC slotting, but a planner could give a better explanation than I can.
This caught my attention as well. OO/UA5045 DVL-JMS-DEN departs DVL 0600, arrives JMS 0702, 82 miles and they schedule 62 minutes for a 23 minute flight. Then you don't depart JMS until 0745, 43 minutes on the ground. Last July this flight was only 40 minutes DVL-JMS then only 30 minutes on the ground at JMS. Appears a lot of extra time is factored in for deicing.
Amazing so much ground time -- I can imagine DLV passengers getting pretty antsy to have first boarded sometime around 0530-0545 and only just be taxiing out in JMS at 0745.
Deicing is good speculation on this extended North Dakota ground times during winter, especially if the actual performance at those airports for that flight are crappy. But Skywest has comparably long block times and stops for their EAS tag and round robin flights in general. For example back when Hattiesburg and Meridian were tags and round robins by OO for AA*, here was the morning originator in June 2018
0825 lv PIB (69 mile hop)
0905 ar MEI
0936 lv MEI (485 mile hop)
1137 ar DFW
Not only was the 31 minute ground time long but the 2:01 block for MEI-DFW was highly padded. It's similar to what AA* was scheduling at that time for BHM-DFW which is 100 miles farther. The long ground times in the evening were similar. The evening flight ORD-MEI-PIB had a 30 minute MEI stop on what was a dump-and-run situation. And it wasn't just Meridian. Hays and Salina had combined flights DEN/ORD and stops were 30+ minutes including a 33-minute late night dump-and-run DEN-HYS-SLN route. In June, so not deicing season. The Quincy stop on the evening ORD-UIN-CGI trip was scheduled at
48 minutes with the summer 2018 schedule.
2018 lv ORD (222 mile hop)
2130 ar UIN
2218 lv UIN (207 mile hop)
2315 ar CGI
So why the long stops? They happen both directions so that doesn't make sense for traffic flow reasons at the hub destination airport. These are from summer so it's not deicing. Best I can figure it might be related to crew work rules and scheduling or related to on-time performance stats and delay reasons. For example if the ORD operation was sluggish due to ATC / Weather the delayed ORD-UIN flight would have that delay reason. However the UIN-CGI tag would be "late arriving inbound aircraft" as the delay reason for that segment. The
root cause was of course ORD but if the UIN-CGI delay was charged to late arriving aircraft, extending the UIN ground time could reduce the number of times UIN-CGI ran late. I've never been able to get anyone to confirm the reasons for Skywest's less-than-aggressive scheduling for EAS tags and round robins, but it has been a consistent pattern. And these are the best reasons I've heard for why it is this way. (The generous block times may also have been to help on-time performance in these non-competitive routes, but they also could have been to lower fuel burn with a slower cruise)
For this reason I have doubts that widespread tags and round-robin routings are a solution Skywest will use. The scare commodity is pilots, and the padded block times and long turn times burn that resource.
Several people think back to the old-style milk runs, so let's look at one. Skywest is temporarily paring back North Platte (LBF) and Scottsbluff (BFF) to 10x/week nonstops to DEN, each from 12x. The old Frontier river run including a 737 on the morning LBF-BFF-DEN routing. Why not have Skywest temporarily run LBF-BFF-DEN and keep it at the 12x/week? Well...it doesn't same much if anything.
Normal Schedule -- 48 total segments 12 nonstop round trips each market per week
24 LBF-DEN and DEN-LBF trips per week
24 BFF-DEN and DEN-BFF trips per week
River-Run Style Combined Schedule -- 48 total segments 12 Denver round trips each market per week
24 LBF-BFF and BFF-LBF trips per week
24 BFF-DEN and DEN-BFF trips per week
a round-robin routing for the mid-day flight would save a 5 segments per week -- twice daily on weekdays and once daily on weekends for 12 total Denver flights.
River-Run Style Combined Schedule with Round Robin -- 43 total segments 12 Denver round trips each market per week.
7 segments on each weekday LBF-BFF-DEN, DEN-BFF-LBF-DEN, DEN-BFF-LBF for a total of 35
4 segments on each weekend day LBF-BFF-DEN and DEN-BFF-LBF for a total of 8
Skywest Reduced Schedule -- 40 total segments 10 Denver round trips each market per week
20 LBF-DEN and DEN-LBF trips per week
20 BFF-DEN and DEN-BFF trips per week
The other thing is that passenger demand drops with those tag flights, especially in the way Skywest's current operation drags them out.
Here's a sample 737 on LBF-BFF-DEN from the early 80's (note that North Platte is Central Time while BFF and DEN are Mountain)
0722 lv LBF
0700 ar BFF
0718 lv BFF
0754 ar DEN
Skywest's morning BFF-DEN is blocked at an hour, and given that LBF-BFF is 10 miles farther than that (160 miles) we can assume about an hour block time for LBF-BFF. So if it was the same 0722 departure from LBF we'd be looking at something like this:
0722 lv LBF
0722 ar BFF
0752 lv BFF
0852 ar DEN
Almost an hour longer than what Frontier used to do. And that burns of up a lot of pilot time, the scarce resource which is causing all this trouble.
I suspect the reason Skywest has gone away from tags and round robins in EAS markets in the past few years is that it doesn't save much crew time, aircraft time, aircraft cycles and fuel versus simply operating each market with nonstops to the hub. DVL and JMS are so comparably low-volume and unusually distant (600-ish miles) from Denver that they are an exception. But for the most part I'd expect to see reduced frequencies like Skywest has been doing than a widespread return to tags and round robins.