DOT published its full 2019 numbers and has rankings on the nations best and worst ontime performance airports.

Best departure Ontime performance
1 Atlanta, GA (ATL) 85.06
2 Salt Lake City, UT (SLC) 84.84
3 Portland, OR (PDX) 83.73
4 Detroit, MI (DTW) 83.68
5 Minneapolis/St. Paul, MN (MSP) 83.38

Worst departure Ontime performance
26 Chicago, IL (ORD) 74.53
27 Boston, MA (BOS) 74.25
28 San Francisco, CA (SFO) 72.22
29 New York, NY (LGA) 70.44
30 Newark, NJ (EWR) 66.01

Interesting that 4 of the top airports are Delta hubs. Are the airports so good because of Delta, or is Delta so good because they operate from these apparently efficient airports?


Full DOT listing
https://www.bts.gov/topics/airlines-and-airports-0

I take BOS almost every week and barring few delays that can happen to anyone, it is possible with any airport. This winter has also been very mild in the East Coast resulting in fewer delays. Maybe I am just attuned to it.

Note that DL also has hubs in BOS, LGA

Where did you find the information on that website? I have looked all over it, and can't find anything.

LAXintl wrote:

Interesting that 4 of the top airports are Delta hubs. Are the airports so good because of Delta, or is Delta so good because they operate from these apparently efficient airports?

That's pretty readily answered. There are lots of cross-check opportunities. Compare DL at ATL to WN at ATL. Compare B6 at JFK to DL at JFK. Compare DL at SEA to AS at SEA. And non-hub to non-hub, like AA at MCI to DL at MCI, etc.

LAXintl wrote:

Interesting that 4 of the top airports are Delta hubs. Are the airports so good because of Delta, or is Delta so good because they operate from these apparently efficient airports?

It's probably a bit of both. DFW has an even more efficient airfield, though a somewhat less operationally-friendly terminal layout, and its OTP was a hair under 8 percentage points worse than ATL. The two airports tend to face similar weather challenges as well. DEN should probably be even better than SLC with its six runways and ATL-style layout but obviously SLC was near the top of the rankings.

iyerhari wrote:

Note that DL also has hubs in BOS, LGA

Eh, LGA has been bad for pretty much forever. At least it's not as bad as EWR.

Amazing after 30 years how efficiently ATL operates considering the typical spring and summer afternoon thunderstorms.

PSAatSAN4Ever wrote:

Where did you find the information on that website? I have looked all over it, and can't find anything.

I found it. From the page in the link, click the second option in the list - "on time" . It's pretty straightforward from there.

Yeah i would have to agree it is a bit of both. MSP is extremely well equipped for snow removal, as I imagine DTW would be too. As far as ATL is concerned I am wondering how many stormy days they had compared to DFW in 2019 . I would think ATL would get more storms than DFW but i could be wrong. When they happen at DFW it is massive diversion time. PDX is a given so I would say more PDX than DL. SLC can definitely have snow but I think overall the weather is fairly good. I have always said that DL is fortunate in that they have hubs in cities that are conducive to a smooth operation.But they also have happy employees for the most part and I think that definitely has something to do with it. IMHO AA has terrible hub locations (except i am thrilled with SEA, not that it will be a hub) for the most part. JFK and MIA. I'd rather stick needles in my eyes than deal with those people. Sorry, that comment was off topic.. I have no trouble with ORD or DFW. CLT, like DFW and ATL would have its share of thunderstorms and again I am not that familiar with the terminal there. SFO has always been a problem. Can someone tell me why? Thanks

ozark1 wrote:

SFO has always been a problem. Can someone tell me why? Thanks

SFO has parallel runways which are too close together. When fog/low clouds set in (frequently) one runway is closed so airport capacity is reduced by half.

[quote="LAXintl"]DOT published its full 2019 numbers and has rankings on the nations best and worst ontime performance airports.

Best departure Ontime performance
1 Atlanta, GA (ATL) 85.06
The information shown is arrival numbers. The departure list order is PDX SLC MSP DTW ATL IAD SEA SAN TPA PHL

ScottB wrote:

iyerhari wrote:

Note that DL also has hubs in BOS, LGA

Eh, LGA has been bad for pretty much forever. At least it's not as bad as EWR.

EWR has significantly more flights than LGA - unfortunately this thread is going to become another B6 bashing on how bad OTP is. I think if you have hubs in the coast areas which are notorious for weather vagaries plus Northeast which is even worse during winter - chances are high that you will have worse statistics. One airport in the Northeast catches a cough and everyone is down with a bad cold, cough and fever.

For those, like me, who are technically challenged, here's the actual page link. Thank you ZazuPIT, for the assistance:

https://www.bts.gov/node/224546

Always interesting that an 85% rating earns an "excellent", even though 15% of the planes are delayed, and 65% rating earns "a trip through hell", at least the way the statistics want you to believe...

I've been flying DL since 2008. Before that AA and before that TWA.
DL is incredibly efficient in turning around planes. You can see the hustle to get planes off the gate on time. I fly about 60 segments a year and they are amazingly consistent. It does not surprise me that ATL, DTW, SLC and MSP are on the best list.

LAXintl wrote:

Are the airports so good because of Delta, or is Delta so good because they operate from these apparently efficient airports?

That's easy to answer: It's because these airports operate/schedule below their design capacity. No one is busting down the door to add flights to these airports so the bigger operators at these airports benefit from the excess capacity or the arrival capacity that doesn't vary much with changes in weather.

Hubs where UA has a larger presence might also be hurt a bit as many of UA aircraft touch SFO and EWR during any given day and the chances of those two airports being delay-free are normally slim. SFO, EWR and ORD are amazing hubs for O&D plus geography but along with that comes the other edge of the sword and that's a lot more competition as everyone else wants to be there as well.

When you operate at or near capacity most of the day, it's hard to recover from weather events in a timely manner.

Delta certainly benefits from having interior hubs with uncongested airspace. But let's not pretend for a second Delta's ops are a result of those airports. Delta's presence literally pulls up airports from the dredges. While there are other structural reasons why JFK is a bit better than EWR, it is not a coincidence that it performs "relatively well" for a NYC airport. It's because Delta is the largest carrier there.

AA should perform just as well at PHX, DFW, and CLT as they do at Atlanta - similar weather conditions (ATL actually has about 10% more thunderstorm days per the National Weather Service than DFW) and yet they score much lower.

In fact, AA has great hub locations for the most part. LAX? DFW? CLT? PHX? MIA? Even PHL shouldn't be terrible minus some airspace congestion issues when flying north. The only challenging hubs they fly out of are ORD, LGA, and arguably DCA. Sure, maybe one more than Delta (Boston is barely a hub yet, and while Seattle has all kinds of gate issues, the airspace isn't congested). But that doesn't excuse crappy performance at the rest.

Delta does a good job of bending their captive airports to their will as well. It shouldn't be a surprise that MSP, ATL, and SLC are well-run airports because Delta makes sure they are. Security lines long at ATL? Delta basically tells ATL to threaten the TSA to go with private contractors in place of the TSA, all while sending an army of staff to help during peak times. MSP is great at snow removal? It's in part because of Delta's own investments in snow removal and de-icing equipment at the airport - and then taking MSP's best practices and holding cross-airport knowledge sharing sessions to replicate at other ones.

I'm not trying to make Delta sound amazing - they have flaws just line any airline (and I have my gripes as a frequent flyer) - but their operational reliability is not a coincidence, and the fact that their hubs are on the top of the performance list is due in large part because they are Delta's hubs.

EWR being at 66% means UA is smart to move hub operations to IAD and make EWR O&D focused.

3 of the worst airports (BOS/JFK/LGA) are also Delta hubs. More to do with airport layouts/airspace than DL although having said that, DL runs a slightly tighter ship than some.

ethernal wrote:

Delta certainly benefits from having interior hubs with uncongested airspace. But let's not pretend for a second Delta's ops are a result of those airports. Delta's presence literally pulls up airports from the dredges. While there are other structural reasons why JFK is a bit better than EWR, it is not a coincidence that it performs "relatively well" for a NYC airport. It's because Delta is the largest carrier there.

AA should perform just as well at PHX, DFW, and CLT as they do at Atlanta - similar weather conditions (ATL actually has about 10% more thunderstorm days per the National Weather Service than DFW) and yet they score much lower.

In fact, AA has great hub locations for the most part. LAX? DFW? CLT? PHX? MIA? Even PHL shouldn't be terrible minus some airspace congestion issues when flying north. The only challenging hubs they fly out of are ORD, LGA, and arguably DCA. Sure, maybe one more than Delta (Boston is barely a hub yet, and while Seattle has all kinds of gate issues, the airspace isn't congested). But that doesn't excuse crappy performance at the rest.

Delta does a good job of bending their captive airports to their will as well. It shouldn't be a surprise that MSP, ATL, and SLC are well-run airports because Delta makes sure they are. Security lines long at ATL? Delta basically tells ATL to threaten the TSA to go with private contractors in place of the TSA, all while sending an army of staff to help during peak times. MSP is great at snow removal? It's in part because of Delta's own investments in snow removal and de-icing equipment at the airport - and then taking MSP's best practices and holding cross-airport knowledge sharing sessions to replicate at other ones.

I'm not trying to make Delta sound amazing - they have flaws just line any airline (and I have my gripes as a frequent flyer) - but their operational reliability is not a coincidence, and the fact that their hubs are on the top of the performance list is due in large part because they are Delta's hubs.

Another piece with DL is also their daily block adjustments (their block team adjusts for DoW changes in traffic volume) which helps ensure performance is met. Likewise, they tend to overblock their taxi-in on the inbound to hub legs to help with turn performance and A14 (typically 2-4 minutes from everything I've seen).

Discussion of airport by airline would be far better though.

Why is EWR's performance so much worse than JFK's? other than "because DL has a bigger operation at Kennedy"

ethernal wrote:

Delta certainly benefits from having interior hubs with uncongested airspace. But let's not pretend for a second Delta's ops are a result of those airports. Delta's presence literally pulls up airports from the dredges. While there are other structural reasons why JFK is a bit better than EWR, it is not a coincidence that it performs "relatively well" for a NYC airport. It's because Delta is the largest carrier there.

Every thing you wrote below this first paragraph I completely agree with but this first paragraph I agree and disagree with. No one can agrue with the fact that DL knows how to run their operation and JFK does benefit from it. But if you compare JFK to EWR on a daily basis EWR ATC flow control always averages higher than it does at JFK and it has a lot to do with EWR's lack of runways. There are times when I get to work at 6 a.m. and EWR is already on a 15-20 minute flow control and it just gets worse as the day progresses. Even on sunny days by noon or 1 p.m. EWR is on a 30 minute or more ATC flow while JFK has none. Also to be absolutely fair there are two entities responsible for the consistent ATC flow control delays, one is the DOT and the second is UA. EWR is no longer slot controlled and if I am going to be honest UA has multiple arrival and departure banks that are over scheduled.

I'm not trying to give UA any type of pass I know our operation system wide does not run nearly as seamlessly as DL which is why I agree with everything else you wrote but EWR and JFK from an ATC perspective are not equal.

ethernal wrote:

AA should perform just as well at PHX, DFW, and CLT as they do at Atlanta - similar weather conditions (ATL actually has about 10% more thunderstorm days per the National Weather Service than DFW) and yet they score much lower.

In fact, AA has great hub locations for the most part. LAX? DFW? CLT? PHX? MIA? Even PHL shouldn't be terrible minus some airspace congestion issues when flying north. The only challenging hubs they fly out of are ORD, LGA, and arguably DCA. Sure, maybe one more than Delta (Boston is barely a hub yet, and while Seattle has all kinds of gate issues, the airspace isn't congested). But that doesn't excuse crappy performance at the rest.

Delta does a good job of bending their captive airports to their will as well. It shouldn't be a surprise that MSP, ATL, and SLC are well-run airports because Delta makes sure they are. Security lines long at ATL? Delta basically tells ATL to threaten the TSA to go with private contractors in place of the TSA, all while sending an army of staff to help during peak times. MSP is great at snow removal? It's in part because of Delta's own investments in snow removal and de-icing equipment at the airport - and then taking MSP's best practices and holding cross-airport knowledge sharing sessions to replicate at other ones.

I'm not trying to make Delta sound amazing - they have flaws just line any airline (and I have my gripes as a frequent flyer) - but their operational reliability is not a coincidence, and the fact that their hubs are on the top of the performance list is due in large part because they are Delta's hubs.

I agree with what you have stated here and I will add that ORD has come a long way from the days of intersecting runways. I think ORD's problems are not related to ATC and flow control I think ORD's placement on the list is both AA and UA's fault because neither airline runs an efficient operation.

NYC is a mess. 3 major airports in the busiest airspace in the US. There's no way that is working out well.

LGA and ORD are both infamous. I am a bit shocked EWR performs so poorly.

OzarkD9S wrote:

3 of the worst airports (BOS/JFK/LGA) are also Delta hubs. More to do with airport layouts/airspace than DL although having said that, DL runs a slightly tighter ship than some.

That's why I limited the comparison to DFW, CLT, PHX, and other airports that should perform beautifully. They don't. If American (as an example) can't get their act together at easy airports, what makes you think they outperform at congested hubs?

BOS is barely a Delta hub.. American still flies more passengers into BOS than Delta does.

Boston is actually a great example.

Delta: 78.2% A14, .3% cancellations
American: 73.6% A14, 3.3% cancellations

How about LGA?
Delta: 73.1% A14, .5% cancellations
American: 70.4% A14, 4.2% (!) cancellations

JFK?

Delta: 81.9% A14, .3% cancellations
American: 78.6% A14, 1.6% cancellations

Delta consistently outperforms American (and United) at every airport they go head-to-head at. Are Delta's A14 numbers as good at LGA as they are at ATL? No, of course not, but they're better than any other airline's. Take Portland - a good weather airport.

Delta: 88.2% A14, .1% cancellations
Alaska: 83.8% A14, 1% cancellations

The most damning thing on these statistics are the cancellations. Delta is just head and shoulders above all others on cancellations. And cancellations are the easy way to deal with delays - because a late inbound flight is a delayed outbound flight. Cancelling clears up the queue and gets you back on schedule. The fact that Delta outperforms on A14 while maintaining ridiculously low cancellation rates (they're just head and shoulders above all other carriers in this regard) is incredible.

I know some people will say it's all just padding, and yes, of course Delta pads. But you know what? On average, Delta doesn't pad more than its competitors (it's very expensive to pad block times.. they have a strong incentive not to). They're just better at predicting when padding is required. Delta is just BETTER at it. They're better at predictive maintenance. They're better at doing dynamic day-of-swapping. They're better at biting the bullet and sending rescue flights (which are incredibly expensive). They're better at doing crew intercepts in JFK when they can't make it to MSP without a crew timeout. They're better at having the equipment they need at the airports they fly planes out (like 767 engine starters).

I'll give perhaps the most prototypical example of what speaks to Delta's operational prowess. It may seem trivial, but I think it speaks to how well they manage the data of their operations (the hardest part). I was on an PHX-ATL flight - decent 4 hour flight in the summer. The gate agents were HUSTLING. They turned the plane very quickly and started boarding 10 minutes early. I was really confused as the jetstreams were pretty good - we were going to arrive early even if we departed ontime (sometimes I see them try to push early if the jetstream is weak so we can still arrive on time).

Anyways, we pushed a solid 15 minutes early. I don't think I thought much of it, until I noticed stepped out of the jetbridge in Atlanta a solid 40 minutes early. The overhead signs said: "ATL-TPA - Scheduled 10:05, Now: 10:07 PM". There had been some bad weather in Atlanta and ops were a mess. The funny thing was, the thunderstorms had run through only 2 hours earlier - while we were already in the air.

Delta literally gave the order for the PHX-ATL flight to do everything in their power to push early. To prepare for the fact that they knew ops were going to be impacted by weather that hadn't even hit yet. So that they could use our plane for a flight that they knew they wouldn't have a plane for. Doing this at scale sounds easy in theory, but hard in practice - especially when there are complex factors (if I decide to do this, will there even be a gate for the plane? Or are they just going to sit on the tarmac? I need to know exactly how the flows will work, how the weather will impact my inbounds and outbounds, and then make a decision on all of this).

Delta has better ops than American and United. It is not even close. There are a lot of things I hate about Delta, but their operational prowess is night and day compared to the other airlines. Anyone who flies as much as I do knows this.

jayunited wrote:

ethernal wrote:

Delta certainly benefits from having interior hubs with uncongested airspace. But let's not pretend for a second Delta's ops are a result of those airports. Delta's presence literally pulls up airports from the dredges. While there are other structural reasons why JFK is a bit better than EWR, it is not a coincidence that it performs "relatively well" for a NYC airport. It's because Delta is the largest carrier there.

Every thing you wrote below this first paragraph I completely agree with but this first paragraph I agree and disagree with. No one can agrue with the fact that DL knows how to run their operation and JFK does benefit from it. But if you compare JFK to EWR on a daily basis EWR ATC flow control always averages higher than it does at JFK and it has a lot to do with EWR's lack of runways. There are times when I get to work at 6 a.m. and EWR is already on a 15-20 minute flow control and it just gets worse as the day progresses. Even on sunny days by noon or 1 p.m. EWR is on a 30 minute or more ATC flow while JFK has none. Also to be absolutely fair there are two entities responsible for the consistent ATC flow control delays, one is the DOT and the second is UA. EWR is no longer slot controlled and if I am going to be honest UA has multiple arrival and departure banks that are over scheduled.

This is totally fair and completely agree. I probably glossed over it a bit much with my comment that there are "other structural reasons why JFK is better". EWR will always score worse than JFK (at least with its current volume relative to capacity).

EWR removing the slot controls has tanked its ontime percentage. I expect it to be the worst until something changes.

LAXintl wrote:

Are the airports so good because of Delta, or is Delta so good because they operate from these apparently efficient airports?

The old chicken or the egg. Obviously both can be factors, but it's clear from the data that the airport is the dominant factor.

ethernal wrote:

I'm not trying to make Delta sound amazing . . .

Except you are.

The data simply doesn't agree with the airline being the driving factor for an airport's performance. When you compare data closer to apples to apples (congested airports, DL's non-core hub stations), DL's ontime advantage whittles down to minor and sometimes reverses compared to its competitors. There's no doubt that if DL was operating the same capacity as its competitors at equally congested hubs, their ontime lead would largely evaporate.

MSPNWA wrote:

ethernal wrote:

I'm not trying to make Delta sound amazing . . .

Except you are.

Here's some things I don't like about Delta (I could go on):

• They don't have enough C+ seats on many of their planes (e.g., their 737-900s) meaning that I often end up relegated to row 36 in coach as a Diamond medallion - even if I want to pay for C+ (since they're sold out weeks before departure).
• Deltamatic is crap and has all kinds of issues with booking what should be valid itineraries. I am not sure if that is because of incompetence or intentional revenue management intentionally making it hard.
• Delta's mileage program for international J is a joke. 980K miles for one round trip ticket to ATL-JNB? For pretty much every day of the year? Yeah, right.
• Plane swaps. If I book 6 months before departure, my seat will be changed 13 times.
• Their 767 business class product (including the refurbed 764s) is garbage and I take connections over nonstops to avoid them if I need to sleep on a redeye.

I could go on. I'm not a Delta fanboy. But their ops are very, very good. I fly nearly 300K butt-in-seat miles every year on multiple carriers (primarily Delta though) and notice a significant difference - even when flying into the same airports.

The data simply doesn't agree with the airline being the driving factor for an airport's performance. When you compare data closer to apples to apples (congested airports, DL's non-core hub stations), DL's ontime advantage whittles down to minor and sometimes reverses compared to its competitors. There's no doubt that if DL was operating the same capacity as its competitors at equally congested hubs, their ontime lead would largely evaporate.

Could you give a few examples? Here's a handy tool for you to do comparisons across airports. While I haven't searched exhaustively, I can't find an airport where Delta has lower performance than other legacy carriers (or any carrier for that matter) where both have non-trivial operations. I am sure there are a few, but it is the exception and certainly not the rule.

You can say a 4-5% on-time differential is trial, but it's not - 75% vs 80% is a 25% relative difference in delays. It is doubly significant when cancellations are 1/5th or less of what their competitors are (cancellations are an easy way to goose your A14 by "solving" significant delays by stranding passengers).

There's no doubt that if DL was operating the same capacity as its competitors at equally congested hubs, their ontime lead would largely evaporate.

Show your work. Delta consistently tops the other majors in on time performance. Ethernal provided numbers.

How much of an advantage is delta being less dependent on the connection carriers, then UA is on express or AA is on eagle, and that they buy and large don't have the cheapest of the bunch carriers doing all that much and in fairly short order any of it after gojet and unfortunately compass leaves. Because scale definitely provides more flexibility and deltas contracts seem to punish cancellations severely.

MSPNWA wrote:

The old chicken or the egg. Obviously both can be factors, but it's clear from the data that the airport is the dominant factor.

In some cases yes the airport is the dominant factor, Take for example UA's operation I would say UA could use that excuse for both EWR and SFO, at these two airport I believe the airport is the dominant factor followed closely by the airlines scheduling departure and arrival banks near capacity.

But lets take a closer look at UA's (I don't work for AA so I can't use them as an example) interior hubs, ORD, DEN and IAH. During peak travel season UA operate about (I'm estimating) 1,700 daily flights between these 3 hubs, these hubs on a year around basis see just as many thunderstorms, snow storms, high winds as any other hub but yet UA's on time performance at these hubs does not come close to matching DL at DTW, MSP and or SLC. If UA were to improve their metrics at ORD, DEN, and IAH we still wouldn't match DL performance because EWR and SFO would still pull us down but we could realistically rank 5th perhaps even 4th in on time performance out of the top 10 airlines here in the U.S.. In 2019 UA ranked 8th or 9th in on time performance and if you compare 2019 to 2018 DOT best and worst U.S. airports you will see a dramatic drop in on time performance at IAH and DEN two airport where UA is the largest carrier.

The time for excuses is over it is time for UA to do better at our mid-continent hubs.

dstblj52 wrote:

How much of an advantage is delta being less dependent on the connection carriers, then UA is on express or AA is on eagle, and that they buy and large don't have the cheapest of the bunch carriers doing all that much and in fairly short order any of it after gojet and unfortunately compass leaves. Because scale definitely provides more flexibility and deltas contracts seem to punish cancellations severely.

Definitely agree that AA's reliance on regional partners at airports like DFW hurt the overall airport stats. That said, even DFW mainline is only 77% on time for 2019 - and that is in a freefall from where they used to be in 2017 (83%).

Delta is consistently more reliable into AA's hubs than DL whereas AA is consistently worse at DL hubs that are "easy" (admittedly it's not that simple.. obviously a lot of flow to DTW may be coming from ORD, LGA, JFK, PHL which are worse airports). But still, I think these numbers speak for themselves. All mainline only.

ATL? DL: 86%. AA: 76%.
MSP? DL: 86%. AA: 75%.
DTW? DL: 87%. AA: 77%
SLC? DL: 87%. AA: 74%


Do the reverse:
CLT? DL: 88%. AA: 83%
PHX? DL: 84%. AA: 81%
PHL? DL: 84%. AA: 80%
MIA? DL: 81%. AA: 80%
DFW? DL: 76%. AA: 77% (Note.. 2019 was an aberration; 2012-2018, Delta was at least 4% above AA.. not sure what happened in 2019).

I'm picking on AA a bit because they're just the absolute worst but you see similar trends with other carriers.

dstblj52 wrote:

How much of an advantage is delta being less dependent on the connection carriers...

DOT data are shown for all mainline, express, and combined. DL mainline beats AA/UA/AS mainline five out of the last six months. In one of those months AS beat DL. AA and UA never did.

iyerhari wrote:

ScottB wrote:

iyerhari wrote:

Note that DL also has hubs in BOS, LGA

Eh, LGA has been bad for pretty much forever. At least it's not as bad as EWR.

EWR has significantly more flights than LGA - unfortunately this thread is going to become another B6 bashing on how bad OTP is. I think if you have hubs in the coast areas which are notorious for weather vagaries plus Northeast which is even worse during winter - chances are high that you will have worse statistics. One airport in the Northeast catches a cough and everyone is down with a bad cold, cough and fever.

DL has more NYC flights than UA does. UA doesn't get a pass because it's at EWR.

FSDan did the work:

NYC (EWR + LGA + JFK) total departures:
DL - 555, 47.7% mainline, 45.6% large RJ, 6.7% 50-seater
UA - 473, 56.0% mainline, 16.9% large RJ, 27.1% 50-seater

viewtopic.php?f=3&t=1420613&start=100

UA doesn't get a pass because it operates ~320 flights at day at SFO out of United's ~4,900.

UA has chosen its hubs. If they don't permit more reliable operations, if they're overcrowded, if they're more price competitive (prove it), it's all on United.

-Delays cost money
-Missed connections cost money

People wonder why delta makes more money, it's main connection hubs are less delayed.

It's not really that surprising that deltas largest hubs are the least delayed airports.

MIflyer12 wrote:

iyerhari wrote:

ScottB wrote:

Eh, LGA has been bad for pretty much forever. At least it's not as bad as EWR.

EWR has significantly more flights than LGA - unfortunately this thread is going to become another B6 bashing on how bad OTP is. I think if you have hubs in the coast areas which are notorious for weather vagaries plus Northeast which is even worse during winter - chances are high that you will have worse statistics. One airport in the Northeast catches a cough and everyone is down with a bad cold, cough and fever.

DL has more NYC flights than UA does. UA doesn't get a pass because it's at EWR.

FSDan did the work:

NYC (EWR + LGA + JFK) total departures:
DL - 555, 47.7% mainline, 45.6% large RJ, 6.7% 50-seater
UA - 473, 56.0% mainline, 16.9% large RJ, 27.1% 50-seater

viewtopic.php?f=3&t=1420613&start=100

UA doesn't get a pass because it operates ~320 flights at day at SFO out of United's ~4,900.

UA has chosen its hubs. If they don't permit more reliable operations, if they're overcrowded, if they're more price competitive (prove it), it's all on United.

Not sure I agree with that. UA isn't going to abandon one of their crown jewels. And United sort of got the short end of the stick when the FAA removed the Level 3 slot controls in 2016. There's a reason that on-time performance at Newark has gone down from 75% in 2016 to 68% in 2019. It's because flight ops went from 115K to 140K after slot restrictions eased after being under 120K since the financial crisis.

UA could do better - I agree 100% (see all my other posts about the fact that Delta is good at ops) - but EWR is congested and UA is not the only carrier there. Only ~5K of those ~25K extra flights are United's.

ethernal wrote:

Could you give a few examples? Here's a handy tool for you to do comparisons across airports. While I haven't searched exhaustively, I can't find an airport where Delta has lower performance than other legacy carriers (or any carrier for that matter) where both have non-trivial operations. I am sure there are a few, but it is the exception and certainly not the rule.

You can say a 4-5% on-time differential is trial, but it's not - 75% vs 80% is a 25% relative difference in delays. It is doubly significant when cancellations are 1/5th or less of what their competitors are (cancellations are an easy way to goose your A14 by "solving" significant delays by stranding passengers).

Yes. Some examples I know of where DL's lead over the other legacies is reduced to a small margin or even reverses are LAX, SFO, the NYC 3, BOS, DEN, DFW, IAH, and I'm sure there are more. And when you think of it, a small margin for DL at those airports isn't particularly impressive considering that often their flight left from an uncongested hub. Since most of DL's flights arrive and leave from an uncongested airport, they should have a significant advantage in ontime stats with an equal operation under their control. DL being the in the lead is not a surprise, and it will be tough for DL to drop below the other legacies unless their operations significantly deteriorate below the rest or DL significantly moves their network ratio into congested areas.

5% is indeed quite trivial mathematically. On average it takes 20 flights for a person to encounter one more delay, and then that one delay may not be a significant disruption in travel plans. Most travelers won't fly that many times on one airline, let alone all airlines. A PAX's specific itinerary is far more important at indicating the delay possibility. Buying a ticket because carrier X is network-wide 5% better is foolishly simplistic. In kind, controllable cancellations are so uncommon among all carriers that again that "1/5th" isn't statistically significant on an aggregate basis to make a buying a decision on that alone. Cancellations can't goose A14s. They are too few to make a significant difference in a carrier's aggregate percentage. And since the causes for cancellations are usually the same as what will cause widespread delays, no carrier will voluntarily cancel flights to achieve a high ontime percentage. No, instead they will take the bad ontime day and keep as much of the operation moving as possible.

delimit wrote:

Show your work. Delta consistently tops the other majors in on time performance. Ethernal provided numbers.

The DOT did the work. Credit goes to them. All I did was take the time to go read it. Also, the debate is in the context of individual airports and why that is, not a discussion about what airline has the highest average.

jayunited wrote:

In some cases yes the airport is the dominant factor, Take for example UA's operation I would say UA could use that excuse for both EWR and SFO, at these two airport I believe the airport is the dominant factor followed closely by the airlines scheduling departure and arrival banks near capacity.

But lets take a closer look at UA's (I don't work for AA so I can't use them as an example) interior hubs, ORD, DEN and IAH. During peak travel season UA operate about (I'm estimating) 1,700 daily flights between these 3 hubs, these hubs on a year around basis see just as many thunderstorms, snow storms, high winds as any other hub but yet UA's on time performance at these hubs does not come close to matching DL at DTW, MSP and or SLC. If UA were to improve their metrics at ORD, DEN, and IAH we still wouldn't match DL performance because EWR and SFO would still pull us down but we could realistically rank 5th perhaps even 4th in on time performance out of the top 10 airlines here in the U.S.. In 2019 UA ranked 8th or 9th in on time performance and if you compare 2019 to 2018 DOT best and worst U.S. airports you will see a dramatic drop in on time performance at IAH and DEN two airport where UA is the largest carrier.

The time for excuses is over it is time for UA to do better at our mid-continent hubs.

Logically it can't be "some" cases. It's either all cases or none. It's either the major variable factor, or it is not as it works both ways on the ontime scale. The airline works as the control variable since operations across airline network are largely the same. If that flips back and forth between being a superior or inferior factor, it indicates the operations across an airline network are less consistent than the differences among individual airports.

It's ironic that you specifically poke at UA at DEN and IAH. In 2019, mainline UA beat mainline DL at IAH by over 4 points and was just a two points behind at DEN. What does the data clearly say is the dominate factor when compared to DL's operations in the top-5?

I've said this before, but my belief is that UA (and today's AA--not the one during the mechanics' slowdown) is within a couple points at most of DL in the operations they can control. In other words, if they flew the same network, the difference is minor and basically statistically the same. The data shows me that although there's always room for improvement, UA is doing very well operationally just like DL and today's AA. UA is playing well the tougher cards they have in their hand.

ethernal wrote:

I'm picking on AA a bit because they're just the absolute worst but you see similar trends with other carriers.

Well, you're comparing the AA that had a mechanics slowdown for much of the year. So yes, the data is accurate and those problems are part of a carrier's operations, but it was temporary and not strongly relevant for today's AA. You'll see AA close the gaps in 2020. Since September, AA has been running 2-3 points better system-wide versus the same period in 2018.

90 minute schedule block for a 55 minute flight equals always on-time. Delta

MSPNWA wrote:

ethernal wrote:

Could you give a few examples? Here's a handy tool for you to do comparisons across airports. While I haven't searched exhaustively, I can't find an airport where Delta has lower performance than other legacy carriers (or any carrier for that matter) where both have non-trivial operations. I am sure there are a few, but it is the exception and certainly not the rule.

You can say a 4-5% on-time differential is trial, but it's not - 75% vs 80% is a 25% relative difference in delays. It is doubly significant when cancellations are 1/5th or less of what their competitors are (cancellations are an easy way to goose your A14 by "solving" significant delays by stranding passengers).

Yes. Some examples I know of where DL's lead over the other legacies is reduced to a small margin or even reverses are LAX, SFO, the NYC 3, BOS, DEN, DFW, IAH, and I'm sure there are more. And when you think of it, a small margin for DL at those airports isn't particularly impressive considering that often their flight left from an uncongested hub. Since most of DL's flights arrive and leave from an uncongested airport, they should have a significant advantage in ontime stats with an equal operation under their control. DL being the in the lead is not a surprise, and it will be tough for DL to drop below the other legacies unless their operations significantly deteriorate below the rest or DL significantly moves their network ratio into congested areas.

What are you talking about? Delta's lead doesn't reverse at those hubs. Delta consistently outperforms A14 both United, American, and other carriers for that matter. For legacies, I went through and checked: the only exception is this year (and it has primarily been this year) has been IAH/DFW by 1-2% - but Delta has historically outperformed at those and this year is an aberration. Compare that to both United and AA flying into Delta hubs - they perform significantly worse. Consistently.

I agree that there are advantages to having your flights from uncongested airports. I've said that consistently in my posts. It is not fair to compare United flying into DTW when the inbound airports are EWR and ORD. But DEN, DFW, LAX (for AA), PHX... these airports are all pretty isolated from the messes at EWR and SFO for United and JFK/BOS/ORD for American. Why don't they achieve better performance?

MSPNWA wrote:

5% is indeed quite trivial mathematically. On average it takes 20 flights for a person to encounter one more delay, and then that one delay may not be a significant disruption in travel plans. Most travelers won't fly that many times on one airline, let alone all airlines. A PAX's specific itinerary is far more important at indicating the delay possibility. Buying a ticket because carrier X is network-wide 5% better is foolishly simplistic. In kind, controllable cancellations are so uncommon among all carriers that again that "1/5th" isn't statistically significant on an aggregate basis to make a buying a decision on that alone. Cancellations can't goose A14s. They are too few to make a significant difference in a carrier's aggregate percentage. And since the causes for cancellations are usually the same as what will cause widespread delays, no carrier will voluntarily cancel flights to achieve a high ontime percentage. No, instead they will take the bad ontime day and keep as much of the operation moving as possible.

It is not trivial at all. It is easy to say "one in 20 flights" but many trips involve 4 flights. If I am connecting, an 85% OTA means I have a 72% chance of one of both my flights being on time as opposed to a 64% chance if I am at an 80% OTA. Take one round trip connecting (4 segments) and it's the difference between "I am more likely to have a delay than not" versus "more likely to not have a delay". And, perhaps your nonchalant attitude of "oh, it's only 1 in 20 flights" is the perspective that American takes but maybe that is why American is bleeding business travelers left and right. I've already flown 24 segments this year, so I've definitely had the opportunity to "notice". Keep in mind that this is not statistical roll of the dice irrespective of time of day. All delays cascade through the day, so morning is way better than evening. I don't have hourly stats, but the times I've had to suffer through a DFW connection, you're pretty much guaranteed delays if you're flying through in the early evening in the summer. The effective on-time rate at 5:00 PM in the summer is more like 40% than 78% if it's at 5 PM. That 5% difference explodes to 10-15% differences at certain times of the day.

And I don't know what to say about cancellations.. but you're just wrong. I have flown over 1000 segments on Delta. I have never had a cancellation. Not one. Admittedly I proactively avoid extremely bad weather - but the great thing is that's pretty much the only time Delta cancels. So as long as I avoid very bad weather, my segments are safe. American? Over the past 5 years, I've had at least 10 cancels on approximately 200 mainline segments - frequently because of WX where Delta would have kept the flights running - even if delayed - or due to MX when Delta would have flown in a rescue plane (there are at least 10 instances where Delta has flown in a rescue plane for my flight. I've never had American send a rescue flight for me - admittedly on fewer segments). The difference is - Delta I can trust (domestically) to get me home unless there is a major weather event assuming it is mainline. American? No guarantees. That is a major difference. I've had two unexpected overnight stays with American on 1/5th the segments. I've never had to have Delta give me a hotel voucher. Ever. Some of this is luck, but most if it is because Delta mainline doesn't cancel under the same circumstances as American.

And cancellations definitely goose A14. You can't think of it as a 1:1 replacement for on-time flights. If a thunderstorm rolls into DFW/ATL in the summer at 3:00 PM and gums up planes for 2.5 hours, then every subsequent flight those planes take that day will be delayed. For local routes, that could be as many as 4-5 segments. Cancelling one flight to get back on track means 3 more on-time segments than I would have otherwise had. When your cancellation rates are 2%, that means I can increase my ultimate on-time rate by 5% by cancelling those flights. Take whatever the difference Delta (or United, who is way less terrible than American) has on cancellations, multiply that by 2 or 3, and you get the "equivalent" on-time rate operationally.

I've said this before, but my belief is that UA (and today's AA--not the one during the mechanics' slowdown) is within a couple points at most of DL in the operations they can control. In other words, if they flew the same network, the difference is minor and basically statistically the same. The data shows me that although there's always room for improvement, UA is doing very well operationally just like DL and today's AA. UA is playing well the tougher cards they have in their hand.

Well, you're comparing the AA that had a mechanics slowdown for much of the year. So yes, the data is accurate and those problems are part of a carrier's operations, but it was temporary and not strongly relevant for today's AA. You'll see AA close the gaps in 2020. Since September, AA has been running 2-3 points better system-wide versus the same period in 2018.

The mechanics issue has primarily borne itself through on cancellations - less so on on-time arrivals. And I will take your bet on "AA closing the gap in 2020". Maybe they'll be a bit better (especially on cancels), but to say they are going to beat United or Delta is ludicrous. American is a mess, and their employee relations are part of that mess. No operational excellence program will ever work when your employees are not motivated and your leadership is a mess. The mechanics slowdown is a symptom of the disease, not a cause. In any service industry, good operations requires good people management.

There are other reasons why I'll take that bet including boneheaded decisions like keeping DFW as a banked hub when it is too large, doesn't have enough gates, and they don't have the operational prowess to run it as a banked hub. Chasing PRASM with short connections while delaying everyone may work in the very short term but loses in the long run (as you already see).

In my line of work, people travel pretty much every week. No one has good things to say about American. Some hub captives continue to fly them of course, but there is an exodus of people who are leaving American. Three people I know in Chicago who are multi-million milers on American switched to United as their primary carrier this year. I realize that this is turning into a bit of an "American sucks" rant, but my point is that it is laughable to try to say that "ops don't matter" when your comparison point is American vs. Delta.

SteveXC500 wrote:

90 minute schedule block for a 55 minute flight equals always on-time. Delta

Average padding is pretty similar for the majors. This data is old, but probably still roughly accurate. Average padding isn't the driver of it. I will say that I do believe that Delta is better at calculating the right amount of padding based on day of week / time of day. But this is something that all airlines have gotten better at in the past few years and wouldn't say it is a major differentiator- this is one of the big data 'low hanging fruits' since it's primarily done long in advance.



When it comes to managing data, where I think there is a significant difference is real-time operational decision making. I mentioned my PHX-ATL example as one, but it is just one of many. Delta is very smart about how they manage their flight ops. And unlike American, they optimize for A14 rather than D0. I fly mid/transcons a lot, and see this happen real-time based on jetstream factors. If there are any operational irregularities going on, Delta frequently intentionally swaps out my inbound flight in ATL to one that is going to arrive later if the jetstream is particularly weak. They use the plane we were originally supposed to be on to catch up on another schedule. I get slightly miffed because I board 10 minutes late, but we still make it to SJC or PDX 15 minutes early.

All this sounds easy, but these are the sorts of things American doesn't do. It seems like they completely lack the ability to do real-time day-of flight ops optimization at scale whereas Delta does it in clearly a somewhat automated fashion. United is starting to do this better, but American is still way behind.

These are all the sorts of things that armchair posters who don't fly much never see and can't fathom why Delta runs ops better. They all do the same thing, so what possibly makes Delta any better than any other? I fly 150+ segments a year, watch my inbounds religiously, and I see the magic that happens behind the scenes at Delta. The magic isn't there at all for American. United has glimpses of excellence on their best days, but often fall short. It's the culmination of small things that makes a difference.

SteveXC500 wrote:

90 minute schedule block for a 55 minute flight equals always on-time. Delta

Um, yeah, slow clap...every airline pads.

Ever since DL created a solid de-ice program at ATL they've really been able to step up their game in cold weather situations. Yes, DL sends temporary duty agents to ATL from DTW & MSP to assist with a major snow or ice event, but on a normal frosty Atlanta winter morning, they have what it takes to handle business. I did a temporary duty assignment there a few years ago due to a snow event and they had gently used Tempest trucks.