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Why Is SFO So Delay Prone Compared To OAK/SJC?  
User currently offlineflaps30 From United States of America, joined May 2009, 287 posts, RR: 0
Posted (1 year 11 months 5 days 2 hours ago) and read 10239 times:

Almost everyday when I check Flightaware, it shows big delays at SFO usually due to low clouds or runway in use. How come there are hardly ever any delays at OAK or SJC when they are getting basically the same weather? Now I know that the volume at SFO is much greater, but they do have 4 runways to operate on. OAK only has 1 commercial runway (they do have shorter general aviation runways as well) and SJC has 2 commercial runways. Do the close proximity of the parallel runways at SFO prohibit smooth ops when the low clods come in? It just seems that OAK and SJC can handle these problems with better efficiency than SFO.


every day is a good day to fly
39 replies: All unread, showing first 25:
 
User currently onlinedartland From United States of America, joined Apr 2005, 643 posts, RR: 2
Reply 1, posted (1 year 11 months 5 days 2 hours ago) and read 10236 times:
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When weather hits SFO, they go down to 1 arrival runway (from the normal of 2), whereas OAK and SJC are ALWAYS 1-arrival runway. So adverse weather does not materially impact them. Their traffic can be handled by 1-runway without delays, so there is almost never a reason for them to have ground delays.

Also, those three airports do NOT have the same weather. SJC almost never gets low clouds/fog, and OAK far less than SFO also. While this is not the primary reason (per my explanation above), it's worth noting how variable the weather is even within a couple of miles in the bay area.


User currently offlinewedgetail737 From United States of America, joined Aug 2003, 5893 posts, RR: 6
Reply 2, posted (1 year 11 months 5 days 2 hours ago) and read 10189 times:
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Quoting dartland (Reply 1):
When weather hits SFO, they go down to 1 arrival runway (from the normal of 2), whereas OAK and SJC are ALWAYS 1-arrival runway. So adverse weather does not materially impact them. Their traffic can be handled by 1-runway without delays, so there is almost never a reason for them to have ground delays.

Also, those three airports do NOT have the same weather. SJC almost never gets low clouds/fog, and OAK far less than SFO also. While this is not the primary reason (per my explanation above), it's worth noting how variable the weather is even within a couple of miles in the bay area.

Also, OAK and SJC doesn't have nearly the traffic volume as SJC or OAK. SFO, I'm sure, has more traffic than OAK and SJC combined.

SFO runways are too close together to meet FAA requirements for parallel IFR landings. Having just one runway for landing pretty much paralyzes them.


User currently offlinegigneil From United States of America, joined Nov 2002, 16347 posts, RR: 85
Reply 3, posted (1 year 11 months 5 days 2 hours ago) and read 10191 times:

Yeah I was going to say, SJC and SFO are almost totally different climates - the delta in temperature can be as much as 30 degrees regularly.

NS


User currently offlineapodino From United States of America, joined Apr 2005, 4254 posts, RR: 6
Reply 4, posted (1 year 11 months 5 days 2 hours ago) and read 10150 times:

You basically said it all right there. SFO has a lot more traffic than either OAK or SJC, especially since both AA and UA pulled out of OAK recently, and with VX setting up shop at SFO. Why SFO is such a problem is, like many of the airports out on the east coast (LGA comes quickly to mind), the airlines build flight schedules that are good for a good weather day. But in the winter time, the airport is very prone to fog, and this causes many problems. SFO operates most efficiently with good visibility which allows the airport to run visual approaches to the 28's, which is necessary because ATC needs the planes to maintain visual separation with the runways so close together. Sometimes in less than ideal conditions, they can run what is called SOIA (which I believe stands for Staggered Outer Inner Approaches), which although not ideal, they can put more planes down by alternating the landing runway. However in a full IFR day where they have to run ILS approaches, they get down to one arrival runway, which usually ends up being a 30 AAR (Aircraft Acceptance Rate) which is half of the normal 60. With demand per hour far exceeding 30 airplanes, delays happen.

I don't have the stats for OAK or SJC. However, as you said at OAK GA is separate from the commercial traffic, meaning that 11-29 drives the operation at OAK, and given the flight schedule, they probably have fewer than 30 commercial arrivals per hour at OAK. SJC has two parallel runways, so they can run a slightly higher arrival rate than 30 (probably between 32 and 36) because the arrival runway is not conflicting with any departing traffic the way it does at both SFO and OAK.

But you do raise an interesting point. With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.


User currently offlinemikeology From United States of America, joined Mar 2012, 124 posts, RR: 0
Reply 5, posted (1 year 11 months 5 days 2 hours ago) and read 10098 times:

Off topic but I like how SFO comes up so much on this forum. My home airport is so popular  

User currently offlinephishphan70 From United States of America, joined Oct 2006, 264 posts, RR: 0
Reply 6, posted (1 year 11 months 5 days 2 hours ago) and read 10098 times:

Quoting dartland (Reply 1):
it's worth noting how variable the weather is even within a couple of miles in the bay area.

This can't be overstated. Driving south on 101 from San Francisco down the peninsula can feel like driving from a freezer into an oven temperature wise, as well as moving from a dark room into the bright sunshine. The topography of the hills that run down the spine of the peninsula really effects where and how the fog and moisture can roll into the area, and the most southern point from San Francisco for noticeable and drastic weather variations tends to be a mile or so south of SFO. I'll go as far as saying most of the time when SFO is experiencing weather, SJC isn't.


User currently offlineflaps30 From United States of America, joined May 2009, 287 posts, RR: 0
Reply 7, posted (1 year 11 months 5 days 2 hours ago) and read 10081 times:

I guess my next question would be, with such a delay prone airport such as SFO, do the "pros" outweigh the "cons" when it comes to an airline operating a hub from there? I imagine with all the delays, the airlines are cutting into their bottom line, which we all know, is really what matters. Didnt WN pull out of SFO years back because of all the delays? I know they are back now, but for how long? Will the delays get them to drop SFO again? I guess my question could be aimed at most of the delay prone airports such as EWR, LGA, ORD, etc. When does too many delays actually start hurting them financially?


every day is a good day to fly
User currently offlineN766UA From United States of America, joined Jul 1999, 8226 posts, RR: 23
Reply 8, posted (1 year 11 months 5 days 2 hours ago) and read 10073 times:

Quoting flaps30 (Thread starter):
but they do have 4 runways to operate on

Not really. Wind and weather reduce SFO to 1 runway for takeoff and 1 for landing more often than not. It's not like they have 4 runways like DTW has 4 runways-- miles apart.



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User currently onlinedartland From United States of America, joined Apr 2005, 643 posts, RR: 2
Reply 9, posted (1 year 11 months 5 days 2 hours ago) and read 10074 times:
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Quoting apodino (Reply 4):
But in the winter time, the airport is very prone to fog,

Actually, fog is a problem all-year, especially in the summer. Winter we get rain, summer has more fog.

Quoting apodino (Reply 4):
But you do raise an interesting point. With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.

SFO is easier than OAK from the city for two reasons:
a) BART service runs to both, but at SFO it puts you right in the terminal. At OAK, you have to take a bus shuttle which is annoying.
b) While traffic can be bad to either -- the Bay Bridge is a huge problem for driving, as is the Nimitz Freeway (I-880) connecting the Bay Bridge down past Port of Oakland, to the airport. Those are two of the most delay-prone highways in the area. While US-101 to SFO is often not great, it's definitely the lesser evil.

OAK definitely has its advantages, especially for short-haul morning flying where traffic might be low and SFO is fogged in, but overall SFO is still the go-to.


User currently offlineN782NC From United States of America, joined Feb 2012, 71 posts, RR: 0
Reply 10, posted (1 year 11 months 5 days 1 hour ago) and read 9985 times:

Quoting flaps30 (Reply 7):

Yes WN pulled out back in March of 2001 citing multiple factors, most importantly the delays. They came back in 2007. Considering that WN's strategy now includes serving airports like EWR, LGA, DCA, which are even more delay-prone, I don't see them exiting SFO again.

Quoting wedgetail737 (Reply 2):
Quoting apodino (Reply 4):
SFO has a lot more traffic than either OAK or SJC, especially since both AA and UA pulled out of OAK recently, and with VX setting up shop at SFO

Exactly, the last couple years passenger traffic and total movements at SFO have skyrocketed. In 2011, SFO handled 41 million passengers on over 400,000 operations, far higher than OAK: 9.2 million with 215,000 ops. and SJC: 8.3 million with 120,000 ops.

Then combine the traffic with our wonderful natural air conditioner and runway separation, and there you have it...



Stairway to Seven
User currently offlineDocLightning From United States of America, joined Nov 2005, 19495 posts, RR: 58
Reply 11, posted (1 year 11 months 5 days 1 hour ago) and read 9957 times:

Quoting dartland (Reply 1):
it's worth noting how variable the weather is even within a couple of miles in the bay area.

Very true. I am not exaggerating when I tell you that I have found myself standing in cold, grey fog downtown. I walk two blocks south and suddenly I am standing in bright, warm sun. I turn around and there is a massive wall of fog hanging there.

Similarly, the south/east end of SFO (the airport itself) can be in bright sun and the north/west end can be in pea-soup fog.

It is my understanding that the issue is that 28L is 50 feet too close to 28R to allow for tandem IFR approaches. The FAA won't grant a waiver.

I really wish there were a way around this.


User currently offlineSJCMSP From United States of America, joined Aug 2012, 60 posts, RR: 0
Reply 12, posted (1 year 11 months 5 days 1 hour ago) and read 9938 times:

Quoting phishphan70 (Reply 6):
This can't be overstated.

Agreed. When I was a kid growing up near SJC, we'd go up to SF when friends would visit from out of town. They would be confused when we'd be loading the trunk with sweatshirts while it was 85 and sunny. When we'd get to SF, they would understand why we brought the sweatshirts.


User currently offlinechrisair From United States of America, joined Sep 2000, 2092 posts, RR: 3
Reply 13, posted (1 year 11 months 5 days 1 hour ago) and read 9938 times:

Quoting apodino (Reply 4):
With BART servicing OAK as well as SFO, and with OAK being geographically closer to San Francisco than SFO, and with no delay problems, why can't OAK attract more traffic? If i was a business traveller, and my time was critical, to me its no decision, unless the weather is perfect, OAK will always get me to the Bay Area quicker than SFO.

OAK is ~20 miles to downtown San Francisco. SFO is 13 miles to downtown.

Someone else mentioned the hellish traffic on the Nimitz and the Bay Bridge. It's taken me three hours to go from the financial district in San Francisco to Hegenberger Rd before.

When going to San Francisco the scenery from the upper deck is just fantastic. One of the best views in the country.


User currently offlineLH707330 From United States of America, joined Jun 2012, 748 posts, RR: 0
Reply 14, posted (1 year 11 months 5 days ago) and read 9797 times:

"The coldest winter of my life was a summer in San Francisco." -Mark Twain. The reason SFO is fogged in is the sea breeze that sucks the fog in from the Pacific through the gap between the mountains and San Bruno. The warmer SJC is, the more rising air you get, thus a stronger sea breeze and more fog at SFO. IIRC, SJC only has one ILS, but when it gets bad there they can just switch to departure/arrival mode and not lose much throughput, not that it matters because the volumes are not that high.

User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 22
Reply 15, posted (1 year 11 months 5 days ago) and read 9776 times:

Quoting DocLightning (Reply 11):
tandem IFR approaches

Never heard it phrased like that before, I kind of like it! Now explain it.   



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User currently offlineDocLightning From United States of America, joined Nov 2005, 19495 posts, RR: 58
Reply 16, posted (1 year 11 months 4 days 23 hours ago) and read 9766 times:

Quoting IAHFLYR (Reply 15):
Never heard it phrased like that before, I kind of like it! Now explain it.

Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways. They are spaced far enough apart that the aircraft don't need to be able to see each-other to avoid a collision or wake interference.

At SFO the runways are 50 feet too close together to allow for legal use of the instrument landing system if two aircraft are landing side-by-side, so if there are clouds below minimums, there will be at least some part of the approach in which the aircraft will not be able to see each-other and so they cannot maintain visual separation.


User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 22
Reply 17, posted (1 year 11 months 4 days 23 hours ago) and read 9760 times:

Quoting DocLightning (Reply 16):
Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways


Maybe not the correct terminology but I still like it!  

You're thinking of simultaneous independent approaches and there are a few different set of standards for the distance between centerlines to operate in that fashion. LAX for example would have 4,300' or more between centerlines and is able to conduct fully instrument approaches, duals that are side by side while IAH, DFW, DEN, and a few more can conduct triple approaches side by side by side as their three parallel runway centerlines are separated by at least 5,000'. ATL has a waiver from the 5,000' centerline standard and has a high update monitor RADAR to conduct triple approaches.

But SFO is no where near having enough distance between the runways to have airplanes side by side unless they are maintaining visual separation from the turn on point to the runway.



Any views shared are strictly my own and do not a represent those of any former employer.
User currently onlinevikkyvik From United States of America, joined Jul 2003, 9897 posts, RR: 26
Reply 18, posted (1 year 11 months 4 days 22 hours ago) and read 9754 times:
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Quoting DocLightning (Reply 16):
Not sure if my terminology is correct, but at an airport like LAX, the instrument landing system can be used to land aircraft on parallel runways. They are spaced far enough apart that the aircraft don't need to be able to see each-other to avoid a collision or wake interference.

At LAX, they can do simultaneous instrument landings to one runway on each side of the airport. So one of the 24s and one of the 25s. They can't do them to 24R and L (745 foot centerline spacing), or 25R and L (800 foot centerline spacing).

Quoting DocLightning (Reply 16):
At SFO the runways are 50 feet too close together to allow for legal use of the instrument landing system if two aircraft are landing side-by-side, so if there are clouds below minimums, there will be at least some part of the approach in which the aircraft will not be able to see each-other and so they cannot maintain visual separation.

I don't think 800 foot centerline spacing gives you this ability, which is what SFO would have if they seperated the runways by an additional 50 feet. For side-by-side approaches, 4300 feet is the number that rings a bell.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineDocLightning From United States of America, joined Nov 2005, 19495 posts, RR: 58
Reply 19, posted (1 year 11 months 4 days 22 hours ago) and read 9728 times:

Quoting vikkyvik (Reply 18):
I don't think 800 foot centerline spacing gives you this ability, which is what SFO would have if they seperated the runways by an additional 50 feet. For side-by-side approaches, 4300 feet is the number that rings a bell.

So, basically, 28R would have to be moved all the way out to the end of the 1/19's. Ouch.


User currently offlineGoldenshield From United States of America, joined Jan 2001, 6002 posts, RR: 14
Reply 20, posted (1 year 11 months 4 days 9 hours ago) and read 9574 times:

Depending on the conditions, they can do one of four things:

1) Visual Approach
2) SOIA
3) staggered ILS approach
4) Single runway ILS (28R, usually)

Number 1 is self-describing.

Number 2 is using the ILS on 28L and an LDA on 28R with a stagger, but can only be used when minimums are 1600 feet and 4 miles, or greater.

Number 3 is staggers the arrivals when demand is low, or SOIA cannot be used.

Number 4 is used when the weather is near CAT I minimums, or lower. 28R being the CAT II/III runway.


When SFO is landing on anything but the 28s, it makes an interesting day for photographers, but hell for ops people since the only other ILS is on 19L.



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User currently offlineaklrno From United States of America, joined Dec 2010, 927 posts, RR: 0
Reply 21, posted (1 year 11 months 4 days 6 hours ago) and read 9549 times:

All of this explains why I will go several hundred miles out of my way to do connections at LAX instead of SFO. I'd use SJC or OAK if they had the connections I wanted. I only use SFO if that is my destination and I am not on a tight schedule. If I'm heading to SF for a same day meeting I usually fly to OAK and take BART or a very expensive taxi. I never depend on anything from RNO to SFO to be on time.

I broke that rule last spring intending to fly RNO-SFO-EWR. To my complete astonishment everything at SFO was on time that day. To make up for that the A320 went tech at the gate in Reno. I ended up hours late, missed the connection, ended up losing my first class set for a middle seat on a redeye in row 273, or something like that.


User currently offlineDocLightning From United States of America, joined Nov 2005, 19495 posts, RR: 58
Reply 22, posted (1 year 11 months 4 days 3 hours ago) and read 9501 times:

Quoting aklrno (Reply 21):

All of this explains why I will go several hundred miles out of my way to do connections at LAX instead of SFO. I'd use SJC or OAK if they had the connections I wanted. I only use SFO if that is my destination and I am not on a tight schedule. If I'm heading to SF for a same day meeting I usually fly to OAK and take BART or a very expensive taxi. I never depend on anything from RNO to SFO to be on time.

Same for me. I live in SF, but if there is a way to get where I'm going from OAK, I'll do it that way. I hate three-hour delays.


User currently offlineKaiarahi From Canada, joined Jul 2009, 2979 posts, RR: 28
Reply 23, posted (1 year 11 months 4 days 1 hour ago) and read 9474 times:

I guess I must be the odd one out. I fly regularly to AKL through SFO (because I detest international transit at LAX) and I've never had a WX delay. Hope I haven't just jinxed myself!


Empty vessels make the most noise.
User currently offlineDocLightning From United States of America, joined Nov 2005, 19495 posts, RR: 58
Reply 24, posted (1 year 11 months 3 days 23 hours ago) and read 9449 times:

Quoting Kaiarahi (Reply 23):
I guess I must be the odd one out. I fly regularly to AKL through SFO (because I detest international transit at LAX) and I've never had a WX delay. Hope I haven't just jinxed myself!

From AKL you might not. The fog at SFO tends to occur on a schedule, better at mid-day and worse in the AM and PM. AKL arrives mid-day. Also, a flight from AKL that departs 12 hours previously is not going to get a ground delay most likely because the precise weather at SFO can't be predicted 12 hours in advance. They can't make a flight from AKL circle for three hours, so the flight probably gets priority.

Flights from Southern California are delayed all the time. I once experienced a WX delay so long flying SBA-SFO that I literally could have dead-headed a rental car and arrived prior to the plane had I known in advance the delay would be so long.

It's a big problem at SFO and there doesn't seem to be a good solution any time in the near future.

SFO is a great airport as long as your flights are on-time. Transferring between terminals is effortless, the AirTrain is very useful and well-designed, the terminals are relatively new and/or refurbished, and there are a lot of destinations that can be reached non-stop (unfortunately, UA has most of the market). But the delays are really bothersome.


25 LH707330 : Unless you have to go through security at the G gates for a flight that leaves in the big lunch-hour bank. I waited in line for almost an hour once..
26 Mir : Simultaneous Offset Instrument Approaches. IIRC, tt's a form of PRM approach: you have a No Transgression Zone (NTZ) the same size as you would for a
27 Kaiarahi : Makes sense. I've never had a WX delay on YYZ-SFO (to connect to SFO-AKL) either, but they also arrive/depart midday/early afternoon.
28 IAHFLYR : Absolutely, only the outboards.
29 macsog6 : Saying that BART services OAK is a bit misleading. You ride BART part of the way, get off, buy another ticket, and ride a bus over to OAK. The rail l
30 Post contains links and images barney captain : As accurate as the statement is, Mark Twain didn't say it. It's author remains a mystery - unlike why SFO has continued delays. "A popular quote inco
31 LH707330 : You learn something every day....
32 apodino : Thanks for the explanation. My carrier doesn't fly into SFO at all but I hear it talked about on ATC telcons...and I always wondered how that whole S
33 Post contains images 777ord : All are valid points. It's just incredible to mention that in ONE state, there is so much variation in climate, topography and vegitation!!! SAN is b
34 BoeingGuy : What's the Alternate for inbound international flights like that if they can't land at SFO? I'm guessing SMF and FAT? I have seen quite a few UA heav
35 SJCflyer : Typically OAK is the primary alternate for SFO. Depending on type, they may also go to SJC. And, there's even NUQ as a potential alternate. I remembe
36 BoeingGuy : AA has used SMF and FAT as alternates for SJC, at least back when SJC's ILS was only Cat 1. I remember a flight attendant telling me they deverted in
37 seb146 : Also, the terminal at OAK is small. The site map says "Terminal 1" and "Terminal 2" but they are both one building and a total of about 25 gates. T-2
38 Longhornmaniac : Hardly. It's not difficult, but any international hub airport in 2012 where you can't connect between all terminals inside the secure area is automat
39 Post contains links LAXintl : Yeah the Bay's microclimates do no favors for SFO. DOT is out with its September rankings and for the first 9-months of 2012, SFO was... #28 out of 29
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