kfinger
Topic Author
Posts: 3
Joined: Tue Feb 05, 2019 9:03 pm

SFO Weather Delays

Fri May 31, 2019 2:27 am

SFO is well known for its delays. So why isn't there a better contingency plan in place to accommodate flights during weather issues?
 
GalaxyFlyer
Posts: 4095
Joined: Fri Jan 01, 2016 4:44 am

Re: SFO Weather Delays

Fri May 31, 2019 3:13 am

The contingency plan should be a new airport, or expanding the current one into the bay. The delays are caused by limits to runway acceptance rates due to close parallels.

GF
 
Georgetown
Posts: 422
Joined: Wed Dec 28, 2005 12:50 pm

Re: SFO Weather Delays

Fri May 31, 2019 4:42 am

GalaxyFlyer wrote:
The contingency plan should be a new airport, or expanding the current one into the bay. The delays are caused by limits to runway acceptance rates due to close parallels.

GF


Yup. Extending into the bay would obviously be the easiest, but there is zero political appetite to do so, which is beyond frustrating. It’s generally the shorter routes that get affected the most, and generally they can be flown from OAK or SJC, but that’s far from a solution. As a United flyer, it’s a killer.
Let's go Hoyas!
 
IAHFLYR
Posts: 4094
Joined: Sat Jun 25, 2005 12:56 am

Re: SFO Weather Delays

Fri May 31, 2019 1:52 pm

GalaxyFlyer hit it right on the money.

Not being involved anymore since retirement with FAA reducing some separation criteria as it applies to closely spaced parallel operations I may be way off base, but using the RNAV (RNP) Y 28R approach when lower weather is involved does help. IF they use that approach in that fashion the required separation standards would have to be reduced further in some manner to increase the arrival rate above what is currently set at during low weather conditions.

Some would say well just put all the RNP capable aircraft/crews on 28R and allow the non-participants to use the ILS 28L. Well speaking from the ATC side it's not the simple to segregate arrivals like that during an inbound push. Oh sure it can be done, but the workload is huge compared to normal ops of which airplane goes to which runway.

In short, back to what GalaxyFlyer wrote as the main issues.
Any views shared are strictly my own and do not a represent those of any former employer.
 
ucdtim17
Posts: 571
Joined: Fri Jun 03, 2016 6:38 pm

Re: SFO Weather Delays

Fri May 31, 2019 4:40 pm

Georgetown wrote:
GalaxyFlyer wrote:
The contingency plan should be a new airport, or expanding the current one into the bay. The delays are caused by limits to runway acceptance rates due to close parallels.

GF


Yup. Extending into the bay would obviously be the easiest, but there is zero political appetite to do so, which is beyond frustrating. It’s generally the shorter routes that get affected the most, and generally they can be flown from OAK or SJC, but that’s far from a solution. As a United flyer, it’s a killer.


Easier than that would be just capping traffic at SFO and forcing more flights to operate at OAK/SJC. There's no entity that can/will do that though, so airlines keep adding flights at SFO as long as they have gate space. Visitors want to fly to "San Francisco" regardless of whether their final destination may be accessed just as easily from one of the other airports. Then you have a feedback loop of so much service being offered at SFO, OAK/SJC just can't compete even for people who would prefer to fly there all else equal.
 
kfinger
Topic Author
Posts: 3
Joined: Tue Feb 05, 2019 9:03 pm

Re: SFO Weather Delays

Sat Jun 01, 2019 12:35 am

Concentrating flights at the hub so heavily means that something has to give when weather cuts SFO runway capacity in half. The regional flights to MFR, ACV, RDD, FAT, SBP, etc. are the first ones cut because less people have to be rebooked. But people there have the fewest flight options, as opposed to hubs like SEA, DEN, PHX which also have frequent service to SJC and OAK. The unawareness of second tier metro airports like OAK, BUR, and HOU that are just as close to the CBD is a question I pose here: viewtopic.php?f=3&t=1423663
 
IAHFLYR
Posts: 4094
Joined: Sat Jun 25, 2005 12:56 am

Re: SFO Weather Delays

Sat Jun 01, 2019 1:01 am

kfinger wrote:
Concentrating flights at the hub so heavily means that something has to give when weather cuts SFO runway capacity in half. The regional flights to MFR, ACV, RDD, FAT, SBP, etc. are the first ones cut because less people have to be rebooked. But people there have the fewest flight options, as opposed to hubs like SEA, DEN, PHX which also have frequent service to SJC and OAK. The unawareness of second tier metro airports like OAK, BUR, and HOU that are just as close to the CBD is a question I pose here: https://www.airliners.net/forum/viewtop ... &t=1423663


The second tier airports are often driven by the location to not only where O/D folks live and want to go. If I live north of Houston why fly into HOU over IAH or if I have business in FTW why fly into DAL, I get your point, but I do believe many have awareness of those OAK, BUR, HOU spots yet they just don't offer all the connections of the larger HUB spots so we take out delays and live with them.
Any views shared are strictly my own and do not a represent those of any former employer.
 
rickabone
Posts: 158
Joined: Tue May 09, 2006 8:06 am

Re: SFO Weather Delays

Fri Nov 08, 2019 8:03 pm

Delays due to weather have been greatly reduced since the introduction and improvement of .308 (Closely Spaced Parallel Runway) approaches. This change now allows aircraft to be separated by 1 mile between the leading aircraft for Runway 28L and the trailing aircraft for Runway 28R all the way down to CAT 1 minimums. While this still reduces the advertised arrival rate, it was a big enough increase in the rate over single file ILS and is available much more frequently than SOIA resulting in greatly reduced delays. There are only a few hours per day where the expected arrival rate is above the .308 advertised rate. And even the advertised rate is an approximation and is frequently exceeded. This winter will also be the start of .308 approaches to the 19's. The initial arrival rate for this is a very conservative one so it may not have that great of an impact on delays when the airport is in a South East configuration. Additionally there is a temperature requirement for .308 to the 19's which would prevent it's use during cold winter storms and would apply more to the warmer spring storms.

While a new runway in the Bay would be the simple answer, technology has given us fixes that have greatly reduced weather related delays.

Now the bigger cause of delays are on the departure side caused by ramp and gate congestion. It has become the norm for several airlines and flights that they will arrive and have to wait between 15 minutes to well over an hour for an available gate.
 
N1120A
Posts: 26509
Joined: Sun Dec 14, 2003 5:40 pm

Re: SFO Weather Delays

Sat Nov 09, 2019 2:09 am

As others have said, the issue is spacing. Another problem is wake turbulence, which has to be accounted for. That is easy when you're visual, but lower visibility creates problems there requiring greater spacing.
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
 
strfyr51
Posts: 4046
Joined: Tue Apr 10, 2012 5:04 pm

Re: SFO Weather Delays

Sun Nov 10, 2019 6:06 am

the enviormental Lobby refused to consider allowing runways 28L and 28R to be offset into the bay on Pilings though they would only have to offset runway 28R and 19L which would allow tandem takeoffs and Landings in any weather. And? They won't unless SFO is threatened to Be closed, Everybody already Knows that OAK or SJC are not foung to solve the problems unless extending the Runways at the Moffett Field Facility or moving to Solano County with an Expansion of Travis AFB is a solution.
SFO was built during the DC6 and L1049 days and right now is stuck in that Design.
 
timz
Posts: 6572
Joined: Fri Sep 17, 1999 7:43 am

Re: SFO Weather Delays

Tue Nov 12, 2019 8:03 pm

rickabone wrote:
This change now allows aircraft to be separated by 1 mile between the leading aircraft for Runway 28L and the trailing aircraft for Runway 28R all the way down to CAT 1 minimums.

Or the other way around? Can the lead aircraft go to 28R?

This is not the offset localizer from a few years ago? That's gone?
 
ucdtim17
Posts: 571
Joined: Fri Jun 03, 2016 6:38 pm

Re: SFO Weather Delays

Wed Nov 13, 2019 11:37 pm

strfyr51 wrote:
Everybody already Knows that OAK or SJC are not foung to solve the problems unless extending the Runways at the Moffett Field Facility or moving to Solano County with an Expansion of Travis AFB is a solution.


I don't think "everybody" knows that. OAK has plenty of runway space and real estate for new terminals, and is more centrally located to the metro region than SFO. Until there's some cap imposed, or delays get untenable, airlines seem to want to route all their traffic through SFO, but that doesn't have to be the case forever.
 
leader1
Posts: 54
Joined: Thu Nov 05, 2015 4:44 am

Re: SFO Weather Delays

Mon Nov 18, 2019 7:52 pm

rickabone wrote:
Delays due to weather have been greatly reduced since the introduction and improvement of .308 (Closely Spaced Parallel Runway) approaches. This change now allows aircraft to be separated by 1 mile between the leading aircraft for Runway 28L and the trailing aircraft for Runway 28R all the way down to CAT 1 minimums. While this still reduces the advertised arrival rate, it was a big enough increase in the rate over single file ILS and is available much more frequently than SOIA resulting in greatly reduced delays. There are only a few hours per day where the expected arrival rate is above the .308 advertised rate. And even the advertised rate is an approximation and is frequently exceeded. This winter will also be the start of .308 approaches to the 19's. The initial arrival rate for this is a very conservative one so it may not have that great of an impact on delays when the airport is in a South East configuration. Additionally there is a temperature requirement for .308 to the 19's which would prevent it's use during cold winter storms and would apply more to the warmer spring storms.


Just curious, but what are the arrival rates for .308 on the 28s and 19s?
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