Why Do PHX-SFO Flights Not Overfly The Sierras

AirCalSNA · Fri Sep 21, 2012 10:44 pm

I've been watching flights between PDX and SFO recently and noticed their routes seem to avoid the southern Sierra Nevada mountains, which would be a more direct route to PDX. Instead, they fly over the eastern LA basin. Does anyone know why this less-than-direct route is used? Thanks.

mayor · Fri Sep 21, 2012 10:50 pm

Are you talking about Portland to San Francisco?? If you are, why would they ever get as far south as the eastern LA basin or even the Southern Sierra Nevada?

71Zulu · Fri Sep 21, 2012 11:14 pm

Most seem to file the Golden Gate 6 arrival,

http://flightaware.com/live/flight/S...9/history/20120921/1853Z/KPDX/KSFO

Can't get much more direct than this.

http://flightaware.com/live/flight/S...9/history/20120920/1639Z/KSFO/KPDX

[Edited 2012-09-21 16:18:49]

N1120A · Fri Sep 21, 2012 11:22 pm

Quoting AirCalSNA (Thread starter):
I've been watching flights between PDX and SFO recently and noticed their routes seem to avoid the southern Sierra Nevada mountains, which would be a more direct route to PDX. Instead, they fly over the eastern LA basin. Does anyone know why this less-than-direct route is used? Thanks.

Are you talking about LAX? Because PDX-SFO would be going way out of the way if they flew over L.A.

Anyway, looking at Flight Aware, it appears they go east and south and take a fairly direct route to LAX. Sort of routes over the Fresno area and fly similar routings.

MDCJets · Fri Sep 21, 2012 11:28 pm

Perhaps you mean PHX? (Phoenix AZ)

AirCalSNA · Fri Sep 21, 2012 11:30 pm

Quoting MDCJets (Reply 4):
Perhaps you mean PHX? (Phoenix AZ)

Yes, I meant PHX, not PDX. Sorry about that!

HAL · Fri Sep 21, 2012 11:49 pm

It has to do with the available routing, depending on restricted areas, other traffic, and weather. There's a huge swath of restricted airspace north of Las Vegas, and also over the northern Mojave desert (China Lake), and these areas are for all practical purposes, always 'on'. A straight-line flight PHX-SFO would go right through the China Lake restricted airspace, so the routes go either north or south of it. Weather can change things to, for instance if a huge thunderstorm is brewing over the desert. But in general it's shorter to swing a bit south over the mid-mojave. You could go right over Vegas, but that airspace is really crowded, and ATC doesn't usually allow those flights to be routed that way. And if you went north, you'd have to take a huge detour to get around all the restricted & prohibited airspace in southwest Nevada.

I flew for America West for two years, based in PHX and LAS, so I did a lot of flying in this area.

HAL

rickabone · Fri Sep 21, 2012 11:50 pm

There's a whole lot of Restricted Airspace on a direct route between PHX and SFO... China Lake, Edwards, Mojave all lie on the route.

Tomassjc · Sat Sep 22, 2012 12:11 am

I've recall being on a PHX-PDX flight during the winter that routed north over Utah, flew just west of Boise and then into PDX. Perhaps a more favorable routing due to winds aloft?

Tom SJC

fat-g4 · Sat Sep 22, 2012 12:33 am

Same thing with the LAS-FAT route. You usually go north out of Vegas following the border, then go direct west into Fresno overflying Shaver Lake. Either that, or they will take the southerly route. Flying out of FAT, alot if times you'll go direct shafter overflying Barstow and whatnot on your way in. They never fly straight across due to the restricted airspace.

mayor · Sat Sep 22, 2012 3:34 am

Quoting fat-g4 (Reply 9):
overflying Barstow

And, THAT, my friends, is the best thing you can do.....

rlwynn · Sat Sep 22, 2012 8:39 am

Quoting mayor (Reply 10):
And, THAT, my friends, is the best thing you can do.....

There is an In-And-Out there.

FX1816 · Sat Sep 22, 2012 8:51 am

Quoting fat-g4 (Reply 9):
Same thing with the LAS-FAT route. You usually go north out of Vegas following the border, then go direct west into Fresno overflying Shaver Lake. Either that, or they will take the southerly route. Flying out of FAT, alot if times you'll go direct shafter overflying Barstow and whatnot on your way in. They never fly straight across due to the restricted airspace.

Out of LAS to FAT you will go to the north. When R2508 overflights are low, then the route on the north side would be SHEAD direct KFAT or even SHEAD---SANGO--KFAT. This is really only on weekends, holidays and evenings. During the day, Monday thru Friday you can expect R2508 overflights to be higher, usually at or above FL310 and due to the fact that KFAT is only about 60 miles west of 2508 it's not really helpful to send KFAT arrivals from any airport through 2508, so you can expect a routing like SHEAD--LIDAT--BIH direct Fresno. The south is a different story, when 2508 is active there are NO overflights in the south due to R2515 over EDW and R2505 and 2524 for China Lake, so a routing to FAT would be something like HEC--PMD--EHF. On the weekend we do get plenty of ASH and AAL flights that come through routed BLH--TTE for the ALTTA8 arrival into KFAT.

Reference flights going to PDX from say PHX, can't happen during the week and the do need to be routed through the south due to more room. There is just a small corridor about 30 miles wide between R2508 and the Nellis Ranges, R4800 complex. It's really only LAS arrival and departure traffic that flies through there. Like I said when we completely open up R2508 we take alot of overflights and the PDX arrivals will be routed direct MOXEE for the MOXEE6 arrival and that takes aircraft from say PHX, directly south to north through R2508.

The Nellis Ranges, R4800 complex, tend to always be HOT and it is rare that they allow overflights at all.

Sorry if I got too technical. Smile

FX1816

[Edited 2012-09-22 01:56:09]

Bobloblaw · Sat Sep 22, 2012 9:49 am

BFL-SLC had good revenue for delta. Good loads and decent yield, but costs were nearly 20% higher than FAT-SLC. I enquirer to Skywest as to why and they said the direct routing of BFL-SLC was over restricted airspace and FAT wasn, so the mileage from BFL was nearly 100 miles longer than from FAT.

rfields5421 · Sat Sep 22, 2012 11:27 am

You really need to look at some aviation charts to see the large restricted areas in California - but basically everything from Bishop in the north to Palmdale in the south - from the foothills of the southern Sierras in the west to the Nevada border in the east is restriced airspace.

Yellowstone · Sat Sep 22, 2012 12:30 pm

Here's a link to a direct PHX-SFO flight plan drawn in Skyvector. Note that it crosses through the restricted areas in central California, outlined in blue markings looking like this: ||||||||||||||||||||||||||||||

http://skyvector.com/?ll=35.54742372...04&zoom=6&plan=A.K2.KPHX:A.K2.KSFO

MrFord · Sat Sep 22, 2012 2:19 pm

Quoting Yellowstone (Reply 15):
Here's a link to a direct PHX-SFO flight plan drawn in Skyvector. Note that it crosses through the restricted areas in central California, outlined in blue markings looking like this: ||||||||||||||||||||||||||||||

http://skyvector.com/?ll=35.54742372....KSFO

Just a quick thanks for allowing me to discover that website! Definitely going into my favorites

mayor · Sat Sep 22, 2012 2:51 pm

Quoting rlwynn (Reply 11):
Quoting mayor (Reply 10):
And, THAT, my friends, is the best thing you can do.....

There is an In-And-Out there.

Well, my experience with Barstow is about 40 years ago, or so.

AirCalSNA · Sat Sep 22, 2012 9:27 pm

Thanks folks ... I guess that should have been obvious to me, but I was thinking maybe they wanted to be over more populated areas in case they needed to set the plane down unexpectedly.

HAL · Sat Sep 22, 2012 9:45 pm

Quoting AirCalSNA (Reply 18):
I guess that should have been obvious to me, but I was thinking maybe they wanted to be over more populated areas in case they needed to set the plane down unexpectedly.

If that were a reason for any airline routing, nobody would ever fly over the oceans. Today, the only things that prevent airliners from making relatively direct flights are restricted airspace, traffic flow routings, weather, and ETOPS requirements.

HAL

Goldenshield · Sun Sep 23, 2012 3:39 pm

Wow. I really overslept yesterday and missed this thread. FX1816 spells it out pretty nicely, though. At my airline we usually go the north route over BTY and OAL to get to FAT, but sometimes, due to driftdown over the Sierras, the southern route over HEC-PMD is the only viable option. Sure, we get everyone there a few minutes late, but at least we get everyone there.

Quoting mayor (Reply 17):
Well, my experience with Barstow is about 40 years ago, or so.

If you ever stop in Baker, you can see what's left of the Silver Lake 4-course range.

[Edited 2012-09-23 08:56:51]

mayor · Sun Sep 23, 2012 3:45 pm

Quoting Goldenshield (Reply 20):

If you ever stop in Baker, you can see what's left of the Silver Lake 4-course range.

When I was in the Air Force, stationed at Travis, we did our winter airdrops (too wet, up north) at a dry lakebed, north of Baker.

FX1816 · Sun Sep 23, 2012 3:46 pm

Quoting Goldenshield (Reply 20):
Wow. I really overslept yesterday and missed this thread. FX1816 spells it out pretty nicely, though. At my airline we usually go the north route over BTL and OAL to get to FAT, but sometimes, due to driftdown over the Sierras, the southern route over HEC-PMD is the only viable option. Sure, we get everyone there a few minutes late, but at least we get everyone there.

Hey better late than never?

If you don't mind me asking, who do you fly for? You can PM me if you want, I'm pretty well versed on alot of these routes working at Joshua Appch.

FX1816

Goldenshield · Sun Sep 23, 2012 3:57 pm

Quoting mayor (Reply 21):

When I was in the Air Force, stationed at Travis, we did our winter airdrops (too wet, up north) at a dry lakebed, north of Baker.

And that would be Silver Lake. The range is just to the NE of the lake.

mayor · Sun Sep 23, 2012 4:03 pm

Quoting Goldenshield (Reply 23):

And that would be Silver Lake. The range is just to the NE of the lake.

Maybe they changed the name......as I recall, it was called Silurian Lake......straight north, out of town, just a few miles and the lakebed was just off the road, on the east side.

Goldenshield · Sun Sep 23, 2012 4:08 pm

Quoting mayor (Reply 24):
as I recall, it was called Silurian Lake......straight north, out of town, just a few miles and the lakebed was just off the road, on the east side.

If it's what I'm seeing on the map, the lake you're talking about is about 20 miles N of Baker. Silver Lake is just N of town, and end about 10 miles N of town. So, okay, we're thinking different lakes. Glad we got that cleared up.

mayor · Sun Sep 23, 2012 4:12 pm

Quoting Goldenshield (Reply 25):
If it's what I'm seeing on the map, the lake you're talking about is about 20 miles N of Baker.

You're probably right.......it's been a long time but the drive didn't seem that far. The dropzone would have to be rather large (and it was) and it would probably be unsafe to use one, right outside of town (althought there's not much "town" in the town).

DocLightning · Sun Sep 23, 2012 4:46 pm

Quoting mayor (Reply 10):
And, THAT, my friends, is the best thing you can do.....

"We were just outside of Barstow, on the edge of the desert, when the drugs began to take effect."

--Hunter S. Thompson

LV · Sun Sep 23, 2012 8:21 pm

Quoting Goldenshield (Reply 20):
If you ever stop in Baker, you can see what's left of the Silver Lake 4-course range.

Baker is a nasty four letter word to anyone who has had to drive between Vegas and anywhere in California

Goldenshield · Sun Sep 23, 2012 8:26 pm

Quoting LV (Reply 28):
Baker is a nasty four letter word to anyone who has had to drive between Vegas and anywhere in California

But! But! Wherever will I get my authentic Greek food, Alien brand Jerky, and the local tempurature?!!

DocLightning · Sun Sep 23, 2012 8:31 pm

Quoting LV (Reply 28):
Baker is a nasty four letter word to anyone who has had to drive between Vegas and anywhere in California

There's that great Greek place, Mad Greek. And the world's tallest thermometer. It read 107F when I was there in 2002.

mayor · Sun Sep 23, 2012 8:37 pm

Quoting LV (Reply 28):
Baker is a nasty four letter word to anyone who has had to drive between Vegas and anywhere in California

But, it's 5 letters.............

Quoting DocLightning (Reply 30):
It read 107F when I was there in 2002.

That's why I'm glad we were there in the winter.

UALWN · Sun Sep 23, 2012 8:59 pm

Quoting DocLightning (Reply 30):
There's that great Greek place, Mad Greek.

In 2005, I spotted the biggest 'roach I've ever seen in a restaurant at Mad Greek... Gyros was good though. The place is crazy.