timz
Posts: 6163
Joined: Fri Sep 17, 1999 7:43 am

SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 8:04 am

The SF Chronicle for 27 October has a short story about the new $20M "hi-tech landing system" that is intended to increase (single-runway?) arrivals from 30 to 38 per hour when visibility precludes simultaneous parallel-runway landings. How's it supposed to work?
 
ERAUPilotATC
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Joined: Tue Oct 12, 2004 4:58 am

RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 8:49 am

The only possible thing that I could think of would be a precision GPS approach. But I'm not sure if they have been certified. Someone correct me if I'm wrong but I don't think they've been certified yet.
 
Goldenshield
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 9:46 am

It's called a SOIA, or Simultanious Offset Instrument Approach. Basically, it's like the ILS PRM found at MSP, but instead uses an LDA, or LDA PRM -- to be precise.

One aircraft flies in on the ILS, while another is following an LDA, or Localizer-type Directional Aid, which is basically an offset ILS. What this does, is sets up a multiple approach to where both aircraft come in, with the LDA aircraft lagging the ILS aircraft, as the LDA aircraft can identify the ILS aircraft better. After a missed approach fix, if the aircraft is not in visual conditions, or has the ILS aircraft in sight, then an missed approach is called; otherwise, the aircraft will deviate from the LDA to align visually with the runway.
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timz
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 9:50 am

Ah-- so they are using the two parallel runways? So it's the regular ILS to 19L and an LDA to 19R? The LDA is parallel and offset, or angled?

Come to think of it, didn't they already try a parallel LDA on runways 28? Whatever happened to that?
 
Goldenshield
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 9:54 am

An LDA's alignment is offset a few degrees from the runway alignment, but not by much. It's just there to allow a 'no transgression zone' between the approaches.

As far as ones on the 28's, I never did hear anything about that. They may have put it into effect there, too.
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tungd
Posts: 101
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 11:10 am

I'm not a GPS expert, but from what I understand, precision GPS is still some years away from implementation; it requires replacement of the current generation of GPS satellites. I think there's 2 or 3 of the new satellites in orbit now, but it will probably be the end of the decade before all 24 active satellites are replaced.

I've also read that GPS landing systems will require airfield ground equipment, but maybe not to the extent that ILS does; mainly just synchronizing transceivers to adjust for the atmospheric disturbances and time lapses due to the satellites being 12,000 miles away. But GPS has the potential to provide instrument landing capability to many more runways than the current (and expensive) ILS system.

Again, I'm not an expert so feel free to correct me!
 
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RayChuang
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 11:25 am

What it sounds more like is a staggered approach for landings on Runways 19L and 19R (north to south landing) and Runways 28L and 28R (east to west landing). They may be implementing this to better accommodate the A380-800 when that plane starts flying to SFO (most likely in the summer of 2006 when SQ Flights 001/002 are switched to this plane).
 
as739x
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Joined: Tue Apr 15, 2003 7:23 am

RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 11:32 am

Tungd-laska dies GPS precision approaches. Its called RNP or required Navigation Procedure ( I know I'm close on that) Its uses 3 GPS satellites and its within 3-6 feet depending on the satellite positioning.

Timz-they are using it on 28L (ILS) and 28R (PRM) approaches. It is not apporoved for 19L/R due to terrain for the planes approaching on 19R. Also, I don't think there is a ILS approach for 19R.

Golden-the most intersting part is that the pilots are listening to two different controllers. They sit next to each other in the tower and one monitors the speed of the PRM plane. Pilots don't seem to keen on the approach. They say there a a lot of planes not knowing what they are doing. Very interesting statement!

ASSFO
"Some pilots avoid storm cells and some play connect the dots!"
 
Goldenshield
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 11:57 am

AS-

I'm guessing that the crews didn't quite soak up the training. I watched a video of it the other day, and understood it completely.
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as739x
Posts: 5018
Joined: Tue Apr 15, 2003 7:23 am

RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 12:13 pm

From what I have heard it was Skywest crews and some Bizjets. Now granted this was the first few weeks so I'm sure things are better now. It seems to help when the ceiling is high enough. Its what 1,900 feet or so? Whats do you fly, if I can ask.

ASSFO
"Some pilots avoid storm cells and some play connect the dots!"
 
Goldenshield
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 12:17 pm

I don't fly. I dispatch.
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corey07850
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RE: SFO's "Hi-Tech Landing System"

Wed Nov 17, 2004 12:44 pm

Tungd:

I'm not a GPS expert, but from what I understand, precision GPS is still some years away from implementation

Precision GPS is already in use, albeit not very widely... It is more commonly called WAAS (Wide Area Augmentation System)... Basically, as said, it uses satellites in orbit along with ground stations to correct for timing errors and delays from the atmosphere, etc. Personally I imagine ILS's will be obselete in less than 10 years with precision GPS's being the norm.

Ironically enough... Here is a paper on the use of WAAS for closely spaced parallel approaches at SFO

http://waas.stanford.edu/~wwu/papers/gps/PDF/sharonparallel.pdf

[Edited 2004-11-17 04:49:08]
 
timz
Posts: 6163
Joined: Fri Sep 17, 1999 7:43 am

RE: SFO's "Hi-Tech Landing System"

Thu Nov 18, 2004 3:21 am

I forgot that myairplane.com would likely have the relevant plate. Turns out the LDA/glideslope approach to 28R gets you to DARNE, where you're to spot the runway 3.35 nm ahead, 3.4 degrees left of your course. And you're to spot the traffic approaching 28L, which ATC will have positioned conveniently ahead of you? Or are you allowed to land without sighting the traffic?

DARNE is 3009 or 3010 feet from the approach course to 28L-- is 3000 ft some sort of limit for dependent instrument approaches?

Wonder how easy it will be to get departures out if they actually are bringing in 38 staggered arrivals per hour.



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