Parallel landing at SFO

[underfire]

How does this work?

https://youtu.be/LEE35V5m98Y

Edit: Notice the split scimitar winglets!

[DaveReidUK]

I think they take advantage of the fact that parallel lines never meet.

[FuelFlow]

It's known as a PRM approach. Google will help you out.

[wiggy]

It's known as a PRM approach.

Somewhat doubt it..but anyway when I've been involved in these specifically at SFO one, or more usually both the aircraft involved have been on a visual approach with no magenta line/ILS/breakout frequencies required....

How does this work?

It's not rocket science, it's a use of basic pilot s***, sadly often long forgotten in the rush to codify everything and label it with an acronym. In short ATC say "fella, it's a nice day, look out the window, fly your aircraft accurately and land on your assigned runway, keeping an eye on the guy on your left/right". Simples.....

The slightly more complex answer is as DR has said, down to parallel lines... Usually how it works at SFO if they are landing to the west is that one aircraft flies a right hand traffic pattern, e.g. flying over San Francisco Bay bay for right turns to a visual approach onto 28 Right, the other traffic will fly a left hand traffic pattern coming in from the south for 28 Left (Google earth might help you visualise this if you are not familiar with the geography).

ATC "caution" you about the other traffic then let you get on with it..it's quite entertaining when you are pointing at each other on base leg....above all the really big thing to remember is not to fly through your centreline...:ooh:

Almost proper flying and it can make for a fun end to a long haul day out....

[Check Airman]

Never been to SFO, but it happens quite frequently at other airports like DEN and ATL. The runways at SFO do seem to be a bit closer together though. No special briefing required, other than "don't overshoot the turn to final".

[Capn Bloggs]

Sounds fun! Where do I sign up? :)

it's quite entertaining when you are pointing at each other on base leg....
What do you do with the TCAS in that situation? Put it in TA?

Now I've watched the video...the lead landed long! :}

[DaveReidUK]

Parallel Runway Operation - SKYbrary Aviation Safety (http://www.skybrary.aero/index.php/Parallel_Runway_Operation)

[LeadSled]

Folks,
Funnily enough, parallel simultaneous approaches have been the norm at KSFO since the place was built --- that is a long time ago.
Separation is fundamentally handled by the LOTW system, apparently unknown to many Australian pilots.

What do you do with the TCAS in that situation? Put it in TA?

As you do (SOPs -- aircraft/equipment/airline operator) in any area of high density traffic in the approach/departure area.

Now I've watched the video...the lead landed long!

Funnily enough, some regard it as normal operations to cooperate with ATC, and arrange their operations to vacate the runway in minimum time. When you have 10,000+ to play with, and it can safely be accommodated, a "normal" touchdown at the threshold is not necessary, aiming to a displaced threshold is not unknown.

[wiggy]

What do you do with the TCAS in that situation? Put it in TA?

That was indeed an Ops manual requirement when we first got TCAS, but that was subsequently amended out and we leave it in RA. It's a while since i've done a close parallel visual there but we didn't get any TCAS alerts/warnings last time. Improved software?

[Capn Bloggs]

Thanks Wiggy.

Slow news day in Australia, Leddie? Trawling the international forums looking for an opportunity to rip in to Aussie pilots, I see...

What do you do with the TCAS in that situation? Put it in TA?
As you do (SOPs -- aircraft/equipment/airline operator) in any area of high density traffic in the approach/departure area.

I'd rather a practising pilot at SFO like Wiggy answer, thanks all the same for your blindingly obvious non-answer. :rolleyes:

the lead landed long
Private joke that you wouldn't understand, Leddee... :rolleyes:

I apologise to the wider audience for the apparent vitriol; what are quite reasonable questions are often answered by LedSled in the manner above on the Aussie forums. Disappointing it spills over into Techlog. Spoils the whole Prune thing, really...

[LW20]

In SFO they separate you by 1000ft until you report your traffic for the other runway in sight. Then you get the clearance for a visual approach with the remark:"Do not overtake" (if you are the follower).

We leave TCAS in RA.

[LeadSled]

Folks,
I note the nasty little tail in Bloggs last post. If I said black was black, he would argue it was white ---- this is a matter of long history.

I rather suspect that if he actually ever operated in US, he would blow a foofle valve, having long battled against any introduction of the US approach to Australian aviation, particularly US airspace and traffic management. He "knows" it won't work !! The fact that it does demonstrably work, and work well, at much greater traffic levels than Australia, is no more than a trifling and inconvenient fact.

Unlike him, I have operated through KSFO (and many other places in US) since long before TCAS was even invented, needless to say, including parallel approaches at KSFO, as P1 in aircraft varying in gross weight from 1600kg through to 398,000 kg.

As to RA v. TA, for many years my then employer, a major international carrier, recommended as per the manufacturer (in my case, Boeing) and the avionics manufacturer, TA in terminal areas, but left the final decision up to the Captain of the aircraft.

In the current operations, in which I have some involvement, we follow the same practice, leave the final decision up to the suitably informed and experienced Captain.

[Capn Bloggs]

As I said... :rolleyes:

Thanks LW20. That looks like it would be huge fun. Oops! Wash mouth out CB... :ok:

[GlobalNav]

Quote:
What do you do with the TCAS in that situation? Put it in TA?
That was indeed an Ops manual requirement when we first got TCAS, but that was subsequently amended out and we leave it in RA. It's a while since i've done a close parallel visual there but we didn't get any TCAS alerts/warnings last time. Improved software?

There's a new wrinkle - the Airbus Autopilot/Flight Director TCAS RA mode. If AP is engaged, and an RA occurs, the AP automatically performs whatever maneuver is directed by TCAS. So for places where "unwanted RA's" might occur, the only option to prevent unwanted disruption of the terminal area operation is for the pilot to select TA-only beforehand. Already approved on A380, and soon, if not already on A350 and as an option on A320 series.

[CaptainMongo]

At our company, the Captain may select TA when operating on closely spaced, non PRM approaches, when noted by company produced airport information pages, unit malfunction or directed by checklist.

When operating in TA (at least on our aircraft) the ND will only display nearby aircraft when a TA is generated, for the period of time the TA is active, after which it returns to not displaying any nearby aircraft.

Is this the experience of others reading this thread?

[underfire]

Sorry, I understand how CSPR works, but the runways are only 750 feet apart, so it seems the ac should not be parallel..

https://www.nerdwallet.com/blog/wp-content/uploads/2014/05/Untitled.jpg

any these pairs? just seems too close...

http://i.dailymail.co.uk/i/pix/2010/12/15/article-1338653-0C6694D0000005DC-742_634x358.jpg

[Design Engineer]

test message to see if the admins delete it (again). Be careful what you post here. If the admins don't like it, expect it to vanish.

[pattern_is_full]

any these pairs? just seems too close...

The two aircraft pictures in your post #16 likely are in exactly the positions your diagram shows. Diagonally separated, not side-by-side.

Look at your diagram. Extend the |----1.5----| lines down and to the left about 15 lengths. That's about where the planespotter was when he made the picture, with a massive telephoto/telecopic lens from a ~45° angle**, that compressed the actual separation.

** note you can see both the front of the wings and sides of the fuselages - thus the picture was not taken directly from the side nor from directly ahead, but from 45° to the flight paths.

[Intruder]

When SFO is VMC, they do parallel visual approaches all the time. They will even turn in a 747 from left base to 28L to parallel a 777 straight-in to 28R.

[Capn Bloggs]

Wake mitigation can be a real problem here.
I see the Goooogle Earth pic of SFO has an A380 up the clacker of a tiddler, deliberately I assume.

[LeadSled]

Folks,
The KSFO operations are justified by long demonstration of successful operation, around 60 years?? I would think that the KSFO simultaneous arrivals and departures on intersecting runways would give some people the willies.

Indeed, all these operations were established long before naysayers could think up all sorts justifications as to why things can't be done.

KSFO is by no means the only US airport with relatively close spaced runway operations, you just get on with it.

Probably a good example of the US "Can do" spirit, versus the more recent spirit of "can't do" elsewhere. A very practical approach to ATC aircraft handling is characteristic of the US, as opposed to the "can't do" theoretical approach more common in large parts of the world.

For Australian readers, not long after WWII, an Australian National Airlines (ANA) DC-4 hit trees on a departure on 28s, going out through the "Gap", not adhering closely enough to the track based on the GAP NDB, and arrived back on the ground with a bit of pine tree lodged in the LE of the wing, between two engines. Some few years later, a BCPA (British Commonwealth Pacific Airways) on arrival for 28s, hit the ridge quite close to Woodside, Half Moon Bay from memory. Shortly thereafter, QANTAS took over the route.



--- deliberately I assume. An equal rights demonstration at work --- giving GA such access in Australia would be anathema to "professional" pilots.

[underfire]

pattern is full. Okay, in that image, but in the video, the ac appear almost parallel?

I was just under the impression at there was a minimum sep...and closely space parallel are considered a single runway for spacing?

[LeadSled]

--- and closely space parallel are considered a single runway for spacing?

underfire,
Certainly, in this case, and other I know in US, the answer is no. On a visual approach ATC is not providing separation.
If it becomes IMC, movement rates, of course, drop, and the whole exercise becomes a tad more complicated, but still always works well.
Given considerable disparity in approach Vref. speeds and actual profiles, it is common to overtake or be overtaken.
Have a look at the lateral spacing of the runways at KLAX, and it is operationally possible to have aircraft in parallel on approach on all four runways. If you want to find a case of seriously "up close and personal" try John Wayne International, although the length of one runway does limit the size of aircraft using it.

[hikoushi]

SFO uses the PRM approaches only when the weather is in the 1200 / 2 vicinity and slightly above. This corresponds to the minimums for the LDA-PRM 28R approach. Significantly better ceiling and vis (that is to say 85 percent of the time) will get you vectors for the parallel visuals described in previous posts, whereas weather below that value will be below minimums for the LDA-PRM 28R approach and turn the operation into non-PRM (staggered) parallel CAT 3 ILS approaches.

Been flying in there very regularly (widebody) for a few years and hardly ever see the PRM procedure, can count the number of times on one hand. The dependent visuals where they precisely time your base leg vector to point you RIGHT at the guy you are following so you CAN'T POSSIBLY miss him, are the standard and a lot of fun.

SFO becomes much more sporty right before a cold frontal passage when the winds crank out of the southwest at 35+ knots off the hills, and you land into them on the 19's.

And regarding GA in the USA, I learned to fly in the Bay Area many moons ago, and used to take adventurous students into SFO to do night touch and goes around 2AM when the traffic load was light. In the world prior to high-speed Internet and LiveATC, they could only collect the landing fee if you stopped, you see.

[back to Boeing]

The sportiest time I've had out of SFO was taking off on 19L. Some of the worst turbulence I've ever had the pleasure of being PF for. Aiming straight at some very big hills I couldn't see. 28L/R arrivals are a complete doddle compared to that

[Capn Bloggs]

An equal rights demonstration at work --- giving GA such access in Australia would be anathema to "professional" pilots.
Get with the program, Leddie. The "tiddler" I was referring to was a 737. :rolleyes:

BTW, what was the message in your gibberish about "28s"? :confused:

[underfire]

but still always works well.
Dont get me wrong, I see how it can work very well, I just see all of the places where the CSPR procedures are such an issue with all of the separation criteria. (the cant do as mentioned)

I cant remember, but at SFO, is it the PRM right approach offset 15 degrees?

[hikoushi]

The LDA-PRM 28R is actually only 3 degrees off from the runway heading, but physically offset from the centerline so that it guides you to a point about 1000 feet to the right of the runway, on about a 4 mile dog-leg final. The final maneuvering portion is visual and feels pretty similar to the last minute "sidestep to 28L" landing that you may get off a visual approach from time to time. Just look out the window, remember your non-moving point aiming technique, mind your speed, and land.

[LeadSled]

BTW, what was the message in your gibberish about "28s"? http://cdn.pprune.org/images/smilies/confused.gif

Bloggs,
Clearly, only a person of your of your limited comprehension would have a problem with my comments.

The sportiest time I've had out of SFO was taking off on 19L.

back to Boeing,
Mercifully, very rare, because when the wind required it, the turbulence was guaranteed. In the good old B707, it was a serious test of manhandling muscle, if I may use such a politically incorrect term.

On a par with a 30kt+ NW at NZWN, for those who have had the "pleasure".

[flyingchanges]

Visual procedure, separation minimum is don't hit the other guy...