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Near miss with 5 airliners waiting for T/O on taxiway "C" in SFO!

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Near miss with 5 airliners waiting for T/O on taxiway "C" in SFO!

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Old 17th Jul 2017, 00:00
  #281 (permalink)  
 
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TARGETS was actually developed by MITRE CAASD an interesting and useful tool to use that may need more work to support curved RNP final approaches such as 'Greener Skies' Report Shows Benefits of ?Greener Skies? approaches at Sea-Tac Airport
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Old 17th Jul 2017, 00:46
  #282 (permalink)  
 
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TARGETS is certified for RNAV but not RNP AR. It can be used to develop an RNP AR approach, but only for preliminary work. RNP AR is too critical to be left to TARGETS.
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Old 17th Jul 2017, 06:57
  #283 (permalink)  
 
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The GPWS is valid, but because some approaches are 2.8 degree (due hot weather), if it is cold and with enough barometric error you are actually low on path compared to the ILS.

If this is true it sounds scary. I've not flown RNP approaches, nor an Airbus, but any IFR approach system that brings you below the ILS GP sounds dodgy to me. Please give more info.

As well as the Gringo event remember the Air Inter A320 at Strasbourg that made a smoking hole on the rushed VORNPA. Due to various nuisance warnings Air Inter had disabled the GPWS systems as it was not yet mandatory, only advisory. By not selecting the ILS you remove the "Below G/S" alerts. As I've mentioned previously, a/c have been designed with back-ups in nearly every system, including 2 pilots, but when on approach to terra concrete SOP's can dilute you down to only 1 nav system. Seems to go against the basic philosophy of back-ups and needs justifying by the SOP scribes. It reminds me of one operator who removed the SBY ILS from their approach Cx list. Why? I've no idea; and indeed no-one ever published why. The result was that some captains taught that it was no longer necessary to select it ON during approach. OMG. Trained monkeyness gone mad.
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Old 17th Jul 2017, 07:36
  #284 (permalink)  
 
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It's true, in high temp environments (ISA+30), a 2.8 degree path will actually give you close to a 3 degree path at those higher temps (the column of air expands with increasing temp). However, the problem is when the temp is low, it is back to a 2.8 degree path and if the ATIS QNH hasn't been updated for a while you can get on the slightly lower angle than the 2.8 (we only get 15 minutes from receipt of the ATIS for a valid QNH).

The RNP already has an allowed vertical error (ANP) of 125'. We also go to RNP 0.1 which can have minima around 370' / 2200m so you can be close to the hard stuff with some degree of uncertainty. If you then get a little low on that path...you are starting to get closer to the weeds than is comfortable.

So, rather than accept a G/S warning (and QAR flag) saying "Hey Gringo, you really are low", just turn the off the warning system and remove perfectly valid, usable, independent and rock stable path indication! Really, although not everyone follows the recommendation

Last edited by CurtainTwitcher; 17th Jul 2017 at 07:53.
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Old 17th Jul 2017, 08:16
  #285 (permalink)  
 
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Thanks. I know about temp corrections, especially the cold stuff. I thought FMS altitude data was supposed to be corrected for cold temp' so that you did not become dangerously low on path. But I've only flown VNAV/LNAV approaches with raw data backup and not the new fangled RNAV GNSS thingies.

It reminds a little of a mate, in his very old car some decades ago, who had an annoying low oil pressure light keep coming on. (no gauge) He kept checking the oil and it was full, so he disconnected the bulb. Engine seized due to broken oil pump. He had confused quantity with pressure. Duh! Now we would never do anything like that, would we? Remove the bulb, I mean.
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Old 17th Jul 2017, 08:37
  #286 (permalink)  
 
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Ha ! Good start to my day Rat 5 ! Thanks. Rhetorically asked , I know, but way back, we really were taught to "think outside of the box" and get the bird home , even if it meant taking out the bulb !
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Old 17th Jul 2017, 10:02
  #287 (permalink)  
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We were parked on a taxiway once and an aircraft was clearly lined up on the taxiway to land. The pilot also told Tower that she sees lights and aircraft on the runway, tower also told her the runway is clear.

For us to have transmitted at that stage ala "where's this guy going? He's on the taxiway" would have risked blocking a vital transmission, either from landing aircraft or from Tower to Go Around, at a critical point. We put all our lights on and waited.. Tower told aircraft to go around, she didn't miss us by far.

It's one of those situations where interference can save you, or it can seal your fate.

"Air Canada go around" from one of the waiting aircraft would have been a far better (and briefer) call than the one made.
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Old 17th Jul 2017, 10:51
  #288 (permalink)  
 
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"... He’s on the taxiway!" cut into AC landing re-confirmation seconds before disaster, this described perfectly the conflict between "we see lights" and "28R clear" Those words were extremely effective in en-lighting the crew and initiated the go around immediately. The tower's "go around" came to late... it could be preceded by a large ball of fire.
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Old 17th Jul 2017, 13:36
  #289 (permalink)  
 
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Naverus is no more, they were bought out a few years ago by General Electric, Flight Effeciency services is the new name under GE
You are funny! (BTW GE calls is simply Navigation Services now, flight efficiency services has been dead for a while)

MITRE for lack of a better term has licensing authority over FAA software called TARGETS that is the basis for building RVFPS.
It can be used to develop an RNP AR approach, but only for preliminary work. RNP AR is too critical to be left to TARGETS.
They use the RNAV-Pro for RVFPS and RNP-Pro for RNP-AR.

2) The operator, with the assistance of the regional All Weather Operations (AWO) and the RNAV and RNP Group personnel assigned to the OSG, must assess the capability of the local DME infrastructure to support all segments of the procedure. The operator should use “RNAV-Pro” for this assessment.

The operator must also document the RVFP procedure on FAA Form 8260-7, Special Instrument Approach Procedure, with an amended title of RNAV Visual.


The FAA then puts the completed procedures into TARGETS to verify the obstacle evaluation.

Last edited by underfire; 17th Jul 2017 at 14:15.
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Old 17th Jul 2017, 14:53
  #290 (permalink)  
 
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Interesting explanation hereCTV News Channel: 'Situation was unusual' | CTV News
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Old 17th Jul 2017, 15:11
  #291 (permalink)  
 
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Already discussed several days ago.

The guy was being interviewed the morning after the incident, before many of the facts had emerged, so "explanation" is a bit of an exaggeration.
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Old 17th Jul 2017, 15:48
  #292 (permalink)  
 
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Originally Posted by underfire View Post

They use the RNAV-Pro for RVFPS and RNP-Pro for RNP-AR.
I'm not sure which "they" you are referring to. I am referring to the FAA, not third-party developers.

I don't know anything about the development of RVFPS, which is not an instrument flight procedure.

Just to be certain I submitted the following question To my FAA procedures manager contact about FAA-developed RNP AR IAPs:

My question:

Which system or tool do your folks used to design FAA-developed RNP AR approaches?
His answer:

We use IPDS and IAPA. Eventually we will be using TARGETS for everything.
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Old 17th Jul 2017, 17:57
  #293 (permalink)  
 
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Originally Posted by ratpackgreenslug View Post
For every approach put the relevant ILS frequency in the box. Identify said ILS (dits and dars) and fly said ILS as presented by wondrous displays on the panel within 18 inches of one's nose.

This cock up is what happens when children of the Airbus magenta line look out the window and decide to go for it. Wonder where they would have ended up on the Quiet Bridge Visual.
Originally Posted by Brain Potter View Post
In the A320 the display of ILS GS and LOC symbology on the PFD is incompatible with using the autoflight system to fly a non-precison approach. The ILS may be hard-tuned but the crew will not see the data unless they select the LS pushbutton or switch the Nav Display over to ROSE LS mode.
Originally Posted by CurtainTwitcher View Post
Thank you Brian Potter! We have a crazy policy recomendation to de-tune the ILS for an RNP approach when the runway is equiped with an ILS, why? Because of occasional GPWS glideslope alerts if the ILS is tuned!
The ILS to 28R was apparently working just fine. TACA 560, another A320, was cleared for the ILS 28R a few minutes before the AC 759 flyby. Sure looks like most A320 operators don't bother with tuning the ILS with a non-ILS FMS approach and it is awkward to view the raw data while getting guidance from the FMS profile.

Listening to the approach control audio in the link posted a couple of times above, AC 759 was coming in on the DYAMD3 arrival, they checked in with NOCAL descending through FL250. They were given at ARCHI join the FMS Bridge Visual 28R. The subsequent controller told other planes to join the FMS Bridge Visual 28R, routing only (I like her style a little better since a couple of planes incorrectly read back the first controller's clearance as 'cleared for the approach').

AC 759 was given depart CEDES heading 270, vectors for spacing. After some vectoring with altitude and speed changes, they were given direct TRDOW, cleared for the FMS Bridge Visual Approach Runway 28R.

Obviously some button pushing to re-intercept the approach at TRDOW, some chances to inadvertently delete a constraint or heal a discontinuity in the wrong place. Still, nothing uncommon at a busy international airport even at midnight in my experience.
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Old 17th Jul 2017, 17:58
  #294 (permalink)  
 
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HUD's should eradicate this, just line her up with the green box directly in front of you.
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Old 17th Jul 2017, 18:19
  #295 (permalink)  
 
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We use IPDS and IAPA. Eventually we will be using TARGETS for everything.
We are speaking the same thing.

The difference here is that IPDS is simply the FAA's acronym Instrument Procedure Design System, but its parts are supplied by a 3rd party contractor. Just as TARGETS is supplied by MITRE. Instrument Approach Procedure Automation (IAPA) is the old version of the system being replaced by IPDS.

I was working with ATSI when the FAA was using SAAR-Pro (I called it RNP-Pro) to design and validate RNP-AR procedures, and helping with the data port to TARGETS. Check with the guys at AFS-460/420 for how they use RNAV-Pro and SAAR-Pro..

That is why the FAA requires operators to use RNAV-Pro, because in reality, that is IPDS and already part of TARGETS.

This is TARGETS: Data file exchange is supported between TARGETS and the Total Airspace and Airport Modeler (TAAM®), the Sector Design and Analysis Tool (SDAT), RNAV Pro™, and MapInfo®

While MITRE has the development contract for TARGETS, MDA had the development contract for IPDS (although I am not certain they still have that)

Last edited by underfire; 17th Jul 2017 at 18:53.
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Old 17th Jul 2017, 18:41
  #296 (permalink)  
 
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Originally Posted by AfricanSkies View Post
We were parked on a taxiway once and an aircraft was clearly lined up on the taxiway to land. The pilot also told Tower that she sees lights and aircraft on the runway, tower also told her the runway is clear.

For us to have transmitted at that stage ala "where's this guy going? He's on the taxiway" would have risked blocking a vital transmission, either from landing aircraft or from Tower to Go Around, at a critical point. We put all our lights on and waited.. Tower told aircraft to go around, she didn't miss us by far.

It's one of those situations where interference can save you, or it can seal your fate.

"Air Canada go around" from one of the waiting aircraft would have been a far better (and briefer) call than the one made.
I have often considered under which circumstances at a controlled airfield a pilot could/should tell another aircraft to go around. Certainly if I saw landing lights coming from the sky in front of me when rolling for take off, I think tha this would be the correct course of action. In this case, from what we know, I also think that it would have been justifiable.... What do other people think? What possible outcomes could there have been for the pilot on the taxiway had he have called the go-around.... in this situation it looks like he may have been justified in doing so.... has anybody else considered this course of action in the past? would anybody here consider following that course of action in the future?
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Old 17th Jul 2017, 19:10
  #297 (permalink)  
 
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well 3J, it looks like just that will be looked at in this case.

you have radio traffic between ac and tower which question runway clear
You had an unknown person, a pilot, radio the ac was on the taxiway
then ATC issues go around
the pilot almost instantly responds go around. (100' or less from the ground facing other aircraft, initiating GA, and one has time to use the radio?)

lots of questions on this one.

you are questioning if you as a pilot should call a GA to another ac, that is all good.

on the flip side, if you were the pilot, and heard go around on radio that was obviously not ATC, what would you do?

On a related note, at YMML, there was recently a case where an unauthorized person on ac band radio in a car called a GA (and the ac responded with a GA)....

Last edited by underfire; 17th Jul 2017 at 19:21.
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Old 17th Jul 2017, 19:30
  #298 (permalink)  
 
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"If you were a pilot, and heard go around on radio that was obviously not ATC, what would you do?"

UF

At that height, most likely go around, I think it would be hard to distinguish whether or not it was ATC, obviously if the message was transmitted with my callsign, I would do around immediately without thinking about it... Likewise with a part of the callsign, at that height, I would most likely go around, if it was, for example... "air canada" go around. If it were something a little more non-standard, "landing aircraft, go around" "aircraft on short final... go around" Again, at that height I would almost defiantely follow the instruction (assuming a normally operating aircraft, wings attached and not on fire, etc) as somebody has likely seen something that I hadn't be it whether I am not aligned with the runway, gear up, something else) probably one of the few situations where I would prefer to be in the air, wishing I was on the ground.... If after asking questions to establish what had happened it turned out it was some ******** hijacking the frequency, I would consider diverting as the information at the airfield at that time would be hard to consider reliable... however, back to the point... I think that the part of any message there that would stick out would be the term "go-around".... no?
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Old 17th Jul 2017, 19:42
  #299 (permalink)  
 
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There's no one on 2-8 Right but you

Originally Posted by underfire View Post

lots of questions on this one. ...
Acknowledging that both the NTSB and the TSB (CA) will conduct their typically exacting inquiries, still, it may be worth noting the categories into which some, at least, of those "lots of questions" will fall within.
1. Factually, who exactly called "Where's this guy going? He's on the taxiway"? And was there a decisive cue for the pilot who did so? (The controller's answer to AC 759's inquiry about lights on the runway, across the runway, in transcript, is "There's no one on 2-8 right but you" - but when played, there is a tone of definiteness in the controller's diction. Did this grab the other pilot's attention? - and what does this all say about RT procedures?)
2. The physics of the situation. How close was the AC aircraft to a collision? Was it approaching a physical state in which a collision was unavoidable? (Yes, no aviator would try to land an aircraft on a runway [taxiway, either] after seeing other aircraft lined up on it - but the issue here is how long it took for that "seeing" to occur and how it occurred.)
3. Did AC 759 initiate the GA prior to the tower calling a GA?
4. Lighting configurations and types, and visual fixating.
5. Approach design and its evidently many technical and varied subparts (instruments and data used in particular approaches, database alignment with particular types of approaches, carrier operational procedures which may vary, whether the "Quiet" aspect of the approach in this incident is a factor, and others as well).
If the impression the thread has given, namely that the AC aircraft had very little margin left in terms of position and momentum, is correct, then at the risk of being charged with excitability, I would advise the safety enquiry authorities to view this as an instance when the Cheese was a bit more viscous or impervious than usual, and precisely how something this close happened must be understood.

Last edited by WillowRun 6-3; 17th Jul 2017 at 21:24. Reason: Correction & clarification
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Old 17th Jul 2017, 20:01
  #300 (permalink)  
 
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AC 759 was given depart CEDES heading 270, vectors for spacing. After some vectoring with altitude and speed changes, they were given direct TRDOW, cleared for the FMS Bridge Visual Approach Runway 28R.
Obviously some button pushing to re-intercept the approach at TRDOW, some chances to inadvertently delete a constraint or heal a discontinuity in the wrong place. Still, nothing uncommon at a busy international airport even at midnight in my experience.


I understand there are the 'new boys on the block' with their toys, and there are 'the old farts' from the days before toys. People talk about button pushing and FMS guidance and programming for a visual approach where you slide pass the bridge in silent mode and intercept a well lit runway with approach lights & PAPI. It strikes me that all these 'bells & whistles' have made an easy job difficult. A B732 or B727 would have had no problems with this, or properly trained/experienced crews would not have. This may open an old discussion that has been going round in circles for a few years, and I don't want to do that; but, it does seem as if people are trying to blame new technology and operating techniques as being at fault. Perhaps they are correct, and that is where I'm wondering if we have just over complicated things on what should be the most basic of manoeuvres; a visual approach.
I know of one erstwhile operator who has a mandatory VNAV/LNAV FMS WPT programmed visual circuit profile for a basically equipped airfield. It's been there a longtime, and I flew into it with B732. Somehow, 35 years later in a more sophisticated jet, it needs magenta lines, both later & vertical, to fly a visual circuit.
The world has gone mad, and I enjoy my stressless retirement. I got out just in time. Straight jackets & handcuffs are useless in a cockpit, sometimes.
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