AC Lining Up with a Taxiway SFO...?

[Rockie]

Today in the WSJ, they reported that the crew did not have the ILS tuned for runway 28R.

I'm only a "rookie", so bear with me.

Assuming this is correct -- of course anything critical could be "fake news".

Someone please give me a reason why NOT doing this somehow enhances the safety of the approach.

Maybe it's Airbus's fault?

Explained on page 3 of this thread. It's not as simple as you imagine on a bus not least because it isn't part of the operating philosophy of the airplane. Not an easy thing to ignore and overcome just because you think it's a good idea. Which it is, and no, you're not the first person to think of it either.

[rookiepilot]

Rockie,

I read Pelmets post, and apart from willfully admitting I don't understand at least half of the technical language, , I don't get why the FMS design would be why one couldn't manually display the ILS track on the PFD. Or one PFD.

Is what it is, i suppose.

So it's obviously not as simple as it seems, at least in crew instrumentation choices.

[av8ts]

I read page 3 and I still don't understand why the ILS was not displaye

[Rockie]

As I've explained, you can display it but it isn't a normal Airbus procedure when there is another non-localizer approach selected in the MCDU nor are crews trained to. Perhaps it could become a normal procedure but with this airplane it's not as simple as just deciding to do so. Few things with this airplane are if you're talking about deviating from Airbus operating procedures. You'll just have to take my word for it.

[photofly]

So the crew were flying a visual approach trajectory to the runway through the auto flight system.

In order to display ILS information the crew would have had to ditch the already programmed visual approach information that was being flown.

If I understood that right.

But if they had the visual approach trajectory (and deviations therefrom) programmed to display on the flight displays, why didn't *that* display the lateral deviation and show that they weren't lined up? If *that* wasn't good enough, would the ILS have helped?

[Rockie]

There are ways to display it but again, it isn't simple. The FMS displayed tracking isn't refined enough to reliably display that kind of offset especially on a procedure that is itself offset toward the taxiway. Plus don't forget...it's a visual procedure.

The report will come out hopefully explaining what caused the crew to misidentify the runway. Maybe it will also discuss the difficulties weighed against the benefit of displaying ILS information on a non-ILS procedure on the bus. I'm sure they could do a better job of it than I can.

[crazyaviator]

Perhaps it could become a normal procedure but with this airplane it's not as simple as just deciding to do so. Few things with this airplane are if you're talking about deviating from Airbus operating procedures.

PERHAPS if the A/C landed on top of at least 1 A/C the above could be instituted or equivalent ? Wait for the dead bodies to pile up to make this kind of simple improvement !

[confusedalot]

I am making lots of assumptions.

airframe involved had no gps.

leading to map shift.

autoflight was engaged in at least horizontal, and probably vertical, modes.

so instrumentation was trusted. perhaps more than it should have been.

lights out on 28L, lights on 28R, C taxiway obviously mistaken for a parallel runway.

and the rest is all about a crew expecting to see what they wanted to. like, 2 parallel runways?

no bus experience, but the old non gps boeings had map shift from time to time. the severity depended on how long ago the dme/dme or vor/dme auto correction occurred and how long the antiquated and slow software took to correct.

I really don't know.

Any takers?

[sportingrifle]

We used to be trained to load the published visual in to the FMS and then just hard tune the localiser in the MCDU or RMP. Of course that was when time in the sim course was dedicated to visual approaches. Doubt they still do it.

[Eric Janson]

I must admit, I was quite surprised that the altitude losses are that low - I imagined a fair bit of momentum and spool up time for the engines.

Disclaimer - This is information only. It is not in any way a commentary on the SFO incident.

There is still a lot of lift (Energy) available in the wing at approach speeds - just need to increase the angle of attack.

For an example of this see the report on the EK521 crash in Dubai last year.

-Go-around made after touchdown with the thrust in idle.
-Gear retraction initiated (drag will initially increase as the gear doors open)

The aircraft reached an altitude of 85' before running out of lift (Energy)!

Someone please give me a reason why NOT doing this somehow enhances the safety of the approach.

Maybe it's Airbus's fault?

As Rockie has already said - deviating from the manufacturers procedures can result in strange/unexpected things happening. That's not what you want - especially on an approach.

When you select an approach in the FMGC you are telling the aircraft what you want to do and it will know which modes need to be armed.

The airbus has an APP mode button which is used for both precision and non precision approaches.

- This arms LOC & GS modes on an ILS approach
- This gives APP NAV and arms FINAL on a non precision approach.

The problem comes when you manually insert an ILS in the RAD NAV page after previously selecting a non precision approach - now the aircraft doesn't know what you want.

Selecting APP mode after doing the above will result in a flashing amber VDEV message which is very distracting. You will also get a message on the FMGC scratchpad if I remember correctly.

To display a tuned ILS there are 2 LS pushbuttons that need to be pushed. On the newer airbus this happens automatically when you select APP mode.

There are actually 3 different ways to fly a non precision approach on an airbus.

This is about as simple as I can make it - the fly-by-wire airbus are extremely complicated technology.

[Meatservo]

As others have stated I don't know much about them, but they sound a little TOO complicated.

[Rockie]

As others have stated I don't know much about them, but they sound a little TOO complicated.

No. It's a tremendous aircraft with technology and design features way ahead of its time...but you have to know how to use it and be disciplined. Anybody who says however that the bus is easy to fly because it does everything for you has NO idea what they're talking about .

[mbav8r]

Rockie,
I read and understand Eric's post re confusing the system so this is just for curiosity, how would you display an ILS on the standby instrument?
The RJ for example, it doesn't matter what nav mode you're in, if you tune an ILS frequency, it will display on the standby instrument. I guess I'm wondering if there is a separate VHF nav receiver for the standby?

[Rockie]

Rockie,
I read and understand Eric's post re confusing the system so this is just for curiosity, how would you display an ILS on the standby instrument?
The RJ for example, it doesn't matter what nav mode you're in, if you tune an ILS frequency, it will display on the standby instrument. I guess I'm wondering if there is a separate VHF nav receiver for the standby?

Most of the buses cannot display ILS on the standby, those that can do not have a separate tuning function and get it from the RAD NAV page like the main systems. Displaying ILS on the PFD is not possible when there is a non-localizor procedure programmed into the MCDU. It would have to be displayed as a basic mode on the NAV display after being manually tuned in the RAD NAV page, but that is not normal Airbus procedure which opens up a potential can of worms that cannot be dismissed based on experience with any other airplane.

Simply saying the ILS was not displayed is an extremely uniformed observation lacking any reason why.

[pelmet]

Due to it being difficult to display the ILS as a backup on the Airbus, one needs to compensate for this shortcoming. On the briefing one should review the lighting to be expected on this approach and the layout of runways and taxiways. Four strips of pavement are in front of the aircraft. Two runways, and two taxiways. After reviewing that, review the approach lighting. They may have different appearances. Review notams as this would have shown that 28L was U/S. Even so, one would be wise to confirm with the tower, which approach lights are illuminated if only one set is illuminated as the other set could be on test.

[Rockie]

Two runways, and two taxiways. After reviewing that, review the approach lighting. They may have different appearances. Review notams as this would have shown that 28L was U/S. Even so, one would be wise to confirm with the tower, which approach lights are illuminated if only one set is illuminated as the other set could be on test.

We do review the approach lighting, and one does not "confirm with SFO tower" which approach lights are illuminated. They would rapidly run out of patience if every aircraft coming on frequency did that.

How about we wait and see what the investigation determines since there are only about 1000 things that could have combined to make the crew misidentify the runway.

[crazyaviator]

Lets hope the American investigation can do a better and more truthful job that the Canuck version of the Halifax F___ up !

[Old fella]

Lets hope the American investigation can do a better and more truthful job that the Canuck version of the Halifax F___ up !

So let me ask, is your knowledge of accident investigation, A320, Air Canada, HAA far superior than those who are in the know. If the "Canuck version of the Halifax F---- up" is such, do share your insights to exactly where. If you criticize fair enough, but point out exactly the issues.

[Jean-Pierre]

The best part is the NTSB is not going to take their report to Air Canada to review first so they can change the part they don't like.

[complexintentions]

I surely hope that you can substantiate your claim that Air Canada tampered with a safety investigation. My cynicism is considerable, but it doesn't extend THAT far. The report is hardly flattering to AC or the pilots involved. If Air Canada did wield influence it didn't count for much.

However, one way that I am fairly certain the US report will be miles better than a Canadian one is in that it will probably be released sometime this century.

So there's that.

[Old fella]

The best part is the NTSB is not going to take their report to Air Canada to review first so they can change the part they don't like.

TSB reports to the Parliament of Canada through the Privy Council and Minister of Democratic Institutions. Air Canada nor any airline has any influence there and doesn't have any authority in that regard.

I don't know where you conspiracy theorists come up with such shit.

[photofly]

The TSB sends a draft copy of its reports to everyone cited in the report, so they can comment to the TSB before publication. I'd be surprised if the NTSB doesn't, too.

[complexintentions]

Sure. But that's not quite the same as "changing the parts you don't like".

Such nonsense.

[Cliff Jumper]

The TSB sends a draft copy of its reports to everyone cited in the report, so they can comment to the TSB before publication. I'd be surprised if the NTSB doesn't, too.

Everybody does, it's an ICAO requirement.

However, one way that I am fairly certain the US report will be miles better than a Canadian one is in that it will probably be released sometime this century.

Do you have any data to support that? I know everyone is always harping on about it, but I haven't seen the numbers to back it up.

Seems to take 1-2 years for either organization to publish a final report. There are lots on NTSB's website that are currently pending final that are older than that.

[pelmet]

Two runways, and two taxiways. After reviewing that, review the approach lighting. They may have different appearances. Review notams as this would have shown that 28L was U/S. Even so, one would be wise to confirm with the tower, which approach lights are illuminated if only one set is illuminated as the other set could be on test.

one does not "confirm with SFO tower" which approach lights are illuminated. They would rapidly run out of patience if every aircraft coming on frequency did that.

Would have prevented this incident that made global headlines. Never hesitate to ask for confirmation of something important from ATC if you can't confirm it yourself. So yes, one DOES confirm as required, just like when you are not sure about a clearance. Can easily be tied in with confirmation of the landing clearance and would be a rare thing as usually both sets of approach lights are illuminated.

These guys took the time to query the controller about another issue, so why not query about something else. I have flown into SFO several times day and night and would definitely be willing to query in a situation like this where no ILS is available and the RNAV apparently, isn't particularly accurate.

If ATC doesn't like it(in reality, they don't mind at all), then too bad. Never let self worry about what ATC might or might not like, or what fellow pilots say ATC might or might not like, have an influence on requesting assistance.