AC Lining Up with a Taxiway SFO...?

[ktcanuck]

Height above the ground for the latter part of the approach and landing is measured by a radar altimeter and it is very accurate as demonstrated in the " retard " voice command just prior to touch down.

Well, that's it then! That's how he figured it was time to go around; the radalt called the pilot flying a "retard" and he hit the switch!!

[ktcanuck]

Confused, how did you escape an entire career without learning the first thing about why investigations are conducted? Really...you're confused and I'm curious.

Your reliance on insults only draws attention to your inability to supply a cohesive intelligent response.

[rookiepilot]

I stand by my comment. It was a non-event.

Sorry - don't agree. Just because it didn't end in disaster doesn't make it a "non-event".

The NTSB doesn't agree with you either.

.

Yep --

Is it the position then that the NTSB is engaging in media hysteria by investigating a "non event"?

Are the NTSB "professionals" at what they do? I think it's bizzare for "professionals" to critique and second guess the "professionals" at the NTSB.

In other words -- the only ones I'd believe that it was a "non event, media hysteria nothing to see here, move along" -- are the NTSB. They are the disinterested party.

They seem to see a reason to take this seriously.

[Jet Jockey]

Height above the ground for the latter part of the approach and landing is measured by a radar altimeter and it is very accurate as demonstrated in the " retard " voice command just prior to touch down.

Well, that's it then! That's how he figured it was time to go around; the radalt called the pilot flying a "retard" and he hit the switch!!

Well, well... That's not very nice of you.

[mbav8r]

Somebody correct me if I'm wrong but those altitude readouts are from the transponder, one thing about transponders everyone should be aware of, they're not precise and that three feet could easily be 23 feet. I'm certain the TSB investigation will not rely solely on that and perhaps use the video they have to calculate exactly how much they cleared by, until then your three feet is purely sensational BS

Since the report talks about altitude referenced to ground level I suspect the height data is from the Radio Altimeter.

This extremely accurate.

The photos showing positions and altitudes of the aircraft, the ones on the taxiway show 13' and AC at 131', they say the go around was initiated at "about 85'" then goes on to say 2.5secs after advancing thrust levers the lowest recorded on the FDR was 59', this I would assume was rad alt. I'm not saying this wasn't a serious situation, the aircraft was in a climb at 59' agl and established in the go around. AC may have crossed the tail of the 747 in question at 100', we don't know and that is what the investigation will show, but I take exception to the posting the worst case(3feet) without anything to back it up because nothing so far has shown the altitude readout at the moment AC was directly over the 747.
Assuming they initiate the go around because the aircraft on the taxiway turned on their landing lights, this happened prior to crossing over them, so no one knows what altitude they were at, at the exact moment they crossed over the tail section with the information provided so far, saying it was possibly 3' is to provoke a sense of very near catastrophe in the reader and to me nothing but exaggeration without proof.

[rookiepilot]

Can't believe some of the tweets. 100 feet clearance isn't serious enough? How close would everyone like it?

What if the engines didn't spool for any reason, instantly? Get real people. We are talking a matter of what a few seconds?

Comedy hour here, except it's not funny.

[photofly]

saying it was possibly 3' is to provoke a sense of very near catastrophe in the reader and to me nothing but exaggeration without proof

"Small war, not many dead."

[ktcanuck]

Can't believe some of the tweets. 100 feet clearance isn't serious enough? How close would everyone like it?

What if the engines didn't spool for any reason, instantly? Get real people. We are talking a matter of what a few seconds?

Comedy hour here, except it's not funny.

Careful not to raise the level of hysteria!

[mbav8r]

Can't believe some of the tweets. 100 feet clearance isn't serious enough? How close would everyone like it?

What if the engines didn't spool for any reason, instantly? Get real people. We are talking a matter of what a few seconds?

Comedy hour here, except it's not funny.

Clearly, this has been addressed, the fact the go around was initiated at about 85 feet and then 2.5 secs later they were at 59 feet covers the spool up and clearly I've stated this was a serious event that requires investigation, my point is posters saying they only cleared by three feet are no better than the hysteria the media is trying to invoke.
Also, we train for low level, low energy go around for this very reason, something on the runway that's not supposed to be or in this case something on what they thought was the runway, the training worked they did a go around, they missed everything on the taxiway and nobody knows by how much until the investigation is complete, anything other than that is pure unsubstantiated speculation with a touch of hysteria.
Does anyone know if SFO has switched to LED lighting? Last few trips in has been during daylight and I'm curious. I do think that blue taxi lights on low could be close enough to white LED to make a mistake, however I can't seem to visualize it and it's been awhile since I've flown in the dark somewhere with LED lights. Is there anything on the charts to indicate if a runway has LED vs incandescent, I've not seen it and am too lazy to look right now.

[55+]

Can't believe some of the tweets. 100 feet clearance isn't serious enough? How close would everyone like it?

What if the engines didn't spool for any reason, instantly? Get real people. We are talking a matter of what a few seconds?

Comedy hour here, except it's not funny.

On a CAT 1 ILS approach at DH 200ft HAT and calculated 3000ft from the 3deg GPI the calculated ROC(required obstacle clearance) is less than 100 ft. Nothing to do with the San Francisco situation being discussed but just to give you a little prospect on numbers when people start float them about.

Carry on with your discussion.

[FICU]

Pretty straight forward... they somehow got lined up with the taxiway and as they got closer and lower realized something was not right then pulled up and went around. Now why the were misaligned, what they saw, and what finally triggered the go-around is yet to be determined but to believe they would have landed on a jet on the taxiway is a real stretch.

The NTSB stated the crew said they did not see any aircraft on the taxiway but at what point? When they called the tower for confirmation of landing clearance when they saw lights or just prior to the go-around or never? My bet is they did see the aircraft prior to the go-around.

[Cat Driver]

The NTSB stated the crew said they did not see any aircraft on the taxiway but at what point? When they called the tower for confirmation of landing clearance when they saw lights or just prior to the go-around or never? My bet is they did see the aircraft prior to the go-around.

This is the most puzzling thing about this whole episode.

Maybe the NTSB will clarify this part before they close their investigation.

Personally I also can not imagine they did not see any airplanes at some point in the approach, Go around and on the initial climb out.

One thing for sure there a lot of people wondering about the same thing.

[BTD]

Going into Denver a week or two ago at night, I tried to see how the taxiway compared to the runway. From about 3-4 miles I couldn't even see the blue taxi lights. However the parallel taxiway had a number of intersecting taxiways. Lots of yellow taxi signs going along that parallel taxiway. Sure they were spaced farther apart then runway lights, but I thought it was interesting.

[Jet Jockey]

The photos showing positions and altitudes of the aircraft, the ones on the taxiway show 13' and AC at 131', they say the go around was initiated at "about 85'" then goes on to say 2.5secs after advancing thrust levers the lowest recorded on the FDR was 59', this I would assume was rad alt. I'm not saying this wasn't a serious situation, the aircraft was in a climb at 59' agl and established in the go around. AC may have crossed the tail of the 747 in question at 100', we don't know and that is what the investigation will show, but I take exception to the posting the worst case(3feet) without anything to back it up because nothing so far has shown the altitude readout at the moment AC was directly over the 747.
Assuming they initiate the go around because the aircraft on the taxiway turned on their landing lights, this happened prior to crossing over them, so no one knows what altitude they were at, at the exact moment they crossed over the tail section with the information provided so far, saying it was possibly 3' is to provoke a sense of very near catastrophe in the reader and to me nothing but exaggeration without proof.

You must be an idiot!

Stop cherry picking my posts and get your facts straight before you speak out of your a$$!

Again I'm not confirming or absolutely saying it was a fact that the aircrafts crossed each other by only 3 feet but clearly stated it was a POSSIBILITY!!!

What 747 are you talking about?

If you are a pilot and can't even get the type of aircraft involved in this serious incident correctly identified than you are no better than the reporters in the media.

For the record and I hope you finally get the facts correctly, the first aircraft in line for takeoff, the one sitting closest to the threshold at a 30 or 40 degree angle, the one that called once perhaps twice to say AC 759 was lined up on taxiway C was a UAL 1, a B-787.

The second aircraft in line which was approaching taxiway W was PAL 115, an Airbus 340. It was followed by UAL 863, another B-787 and finally the last aircraft, UAL 1118, a B-737.

AC 759 crossed the beginning of taxiway C at about 131 feet, perhaps crossing over head UAL 1 and was still descending and this is where things get even more dramatic not to say "sensational"...

From the NTSB report... "The incident pilots advanced the thrust levers when the airplane was about 85 ft agl. FDR data indicate that the airplane was over the taxiway at this time, approaching the vicinity of taxiway W.

Now do you get that mbav8r? This means AC 759 is at 85' AGL east of taxiway W and still descending to a final altitude of 59' AGL... This took a total time of 2.5 seconds. How far did AC 759 travelled along taxiway C in that 2.5 seconds?

PAL 115, the Airbus 340, was just west of taxiway W and I bet you that 2.5 seconds descent to 59' AGL ate up most of that taxiway C separating both AC 759 and PAL 115 before it started to climb. AC 759 must have been very, very close to PAL 115 at 59' AGL and yes the vertical separation of both aircrafts could have been as little as 3 feet taking into account that the 340's tail is 56 feet tall.

Again, let me stipulate both aircrafts could have been as little as 3 feet apart, or maybe 20 feet apart. Even if they were 50 feet apart, it was way, way too close and yes a near disaster, that's why the NTSB is treating this as a "Serious Incident".

I will also add that the AC 759 crew questioned the tower at 0.7nm out about lights on the runway but continued on their course to taxiway C, when closer in and at less than 100' AGL they were still committed to land on taxiway C.

IMHO it took perhaps one or two calls from UAL 1 to start to wake up the crew of AC 759 that something was really wrong but I really believe it was PAL 115's crew action to turn on their landing lights that saved the day and then AC 759 decided to go around but not before it almost came in contact with PAL 115.

This was a near miss as close as it can get in vertical and lateral separation.

Aside from why and how this happened I'd really like to know why the crew initiated a "Go Around" if like they claim they never saw any aircrafts on taxiway C? There is something not very kosher here.

NOTE: Not my doing, found this on another aviation forum. The cross section was made using the NTSB's information.

[pelmet]

The NTSB stated the crew said they did not see any aircraft on the taxiway but at what point? When they called the tower for confirmation of landing clearance when they saw lights or just prior to the go-around or never? My bet is they did see the aircraft prior to the go-around.

This is the most puzzling thing about this whole episode.

Maybe the NTSB will clarify this part before they close their investigation.

Personally I also can not imagine they did not see any airplanes at some point in the approach, Go around and on the initial climb out.

One thing for sure there a lot of people wondering about the same thing.

Having been in a similar situation of misidentified landing surface, the brain makes excuses for what might seem out of the ordinary. I expect that what happened was that they saw something unusual(unexplained lights) and asked about it. Tower confirmed that the runway was clear. They therefore thought that the surface they were looking at was clear. There can be some different light situations on different runways such as exit lights for the high speed exit, for example.

In such a situation I can only suspect that what went through their mind was that the unidentified lights were from something that was unexplained yet not unsafe and therefore decided to ignore them with a plan of pressing on to land regardless of those lights which would either become obvious as to what they were as they got closer or would pass by unexplained but harmlessly.

Perhaps there was some continuing nagging slight doubt in their minds and once they heard transmissions of the other airliners, it simultaneously became clear to one or both pilots of the hazard ahead and then came the calls for go-around.

This is how it happens.

[Cat Driver]

I may have this all wrong, but one of the reports seems to have said they told the investigators they " never " saw any airplanes on the taxiway at any time during their approach or go around.

Perhaps there was some continuing nagging slight doubt in their minds and once they heard transmissions of the other airliners, it simultaneously became clear to one or both pilots of the hazard ahead and then came the calls for go-around.

Also there are reports that one of the airplanes on the taxiway turned on its landing lights just before A. C. did the go around.

So how could they not have seen at least one airplane?

[mbav8r]

The photos showing positions and altitudes of the aircraft, the ones on the taxiway show 13' and AC at 131', they say the go around was initiated at "about 85'" then goes on to say 2.5secs after advancing thrust levers the lowest recorded on the FDR was 59', this I would assume was rad alt. I'm not saying this wasn't a serious situation, the aircraft was in a climb at 59' agl and established in the go around. AC may have crossed the tail of the 747 in question at 100', we don't know and that is what the investigation will show, but I take exception to the posting the worst case(3feet) without anything to back it up because nothing so far has shown the altitude readout at the moment AC was directly over the 747.
Assuming they initiate the go around because the aircraft on the taxiway turned on their landing lights, this happened prior to crossing over them, so no one knows what altitude they were at, at the exact moment they crossed over the tail section with the information provided so far, saying it was possibly 3' is to provoke a sense of very near catastrophe in the reader and to me nothing but exaggeration without proof.

You must be an idiot!

Stop cherry picking my posts and get your facts straight before you speak out of your a$$!

Again I'm not confirming or absolutely saying it was a fact that the aircrafts crossed each other by only 3 feet but clearly stated it was a POSSIBILITY!!!

What 747 are you talking about?

If you are a pilot and can't even get the type of aircraft involved in this serious incident correctly identified than you are no better than the reporters in the media.

For the record and I hope you finally get the facts correctly, the first aircraft in line for takeoff, the one sitting closest to the threshold at a 30 or 40 degree angle, the one that called once perhaps twice to say AC 759 was lined up on taxiway C was a UAL 1, a B-787.

The second aircraft in line which was approaching taxiway W was PAL 115, an Airbus 340. It was followed by UAL 863, another B-787 and finally the last aircraft, UAL 1118, a B-737.

AC 759 crossed the beginning of taxiway C at about 131 feet, perhaps crossing over head UAL 1 and was still descending and this is where things get even more dramatic not to say "sensational"...

From the NTSB report... "The incident pilots advanced the thrust levers when the airplane was about 85 ft agl. FDR data indicate that the airplane was over the taxiway at this time, approaching the vicinity of taxiway W.

Now do you get that mbav8r? This means AC 759 is at 85' AGL east of taxiway W and still descending to a final altitude of 59' AGL... This took a total time of 2.5 seconds. How far did AC 759 travelled along taxiway C in that 2.5 seconds?

PAL 115, the Airbus 340, was just west of taxiway W and I bet you that 2.5 seconds descent to 59' AGL ate up most of that taxiway C separating both AC 759 and PAL 115 before it started to climb. AC 759 must have been very, very close to PAL 115 at 59' AGL and yes the vertical separation of both aircrafts could have been as little as 3 feet taking into account that the 340's tail is 56 feet tall.

Again, let me stipulate both aircrafts could have been as little as 3 feet apart, or maybe 20 feet apart. Even if they were 50 feet apart, it was way, way too close and yes a near disaster, that's why the NTSB is treating this as a "Serious Incident".

I will also add that the AC 759 crew questioned the tower at 0.7nm out about lights on the runway but continued on their course to taxiway C, when closer in and at less than 100' AGL they were still committed to land on taxiway C.

IMHO it took perhaps one or two calls from UAL 1 to start to wake up the crew of AC 759 that something was really wrong but I really believe it was PAL 115's crew action to turn on their landing lights that saved the day and then AC 759 decided to go around but not before it almost came in contact with PAL 115.

This was a near miss as close as it can get in vertical and lateral separation.

Aside from why and how this happened I'd really like to know why the crew initiated a "Go Around" if like they claim they never saw any aircrafts on taxiway C? There is something not very kosher here.

NOTE: Not my doing, found this on another aviation forum. The cross section was made using the NTSB's information.

Are you?
Who cares what type of aircraft it was, the only relevance that has was how high the tail is which I'm certain is very close to the same. Thanks for all the facts but I already had them other than the aircraft type.
The crew initiated, on their own because they finally saw something, are you a pilot? Have you not initiated a go around from low altitudes, of course they cleared them by some distance yet to be determined, get this through your thick skull, they cleared them and nobody knows by how much so by saying "possibly" or maybe or could have been, doesn't change the fact, you're speculating and using 3' is still, no matter how many facts you throw out, an exaggeration of the facts so far.
Your, "not my doing" but posting a photo of a grade three cut and paste project is no less of an exaggeration of the facts, unless somebody has more facts that weren't made available to the general public.
You're clearly frustrated and frankly I'm done with this part of the conversation, maybe you could call FOX news and offer your services as a aviation expert with all your facts.

[55+]

Here is one non disputable fact: at the missed approach/go around altitude, the aircraft in question had attained sufficient climb gradient to clear the obstacles in front of it. If the ROC at the location of the first obstacle was 3 ft, 50ft , 100ft or a coat of paint, clearance was accomplished. Debate the semantics and pontificate as you wish but I am done.

[Jet Jockey]

The photos showing positions and altitudes of the aircraft, the ones on the taxiway show 13' and AC at 131', they say the go around was initiated at "about 85'" then goes on to say 2.5secs after advancing thrust levers the lowest recorded on the FDR was 59', this I would assume was rad alt. I'm not saying this wasn't a serious situation, the aircraft was in a climb at 59' agl and established in the go around. AC may have crossed the tail of the 747 in question at 100', we don't know and that is what the investigation will show, but I take exception to the posting the worst case(3feet) without anything to back it up because nothing so far has shown the altitude readout at the moment AC was directly over the 747.
Assuming they initiate the go around because the aircraft on the taxiway turned on their landing lights, this happened prior to crossing over them, so no one knows what altitude they were at, at the exact moment they crossed over the tail section with the information provided so far, saying it was possibly 3' is to provoke a sense of very near catastrophe in the reader and to me nothing but exaggeration without proof.

You must be an idiot!

Stop cherry picking my posts and get your facts straight before you speak out of your a$$!

Again I'm not confirming or absolutely saying it was a fact that the aircrafts crossed each other by only 3 feet but clearly stated it was a POSSIBILITY!!!

What 747 are you talking about?

If you are a pilot and can't even get the type of aircraft involved in this serious incident correctly identified than you are no better than the reporters in the media.

For the record and I hope you finally get the facts correctly, the first aircraft in line for takeoff, the one sitting closest to the threshold at a 30 or 40 degree angle, the one that called once perhaps twice to say AC 759 was lined up on taxiway C was a UAL 1, a B-787.

The second aircraft in line which was approaching taxiway W was PAL 115, an Airbus 340. It was followed by UAL 863, another B-787 and finally the last aircraft, UAL 1118, a B-737.

AC 759 crossed the beginning of taxiway C at about 131 feet, perhaps crossing over head UAL 1 and was still descending and this is where things get even more dramatic not to say "sensational"...

From the NTSB report... "The incident pilots advanced the thrust levers when the airplane was about 85 ft agl. FDR data indicate that the airplane was over the taxiway at this time, approaching the vicinity of taxiway W.

Now do you get that mbav8r? This means AC 759 is at 85' AGL east of taxiway W and still descending to a final altitude of 59' AGL... This took a total time of 2.5 seconds. How far did AC 759 travelled along taxiway C in that 2.5 seconds?

PAL 115, the Airbus 340, was just west of taxiway W and I bet you that 2.5 seconds descent to 59' AGL ate up most of that taxiway C separating both AC 759 and PAL 115 before it started to climb. AC 759 must have been very, very close to PAL 115 at 59' AGL and yes the vertical separation of both aircrafts could have been as little as 3 feet taking into account that the 340's tail is 56 feet tall.

Again, let me stipulate both aircrafts could have been as little as 3 feet apart, or maybe 20 feet apart. Even if they were 50 feet apart, it was way, way too close and yes a near disaster, that's why the NTSB is treating this as a "Serious Incident".

I will also add that the AC 759 crew questioned the tower at 0.7nm out about lights on the runway but continued on their course to taxiway C, when closer in and at less than 100' AGL they were still committed to land on taxiway C.

IMHO it took perhaps one or two calls from UAL 1 to start to wake up the crew of AC 759 that something was really wrong but I really believe it was PAL 115's crew action to turn on their landing lights that saved the day and then AC 759 decided to go around but not before it almost came in contact with PAL 115.

This was a near miss as close as it can get in vertical and lateral separation.

Aside from why and how this happened I'd really like to know why the crew initiated a "Go Around" if like they claim they never saw any aircrafts on taxiway C? There is something not very kosher here.

NOTE: Not my doing, found this on another aviation forum. The cross section was made using the NTSB's information.

Are you?
Who cares what type of aircraft it was, the only relevance that has was how high the tail is which I'm certain is very close to the same. Thanks for all the facts but I already had them other than the aircraft type.
The crew initiated, on their own because they finally saw something, are you a pilot? Have you not initiated a go around from low altitudes, of course they cleared them by some distance yet to be determined, get this through your thick skull, they cleared them and nobody knows by how much so by saying "possibly" or maybe or could have been, doesn't change the fact, you're speculating and using 3' is still, no matter how many facts you throw out, an exaggeration of the facts so far.
Your, "not my doing" but posting a photo of a grade three cut and paste project is no less of an exaggeration of the facts, unless somebody has more facts that weren't made available to the general public.
You're clearly frustrated and frankly I'm done with this part of the conversation, maybe you could call FOX news and offer your services as a aviation expert with all your facts.

LMAO... "I'm frustrated?" I think it is you that needs to take at look at yourself.

In all of my flying career (+15,000 hours of flight, flying light turboprops, Dash 8s and 7s, Fokker jets and various business jets, flown all over the world, of which 3 years based in Paris), I have had to make a few go arounds for various reasons but never once I had to go around on a visual approach in good VFR conditions where I had directly overflown four aircrafts at extremely low altitudes that were taxiing for takeoff on a parallel taxiway to the takeoff/landing runway.

I hope you don't work for Air Canada because I would not want to be a passenger with you at the controls. After Halifax and now this, perhaps it is time for me to re-evaluate my first choice of airline when I deadhead.

[pelmet]

Instead of arguing over the seriousness or not of this case, I think we could be a lot more productive in trying to making posts on how to prevent this sort of occurrence from happening again.

There really is some good stuff on PPrune sometimes which is more technical in nature and experience from around the world(in my opinion).

If you want a view from an aircraft into SFO with one set of approach lights on short final on a dark night....look at this link.

http://www.pprune.org/rumours-news/5969 ... ost9852871

[Cat Driver]

I was going to suggest going to Pprune and looking at those pictures, but now you have I don't have to .

Like Jet Jockey I also have never had to do a go around when landing VFR at night because I was about to land on a Taxiway.

In my opinion it is easier to identify a runway versus a taxiway at night because of the difference in colors of the edge and center line lighting even if there are no approach lights.

So regardless of the fact they did not hit anything and successfully went around that does not change the fact it was a very serious incident...and the NTSB also thinks so.

[Cliff Jumper]

So, in the end, although numerous posters have pointed out that it`s impossible to mistake the taxiway for a the runway....

It happenned. To both pilots.

Unless of course, someone is suggesting something else.....?

[GyvAir]

They both had the chicken? There was an unnoticed cabin pressurization issue and they flew the leg (or the day) at a higher than ideal cabin altitude, giving them a touch of hypoxia? They both had a touch of the flu? They were both tired? They were both badly in need of new prescription glasses, but didn’t realize it? They had just flown through a flock of migratory sand gnats, coating the windscreens? Some combination of the above, plus some other factor that none of us would ever guess?

[Cat Driver]

They both had the chicken? There was an unnoticed cabin pressurization issue and they flew the leg (or the day) at a higher than ideal cabin altitude, giving them a touch of hypoxia? They both had a touch of the flu? They were both tired? They were both badly in need of new prescription glasses, but didn’t realize it? They had just flown through a flock of migratory sand gnats, coating the windscreens? Some combination of the above, plus some other factor that none of us would ever guess?

Any of the above could have caused them to do what they did.

The NTSB has a good history of finding out what went wrong so I believe we will eventually know what the cause was.

For sure in the interest of safety the cause should be identified to maybe prevent others from doing the same thing.

Even though I no longer fly airlanes I still fly on them so I have a personal want to know.

[confusedalot]

As the ancient cliché goes, ignorance is bliss.

Is is not unsettling to know what goes on in the pointy end at times?