Air Canada 759 at San Francisco – July 7, 2017

There but for the Grace of God . . .

Air Canada 759 at San Francisco

July 7, 2017

During the fifteen months between the incident and the adoption of the Final Report, details leaked out via the press and the grapevine.

Everyone knew that AC 759 had lined up with a taxiway. Most people knew that there were aircraft on that taxiway, awaiting takeoff. They knew the AC 759 pilots were tired – they were on reserve and on Eastern Time, and the incident took place just before midnight Pacific Time.

Then, through the grapevine, it came out that the pilots had not tuned the ILS for the landing runway, 28R. That is a big no-no in airline operations – indeed, in any operation – and especially so at night.

It seems pretty well cut and dried. The tired crew screwed up. Somehow they decided to go around at the last second and did a missed approach.

But it doesn’t stay that simple. New knowledge, as always, complicates the case:

  • the lights were off on runway 28L and adjacent taxiway Foxtrot

  • The FMS Bridge Visual 28R was the only approach in the database that did not autotune the ILS

  • the tower frequency was saturated for a minute and a half while AC 759 was on final approach

  • the crew’s effectiveness was compromised – by fatigue, by their own decisions, and by the culture in which they were operating

The AC 759 pilots were not the only ones who were confused. The pilots of the Delta flight which preceded AC 759 on approach couldn’t make sense of what they saw. They flew instruments down to 300 feet. When their landing lights picked up the painted numbers on runway 28R, they decided to land.

You’re tired. You felt OK during climb, even though you had already been awake for fourteen hours.

It was a bit stressful maneuvering through that line of thunderstorms west of Chicago. Still, nothing out of the ordinary. But the last two and a half hours have been a bitch. You have felt like slapping your face every few minutes. Maybe you did slap your face every few minutes.

Won’t be long now. The airplane has been doing its thing, flying the DYAMD Arrival and transitioning to the FMS Bridge Visual 28R. Gear’s down. Before Landing Check is complete. One minute more. Two minutes, tops.

There are a few things you haven’t been thinking about, and of which you may be unaware in your fog of fatigue. And you haven’t yet experienced the illusion that troubled the Delta pilots who flew this approach a few minutes ago. They struggled with their perceptions. There were two sets of parallel lines of lights. The Pilot Flying followed the LNAV all the way to the runway, which lined them up with the the lights on the left. They weren’t sure it was 28R until their landing lights picked up the painted numbers. That was at 300 feet. It was confusing as hell, even though they both knew that 28L was closed.

But you don’t. To be fair, 28L was open until 2300 Local, and that was just 45 minutes ago. And also, finding a pertinent NOTAM is like finding a needle in a haystack.

Now, through that fog of fatigue, the lights of the airport appear. You believe your eyes. Vision is powerful. Our orientation is always 70% vision. Only through the discipline of instrument flying can we ignore our vision and go with the gauges. But it is a clear night, and we’re visual. You are looking out, and there is no Heads Up Display. There is no overlay of NAV data on the picture you see out the windscreen. Your perception is free to make sense of the visual field using what you know about KSFO – a big double-lined X. Two sets of close parallel runways, the 28’s and the 19’s sticking out into the bay on fill, the approaches over water until the last seconds. Two close parallel runways. 28R is the one on the right. Right?

Minutes before midnight local time, Air Canada 759 lined up on taxiway Charlie. There were two sets of parallel lines of lights visible. Runway 28R was the left set of lights. Taxiway Charlie was on the right.

Runway 28L was NOTAM’ed closed. Its lights were off, as were those of the adjacent taxiway Foxtrot.

Air Canada 759 was cleared for the FMS Bridge Visual 28R approach. The track for this approach lies to the north of ILS 28R (track 284°) and slowly converges with it. The crew did not tune the ILS 28R as a backup.

At the end of the NTSB Incident Report (adopted September 25, 2018) are two concurring statements by NTSB board members. Vice Chairman Bruce Landsberg begins his like this:

This incident report should be required reading for all pilots. Only a few feet of separation prevented this from possibly becoming the worst aviation accident in history.

What, exactly, does he mean by only a few feet of separation?

Air Canada 759 overflew the first airplane on taxiway Charlie (UAL 1, a B-787) at 100 feet AGL, still descending. The thrust levers were advanced for Go-Around two seconds later. Two seconds after that, AC 759 overflew the second aircraft on Charlie (PAL 115, an A-340) at the lowest altitude in its trajectory, about 60 feet AGL. The security camera video of the approach and overflight (Google AC 759) clearly shows the change in pitch attitude and flight path in those four seconds.

TwoStillsGoogling A-340 tail height, I get figures between 54 feet 9 inches and 55 feet 9 inches. (In the real world the number will depend on main and nose gear oleo extension.)

The NTSB calculates the separation between AC 759 and PAL 115 to have been 13.5 feet.

Where was the first hint of doubt? When you said, “Confirm runways clear”? Was it seven seconds later, when someone on the frequency said, “Where is that guy going”? Or four seconds after that, when another voice said, “He’s on the taxiway”. At that point you were over the first airplane on the taxiway, your altitude 100 feet.

Timeline2In any case, you reacted quickly to your doubt. The second voice hadn’t released the mike button when you pushed the throttles up. By the time the tower said “Go Around” you were already climbing.

You didn’t yet know what just happened or didn’t happen. You were flying the missed approach, that was all. Everything was normal except you. Tower said, “Fly heading 280 and climb to 3000 feet. That made sense, and you were doing it. They had also said, “It looks like you were lined up for Charlie.” What’s Charlie? Never mind. You’ll figure that out later, when you’re not so busy.

From the Pilot/Controller Glossary:

VisualApproachA Visual Approach is an approach conducted on an IFR flight plan. The pilot must, at all times, have either the airport or the preceding aircraft in sight. At 23:46:19 local time (go-around was initiated just under ten minutes later, at 23:56:05) the controller asked AC 759 if they had the airport or bridges in sight. The crew replied they had the bridges in sight. AT 23:46:30, the controller cleared AC 759 for the visual approach.

It was a typical, lovely summer night in the Bay Area. KSFO Information Quebec gave the visibility as 10SM, the sky as CLR. Those on the ground could see the string of pearls – the aircraft on arrival and approach – at least fifteen miles away.

That’s from the ground, looking up. It is what I can see many nights driving south on the Interstate 280. However, it is not what pilots see. Pilots see a black hole. Were it not for the San Mateo Bridge, it would be a classic black hole, inviting duck under. And once you pass the bridge, it is a classic black hole – lights beyond, but no lights at all beneath.

Day28RCompare these images of the pilot’s view on short final to runway 28R. Here we are over, or almost over, the approach lights, which are on stanchions in the bay.

Night28RAt night, without the PAPI or ILS, a pilot is literally stabbing in the dark.

Do you see the slippery slope? It is a visual approach, but it is night. For those on the ground, it is CAVOK. For pilots, it is an intermittent black hole. For controllers, if you can see the San Mateo Bridge, you’re good. For pilots, once past the bridge, you’re on your own.

If, like me, you are puzzling this out at the kitchen table over morning coffee, it is clear as a bell. If you are a pilot at the bottom of your circadian rhythm, nineteen hours since last sleep, not so much.

The Delta pilots, who preceded AC 759 on approach, called the tower an hour or so after landing, and suggested that flight crews should fly ILS approaches to 28R, or the tower should turn on the lights for runway 28L.

Why are we, as pilots, accepting visual approaches at night?

You know and you don’t know. Your sleep has sorted much of yesterday and put it safely into slots. You are free to look. Or not.

It is a new day. What a blessing it is to be free of that fog of fatigue! Work and the daily routine are approached fresh, Peet’s latte still in hand. As always, you borrow one of the agents’ computer stations and print out the flight plan and weather.

The two of you have a discussion about last night. Well, it is not really a discussion. You each refer to it, but obliquely, as if you had a hand on it, patting it, but are looking elsewhere. You both know it has to be acknowledged. But like a dog, it doesn’t speak. It lets you put words into its mouth. It was a routine go-around. An uneventful circuit and second approach. A successful landing.

But dispatch should probably know about it. And perhaps before you get into the airplane and fly back to Toronto. Because last night’s airplane has already gone. It is in Montreal or somewhere beyond, the Cockpit Voice Recorder overwriting, overwriting. You didn’t have to do like Hoot Gibson, so long ago, and erase and erase and erase that – what was it? A piece of foil? A wax cylinder? No. Just let it go. The new day sweeps clean.

So what do we lose without the voice recorder? Corroborative detail. Embarrassment. (The whole thing is embarrassing enough.)

Mostly, we lose the play-by-play about how fatigue can erode good cockpit practice. Like using Open Descent without really thinking about it. That way it’s simpler, and you don’t have to plan. And it’s even safe, until the Final Approach Fix. At least as long as the AutoThrottle is on, and the Flight Mode Annunciator says IDLE/OP DES, and there is an altitude set below you. But God help you if you use it after the FAF, and the Pilot Monitoring has set the Missed Approach Altitude.

But you guys don’t fall into that trap. You have Standard Operating Procedures. You do it the same way every time. Sort of. And that saves your butts.

Timeline1Still, thirty-four seconds elapse between Autopilot Off and Flight Directors Off. That should be a package. F/D’s Off is what switches the A/T mode to SPD, annunciated on the FMA. The only acceptable A/T modes inside the FAF are SPD or OFF. So you’re foggy, but OK. You’re also slow.

Now the cockpit discipline breaks down. You want to ask about the runway, about the lights you see. But you can’t. There is one controller. He can handle the load, but the frequency can’t. It is close to meltdown as he transmits on Tower and Ground to airplanes and vehicles. You can’t break in for a minute and a half. That’s a long time, on final approach.

In that time you have flown from the F101D at 1100 feet to 0.66 mile from the runway at 300 feet. And what do you do when your PM can’t break in? You ask him to set the missed approach heading. He has already set the altitude, but you want the heading? Runway 28? Two-eight-zero? Good enough?

I guess not. He goes head down inside the FAF, at night, and inspects not one, but two different charts. Make-work. Distraction. And it leaves you alone.

And Pilot Monitoring – what are you doing obeying your captain when he asks you to do something stupid? You’re not there to obey him. You’re there to save his ass. And your own. Thank God you look up at three hundred feet and see. This shit ain’t right.

By the way, why is it still an SOP to set the missed approach altitude when passing the FAF? Because we have always done so? But does that still make sense in today’s fly-by-wire aircraft?

Sure, it still makes sense once the glide-slope is captured on an ILS or LPV approach. But on a non-precision approach or a visual approach? If the AC 624 crew in Halifax had set the MDA after the FAF, that aircraft would still exist.

Similarly, we have known since Bangalore that in Airbus aircraft, when you disengage the autopilot you must also turn off both Flight Directors if you expect the auto-thrust to work. It is a verbal call, a mantra, always the same: Autopilot OFF, Flight Directors OFF. Is it important to know what your auto-thrust is doing when you are hand-flying? Remember Asiana 214, also at KSFO?

OK, let’s back up a bit here. Open Descent? Your F/O says you used Open Descent on the arrival. Did you? If so, why?

DYAMDOn the DYAMD Arrival there are seven waypoints. Four have slowdowns – that is, a new, lower speed to fly. All but one have some kind of altitude restriction – a hard altitude, an above, or a window. That’s busy. Open Descent? Selected Speed? You, as a team, could have had all that under control by activating the DYAMD Arrival and using Managed Descent. In any case, your F/O:

perceived that the descent was being flown using the open descent mode, which increased his workload during a critical phase of flight because he had to ensure, among other things, that altitude constraints were met. The First Officer stated that he thought it was unusual to use the open descent mode, but he did not notify the captain about his concern because the procedure was allowed (until reaching the final waypoint on the approach, F101D).

OK, we’ll leave that. Nobody complained to you about busted speeds or altitudes during either the arrival or the approach. Maybe you weren’t talking to each other enough. It is easy enough to get into that state in a dark cockpit in the wee hours. And you guys were tired.

But so far so good. You have even included your Threats Briefing in your Approach Briefing, as you are supposed to.

But there are a couple of threats you haven’t briefed. One – the fact that runway 28L is closed – you haven’t briefed because it blew by you. But the other is more sinister. You are about to get out-foxed, skunked, bamboozled – had, in short – by this approach, which is non-standard in three major ways. (And that doesn’t include the qualifier that this is a visual approach being flown at night.)

  1. This is the only approach in the database that does not tune the ILS

  2. This approach has two pages

  3. This approach has a dogleg

The first two come from the fact that Air Canada bought this approach from United. Air Canada’s policy is to use it unchanged, except that they have added a second page, wherein they instruct the pilots to tune the ILS.

The dogleg is there because as noted above, the approach lies to the north of the runway centreline and slowly converges with it. That is normally not a problem, because it is a visual approach. You will most likely be heads up, aligning with the extended centreline and descending via the PAPI or VASI.

Tonight, though, it is a problem. The Delta crew looked out and didn’t like what they saw, so the captain, who was pilot flying, hung on to the LNAV guidance all the way to the runway. That track would have been 275° from TRDOW (20 miles final) to SAMUL (7 miles final). At SAMUL it jogs left to 267°, and then at F101D back right to 281°. The plan view shows F101D to be on the extended centreline, and the final track to the runway to be 281°. The ILS track is 284°, and in the boxes above show the Final Apch Crs to be 284°, and the box to the right says No FAF.

But wait – were the Delta pilots flying this approach? Perhaps they were flying the Quiet Bridge Visual. The track is 275° all the way from 20 DME to the runway, defined by the 095° radial of the SFO VOR. No dogleg. Was that also the LNAV track the Delta pilots used?

The bottom line? If you don’t tune the ILS you don’t have good instrument guidance to the runway. And the chart designers (of the FMS Bridge Visual 28R) are essentially saying that if you use any part of this approach after passing F101D, it’s not on us.

No sweat, right? On a visual we fly the VASI or PAPI and track the extended centreline. Except it’s night, it’s a black hole, and the lights are off on 28L.


Canada has a Night Rating and an Over-The-Top Rating you can add to the Private Pilot Licence. Does that make you safer than in the USA, where you can fly at night with recency only? I would argue that no, it gives you a false sense of security.

Every experienced pilot knows that night flying varies from almost-daylight conditions to total confusion. Remember John Kennedy Jr.’s fatal flight over Long Island Sound? There were plenty of lights, but it was so hazy that there no horizon, and stars were indistinguishable from lights on the ground.

The solution is to fly IFR at night. To fly as if everything you see out the windscreen is an illusion. To use all the cues (not just the one-of-a-list that the Regulations require) to identify the “runway environment”.

There’s more. Here is NTSB Vice Chairman Bruce Landsberg on NOTAMS:

The current system prioritizes protecting the regulatory authorities and airports. It lays an impossibly heavy burden on individual pilots, crews, and dispatchers to search through literally dozens of irrelevant items to find the critical or merely important ones. When one is invariably missed, and a violation or incident occurs, the pilot is blamed for not finding the needle in the haystack!

Ditto for Standard Operating Procedures (SOP’s), Crew Resource Management (CRM), the Swiss Cheese Model (SCM), and Threat and Error Management (TEM). Sounds good, but mainly it is make-work and distraction. Managers, regulators, and airlines pay the smart consultants, put all this in place, and hey – they’re done! Their asses are covered.

But where does that leave us, as pilots?

Out on a limb, alone.

The Manuals contain Controls And Indicators (CAI), and a pablum of the other Three-Letter-Acronyms (TLA’s) mentioned above. Our training is woefully insufficient. We have to know the manuals practically word for word. Is that going to save our collective butts?

No way. Now we have to:

  • learn to fly (a career-long challenge)

  • learn our airplane (you can never know too much)

  • implement the SOP’s in a meaningful way (because we have to work together, and we have to obey the pilot commandment: Thou shalt do it the same way every time)

  • incorporate the other TLA’s into our psyches, so, for example, TEM is part of every waking hour, not just something we bow down to at work.

A challenge? Sure. But meeting that challenge is where the satisfaction lies. Girls and guys, don’t let yourself get dumbed down. All those TLA’s are going to save someone else’s butt, not yours. Wake up! Demand the information you need to do your job! Don’t let up!

And please – don’t hide behind your competence. Don’t think for a minute that any of us are better than these guys.

Think humble. Think, there but for the Grace of God, go I.

Do you remember that four-second sequence of events? When doubt crept in? A pilot in UAL keyed the mike and said, “Where is that guy going?” A pilot in PAL 115 turned on landing lights and said, “He’s on the taxiway.” A pilot in AC 759 said, “Go-around!” A pilot in AC 759 pushed the thrust levers forward and pulled nose-up. Who was it that saved the day? Who prevented this from possibly becoming the worst aviation accident in history?

Pilots. That’s you, ladies and gentlemen. Take heart.

Chris Brown

21 December 2018