Huge kudos to the United Airlines pilots here, and you also can’t help but feel a bit bad for the air traffic controller’s high workload and obvious fatigue…
In this post:
SFO ATC gives wrong instructions to United 737
VASAviation has the air traffic control audio and a visual recreation of an incident that happened on the morning of June 24, 2025, at San Francisco International Airport (SFO). While SFO’s runway layout is great for maximizing space, it’s kind of awful in terms of the frequency with which runways have to be crossed while taxiing, especially for such a congested airport.
In this incident, you have one air traffic controller working tower, who was clearly overworked. He was giving takeoff and landing clearance, giving instructions for after takeoff, and was also clearing taxiing planes to cross active runways.
Runway 1R was the primary runway being used for takeoff, with one takeoff after the other. United flight UA1111, a Boeing 737 MAX 8 bound for Lihue (LIH), was given taxi instructions, which were read back correctly:
Controller: “United 1111, San Francisco tower. At F, cross runway 1L, cross runway 1R.”
United pilot: “Cross runway 1L and cross 1R on F, United 1111.”
The instructions were clear, and the United pilot read those instructions back correctly. There was only one problem — the controller clearly didn’t actually mean what he said, and wasn’t focused enough to listen to the read back.
While the United 737 taxies, two different sets of planes are cleared for takeoff from runway 1R. Obviously that poses a major issue — you don’t want to clear planes to takeoff from a runway that another plane is also cleared to taxi across.
Fortunately the United pilots had stellar situational awareness. They crossed runway 1L, and then decided to hold short of runway 1R, and check in with air traffic control:
United pilot: “United 1111, holding short 1R.”
Controller: “United 1111, I know, hold short of 1R.”
United pilot: “No, you gave us a cross, United 1111.”
Controller: “United 1111, I told you cross 1L, hold short of 1R.”
The United pilots didn’t argue further. After holding a moment longer, they were cleared to cross the runway, and the flight continued without incident.
What can we learn from this incident?
The United pilots handled this situation perfectly. They read back the instructions correctly, while maintaining situational awareness, and not just blindly following the instructions they were given.
They also politely checked in with the controller while holding short of runway 1R. They clearly realized something wasn’t right, so they took the politest approach imaginable to nudging the air traffic controller. The controller had a bit of an attitude with the pilots (“I know”), but they kept their calm, and the pilot didn’t argue with the controller. He was more focused on safety than being right.
The fundamental issue here is that the controller not only gave incorrect instructions, but the pilot actually read it back correctly, and the controller didn’t notice. Typically when we see a plane enter the runway at the wrong time, it’s because something isn’t read back correctly, or instructions aren’t followed correctly.
The thing is, you also can’t help but feel bad for the controller. He sounds exhausted, and he’s rattling off one instruction after the other. Imagine having to be right with every single instruction that comes out of your mouth, with hundreds of lives being on the line.
I imagine the controller didn’t even pay attention to what was being read back, because he was already so focused on giving the next instruction to another plane.
Bottom line
There was a close call at SFO, as a United 737 was cleared to cross a runway that was being used for takeoffs, with multiple planes being given takeoff clearance. Fortunately the United pilots had good situational awareness, and held short of the runway.
The controller clearly didn’t realize the instructions he had given the pilots, because he had a bit of an attitude when they even checked in to share that they were holding short of the runway. You can’t help but feel bad for him, though, given his workload.
What do you make of this SFO runway incident?
Me: 20+ year career passenger airline flying into/out of SFO including being based there for most of it. This controller did not have "obvious fatigue" and things like this happened in the past in SFO, LAX, SEA, PHX, etc. Fortunately it did not happen often, but it did happen. The difference is back then, the public couldn't access the ATC ground radar and communication tapes to find out so immediately and easily.
Any pilot familiar...
Me: 20+ year career passenger airline flying into/out of SFO including being based there for most of it. This controller did not have "obvious fatigue" and things like this happened in the past in SFO, LAX, SEA, PHX, etc. Fortunately it did not happen often, but it did happen. The difference is back then, the public couldn't access the ATC ground radar and communication tapes to find out so immediately and easily.
Any pilot familiar with SFO operations will recognize that this controller was "in the flow" with the dance of "two landings / two departures / repeat" as he is clearing landings on 28L/R, departures on 1L/R, managing 1L/R crossings (which happens while aircraft are landing on 28, to maximize efficiency and safety), and 28L crossings for aircraft that land 28R. He was actually doing quite nicely, didn't sound stressed nor rushed, and there were several pauses in time in the tape which shows me he was not at "max level" in the number of aircraft he was handling. But he just made a simple error.
Hawaii flights nearly always use 28L/R for departures. These flights are sometimes crossed on both 1L/1R (at "F") in one instruction if landing traffic on the 28s momentarily block 1L/1R departures anyhow. However, if there is departure traffic on only 1R (as in this case) the controller will give the "Cross 1L, hold short 1R" instruction to position the crossing aircraft as near to 1R as is safely possible - to minimize the length of time it takes to cross, and not interrupt the "two landings / two departures" flow that makes the airport run efficiently.
The controllers repeat these instructions hundreds of times a week, over and over. He did simply think he gave the "hold short" for 1R when he obviously didn't. And he didn't catch the readback with the permission to cross both runways by the pilots. So, one of the safety links failed (an careful, correct ATC instruction with confirmation the pilot understood it via the readback).
Fortunately, two other systems didn't fail - the pilots being situationally aware of the departures - and NOT crossing 1R (they likely heard the "flight (xxx) cleared for takeoff, 1R" and caught the conflict). The other system that didn't fail was the Runway Status Lights (installed for 1L/1R on taxiway F) which would have illuminated upon detecting the moving departures on 1R (for commenters advocating for an automation-based solution, this is one in use already). These lights monitor takeoffs and landings, and illuminate red to indicate pilots should not proceed, even if they have a verbal instruction to do so. They are not turned on manually, and many airports have them installed where runway incursions were more likely. They're light a red light version of a crossing guard.
To sum up: This issue actually happens more than most realize, but fortunately it happens infrequently. But it does happen. And as in this case, a set of experienced pilots caught an ATC error - just like the SFO ATC controllers have caught pilot errors (look up Air Canada lining up to land on a taxiway in SFO after a long duty day around midnight as an example). That's the way the system works. It's impossible for everything to be perfect, but having multiple layers involved allows one to cover for the other when mistakes do happen.
When I was a controller at SFO during busy times there were two data men, who were fully qualified, that listened to the Local Controller and assisted to prevent situations such as this. However, we did have our incidents.
I don’t feel bad for the controller at all. If he can’t handle the workload, he should tell his employer he needs a break or quit his job. Shouldn’t risk the lives of hundreds of people. Absolutely ludicrous
Every time I look at the map from one of these incidents, it seems that there is really no need to have aircraft crossing active runways.
Presumably SFO never had crossing runways active at the same time - so this was part of a changover from one pair of runways to another.
Then why not just wait the extra 2 minutes to allow the old ones to clear before going to the new ones?
The 28s and 1s are almost always used simultaneously - 1s for narrowbody takeoffs, 28s for landings and widebody takeoffs. There was no "changeover" going on.
This is the case 90% of the time. The peninsula is set up so that there's almost always wind coming from the west. When the wind is really strong, they don't take off from the ones. If landing and longhauls aren't on the 28s, then it's raining.
Also, SFO is the busiest US airport with a single tower frequency/controller. With the layout, it can't be otherwise: two sets of parallel runways close together (they...
This is the case 90% of the time. The peninsula is set up so that there's almost always wind coming from the west. When the wind is really strong, they don't take off from the ones. If landing and longhauls aren't on the 28s, then it's raining.
Also, SFO is the busiest US airport with a single tower frequency/controller. With the layout, it can't be otherwise: two sets of parallel runways close together (they wouldn't build that distance between the parallels today), intersecting. Everyone needs to be on frequency, for just that reason.
The controller failed. That happens, but we'd like to minimize it happening. The system had additional redundancy built in: stop bars, two sets of pilots. The system didn't come close to failing.
I get nervous as a passenger looking out the window and looking on my phone with flight radar24 when I see we have to cross several runways.
When will secretary Duffy act on the ATC manpower shortages? Rehire retirees, temporarily reassign military controllers, e.g.
The correct answer is fully automated it and remove all humans forever.
This
Another clever troll. At least you guys give us a few chuckles.
Proof that Trump is at fault and that socialism is better. Wouldn't have happened if AOC were president.
You are proof why lucky needs to stop the guest commenting.
Your post has nothing to do with this topic.
It's obviously just a troll comment. It's actually quiet clever and amusing, though.
There is no reason why these types of communications cannot be automated and transmitted electronically - even if also by voice - and run through computers to check for conflicts - other than that the global ATC system is hopelessly stuck in the past.
These types of incidents are the largest source of potential accidents.
Respectfully, you are completely wrong on this. Ground instructions are not the largest source of potential accidents. Pilot error is.
pilot error is the cause of ACTUAL accidents.
There are indeed more close calls on the ground because of failed radio communications.
Flight simulator developers can’t even get video game automated atc to work properly, even with ai. If I wouldn’t trust automation to be ATC for my video game, there’s no way I’d trust it with my actual life
@Speedbird
We must be paying a completely different flight sim.
You must have mistaken it for GTA.
and the first step is to send it by text message in addition to the current voice system.
I didn't tell you to trust AI w/ your life.
I said to start w/ creating a text duplication to the current voice process.
It is incredible that we send critical information via voice that is not only secure but is fraught w/ potential for misinterpretation.
Greedy obsolete JoeAmateur and colleagues refusing to be extinct will eventually costs lives. But they still want a raise.
It's just a matter of when.
You don't know anything about ground control. Go ride your tricycle.
You don't know anything about technology.
tricycle?
You're still suggesting a human powered vehicle? How rudimentary.
We have hover boards.
Where we're going, we don't need roads
Eskimo continues his trolling rampage... he DGAF about lives, he GAF about talking shit about other people.
Case in point--- there is literally no company or government that has put forward a system/proposal to replace ATC. But instead of advocating for the best possible conditions for the people who keep him safe
(until such time they finally can be replaced), he shits on them by calling them greedy, obsolete dinosaurs.
It's kinda weird...
Eskimo continues his trolling rampage... he DGAF about lives, he GAF about talking shit about other people.
Case in point--- there is literally no company or government that has put forward a system/proposal to replace ATC. But instead of advocating for the best possible conditions for the people who keep him safe
(until such time they finally can be replaced), he shits on them by calling them greedy, obsolete dinosaurs.
It's kinda weird that he flies at all for all his **alleged** concern.
Anyway, I'll never compromise on safety, but when the public rages against the people responsible for their safety-- and doesn't want them to be fairly compensated, they are unwittingly adding a level of stress to those controllers. Ironically, the kind of tirade Eskimo is on about regarding ATC--- well, THAT could cost lives.
But, to repeat my initial statement--- he doesn't **actually** care about lives. So dollars to donuts you'll see him here again with his fake "replace them all" sentiment.
Also--- "Refusing to be extinct" --- that's... not a thing.
Despite the correct read back, the proper procedure in the US is for ATC to never give a clearance to cross 2 runways at the same time, even if a runway is closed. A clearance is issued to cross one runway, hold short of the next runway, then clear an aircraft to cross the next runway once clear of the first runway. Luckily disaster was avoided here.
That is the standard, however SFO has an exception where they are allowed to clear aircraft across 2 runways at once. It's very much the norm there. I'm sure events like this cause them to reevaluate this policy.
SFO also has an independent automated runway status light system that illuminates red lights at taxiway crossings whenever an aircraft is taking off or landing, as well as red lights on the runway whenever anything is deter crossing downfield.
What SFO has independent "automated" runway status light system.
But dinosaurs here all hate automation.