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Comment by lamplovin | Hacker News Reader

The comments so far seem pretty negative, but for a pause of (what the article says) of 15 minutes I'd say that sounds like a pretty good call on the FAA's part for what reads like a moment of uncertainty with the risk of being wrong very great?

Personally I'd think 15 minutes of inconvenience would be pretty petty of me to prioritize over protection from a potential national security threat

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FWIW, it isn't 15 minutes of inconvenience. It's far, far more due to the traffic propagation. A 15 minute pause can result in hours of delays due to a traffic wave[0], which affects airliner takeoff scheduling as well. FAA definitely knew this and took it into account, which makes me even more curious as to the validity of the threat and what made them issue a ground order.

[0] https://en.wikipedia.org/wiki/Traffic_wave

Flight schedules always have slack built into them, I'm betting 15-20 minutes is probably the upper limit of what would not cause a large waterfall of issues.

This is absolutely true.

I can't count the number of times I've been on a flight where the captain said something like, "Well, we left a little late, but we'll make it up on the way there, and expect to arrive on time."

I've had international flights leave an hour late and still arrive on time.

By default, flights are optimized for cost. Pilots can fly faster and burn more fuel to arrive at a destination (depending on reserve and bingo fuel of course) sooner. The goal is to use the minimum amount of fuel to get somewhere however and incur the most profit per passenger as a result. When you look at it, life really is an engineering problem.

By default, flights are optimized for cost.

Decades ago, before all of the routes and scheduling got to be more of a mesh than an ideal hub-and-spoke, this was an absolute. But now, being late can cost far more money than what would be spent in fuel.

Now, very often the airlines would rather burn some fuel and keep a plane on time than delay or cancel a dozen connecting flights at the destination.

I was noting the fact that they are able to change the speed of a plane to optimize for the specific key performance indicator they deem the most necessary at the time.

I used to work in IT for delta a touch over a decade ago as a systems engineer.

Optimize for fuel cost means that planes usually don't fly at maximum speed. It also provides margin to avoid being late by speed up.

Precisely!

Yeah, a strong wind could literally cause an average delay of 15 minutes for all flights in a given area. It's not a big deal.

Anyone who knows US aviation knows that its foundation is "safety over time," precisely because it's such a multivariate problem and trying to be overly fixed to a schedule gets people killed.

This was limited to airliner taking off from a few west coast airports. That said it does take a little while for slack to get things back to normal, but no individual should have been inconvenienced by more than 15 minutes.

The words "national ground stop" are quoted a few times in the article. If that terminology got back to various airline dispatchers, it may have been more broad than a few airports.

That’s what a specific airport heard but, “Other West Coast airports contacted by CNN said they were unaware of the order.”

Sure. Airlines will hold flights, though, on input/direction from other than a specific airport.

The original article makes it seem like a very local event from “a regional air traffic control facility” mentioning a few individual conversations with pilots. I guess in theory pilots could have said something to their airlines but that’s not a big window for the airlines to actually do anything.

https://www.cnn.com/2022/01/11/business/faa-ground-stop-nora...

It's possible that controller may have just misspoken or been fed words from another controller and said 'national' when in fact it was for the west coast centers (ARTCC) only (Los Angeles, Oakland).

One of the quoted GA pilots told to land in another story was in Oregon, iirc.

It means, the FAA agrees with the GP. Safety is never convenient, it's always a balancing act. For example, simply pulling out your keys (or your phone) to lock or unlock your front door is more of a hassle than leaving it unlocked. But less of a hassle than getting robbed.

Article says a Cessna pilot was told to land. That is not just a little hassle in the name of safetyism, it is a diversion from the flight plan for no rational reason.

From article, '... captures the controller telling the pilot of a Cessna to land ...'.

It's a bigger hassle to the Cessna pilot than going about his business and flight plan, and a smaller hassle than his getting caught in the middle of a jet scramble or other military response perhaps.

Also, it's not necessarily entirely about the pilot's safety/inconvenience tradeoff. The Cessna IS a hassle, for anybody trying to scramble jets or launch an anti-missile interceptor or who-knows-what. The Cessna, on the ground, perhaps with its pilot quietly bitching about his ruined flight plan, is a smaller hassle.

> A 15 minute pause can result in hours of delays due to a traffic wave[0],

Anything "can" happen; but did it?

Doesn't that depend very much on the variables encoded in "inconvenience", "protection" and "potential"?

I mean, I can spend 15 minutes putting on a full ABC suit every time I go outside, and would certainly protect me from some possible national security threats, but the extent of the inconvenience, the limited range of protection, and the very low potential would make that an unnecessarily foolish habit.

In more of a real-life scenario, millions of people have spent the last 20 years wasting way more than 15 minutes standing in line to take off their shoes and get x-rayed every time they fly in an airplane to protect against a "potential national security threat" when the only thing that actually needed to happen was locking the cabin doors while the plane is in flight.

A hostile nation with nuclear weapons launched a missile. If you're going to take precautions, that's approximately when the cost/value proposition starts making sense.

Sure, I don't actually know the threat level here, and you could well be correct that this was an appropriate calibrated response. My only argument is that the US have strayed very far into "inconvenienced" territory (forgetting we had any compunctions about torturing people, spying on everyone in the developed world, attempting to entrap entire communities of people based on their religious affiliation) by using the "it's for national security" excuse. Americans would be well advised to be skeptical each and every time that excuse gets used.

The military made the call that South Korea was not in danger. Same for USA. Whoever in FAA started the call for ground stop should face discipline.

The Karens waving their arms about safety seem addicted to their fear-based adrenaline rush.

> In more of a real-life scenario, millions of people have spent the last 20 years wasting way more than 15 minutes standing in line to take off their shoes and get x-rayed every time they fly in an airplane to protect against a "potential national security threat" when the only thing that actually needed to happen was locking the cabin doors while the plane is in flight.

Where the unstated goal is to prevent hijackers from turning airplanes into aimable missiles? Yeah, I like your argument, what are the counterpoints?

Option 1: After 9/11 the airlines were desperate to get people to fly again, needed some theater to comfort people (because evidently "still orders of magnitude safer than cars per vehicle miles traveled" wasn't convincing), and this let them offload what security they needed to do onto the federal government.

> Personally I'd think 15 minutes of inconvenience would be pretty petty of me to prioritize over protection from a potential national security threat

Presumably even that would work out okay as long as we haven't simultaneously sent hundreds of fighter jets on a training mission in Alaska with only 14 remaining to defend CONUS http://web.archive.org/web/20020917072642/http://www.aviatio...

Fighter jets won't do crap against an ICBM.

The other way around, though... best to have them in the air.

Given the amount of infrastructure modern air forces require, it doesn't matter if the jet is alive and well in the air if all of the supporting cast is incinerated.

Good point. Although, if there's any chance of these difficult to replace assets surviving you'd probably want to take it. Any local airfield with a strip just barely long enough would do.

Deterrence from opportunistic attacks by other parties is also something that comes to mind, but I'm not sure if that makes any sense in these scenarios.

No, but their onboard ordinance might be designed to take it out:

https://futurism.com/military-f35-nuclear-missiles

That's an interesting article. But no fighter-jet will ever be useful at stopping an ICBM once it hits Mach10+.

It seems like the F35 anti-nuke idea is to fly the F35 into enemy territory, and then shoot down the missile _BEFORE_ it reaches those speeds. I don't know what kind of situation would give us advance-warning of a nuclear launch, enough time for F35 to scramble into North Korea (violating the DMZ) and then effectively shooting down an ICBM before it reaches top speed, but... hey... weirder things have happened.

Weird contingency plans are basically the military's job. Maybe the situation will come up. Or maybe that situation is aimed for some other nuclear-armed country with a space program (China, Russia?)

What about something like this rather old https://en.wikipedia.org/wiki/ASM-135_ASAT ? There should be some updates meanwhile. Anyway. Assuming NORAD or similar has the rough ballistic track of the potential intruder, and can thus determine the entry ellipsoid, why wouldn't some jets on air patrol in or around that ellipsoid be capable of intercepting it with an air launched system?

edit: Or even from the sea, like this: https://en.wikipedia.org/wiki/RIM-161_Standard_Missile_3

As I understand it in my utter ignorance, you don't have to race with something coming in and down at Mach 10, or more. You just have to be in its way at the right time. Which seems doable, in this case, coming from NK, high over the Pacific.

I think you're misreading that article.

> AT THE TIME, NORAD had 20 fighters on armed alert throughout the North American continent. Only 14 were in the continental U.S. at seven bases; the rest were in Alaska and Canada. Within 18 hr., 300 fighters would be on alert at 26 locations.

It's not saying they sent them all to Alaska. They're saying of the 20 alert fighters - pretty standard numbers in peacetime - six were in Alaska and Canada.

> Personally I'd think 15 minutes of inconvenience would be pretty petty of me to prioritize over protection from a potential national security threat

I can’t buy into this anymore, it’s the new think of the children. Used and abused. I’d rather live life like a normal human and if I perish, well, I had to die from something.

If anything, it served as a great test of that system. But from the sounds of it, NORAD declared this a non-issue and yet a portion of the FAA still proceeded with the shut-down. So whether this was a pass or a fail depends on who has the final authority over shutting down airspace.

It's asymmetrical though right, accidentally not shutting down when it's unclear has a small likelihood of a massive loss of life. Accidentally not shutting down results in some eocnomic loss and lots of delays, but in a real way you know there's seriously limited downside. I don't know how the US is doing right now, but in other countries airlines are running way under capacity at the moment anyway, so they can recover from down time much better than usual.

I’m not sure what possible risk there was to our aircraft. Specifically from a missile launch in NK.

I’m not saying there are no risks, but I can’t think of any.

Do you have sufficient expertise in this area that would make you qualified to assess such a thing?

We don't want our anti-missile systems to mistake our aircraft for an enemy missile.

I'm not an expert in any of those things, but that's the best I can come up with.

This is it. Look at how often this happens, recently in Iran and before that in Ukraine. Anti-missile and anti-air systems are extremely dangerous and reckless machines. Civilian flights get blown up all the time and being extra cautious makes a lot of sense.

I don't think civilian flights get blown up all the time, but it does happen.

https://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007

https://en.wikipedia.org/wiki/Iran_Air_Flight_655

https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_17

Consistent with "all the time" for me. e.g. much more often than massive Tsunamis or electrical grid-affecting Coronal Mass Ejection events.

That's fair. It should happen 0 times, but has happened infinitely more than that.

Me too. Was thinking same thing. Don't want planes getting caught in the crossfire considering we would probably throw a drag net of intercepting missiles at it.

I'm not an expert or even novice on military weapons or defenses, so this response might just be Hollywood talking, but couldn't taking the planes out of the sky allow for a clearer shot of any deflection missiles/anti-air missiles or something like that?

That sounds pretty plausible. Also, how far does the EMP wave from a nuke travel? Would it minimize the potential damage to flying aircraft if they were on the ground compared to in the air? Or would it be a moot point and if in range of the emp, the blast itself would do more damage?

> In July 1962, the US carried out the Starfish Prime test, exploding a 1.44 Mt (6.0 PJ) bomb 400 kilometres (250 mi; 1,300,000 ft) above the mid-Pacific Ocean. This demonstrated that the effects of a high-altitude nuclear explosion were much larger than had been previously calculated. Starfish Prime made those effects known to the public by causing electrical damage in Hawaii, about 1,445 kilometres (898 mi) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms and damaging a microwave link.

I guess that's the smallest of your worries if you are hit by a nuke.

> I guess that's the smallest of your worries if you are hit by a nuke.

Well.. from what you posted I guess it depends on if you are in the plane or not. It sounds like you could be at a distance where you survive the blast but are impacted by the EMP and it would probably suck to be at 30k feet in a plane that is hit by an EMP.

I don't think an EMP from a ground explosion would be significant. At least for a something 30k feet above it as I believe the pulse to be shaped horizontally and weak. To generate a significant EMP you have to detonate a nuke at high altitude as to cause a secondary EMP due to Earth magnetic field.

Even if a plane is hit by an EMP I believe the engines will keep working and the plane will have backup controls. Unless it's a Boeing of the newer generation where everything is electrical/digital. And even if everything stops working it will keep gliding unless at an odd angle/speed at the moment of the hit. That said loss of instruments and radio would be painful. Components getting damaged depends on the magnitude of the EMP and a weak pulse might cause only transitory malfunctions.

Note: my knowledge on this subject is superficial and I'm probably wrong.

If you are Vesna Vulović you can survive anything.

Maybe they've developed an intercontinental anti-aircraft missile? b^)

It's not about the risk of your aircraft. It's the risk to your aircraft. In an actual emergency involving airspace violation, anything in the sky becomes a potential threat for interception.

Exactly. If you're potentially activating missile defenses, you probably want all civilian air traffic out of the sky. For their own sake.

Give the timing, uncertainty, countermeasures, and consequences of not intercepting... "Your flight leaves 30 minutes later" is a small price to pay vs "Passenger airliner shot down."

Airliners carry less than 1,000 people. Usually a lot less.

Nukemap says 10kt on downtown LA would result in about 71,000 immediate casualties.

Would you want to be in the air when someone at NORAD has to make a call on something that may or may not be a passenger airliner?

EMP, perhaps?

NK does not announce where their missiles are going, and NORAD probably wanted to clear some airspace to better track the missile, especially given that NK has missiles that can reach the west coast. The military also probably wanted to avoid dangerously confusing situations, like a civilian aircraft failing to squawk as expected or even a civilian plane crashing (just imagine what might happen -- NK is launching a missile, and suddenly NORAD is also tracking another object that seems to be an airplane without a transponder heading directly toward the Bay Area or receiving a call that some kind of explosion was just reported in LA following the object rapidly losing altitude...). It is not as if confusion during a tense moment leading to needless death is unprecedented in the history of aviation:

https://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007

> NORAD probably wanted to clear some airspace to better track the missile

I can't see any way planes in Western US airspace could possibly interfere with tracking an NK launched ICBM, even by clutter, except maybe in the last minutes of the terminal phase of warhead descent at which point any defense (active or civil or both) would already have to have been committed to do any good.

Grounding planes is to mitigate risk to the people on the planes, and maybe to clear lines of fire for anti-missile systems (which is mostly about protecting people who aren't on the planes, but incidentally also protects those on the planes, too.)

Like I said, what if one of those planes had a malfunctioning transponder? It is a somewhat stretched scenario, but the NK military might have gotten bold and decided to shoot a missile all the way to the boundary of US territorial waters or airspace. In the middle of nervously tracking a missile that seems to be headed directly toward the west coast, NORAD suddenly sees another object that looks just like an airplane heading toward LA or SF, but it is not identifying itself. Now NORAD personnel have to take time to figure out if this airplane is just a malfunctioning civilian plane or some kind of NK attack.

Sure, NORAD probably tracked the plane from whatever airport it departed from, but during the missile test they probably want to have their personnel focus every second of their attention on the missile and not on checking some flight path.

Maybe it was because we have a secret Anti-Ballistic Missile system that "throws darts" at inbound missiles and we don't want any planes in the cross fire ?

The radar signature, altitude and speed would be completely different than any civilian aircraft. That was a mach 10 missile. For reference SR-71, the fastest plane that entered service (at least of those we know) has a speed of 3.2+ mach.

...because there is no way that a country would try to use a missile launch as a distraction while conducting an actual attack with an airplane...

In war and love everything is possible.

NORAD probably wanted to clear some airspace to better track the missile

But NORAD said they didn't ask for it:

The official says it was not a national ground stop and may have been issued by a regional air traffic control facility.

“No warning was issued by NORAD HQ,” regarding a potential threat to the US, according to Captain Pamela Kunze, the chief NORAD spokesperson.

> I’m not sure what possible risk there was to our aircraft. Specifically from a missile launch in NK.

NK nuclear armed and, has the estimated ability to hit the West Coast of the US with ICBMs, and is believed to be able to make warheads small enough to mount on its ICBMs now. (The first two have been true for quite a few years now, the last is more recent.)

The threat to people in planes is at least twofold:

One: EMP from a nuclear blast is not a good thing for aircraft.

Two: People on the ground can shelter to mitigate some of the risk from a confirmed incoming attack, people in planes cannot.

I can only speculate - but I'm really curious.

Looks like they may have launched a hypersonic missle that reached speeds of ~Mach 10[1], and the US (publicly, at least) seems to be lagging behind China and Russia in Hypersonic R&D - at least as of 2019[2].

How long would it take for a missile traveling at Mach 10 to reach a point where a high-altitude EMP attack[3] would cripple the west coast of the US?

Is that time longer than it would take for aircraft to return to a place where they could land? If NORAD spots a bogey moving that fast, is the rule right now just... everything stops until we understand what's happening?

Would love for someone who knows about hypersonics, NK missle capabilities, EMP attacks, etc. generally to say more.

[1] - https://www.reuters.com/world/asia-pacific/nkorea-launches-p...

[2] - https://www.defensenews.com/naval/the-drift/2019/11/15/dont-...

[3] - https://spectrum.ieee.org/one-atmospheric-nuclear-explosion-...

I'm not an expert, just a rocket enthusiast, but "hypersonic" really just means "near orbital velocities".

There's a lot of noise about admittedly really impressive low-altitude air-breathing scramjets, but - as your articles point out - those are still a long way away. The war hawks like to complain that we're not spending sufficiently many billions on developing futuristic hypersonic scramjet missiles. They point to our lack of a working scramjet as evidence that we're doing poorly. And look! North Korea's launched a hypersonic missile, China's launched hypersonic test missiles, Russia's launching hypersonic missiles; we're behind in the next war and it hasn't even started yet!

But those are just orbital or sub-orbital rockets at 50-100km altitude. Of course they're hypersonic, but that's not really that difficult - just build a big rocket, go up for a while, then turn sideways. We've been doing it since the 50s, tech is good enough now that relatively small companies like Firefly Space are launching small satellites to LEO with Series A fundraising of just $75 million. Tada! Hypersonic! The main point is that everyone has the capability to launch lots of these simple rockets, which can be devastatingly effective. Not as effective as highly steerable reentry vehicles or hypersonic scramjets, but enough that no one wants to be a target.

I’m not sure what possible risk there was to our aircraft. Specifically from a missile launch in NK.

It's not exclusively about the risk of a jet being hit in the air. But you don't want to route a bunch of jets to land in a city that no longer exists.

Realistically, what are the odds that a NK launch could hit US aircraft traffic?

In fact what are the odds that any nation except perhaps Russia could? Could the UK? France? China? I guess they have the technology, but I bet they couldn't deploy it from thousands of miles away. For example, the somewhat heroic story of the UK bombing Port Stanley from from the Ascension Islands on the equator during the onset of the Falklands War ... (yeah, ok that was 1982, but still).

https://en.wikipedia.org/wiki/Operation_Black_Buck

If NK had a sub off the coast of CA, then maybe, just maybe they could shoot down an airliner, although I'm still skeptical they could hit it with something that wasn't a sea launched Buk (i.e. built by Russia).

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