[jjcm]

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

[skrtskrt]

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.

[RC_ITR]

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.

[reaperducer]

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.

[SEJeff]

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.

[reaperducer]

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.

[SEJeff]

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.

[fomine3]

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.

[SEJeff]

Precisely!

[rdiddly]

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.

[landemva]

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 ...'.

[rdiddly]

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.

[Retric]

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.

[tyingq]

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.

[AceyMan]

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).

[beerandt]

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

[Retric]

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

[tyingq]

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

[Retric]

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...

[1024core]

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

Anything "can" happen; but did it?