Why is your airplane late?

January 30, 2008 7:18 AM

Why is your plane late?Airlines can make more money selling 70 airplanes worth of tickets per hour than they could if they limited themselves to the 60 airplanes per hour that the runway can handle. A long but excellent post on what is causing the delays at the airport.
posted by Coop (34 comments total)

Wow.

I wonder if anyone here can elaborate on whether, when one plans a trip from point A to B, there is some logic to trying to pass through less heavily trafficked airport en route?
posted by docpops at 7:26 AM on January 30, 2008

Gah, paging eriko to this thread. I'm trying like hell to find his comments about it, but all I can say is I learned about the stuffed to the gills departures/arrivals from eriko here on the blue.
posted by cavalier at 7:26 AM on January 30, 2008

Along with several other pieces of information about airline travel in general that make me worship eriko as a god in general, ahem.
posted by cavalier at 7:27 AM on January 30, 2008

This is another (pilot-based) viewpoint on what causes the delays.

It takes a different angle, but 'too many planes' plays an interesting part in it as well.
posted by Tacos Are Pretty Great at 7:29 AM on January 30, 2008

and this is another relevant column.
posted by Tacos Are Pretty Great at 7:31 AM on January 30, 2008

Excellent post.
posted by Prospero at 7:40 AM on January 30, 2008

Wow, I'm getting summoned now? (blush.) There better be some good rye in that pentagram, or somebody's soul is getting routed MIA-ATL-JFK-ORD-SFO.

This article is *so close.* Everything written is exactly true. What he missed was " Airlines can make more money selling 70 airplanes worth of tickets per hour than they could if they limited themselves to the 60 airplanes per hour that the runway can handle." They're so close they can taste it.

The factor they missed -- how many passengers are on those seventy planes? Answer: Not as many as you think, because a large fraction are ~40 seat regional jets, not 130+ seat airliners. At ORD, over *half* the traffic is in regional jets.

RJs take the same slots as narrow-body airliners. (Wide-body airliners need more separation, etc.) but carry half to less than half the pax.

Fly one MD-80 or 737 instead of 3 RJs, and ORD is fixed.

But, the conclusion is correct. Right now, if you mandate that JFK only handle 50 arrivals an hour, and that ORD has only 75, then they'll be able to catch up after arrival rates drop. ORD is a real problem -- there are days where ORD can't handle more than 68 an hour all day. You'll get 7 cancels an hour if you're slot limited to 75. You get 32 now -- with airlines trying to land 100 an hour.

ORD, in fact, is one of the very few airports where the right answer is "new runways." ORD doesn't need more of them, it needs them rearranged, and that's exactly what the plan is -- to go from three pairs of runways, 60 degrees apart to six parallel. This will dramatically increase ORD's capacity, to over 150/hr, even in low visibility- but if we try to fly 180 jets an hour there, it won't help.
posted by eriko at 7:43 AM on January 30, 2008 [12 favorites has favorites]

I wonder if anyone here can elaborate on whether, when one plans a trip from point A to B, there is some logic to trying to pass through less heavily trafficked airport en route?

The short answer is maybe, and it really depends on the airline and its procedures. While a less-congested airport means that you won't endure (as many) delays on arrivals, you could still end up delayed because the plane for your flight is arriving late (as a result of delays at another, larger airport that the plane flies into). This principle is why there are still delays throughout the system sometimes days after a snowstorm or other major disruption; planes aren't where they need to be when they need to be there to handle the flights.

The reason I say it depends on the airline and their procedures is that some of the LCCs save on their costs by flying to ONLY the smaller airports. In the New York City area, for example, while JetBlue has flights to JFK and LaGuardia and Virgin America flies to JFK, Southwest operates to Islip (about an hour's drive east of JFK) while Skybus operates to Stewart/Newburgh (an hour and a half north of Newark) and they both claim to serve New York City. Skybus, for example, operates into all sorts of smaller, distant airports while claiming to serve the metropolitan area.

The advantage of that is that they're more able to operate on-time because the airports they use aren't the ones packed to the gills with 70 scheduled flights on a 60-flights-per-hour runway. Islip, for example, doesn't have any other scheduled airline service (only business jets and general aviation traffic) and while Stewart has some other airlines it's not nearly as busy as JFK or Newark.

The obvious disadvantage is that while you're on-time at the airport, you're not usually where you need to be, and you have to find some other way of getting to your final destination (cab, train where available, etc.).
posted by Godbert at 7:45 AM on January 30, 2008

After this weekend, where I was stuck in Chicago after my EWR-ORD flight was delayed two hours (and I had an hour and a half layover, which I thought was fine), reading this merely filled me with a mild irritation than the burning rage I was having earlier.

(At least, after some, er, explication, I was able to get the distressed traveller rate at a hotel from the airline due to the fact that there were two flights a day from ORD to my destination, and they landed us half an hour after the second flight left. (And then we had to sit on the ground because the GATE was still in use.)
posted by mephron at 7:54 AM on January 30, 2008

Wow, eye opener..
posted by salvomix at 8:04 AM on January 30, 2008

Fantastic Post, thanks..

It should allow me to be a little calmer, next time my flights delayed.
posted by the_epicurean at 8:06 AM on January 30, 2008

Oops flight's
posted by the_epicurean at 8:09 AM on January 30, 2008

Airlines should really have to pay more to the government per plane. This will encourage them to use smaller number of flights carrying more passengers, reducing the strain on the air traffic control system. I'd imagine this would produce less pollution too.
posted by grouse at 8:24 AM on January 30, 2008

This is a very naive question, but can someone explain to me the economics of building more runways? How much does a standard-length runway cost, if one already had rights to the land? More runways would solve the problem, right?
posted by NucleophilicAttack at 9:05 AM on January 30, 2008

This thread is already sidebar material.

I really hope a journalist picks this up.
posted by mecran01 at 9:11 AM on January 30, 2008

More runways would solve the problem, right?

Mostly. With more runways, though, you need additional taxiways to avoid turning the existing ones into parking lots (the second column that Tacos linked to talks about that) and to have the airlines make sure there are enough gates available for their planes.

As for the cost, that depends a lot on the airport. The "Ask the Pilot" column put the figure for a new runway at Denver at $165 million, though that might also include land acquisition costs.

The problem with the idea of building new runways, though, is that sometimes it just isn't possible. LaGuardia, JFK, and Newark are not the remote locations like Denver is, and stuff is built up right up to the existing airport boundaries. There just isn't room to build another runway, at least not without a massive expense for land acquisition and a massive headache for everyone as roads are eliminated/rerouted, not to mention the environmental and societal hurdles you'd have to overcome.
posted by Godbert at 9:22 AM on January 30, 2008

So, eriko, does that mean that the prevailing winds at ORD are that consistent? I can just imagine the level of amusement that would ensue if all six runways ended up perpendicular to the wind for any meaningful period of time.

And, before we go alerting the media, could we ask this dude to tone down the "won't somebody please think of the children" vibe and replace "safety" with "capacity"? I mean, honestly, with the exception of two crashes in the past 18 years (at least one of which was ruled pilot error), he really didn't cite any safety impact, since the flights get delayed and/or canceled. I'm not saying I enjoy sleeping on a bench at some big midwestern hub airport, but it hasn't killed me yet, and, IMO, what we don't need is more artificial "safety" noise surrounding air travel these days.
posted by MadDog Bob at 9:31 AM on January 30, 2008

The blog post doesn't quite make the connection between overallocation of slots and safety. The Avianca crash appears to be a failure of communication (see the Wikipedia article) rather than directly caused by lack of slots, though you wouldn't know from the emotive way it's framed here.

I think it's up to the airports how much they wish to piss off airlines, and how much airlines wish to piss off customers. The safety effects of the practice appear to be accounted for by carrying extra fuel, and allowing planes low on fuel to land immediately.

I mean, it's an informative article, but I wish the author hadn't been quite so tempted to put a "profits over safety" spin on it, or at east done a better job.
posted by cillit bang at 9:41 AM on January 30, 2008

MadDog, there are a couple of other airports that also have all their runways parallel (or nearly parallel). Atlanta is the biggest example I know of, with five east-west runways. I have no idea what happens there if there's a strong north or south wind, but I can't imagine it's good for anyone.

Chicago, though, strikes me as an odd case. If the winds are consistently from one direction (or it's opposite), why built runways at other angles in the first place?
posted by Godbert at 9:43 AM on January 30, 2008

Yeah... deregulation + corporate greed is causing my plane to be late. What a news flash.
posted by Jay Reimenschneider at 9:55 AM on January 30, 2008

There are some things that government needs to watch over, folks. This is one of them.

Fucking Reaganites.
posted by Jay Reimenschneider at 9:56 AM on January 30, 2008

Greed replaces money as root of all evil.
posted by tommasz at 10:00 AM on January 30, 2008

If you're interested in this I recommend downloading the Xavius ATC Simulator. I can't vouch for its absolute accuracy, but it's definitely worth reading through the documentation and maps and having a play - it seems to be pretty faithful to reality. You are given a sector to control and have to handle the planes within it, either those flying over without (necessarily) needing an altitude change or those arriving (and need to be descended to a certain level before passing off to another sector) and departing (need to get to a certain altitude).

Each plane follows a path (some of which cross of course) which you can change, either cutting out a dogleg so they're out of your area (and at their destination - this is appreciated in real life) quicker or in the case of flying too close to another plane (5 miles of horizontal and 2000ft of vertical separation). If you fail to keep these separation levels, you have a "deal" and have to retrain on that sector. You may also need to hand each approaching plane with 5 or 6 miles of separation.

It does take up quite a lot of time to get into it properly but it's a fascinating insight into how ATC works, and bloody hard to get right - the stress levels can really rise and it's very easy to "lose the picture".
posted by jontyjago at 10:28 AM on January 30, 2008 [2 favorites has favorites]

More runways would solve the problem, right?

I think it would help initially, but I suspect that in the long run, it would just lead to even more overbooking; to steal an expression: The demand upon a resource always expands to match the supply of the resource.

Airlines have demonstrated that they are completely profit driven (in many cases, to the exclusion of customer satisfaction, and occasionally people's safety), and I think that, given the opportunity to bring in even more money, they would gladly fill up any additional runways that are built, in the same way they are overbooking the ones that already exist.

Disclosure: I think the airline industry needs to be completely overhauled, from the very foundations. It has systemic failures at nearly every level and any efforts to patch it up only seem to make things worse. In other words, I may be a bit biased here.
posted by quin at 10:53 AM on January 30, 2008 [1 favorite has favorites]

tommasz: Greed replaces money as root of all evil.

um, no. The actual text in most translations is "the love of money is the root of all evil" (or equivalent). It's not the money itself, it's the love of money, which is (all together now) greed.
posted by jlkr at 11:17 AM on January 30, 2008 [2 favorites has favorites]

You know how when you fly enough you get used to the routine of turn onto the runway, wait a few seconds, then the engines fire up and off you go? A few years back I was on a flight where the pilot was hitting the gas right as we started the turn onto the runway. He just whipped us around the corner and off we went. I've flown more than most people in my life and that was the first time that ever happened to me. This article makes me wonder if we were trying to get out of something's way.

(Oddly enough, the same pilot pulled off the smoothest landing I've ever had on the other end. Probably didn't even lose any rubber off the tires.)
posted by Cyrano at 11:29 AM on January 30, 2008

This is wonderfully explained. Thank you.
posted by LobsterMitten at 11:53 AM on January 30, 2008

More runways would solve the problem, right?

When people choose safety over fighting eminent domain, people will choose fighting eminent domain.

Also, runway expansion is intended to increase capacity, not handle existing capacity more safely.
posted by Blazecock Pileon at 11:57 AM on January 30, 2008

Great, another blog to add to my RSS aggregator.

that's snark-ish for excellent post
posted by deadmessenger at 12:03 PM on January 30, 2008

Great post.
posted by klangklangston at 12:45 PM on January 30, 2008

So, eriko, does that mean that the prevailing winds at ORD are that consistent?

No -- though the vast majority of the time, ORD lands to the west or east. ORD was built in the prop era. The propeller driven airlines were much more sensitive to crosswinds, and didn't have nearly as much reserve power. So, it was important to land as close to the winds as possible.

Nowadays, airliners only really care about extremely high crosswinds. Indeed, ORD often will adopt a landing configuration that will have one of the runways running a slight tailwind -- if that allows them to use a more efficient configuration.

ORD will keep a crosswind pair (the current 4-22 runway pair) in cases of very strong southerly or northerly winds. Days like these will still mean delays, but days where ORD is dealing with 40kt winds to the S or N are very rare indeed.

No airport is weatherproof. The problem with ORD, as currently built, is that it's not even weather resistant. Anything that gets the runways wet, that drops visibility below 3 miles, or drops the ceiling below 1000' AGL means that ORD will quickly drop to an arrival rate of 80 or 68.

When they open the north runway this year, ORD should be able to maintain an arrival rate over 90 almost every day, and on many days will easily handle 110. Once the south runway is built, 150 becomes easy to handle, but at that point, terminal space will become the choke point. The important thing is that ORD will be able to run that rate 90% of the time -- as opposed to the 50% of the time when it can't run the 100 arrivals an hour that are currently scheduled.

LAX and ATL are two other airports with unidirectional runways. DFW has 5 parallel, but also has two crosswinds, just in case. ORD, as finally reconfigured, will have 6 parallel and 2 crosswind. It'll work like DTW (4 and 2) except the middle two will be double runways, one longer for departures, one shorter for landings. So, ORD will land 60/hr on the N and S runways, and a variable number on the center runways, depending on departure load.
posted by eriko at 12:50 PM on January 30, 2008 [1 favorite has favorites]

I'd love to see the FAA limit the number of landing slots, and then auction them off. It'd make flying at peak hours a little more expensive, and thus likely a little less popular.

Of course that's assuming that the airlines would pass the costs on in a sane manner, which given the nature of modern ticket pricing is probably a terrible assumption.
posted by Tacos Are Pretty Great at 1:44 PM on January 30, 2008

I'd love to see the FAA limit the number of landing slots, and then auction them off.

The fun part will be the in-flight bidding.
posted by Blazecock Pileon at 2:30 PM on January 30, 2008 [1 favorite has favorites]

Hmm... It would be interesting if all the airlines flew half as many flights and charged three times as much for a flight. They might be able to afford to give out those decks of cards and peanuts again.
posted by bugmuncher at 9:14 PM on January 30, 2008