JFK’s Virtual Slots Help Reduce Lengthy Ground Delays

One of the biggest complaints that I see when we start talking about long ground delays here on the blog is that nobody seems to have a good solution. We can all jump on bad solutions like the DOT rule we have now, but there are rarely better suggestions that are workable. I’ve found one, and it’s actually temporarily in place at JFK right now.

Plane Meter

Some of you may know that I write the monthly newsletters for PASSUR Aerospace. PASSUR is a very cool little company that actually has its own private radar network at over 100 airports, primarily in the US and Canada. There are a million things that they do with this data, but as I was putting together the current newsletter, I found out about a temporary but truly awesome project going on at JFK during the runway construction that’s happening today. They’ve effectively created virtual queues so that airplanes don’t have to push off the gate until it’s closer to actual departure time.

Here’s how it works. During peak periods (operational for ten hours a day), a central command coordinates all departures and arrivals at the airport. A couple hours before scheduled departure time, each flight is assigned an actual departure time by the system. So maybe your flight was supposed to leave at 1p, but at 11a, the airline will be advised that the departure time will now be 2p. That means they can keep you at the gate and let you roam free. If they need that gate for an arriving flight, they can still board you and then push you out of the gate, but you’ll have a very clear picture of when you will actually take off. Expectations can be set appropriately, and they shouldn’t push you off the gate if a 3 hour delay is anticipated.

The result of this is that at any one time you end up with no more than eight airplanes waiting to take off (you need some kind of buffer in there) instead of 30 or more. This is good for passengers, but it’s also good for airlines. When they’re in that long line waiting for takeoff, they have to keep an engine running, sucking up gas as they wait. Now that won’t be an issue. In addition, if the winds shift and the airport needs to turn around and use different runways, there are fewer planes that need to be turned around so it can be done more quickly.

Awesome, right? Now this isn’t a fail-proof solution. When bad weather rolls in, that messes a lot of things up. A version of this system is actually used during severe weather events now at JFK for metering departures, but it doesn’t solve everything. If you have a ton of planes coming in on diversions or several planes landing while others can’t take off, you may need to free up gate space due to storms. Things can and will still go wrong, but this process is a big improvement.

So how has this been working? Well, during March 2010, they were able to handle just about the same amount of traffic as they handled in March 2009 but with one runway down for construction. Taxi-out times are virtually the same. And the average delay has actually gone down by about 5 minutes. Great stuff.

Unfortunately, this program is currently scheduled to end on June 30, when the big construction work on the runway is done. With any luck, the airport will see the benefit and decide to keep it around . . . and then hopefully other delay-prone airports will consider it as well.

[Original Photos via AZ DOT and abdallahh]

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Chris JGrant McHerron (aka Falcon124)CFThe DispatcherKevin Recent comment authors
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I always find it interesting that a lot of US industry observed find runway slot management such an innovative solution – this is exactly what happens at most airports around the world. Planes don’t push back until their allotted time on the runway is due. This creates no (or very little) queues. In Europe, the joined-up thinking extends even further, with aircraft not pushing back from the gate until their runway slot, route slot and landing slot have all been confirmed. Of course, this doesn’t always work as it is perfectly meant to, but most of the time it works… Read more »


If they need that gate for an arriving flight, they can still board you and then push you out of the gate, but you’ll have a very clear picture of when you will actually take off. Expectations can be set appropriately, and they shouldn’t push you off the gate if a 3 hour delay is anticipated. ====================================================== On the several 4 hour Plus Tarmac Delays I’ve encountered, that’s just it. There is NO gates available to return to the terminal………all the gates are occupied. Furthermore, care to predict when fog will lift? Snow will stop? Thunderstorms will end? And, many… Read more »


This is exactly the point – in most countries (or should I say at most airports), the capacity of the airport is set by the capacity of the runway. Airlines are forced to work together to ensure that when a runway hits capacity of movements, they increase the size of the aircraft to get more passengers per movement. The other issue in a lot of these congested US airports is the prevalence of regional jets which just EAT runway capacity.

Brian Lusk

Can you clarify. Years (and years ago) when I worked for operations, departure would give our airplanes a “wheels up” time, and we would push about 8 minutes before that time. Granted this wasn’t on every flight and usually had to do with ground stop/ground delays at the destination airport. Am I guess the JFK situation is different because it involves every flight?

Brian Lusk

I meant to add for Delta operations

David SF eastbay

Once we get pass the metering lights is there a ‘plane’-pool lane?
200-passengers or more please….lol

Good photo you added to the blog.

Maybe it’s time for busy airports to be thinned out for the good of the whole industry. It won’t be popular with some, but forget trying to have service on small planes to small cities just to have service. Those little planes take up space for a small amount of people. Maybe large/busy airports should only be to/from large cities with larger planes to ease congestion on the ground and in the surrounding air.

Airline Complaints

i second the initial comment, as a frequent traveler to amsterdam i have noticed 2 main differences to the usa that have made my experience so good.

1) they do not pull back until a full comfirm of clearance is received

2) the runways are very close to the gate. taxing time is almost non existent. you pull back and the next thing you know you are in the air

Hill Rider

Oh, look: once the DOT (finally) puts in place a sensible pro-consumer rule that costs airline money to break, magically solutions like this one that were “impossible” for years on end start appearing.

Disgusting. Simply disgusting. Airlines simply found cheaper and more convenient to imprison people on planes. Three cheers for the DOT!

The Dispatcher

DOT’s “solution” is anything but sensible, as it doesn’t do anything to discern the various reasons and contexts for delays, and instead Ms. Hanni, DOT Secretary LaHood, and all the “airline experts” without frontline airline operational experience have all taken the overly simplistic tact that “ALL” airline delays are equally bad, irrespective of the reason. The delays that Ms. Hanni et. al. experienced at Austin, TX, and that the CoEx passengers experienced at Rochester, MN, were all related to diversions, i.e. on the back end of their flights. The NWA and JBU blizzards at DTW and JFK, respectively, involved the… Read more »


I knew that picture looked familiar, looks like the 202 onramp at 44th street in PHX.

I can only imagine the torture that is JFK at 5 pm these days.


I have been saying that this type of solution can and should be a solution that is implemented. I mean having 20-30 planes waiting to departure is just bad (for many reasons). I routinely face this situation at Newark at peak departure times. Many people like to say that airline scheduling is the problem and you know what it may be, but then again a system like this would ‘force’ the airline to reschedule those that are constantly delayed. Brett, do you know if they utilize the same prioritization scheme that they use for overall metering (for weather). Like size… Read more »


Delta doesn’t seem to have a problem or mind getting on that list!

Grant McHerron (aka Falcon124)

You know, it’s about time an airport the USA got a system like this. Still, given how far behind the USA is on satellite based systems, maybe it’s not a surprise. I am continuously amazed beyond belief that airports in the USA can have scheduled movements that run at (or even exceed) capacity for so many hours in the day. It’s insanity. Wake up & smell the roses guys – schedule only as many movements as the airport tarmac & ATC can handle, then have a few “slack” periods where delays due to weather & such can be picked up… Read more »

Chris J

This system may sound good, but its NOT! Do you know how many times there are ZERO planes at the runway during JFK dept push? During periods of SWAP where lets say only the SHIPP and WAVEY routes are open, PASSUR only releases RBV or COATE depts, and keep the SHIPP and WAVEYs which CAN go, sitting down around hanger 19 shut down. I can go on forever. Taxi time may be 5 min, but you are sitting at the gate, or on the plane parked somewhere for 2 hours waiting for your “metering time” to come up, 5 min… Read more »