ibrandsguest

Out of curiosity:

Do airports and airlines manage the direction in which planes take off and land, and where their gates are, to minimize the time needed for the planes to circle around the airport before landing and taxi around the airport?

I frequently fly through a large American Airlines hub. The "commuter" gates are at one end of the airport, and taxiing when flying to and from those gates always takes at least about 20 minutes of driving around the airport, even though there are multiple runways and terminals.

In addition, when I fly to that hub, even though it would be quick for the plane to just keep flying and land on one of its runways, sometimes the plane has to circle around the airport and then approach the airport for landing, traveling in the opposite direction from its original trip, which adds time.

Is there some software that programs which gates planes should have, and the runways that they should use, to minimize taxiing (and time circling around the airport before landing)? Or how is that otherwise determined?

Thanks.

Cloudship

The direction planes land is dictated by the direction of the wind. They try to land as straight into thew wind as possible. Ever see those videos of planes landing sideways, or feel one of those landings where there is a big jerk when you touch down and the plane is swaying back and forth? That is because there is no runway perfectly pointed into the wind and the wind is strong.

As for going straight in, airports have traffic patterns to handle all that traffic. The major parts are downwind (which is along the runway to the side opposite the direction you will eventually be landing, base, parallel to the runway (but long after you have passed it) and then final, which is the actual approach to the runway.

Look at one of the airport radar sites for a busy airport, and watch the pattern of planes landing.

Efrem

Gates are definitely assigned to minimize taxiing. The aircraft with the most passengers (which tend to be the largest aircraft) are assigned to the gates closest to the runway, logistics of when they arrive and what gates are open then permitting. Naturally, those are also usually the furthest gates from the terminal. So, if you think the airline gods always frown on you and make you walk to the end of the pier - statistically, you're right.

saxman66

Airports "flow" depending on the wind direction. If you're talking about DFW, the aircraft generally land on the outer runways and takeoff on the inner runways. If the wind is from the south, they'll operate on a "south flow." Wind from the north, "north flow." This is in fact true for most airports with multiple parallel runways (ATL, ORD, LAX). Arrivals and departures are usually sequenced depending on the general direction they are coming from or to. So coming from the west at DFW, you'll usually land on the west complex, regardless if your gate or terminal is on the east side. Same goes for departures as well. ATC likes to minimize criss-crossing traffic for obvious reasons. There's always caveats though. AA pilot's going into DFW usually tell the approach controller which side of the airport they are parking on and more often than not, the controller will accommodate a same side runway. If it's a heavy arrival time though, you get what you are assigned to keep the optimum flow going. Exceptions are always made for emergency or medical flights though.

LarryJ

Landing direction is based on wind. Landing runway, when more than one are in use, is based on direction of arrival (unless traffic flow is light).

I've never heard of coordinating gate assignments with runways.

satman40

The active runway is determined by the wind direction,

I would like to see the gates further from the terminal, much safer, and less taxi time..

lhrsfo

The point about wind direction is that airlines fly at airspeed, ie the speed of the plane through the air. That's quite different from groundspeed, unless there's no wind.

The airspeed at which a plane lands or takes off is set. What they want to do is to minimise the groundspeed otherwise, in extreme circumstances, the plane would run out of runway. Hence the need always to take off or land into the wind, maximising airspeed and minimising groundspeed.

Proudelitist

Gate assignment is mostly about carrier and capacity. Airlines "rent" gates at airports. More volume means bigger gates. Domestic is usually pretty uniform across airlines and terminals, but for heavy metal intl' bigger resources are required.

Landing/take off directions are determined by the wind most of the time, except at PHX where a civil ordinance has them change in the afternoon if the wind doesn't force a change, and winds are usually calm at PHX.

Some airports, where the wind direction is generally always the same, MAY place long haul heavies and heavy cargo ramps nearest the most active runway to reduce taxi time and therefore fuel consumption. Some have non-gate tarmac boarding where you have to bus out to the plane to a mobile gate. But take an airport like LAX, where the wind is usually out of the west..Tom Bradley Terminal is at the west end of the airport, meaning taxi's are longer to the thresholds for the heavies, and shorter for the commuter planes on the east side of the airport.

Other airports like DEN and FRA are going to have long taxi times no matter where the gate is.

fassy

Absolutely not. (at least in most parts of the world)

At many airports around the world you will see the same plane always docked at the same few gates, e.g. in CPH the OS flights to Vienna are always at A15-A17, the SK flights needing air-bridges at the B-gates and naturally the non-Schengen flights in the C/D gate-wing. No matter which runway and direction they landed or need to take-off.

Most airports gate-assignments are grouped based on blocks for specific carriers/alliances and what is needed (e.g. a jet-bridge, two jet-bridges, busses, immigration and customs, extra security, etc.)

Efrem

We're both right. Obviously, parameters such as fixed gate assignments to a particular airline, space needs of specific aircraft types, and (where applicable) need for customs and immigration services trump everything else.

Once these are satisfied, as they automatically are at many large US airports which handle only domestic traffic at some terminals and which are dominated by one or two airlines, the factor I mentioned comes into play.

I should have been clearer about that. Sorry.

jrl767

here's a case study of "sometimes" -- Alaska Airlines uses Terminal 6 on the south side of LAX ... most of their flights from SEA/PDX and other cities to the north land on the northernmost runway (24R); most of their arrivals from Mexico use the southernmost runway (25L) ... I've taken their DCA-LAX flight about half a dozen times in the past year, and have been on each runway about half the time

ATC only cares about how they are able to most safely fit any particular flight into the arrival flow, not about the impact of the much longer taxi from 24R to T6 on Alaska's operations

sbm12

I've seen what appears to be such many times. At LAX, for example, UA is more frequently on the south runways while WN is on the north runways. Not 100% of the time, but well above average.

jrl767

as with arrivals, a lot also depends on which departure flow ATC is fitting them into, which is based on the first part of the flight plan

LarryJ

Maybe I misunderstood. I thought the claim was that the gates were assigned based on which runway would be used not the other way around?

If so, I'll go back to what I wrote in post #5: "Landing direction is based on wind. Landing runway, when more than one are in use, is based on direction of arrival (unless traffic flow is light)." With light traffic you can request, and receive, runways other than what would normally be assigned for your arrival.