Moderator Note
jimbuff314, let’s not take personal jabs at other posters in this forum. No warning issued, but don’t do this again.
Colibri
General Questions Moderator
With only two runways, Heathrow handles nearly 1300 traffic movements, and nearly 200,000 passengers a day averaged over the year. (No small planes here).
On a clear day, you can stand on the road outside and see a plane landing, with three more in sight, following it down.
Had that happen to me 3 times in my career at a big fields while following instructions. It is not as fun as you might expect. It is quite exciting in retrospect & with clean pants on.
Small uncontrolled fields, you really need to pay attention, can get plumb exciting way too often if your head is up & locked.
And that means only two runways in you at a time.
Nope - it is an on-going cost. Runway 16L at Reno has ben closed for about 6 weeks while they do concrete work. I’m looking forward to them reopening it because GA and Commercial jets sharing 16R is a bit of a pain at busy times of the day.
And there’s the answer. Who needs new runways? Just get more planes on the ones we’ve got.
Nitpick: you mean “into the wind”, right?
OOPS !!! 
:smack:
Hundreds of thousands? Maybe millions? Great Og! Tell me it ain’t so!
But seriously, I’m guessing you don’t have much to do with big business. If any major airport could get any it’s runway maintenance bill down to hundreds of thousands maybe millions of dollars a year it would be ecstatic.
I did almost exactly that late one evening coming into Baltimore in a 727. There was another airline’s 737 coming from the opposite direction, the skies were clear, and the surface winds were calm. We were the only two jets in the sky and as luck would have it would arrive just a couple minutes apart.
Looking at it from the tower & radar controllers’ points of view the spacing would work out fine for us to land opposite direction on the main runway preferred for late night noise abatement. We’d both be able to fly & land straight in, saving time & money & noise vs. one of us making a traffic pattern to follow the other. He’d land first and pull off the runway at mid-field while we would still be about a mile from landing the opposite way on the same runway.
Looks good right? We could all see each other visually & on our traffic scopes from 10+ miles out and we all agreed it’d be fine. What could go wrong??
Then we both descended into a low-level jet where the wind was blowing 35-ish knots; headwind for him, tailwind for us. As we both drove closer & closer to the runway he was getting behinder & behinder while we were getting aheader and aheader. Things got increasingly nervous and we all discussed who’d go around how if the spacing didn’t work out.
In the end he landed, jumped on the brakes and made an early turn-off very shortly before we got to the opposite runway threshold a mile-and-a-half away. Had the spacing worked out 5 seconds closer we’d have gone around, wasting $1000 and 10 minutes.
Bottom line:
I’ve spent a lot of years shoe-horning slightly too many jets into slightly too few landing slots at overcrowded airports. That was not a maneuver I’d like to repeat more than once or twice a career. And it was in the most benign conditions imaginable. It’s certainly not a procedure one could plan on using routinely to increase capacity.
Snark aside, the marginal cost for maintenance of an additional runway wouldn’t be as much as the maintenance budget for the existing facilities. Economies of scale or something like that.
But that’s missing the point, anyway. The point is that an additional runway doesn’t imply only a sunk cost but ongoing expenses.
So, is it no longer preferred for aircraft to take off and land into the wind?
It’s not at all uncommon to be driving near the airport and see at least 3, sometimes 4 planes coming in on final approach in parallel on the N-S runways. Kind of an impressive sight.
My guess is that modern planes can land in pretty heavy crosswinds, and there’s usually not enough traffic at most airports to really warrant extra runways.
Heathrow actually had three pairs of (criscrossing) runways until the 1960s. I can’t believe there are only two now; I’ve flown all over the world from that airport and it seems to take up nearly all of west London. I was sure there would be a dozen or so runways squeezed in there.
You bet your ass they can.
As aircraft get bigger and bigger, the limiting factor at a lot of airports is their ability to handle the passengers.
At some, the limiting factor is the ability of passengers to get *to *the airport, not anything within its property limits.
The proposals to add a third runway at Heathrow (on the north side, taking out some houses already there) come and go. The crossing runway was eliminated to make room on the ground.
I guess you missed the part where I said “… the surface winds were calm”.
Winds can vary significantly in direction and speed with altitude. The only wind info the tower folks have is what their ground-level instruments tell them. The only wind info we have nowadays is that same ground info relayed to us via voice, plus an instantaneous readout of the wind where we are right now. Which tells us nothing about how it may vary as we climb or descend.
In fact back in the Olden Dayes on the 727 we didn’t have any instantaneous wind info at all. I suspect the same was true of the other 737 that evening as well. So “winds calm on the ground” was all anyone involved knew.
Let’s consider it this way. Atlanta’s airport (the world’s busiest) has five runways, and a maximum capacity of 134 arrivals and 120 departures per hour.
Now, once a plane arrives, it must go to an open gate, unload passengers, have the flight crew go through quickly to clean up a little, restock the bags of peanuts, unload the baggage and load up the passengers and their baggage for the next leg of the flight. That’s assuming the plane doesn’t need refueling, has mechanical issues or is going through a crew change.
Southwest Airlines is about as good as the industry gets when it comes to moving passengers and their luggage. They only fly one type of plane (the 737), which carries about 110 passengers, and everything is as regular as possible.
Southwest tries to schedule its stops at destinations to about 20 minutes. Assuming the very best conditions possible, that means one gate can handle three flights per hour.
That means Atlanta needs a minimum of 45 gates just to keep up with its runway capacity. And given that many planes are bigger than the 737 and that most airlines prefer to lease gates they need on a 24/7 basis rather than hoping their pilots can find a parking place when they land, the airport needs many, many more gates than that. If I count correctly, Atlanta has 199 gates.
The problem isn’t the capacity of the runways, it’s how big the airport can get before it collapses in on itself.
Heathrow 1966. Already the crosswind runways are being turned into taxiways as the apron expands to accommodate large jets.
Heathrow 2009 Only one of the old crosswind runways survives substantially as a taxiway.
Heathrow today(South to the top) … and THAT’s gone
Overlayof where the Old was relative to New. (Conspiracy Theorists must have loved the old one…)
