On average there are approximately 9,700 aircraft in the sky. A question for ATC, and pilots, especially veteran pilots who have been around long enough to have witnessed and operated when that number was significantly less.

How much more can this number grow before it becomes a real problem? Or, is it becoming one already?

Obviously, technology both with ATC and with the modern aircraft helps to accommodate the ever increasing traffic in the skies. I would imagine that say the technology of the 1960's if there were nearly 10,000 aircraft in the sky that would have been quite problematic.

So, how much more can this number grow while maintaining our current level of safety, that being flying being by far the safest way to travel.

It can grow a lot, but not everywhere. Some areas, e.g. London and New York, are very congested and have been so for decades. ATC improvements help but there is no silver bullet.

Antiquated airport layouts with deep alleys don't help. JFK, for example, would benefit from a more modern taxiway and apron layout.

As starlionblue stated, the congestion that gets the headlines is heavily concentrated around major cities (only a few of them, too) and on the ground with terminals built for traffic levels of the ‘70s or 80s. Not just the New York and London where it’s expected, Mumbai, Delhi, and Hong Kong can be very busy. The Atlantic crossings are busy during the track system hours and empty at the in-between hours. Fly São Paulo to Tahiti at anytime and very unlikely to see or hear another plane. Altitudes also separate planes. High level operations are popular with bizjets as you are above the airliners until landing anyway. There are vast areas of the globe one can fly for hours and not see another plane.

Kinda like we could physically fit the entire worlds population in the state of Texas....

It's really the angle I was thinking of anyway, the major hub airports. Unless they build more runways, how much more traffic can they handle? And many airports are not able to build more runways.

Something you guys mentioned as well is the amount of people in the terminals. I've had the most unpleasant experience of FLL during spring break. I'm no fan of JFK either. Without getting into politics Trump was right in stating U.S. airports are generally out of date compared to many international airports although I'm sure there's some duds outside of the U.S. as well. Having been stationed in Germany I've had the luxury of being on both sides. Back in the mid 80's when I would fly back to the states on leave, I thought Frankfurt to be a very nice airport at the time. And back then they would have heavily armed guards walking the catwalk. I don't know if they still do that now. It was a bit of eye opener having never flown outside of the U.S. before.

I'm not nervous about the amount of air traffic at major airports, but I do wonder how much more they can handle without major restructuring and more runways if they are able to build them.

Excellent replies by Starlionblue and GalaxyFlyer:

Starlionblue wrote:

It can grow a lot, but not everywhere. Some areas, e.g. London and New York, are very congested and have been so for decades. ATC improvements help but there is no silver bullet.

Antiquated airport layouts with deep alleys don't help. JFK, for example, would benefit from a more modern taxiway and apron layout.

GalaxyFlyer wrote:

As starlionblue stated, the congestion that gets the headlines is heavily concentrated around major cities (only a few of them, too) and on the ground with terminals built for traffic levels of the ‘70s or 80s. Not just the New York and London where it’s expected, Mumbai, Delhi, and Hong Kong can be very busy. The Atlantic crossings are busy during the track system hours and empty at the in-between hours. Fly São Paulo to Tahiti at anytime and very unlikely to see or hear another plane. Altitudes also separate planes. High level operations are popular with bizjets as you are above the airliners until landing anyway. There are vast areas of the globe one can fly for hours and not see another plane.

There are few areas where demand at peak times is limiting the number of air traffic movements. EWR comes to my mind first, especially since the FAA eliminated the slots at EWR. SFO is another example.

In those few areas where the system is at capacity, carriers will either need to upgauge the aircraft size - like UA's plan to shift RJ flying out of EWR in favor of IAD - or move the traffic to times that aren't already maxed out.

So in my experience, there are times at a relatively small number of airports that are limited, but most airports still have excess capacity; DEN comes to mind, although DEN is limited when surface winds are strong from the west (DEN really needs at least one more east-west runway).

Starlionblue wrote:

Antiquated airport layouts with deep alleys don't help. JFK, for example, would benefit from a more modern taxiway and apron layout.

What does this mean? Is the problem that the alleys are too narrow and can only allow one airplane in our out at a time? I'm always amazed at DEN, for example, how much space there is between terminals. That's a lot of concrete to move around on.

The ramps between concourses ideally would be wide enough so both opposing gates can push nearly simultaneously. LGA’s alley used to be horrible crowded and caused delays, probably still is.

ATL’s original concourses always remind me they were built for the DC-9/B727 capacity planes when each gate area spills out into the concourse itself. OTOH, making concourses and gate areas bigger makes the walk on connections longer.

At night on the NATS, there’s twinkling lights always visible. Trans-Siberian legs at night are pretty lonely, each controller often clears you direct to the fix on the other side of his airspace.

BTW, there’s almost 200 million square miles of Earth, even discounting the high latitudes (can’t off the top of my head compute the area), it’s a lot of area for 9,700 objects, but I’d bet the actual number is two or three times that—GA, military, etc.

GF

I pulled the 9700 # from the net and it didn't specifically say only commercial or a/c entirely. I wouldn't doubt the actual number being higher and that number was stated as an average.

Actual earth space was not really part of my inquiry. Mostly it's the major hub airports and how demand will continue to grow.

Lemmy wrote:

Starlionblue wrote:

Antiquated airport layouts with deep alleys don't help. JFK, for example, would benefit from a more modern taxiway and apron layout.

What does this mean? Is the problem that the alleys are too narrow and can only allow one airplane in our out at a time? I'm always amazed at DEN, for example, how much space there is between terminals. That's a lot of concrete to move around on.

Yes. Many older airports have relatively narrow alleys. They were designed for smaller aircraft than today, and lower traffic density. Look at airports built in the past few decades, e.g. Hong Kong and the brand new Beijing Daxing, and you can see that alleys like are absent. Lots of space between the "arms" of the terminal, making ground traffic much simpler.

HKG


PKX


In contrast, here is LGA...


... and JFK

One of the problems with JFK is LGA. The airspace overlaps and LGA drives the JFK runway usage. The best solution would be to construct new airports, but people don't like new airports. LGA's replacement would be miles away so as to not impinge on JFK. And there are numerous other examples of airports that overlap and different runway configurations are not possible.

Should the FAA and airlines use the full capabilities of the latest generation of aircraft, that would certainly help in congestion in the local areas. But, that is more of a political issue than anything else.

Congestion in the upper space isn't really an issue. The military has a lot of airspace blocked off, but if it's not being used the FAA and Military have various letters of agreement which allow the FAA to use the airspace.

JFK is barely recognizable today vs. that pic above... in part for just this reason.

spacecadet wrote:

JFK is barely recognizable today vs. that pic above... in part for just this reason.

Thanks for that info.

Starlionblue, the photos you posted of the various airports clearly illustrate the improvements that have been made in airport terminal design. Thank you. As spacecadet mentioned in Reply # 11, KJFK doesn't really look like that anymore. Yes, there are still issues with alley congestion, particularly between Terminals One and Two, and also occasionally at Terminal Four, but the Port Authority of New York and New Jersey has made considerable progress to improve ground operations at the airport. If the JFK redevelopment plan ever materializes, it will reduce the number of terminals to four and further improve ground movement of aircraft on the aerodrome.

Similarly, with reference to the photo of LaGuardia airport, it provides an outstanding example of the limitations and constraints of multiple parallel concourses that were designed for the DC-3, Convair 240, and perhaps a DC-6, DC-7 or Electra, but LGA doesn't look like that anymore either. LaGuardia is undergoing a multi-million dollar renovation to completely redesign the terminals and concourses into a more "curvilinear" style, which will reduce, and in many parts, eliminate, the alley constraints.

I have heard many pilots complain about the LGA redevelopment program stating, "The terminal will be very nice, but it will do nothing to improve capacity or aircraft movement."

Well, that's not exactly true. While the LGA redevelopment program does not provide for additional runways, or lengthen the two existing runways (each 7,000 feet - 2134 m), the redesign of the terminals and concourses will greatly increase aircraft movement area, improve flow of aircraft on the ground, and reduce/eliminate delays with regard to aircraft approaching or departing terminal gates (i.e., alley delays).

e38

Another airport that badly needs updating is Sydney, in particular the international terminal at the northwestern end. The alley at the south end of the International Terminal is notorious for delays. (You can see a red 737 in the middle of it in this pic.)



It doesn't help that aircraft landing on 34L and bound for the international terminal tend to vacate on Alpha 2, putting them directly in the path of aricraft taxiing out for 34L. The intersection of Hotel and Alpha becomes a bit of a choke point, with aircraft coming out of the alleys and taxiing east on Golf, and inbound aircraft being held on Hotel or Juliet, or even on 07/25.


On the runway front, while there was certainly a need for a second parallel runway, placing 16L/34R way out there makes for long taxi times for the fligths that use it (mainly domestic).

While airport ground operations are also a problem to consider as the need or at least desire for more flights continues to grow, through population growth if nothing else, my query is about airspace in congested areas with multiple large airports. NYC area actually has 4 teterboro while smaller than the main 3 is still large enough to handle planes like the A320. There are other densely populated areas besides the NYC area but that is probably thought of 1st. Our most congested areas, how much more airspace are they capable of handling? ATC and pilots are likely most knowledgeable on what limits there are, how difficult it is becoming during the busiest times of the day.

Technology has helped, I'm fairly certain that in 1960 we wouldn't be able to handle the current amounts of air traffic. And technology will continue to help us in the future. Still, at what point are we simply able to handle no more increase?

timh4000 wrote:

While airport ground operations are also a problem to consider as the need or at least desire for more flights continues to grow, through population growth if nothing else, my query is about airspace in congested areas with multiple large airports. NYC area actually has 4 teterboro while smaller than the main 3 is still large enough to handle planes like the A320. There are other densely populated areas besides the NYC area but that is probably thought of 1st. Our most congested areas, how much more airspace are they capable of handling? ATC and pilots are likely most knowledgeable on what limits there are, how difficult it is becoming during the busiest times of the day.

Technology has helped, I'm fairly certain that in 1960 we wouldn't be able to handle the current amounts of air traffic. And technology will continue to help us in the future. Still, at what point are we simply able to handle no more increase?

Plus HPN, MMU, FRG and ISP, all in the NY TRACON and within 50nm of LGA.

So GF, In your days of flying commercial and bizjets, what are or were your thought while flying into any one of these airports? How high did the stress level go? How much of the time were you spending on tcas alerts or ATC diversions due to traffic? Do we still have room to grow or are we getting close maxing out airspace with our current regulations?

Not very much elevated, anticipate being busy, listen up on the radio, be briefed and ready. Moscow morning arrival with about 6 different STARs and transitions, change over to QFE and language problems with little traffic could be worse than NYC with lots of traffic.

Runways are more restrictive than airspace, as SFO shows frequently. Mumbai is awful, but it’s busy and basically a one runway operation.

To quote a show on PBS USA "at any time over a million souls are airborne " which surprised me but do the math it's probably significantly higher.

If the number of civilian commercial planes is roughly 10k, averaging 100 pax per plane there's your 1m. Adding in all military around the world. Island hoppers of the Caribbean, the Mediterranean middle east, far east and cargo we could easily double both numbers.

GPS has substantially increased the capacity for aircraft in the sky. It allows for much simpler RNAV and en route navigation and relieves congested areas

From what I'm gathering, overall we aren't running into a situation where the skies are getting so full as to be dangerous or that as improvements are made on all levels we can continue to grow, especially if there is adequate runways. That seems to be a big key. I'm not a particular fan of PHL. Its obviously a large airport but isn't a top 10 worldwide. It has 4 runways 2 running in a parallel direction, staggered. Both large enough to serve anything except the space shuttle. Then 2 more smaller ones so as far as the runway layout I could be wrong, but it would seem to me pilots and ATC struggle less with then some of the others. But, I have zero expertise on this, I'm going only by what it appears to me.