ARTCC altitudes

[jnmeade]

I'm trying to wrap my mind around how ARTCC sectors are divided up by altitude. Here's what I think I have figured out. Please correct, comment or amplify as appropriate:

1. Low altitude sector - FL230 and below, but sometimes (like around class B?) 10,000 and below
2. Intermediate sector - 11,000 through FL230 (probably used over a Class B?)
3. High sector - FL 240 and above, but sometimes FL 240 to FL330.
4. Ultra high - FL 350 and above where used

I suspect the above information is dated, for example, it doesn't look like it accounts for RVSM separations.

I don't have any good feel for why UH is separated out as if it goes from the ground up in one area, as opposed to being all airspace over FL330 or some other altitude.

References, web sites, etc. appreciated.

 

[ScottM]

I really don't know, but on PoA ApacheBob is a center controller. Drop him a line.

 

[HPNPilot1200]

Generally speaking, that is correct. Low normally goes up to FL230, Hi from FL240 to FL330, and Ultra Hi from FL330 and up. Some Hi sectors will take FL240 and above with no ultra hi above it. It varies from facility to facility and sector to sector.

 

[Doggtyred]

I don't have any good feel for why UH is separated out as if it goes from the ground up in one area, as opposed to being all airspace over FL330 or some other altitude.

References, web sites, etc. appreciated.

This is one of those issues that has more of a local, than centralized, approach. Airspace sectors are designed with traffic and flow in mind, and maintaining separation. (but you knew that, I'm guessing).

If a particular area has a relatively large amount of high flying traffic passing through, it may warrant its own piece of the pie in the form of an ultra high sector. The altitudes used for this vertical segregation vary based on the airspace's traffic loads. Thats why in one center, the Ultra High may start at X and the others start at Y... and in other places there may not even be a need for an ultra high sector.

Some relatively low traffic areas may go from surface to unlimited and never warrant even vertical segregation into low and high, or much more than low and high.

One of the center guys on here can pipe in about what the feds consider an acceptable workload for a Center sector..

 

[BillTIZ]

It all depends on where you are and what the traffic flow is.
Class B in most cases is controlled by the local TRACON, not ARTCC.
Class B here in LAS goes to 9K MSL, but the IFR TRACON airspace goes up to FL230.
The Class B boundries do not line up with the TRACON/ARTCC boudries.

Within each ARTCC, there are sectors, high and low depended on traffic flow and radar coverage. Radar coverage is not as much a factor as in the past with mosaic overlays of digitized radar data.

Years ago when I worked ZBOS, Boston ARTCC, high and low sectors were divided at the Class A boundry, FL180 and above was the high sector, 17,000 and below was the low sector with underlying approach controls in varios areas.