Say Again? #64: Flying Higher

You wanna go high? Wanna take that single-turbroprop or new VLJ into the the rarefied air above FL240? Things are a little different there, as AVweb's Don Brown explains in this month's Say Again? column.


Everybody wants to move up. I guess it’s just natural. Most pilots start out flying “low and slow” and long to go higher, faster, further. The Cessna 150 turns into a 172 and then a 210, to a twin and now everybody is dreaming about a Very Light Jet (VLJ).You see it somewhat in controllers, too. Most of the young people in Towers dream of moving “up” to a radar room. And many can’t wait to get to one of the “big houses” like Atlanta, Chicago or New York Approach. Or a Center. Even once they’re in the Centers, most want to work the high-altitude sectors and work “the big jets.”There are a few oddballs like me who would rather work the low-altitude sectors. If the truth be known, I think working a small Tower would suit me just fine. And the only airplane I’d consider owning would be along the lines of a Piper Cub. Low and slow with the window open, watching the countryside unfold in endless shades of green set against that blue, blue sky with those cotton ball clouds …

Changes in Altitude

Back in the land of reality, the trend in a pilot’s career and the current trend in new airplanes is to move up and that is what I’d like to talk about this month. There are some subtle (and not so subtle) changes in air traffic control as you get into the higher altitudes. The higher you go, the more pronounced the changes.As I told you in a previous column, there are (or were) four basic strata in ATC. Most Approach Controls “own” from 10,000 feet MSL to the ground. Then you have the low-altitude sectors in the Centers — from 11,000 to Flight Level (FL) 230. Above that are the high-altitude sectors from FL240 to FL340, and then the super- (or ultra-) high sectors at FL350 and above. And just to head some folks off at the pass … yes, we do work some aircraft above FL600 but I won’t be entertaining any questions about them.There are many exceptions to these four basic strata. The reduced vertical separation minimum (RVSM) program has increased the number of exceptions but those won’t be a factor in this article. The exceptions you are more likely to run into are some Approach Controls that go higher than 10,000. Some own up to 12,000 or 14,000 and there is even a rare case or two that make it into the Flight Levels.

Up, Up and Away

Most single-engine airplanes in general aviation stay below 11,000 most of the time. On the East Coast, that means that most of them spend a lot of time working with Approach Controls, even while en route. Once you get above 11,000, subtle changes start to occur. First of all, you’re almost certainly in Class E airspace. There are fewer VFR airplanes up here, but it’s important to remember that ATC provides no separation services to VFRs.

3-2-6. Class E Airspacef. Separation for VFR Aircraft. No separation services are provided to VFR aircraft.

You’d do well to remember that some of the VFRs that are in this airspace can really move. You left the 250-knot speed restriction behind at 10,000 feet. It isn’t all that uncommon to have a corporate jet that took off and couldn’t get an IFR clearance, flying VFR, working on getting a clearance up here. Ditto for military aircraft that have been in a low-level training route and are trying to find the right sector frequency to get their IFR clearance for the trip home.You might notice that the sectors are bigger up here, too. Most sectors in the 11,000 to FL230 stratum could easily contain most any Approach Control. In that most airplanes up here are faster than down lower, the time between frequency changes might not be greater but the distance usually is. There’s another subtle difference that starts in this stratum, too: I don’t know if it’s the difference in job functions or the size of the airspace or what, but Center controllers don’t vector nearly as much as Approach Controllers.

Vector vs. Victor

I remember taking a short hop from the south side of Atlanta to the northeast side one time. The entire trip was within A80’s (Atlanta Tracon’s) airspace. We were on a vector the entire flight, from “radar contact” leaving Tara Field to joining the final approach course at Gwinnett County. I remember thinking how strange that was and it’s made me take notice of the difference ever since.It seems as if Approach controllers vector everybody for everything. Center controllers don’t. Unless we’re sequencing arrivals, it’s unusual to have more than two to three aircraft on a vector at any one time. We use altitude separation instead of lateral separation for the most part. I don’t know if anyone else has noticed this difference or not. Pilots don’t think twice about getting a 50-degree turn below 10,000. Issue a 50-degree turn in the flight levels and everybody wonders what went wrong.When you get above 10,000 feet you leave most of the student pilots behind. As you get higher and higher, this trend continues. When you leave 17,500 and climb above FL180 into Class A airspace, you leave the VFRs behind, too. If you leave the low-altitude sectors and climb into the high-altitude sectors at FL240 or above, you may not recognize it but you’ve entered another world entirely … at least as far as controllers are concerned.


The transition from the low-altitude sectors to the high-altitude sectors at FL240 is where I perceive we’ll have some problems in the near future. There is a real mental shift that occurs for controllers at this boundary. At the risk of offending some, controllers consider this to be “professional” territory. Let’s look at it from a historical context to explain what I’m talking about.At FL240 and above, we’ve left all the student pilots and VFR pilots behind. Way behind. Above FL230 controllers expect to be working high-performance airplanes with two-person, professional crews — people who fly for a living, the vast majority of whom are airline pilots. Hopefully you’ll remember from my other articles that I tend to divide Center controllers into two camps: Those that like low-altitude sectors and those that like high-altitude sectors. The high altitude guys are drawn to the factors that have always existed up here.You can talk faster on the high side. Everybody up here has been talking on the radio for years and, besides, you know there are two people in the cockpit to handle the duties. Nobody asks any oddball questions. As a matter of fact, except for asking for the score of the ball game or “Can we get direct?” there are hardly any questions at all. Well, OK, there’s the constant “How are the rides?” and that kind of thing, but there aren’t any of the real puzzlers like student/VFR/low-time pilots can ask.

Simply Busy

Life on the high-altitude sectors is just a lot simpler for controllers. Well, that’s not quite right, either. The high-altitude sectors can be exceedingly complex and unbelievably busy. We have the Operational Errors to prove it. The vast majority of our errors at Atlanta Center are in the Flight Levels, but the rules are simpler. It’s five miles or a thousand feet. There isn’t any visual separation, minimum instrument altitudes (MIAs) or instrument approach procedures to worry about. Everybody has their own weather radar and the vast majority fly the same routes every single day.At least it used to be that way. You probably already see where I’m going with this, don’t you? Life is changing on the high sides and we can expect some growing pains. Enter the Meridians, TBMs, Pilatuses and who-knows-what-else these days. And soon, the VLJs.Intermixed with the J22 traffic to IAH, the J48 traffic to ATL, the J85 traffic to DTW, the turboprops and the corporate jets, we now have single-engine turboprops certified for single-pilot operations. Controllers (in total) are not really familiar with the performance capabilities of the airplanes or the crews. And while the performance specifications of the airplanes may be written in black and white, the performance of the crews never will be.

A Crew of One

It has been my (limited) experience that the performance level of the crews covers the entire spectrum. Some blend right in and others, well, they stick out like a sore thumb. For instance, controllers don’t give much thought to issuing an arrival routing to flight crews in this rarified air. The professional crews expect it (even if some still don’t file it like they should) and instead of “prompting” them like we might in the lower altitudes, we just key the mic and issue it.

“Lear three four five six seven cleared to Peachtree-Dekalb via direct Snowbird the AWSON one arrival.”

It might or might not work that way with some of the single-pilot aircraft. Life starts getting real difficult for controllers if we get too many replies like,

“Uh, Center, can you say that again?”

“Piper five six seven eight niner cleared to Peachtree via direct Snowbird the AWSON one arrival.”

“OK Center, direct Snowbird the AWSON one. Can you spell the identifier for Snowbird intersection?”

“Piper five six seven eight niner, Snowbird in a VOR sir. The identifier is Sierra Oscar Tango”

Unfortunately, sometimes the conversation goes on even longer. This isn’t all that unusual in the lower altitudes and controllers have learned how to deal with it. We can’t really expect the guy who only flies a few times a month to operate at the level of those that fly daily. Nor can we expect one person to perform at the same level as two people. But in the high-altitude sectors, there’s a big difference. That difference is the volume of traffic.

Discount Volume

Think of it this way: If you fly into a major airline hub, you expect it to be busy, right? You know there will be lots of airline traffic and the controllers will be busy and pressed for time. When all those airliners depart, they may scatter to the four winds but almost every one of them is headed for the high-altitude sectors.It isn’t unusual to have 20-25 airplanes in the same sector in the high-altitude sectors. It’s cyclical, just like the arrival and departure pushes at the hubs. And just like the airline hubs, it’s as regular as clockwork. Until the weather hits, that is. Then it’s just pretty much constant.I still haven’t found a better analogy to help you understand this problem than that of a telephone conference call. Most people can relate to the fact that the more people you have on the frequency — the conference call — the less each person will be able to say. Having five people on a frequency is pretty manageable. Having 25 isn’t. With that many people on the frequency you don’t have a lot of time to waste talking.The mental block for pilots is the same as I’ve highlighted before. In the departure and arrival phrase of a flight a pilot is busy. If it’s at a major airport, you expect the controllers to be busy and it sounds busy. It feels busy. But if a pilot is in the en route phase — on course, level and the autopilot is on — he doesn’t feel busy. If he isn’t busy, no one else is either. Right?

Humans Without Humor

It’s just human nature. Controllers have the same problem with other controllers. A controller at one sector is working 20+ airplanes and the controller at an adjacent sector is only working five or so. The second controller doesn’t feel busy, and if he’s not busy no one else is, either (or so he thinks). So he starts “making work” by ignoring procedures and making the resulting telephone calls to coordinate.

Controller 1: “Override LANIER”Controller 2: “Uh, yeah, this is SALEM. Pointout, two zero northeast of Snowbird, Continental one twenty three, flight level three zero zero, direct Vulcan.”Controller 1: “Point out approved.”

Just as with pilots, the busy controller will tolerate it for a little while. Right up until the point that they’ve had enough. Unlike with pilots, we don’t try to hide our displeasure with a controller who is “making work.”

Controller 1: “Override LAINER”Controller 2: “SALEM again, point out, one five north of Sugarloaf, Northwest six seventy eight, flight level three three zero, direct Alma.”Controller 1: “Unable point out.”Controller 2: “You can’t take a point out?” (In other words, the logic goes like this: “I’m not busy so how can you be so busy you don’t have time for a point out?”)Controller 1: “What part of ‘unable’ don’t you understand? Now stop shortcutting airplanes through my airspace and stay off my override!”

Trust me, that’s mild compared to some of the stuff you hear when things start really getting out of control. Which is the whole point of the business of air traffic control. We’ll do whatever is necessary to make sure it doesn’t get out of control.

Radar Rewind

One other thing I want to mention before I wrap this up. Remember when I said this above: “Everybody has their own weather radar and the vast majority fly the same routes every single day.” There are two things in that statement I want you to key in on if you ever find yourself as the new guy, flying up in the Flight Levels.Center controllers in the high-altitude sectors are used to working airplanes that have weather radar superior to ours. The airline crowd doesn’t ask for much advice on thunderstorm avoidance and we’re not used to giving it. Most of them start asking for deviations before we even start “painting” the weather on our radar. Think about it: The thunderstorm clouds start building up long before the precipitation gets up that high. If we’re filtering out the precipitation returns down low, we never see anything until long after the buildups are in the flight levels. Radar doesn’t “paint” clouds. At least ours doesn’t.To compound that problem, most of the airlines are on the Jet Routes (the high-altitude airways) and they all tend to deviate the same way. For some odd reason, general aviation aircraft don’t file Jet Routes very often. Are you adding that up? In the high altitudes, controllers aren’t used to warning pilots about thunderstorms and we tend to fixate on the major routes (the airways) in our airspace. It’s real easy to overlook that one airplane that doesn’t fit in with the rest of the group. And that one airplane is usually a lot closer (think altitude) to the thunderstorms than the other airplanes.Even if a single-engine aircraft has weather radar, I doubt if it is as effective as the big dish on the big nose of a big airliner. If you don’t have weather radar, always keep in mind that you’re the only guy up here that doesn’t. If you need some help getting around the thunderstorms, say so. It won’t endear you to a controller who is probably covered up with airplanes already, but it will help keep you alive. We know which is more important and we’ll make it work.Have a safe flight.

Don Brown
Safety Representative
National Air Traffic Controllers Association

Want to read more from air traffic controller Don Brown? Check out the rest of his columns.