CTC APP Within 20 NM of a Class C. Always?

SixPapaCharlie

SixPapaCharlie

May the force be with you
Joined
Aug 8, 2013
Messages
16,509
Display Name
Display name:
Sixer
Here's a question that might be dumb but it was never explained to me.
When approaching a class C airport, it will say on the sectional, contact app within 20 nm.

Is that only a requirement if you are landing there.
The whole time I have bene flying, I have always contacted the approach for class C airports when I pass within 20 miles. They give me a squawk and I end up on flight following.

It just dawned on me that maybe that note on the map is just for those intending to land there.

Screenshot_2.jpg
 
I'm under the understanding that it's only if you want to enter the airspace. Leaving the cmi class c, they're perfectly happy to let you terminate radar services as soon as you're 10.1 miles out. The crop dusters don't talk to anyone unless they have to enter the surface area.

Also, they will give you radar services much further out than that if it's their airspace. They have something like 40 miles to the east.
 
It's two things. It's intended to have you contact TRACON so they have time to sequence you for landing. And it's a recommendation to those not landing there because approach/departure corridors for jets usually extend well beyond the boundaries of the Class C.
 
AggieMike88 said:
That's the primary use case.

Why do I remember you always being a big fan of and using Flight Following on every flight. Even your 15 minute hops between KDTO and KGLE?
Click to expand...

I used to before I had all this fancy traffic alert stuff. Queue @Ravioli to tell me my 45 year old eyes are better at spotting traffic than radar.
I still use FF sometimes but not as much and certainly not as much as I should.
 
Any controller I have ever talked to about this said they would prefer for you to call them. You know what your intentions are, but they don't. They can also not rely on your Mode C (altitude) for separation unless they confirm your altitude over the radio. So you talking to them helps them with separation, and with providing flight following for others (and for you, obviously). So while there is no hard requirement in the regulations to call them, I do it whenever I can.

- Martin
 
midlifeflyer said:
It's two things. It's intended to have you contact TRACON so they have time to sequence you for landing. And it's a recommendation to those not landing there because approach/departure corridors for jets usually extend well beyond the boundaries of the Class C.
Click to expand...

I’d add that the local Charlie really really really wants to be talking to everyone, landing or not. It’s a regular fustercluck down there. (KCOS)
 
SixPapaCharlie said:
Queue @Ravioli to tell me my 45 year old eyes are better at spotting traffic than radar.
Click to expand...

You have radar in your Traveler? That's awesome.

Someday the illustrious FAA will re-write the rules from "See and avoid" to "play with your electronic ******** in VMC". Until then, your old beautiful eyes are primary and "It wasn't on the fish finder" will be a sorry excuse.
 
Only a requirement if you are going to land there or fly through their airspace. But as others have said, they usually prefer to talk to you. I was flying near a Charlie last year, there was a baron flying right near the airspace. The controller was guiding an Airbus into the airport, when he frantically started calling the Airbus and told him to turn. The baron was flying a consistent path, when he decided to turn, right into the approach course for the Airbus. The baron did nothing wrong, but it was an eye opener for me to see and hear how it can affect things.
 
I think you are over-fixated on the 20 nm. The real point of that box is to tell you the frequency, because it varies depending on the direction you are arriving from.
 
AIM 3-2-4 covers Class C areas.

3-2-4 c. 3. Note 4:
Class C airspace areas have a procedural Outer Area. Normally this area is 20 NM from the primary Class C airspace airport. Its vertical limit extends from the lower limits of radio/radar coverage up to the ceiling of the approach control's delegated airspace, excluding the Class C airspace itself, and other airspace as appropriate. (This outer area is not charted.)​

That's the 20nm. 3-2-4 d. explains what it does.
d. Air Traffic Services. When two‐way radio communications and radar contact are established, all VFR aircraft are:
1. Sequenced to the primary airport.
2. Provided Class C services within the Class C airspace and the outer area.
3. Provided basic radar services beyond the outer area on a workload permitting basis. This can be terminated by the controller if workload dictates.​
 
SixPapaCharlie said:
Here's a question that might be dumb but it was never explained to me.
When approaching a class C airport, it will say on the sectional, contact app within 20 nm.

Is that only a requirement if you are landing there.
The whole time I have bene flying, I have always contacted the approach for class C airports when I pass within 20 miles. They give me a squawk and I end up on flight following.

It just dawned on me that maybe that note on the map is just for those intending to land there.

View attachment 96093
Click to expand...

There is a thing called the Outer Area. It's a 20 mile radius of the airport with some local exceptions. It's not charted anywhere. If you are out of the C but in the Outer Area, they provide the same services that do in the actual C, IF you are talking to them. In case ya missed the if highlights, it's if. You don't have to be like you do while in the actual C. Do you have to Contact them within 20 miles? Let the arguments begin. I'll start it off with Contact is an action verb in the imperative sense and therefore implies it is a 'Shall' thing. And it is printed on an oh fish e ul FAA document, the Sectional. So ya better do it. Or do like I do. If I don't want to talk to them, I don't. Haven't done that often, but I have.

EDIT: shoulda kept reading. @Larry in TN had it all covered in post #12 with paragraphs and stuff
 
Last edited:
Ravioli said:
You have radar in your Traveler? That's awesome.

Someday the illustrious FAA will re-write the rules from "See and avoid" to "play with your electronic ******** in VMC". Until then, your old beautiful eyes are primary and "It wasn't on the fish finder" will be a sorry excuse.
Click to expand...

I can never see the traffic.
I can avoid it by looking at an electronic doodad and altering my course.
My vision is down to about a mile before I can spot anything and its only about 20% of the time I ever see it.
FWIW I'm far sighted.
 
In my mind, I preface it with "You can", or more completely "If you want Class C or radar services, you can {contact Approach within 20 nm on xxx.xx}"

I consider it an advisory of the frequency to use, and that you should definitely be able to reach them once you're within 20 nm.

Most Class C radar service, of course, extends much further than 20 nm from the main airport. 40 nm is not unusual, but that depends on local agreements between ATC facilities as far as airspace control goes - where approach ends and Center starts.
 
RussR said:
In my mind, I preface it with "You can", or more completely "If you want Class C or radar services, you can {contact Approach within 20 nm on xxx.xx}"

I consider it an advisory of the frequency to use, and that you should definitely be able to reach them once you're within 20 nm.

Most Class C radar service, of course, extends much further than 20 nm from the main airport. 40 nm is not unusual, but that depends on local agreements between ATC facilities as far as airspace control goes - where approach ends and Center starts.
Click to expand...

Yes. Beyond the Outer Area is the Outer Limits. Substitute your airplane for your television
 
SixPapaCharlie said:
I can never see the traffic.
I can avoid it by looking at an electronic doodad and altering my course.
My vision is down to about a mile before I can spot anything and its only about 20% of the time I ever see it.
FWIW I'm far sighted.
Click to expand...

FWIW there’s still plenty of aircraft that aren’t ADS-B equipped. Guess where they’ll be skirting a Charlie...
 
SixPapaCharlie said:
I can never see the traffic.
Click to expand...

I was having a tough time the other day. ADSB is giving me the position but the haze and the glare made seeing anything really tough. I finally spotted the target about a 1/4 mile ahead and 1K below me. Was a delta winged trike. Looked about like this one:
iu
 
And it assuming that you don't get the response "aircraft calling standby and remain clear of the Class Charlie"
 
I’ve skirted around class C just outside the airspace, been under the shelf, and fly directly overhead hundreds of times without ever speaking to them.

only required to talk to them is when you are entering the airspace.
 
SixPapaCharlie said:
I can never see the traffic.
I can avoid it by looking at an electronic doodad and altering my course.
My vision is down to about a mile before I can spot anything and its only about 20% of the time I ever see it.
FWIW I'm far sighted.
Click to expand...

As much as I admire you as person, an aviator, and a parent I have to say you're wrong about electronic stuffs. And as you know, my silly little flying lawn mower has a lot of electronic **** in it. All of which is secondary in VMV.
 

Attachments

  • panel.jpg
    panel.jpg
    152.9 KB · Views: 53
Ravioli said:
As much as I admire you as person, an aviator, and a parent I have to say you're wrong about electronic stuffs. And as you know, my silly little flying lawn mower has a lot of electronic **** in it. All of which is secondary in VMV.
Click to expand...
I think you’re both right in some ways, although, I tend to agree with Bryan a bit more on this. Spotting traffic with your eyes is always primary, but it’s a whole lot easier to see what’s around via our electronics and avoid before it becomes a conflict. During the day it can be pretty difficult to spot traffic until it really gets too close for comfort. Much easier at night. It doesn’t mean we’re constantly eyes down, but a quick glance here and there for situational awareness isn’t a bad thing.
 
When this scary new "ARSA" thing appeared in Austin, TX in 1983-ish, most of the local pilots I knew avoided the whole thing and would fly 20 miles away from the Mueller airport.

The FAA Operational Report is interesting reading and there is a section on the local pilots' response to the airspace change.

Per section 3.3.1:

"Perceived Impact On Pilot's Flying:
A majority of the respondents (56%) felt that implementation of the ARSA has caused no change to their flying while 25% felt that an increase in radio contacts has occurred. About 10% felt that they have either altered their route of flight, their altitude, or both to avoid ARSA."

https://apps.dtic.mil/dtic/tr/fulltext/u2/a150008.pdf
 
Ravioli said:
As much as I admire you as person, an aviator, and a parent I have to say you're wrong about electronic stuffs. And as you know, my silly little flying lawn mower has a lot of electronic **** in it. All of which is secondary in VMV.
Click to expand...

Appreciate that. And please let m kids know.
But you have to admit you don't spot all the traffic w/ your eyes (Which are WAY older than mine) OK I was kidding about that. I suspect we are about the same age but still.....
 
Remember that ads-b traffic has a delay. Just as the weather has a delay. You may start a turn to avoid traffic on the iPad but end up turning into the traffic. Something to keep in mind.
 
SixPapaCharlie said:
But you have to admit you don't spot all the traffic w/ your eyes (Which are WAY older than mine)
Click to expand...

My lying eyes are about 11 years older than yours IIRC. I'm 55. And I'll stand by my previous statements about what a fine man you are.
 
Hmm. The way it was explained to me, way back when, was that i was supposed to wait until i was within 20 miles to call unless i wanted flight following. i.e. don't key up and request landing while i'm still 40miles out unless i want flight following or need something. Maybe that's not the right interpretation?
 
@SixPapaCharlie - I'm a bit of dip****. I only replied to your quote at me.

The original post is that you only need to contact the Charlie approach 20 miles out IF you were going to enter the airspace. So if you were to overfly Little Rock (as shown) at greater than 4300' you need not talk to them at all.
 
Last edited:
wsuffa said:
And it assuming that you don't get the response "aircraft calling standby and remain clear of the Class Charlie"
Click to expand...

In that case they don’t need to say remain clear of the Charlie. You can’t go in yet. Communications haven’t been established. If they used your Call Sign and said standby, comm has been established and you can go unless they say stay clear.
 
IK04 said:
When this scary new "ARSA" thing appeared in Austin, TX in 1983-ish, most of the local pilots I knew avoided the whole thing and would fly 20 miles away from the Mueller airport.

The FAA Operational Report is interesting reading and there is a section on the local pilots' response to the airspace change.

Per section 3.3.1:

"Perceived Impact On Pilot's Flying:
A majority of the respondents (56%) felt that implementation of the ARSA has caused no change to their flying while 25% felt that an increase in radio contacts has occurred. About 10% felt that they have either altered their route of flight, their altitude, or both to avoid ARSA."

https://apps.dtic.mil/dtic/tr/fulltext/u2/a150008.pdf
Click to expand...

For anyone wondering, ARSA and Class C are the same thing. The name got changed in 1993 when Alphabet airspace started.
 
My home airport is under the C shelf, and there are plenty of times I come in/go out VFR and never talk to approach. If I'm headed for the little airport and I'm descending to be below the shelf, they pretty much know where I'm going.
 
SixPapaCharlie said:
Appreciate that. And please let m kids know.
But you have to admit you don't spot all the traffic w/ your eyes (Which are WAY older than mine) OK I was kidding about that. I suspect we are about the same age but still.....
Click to expand...
It's certainly true that electronic traffic detection systems often spot traffic that we don't, but we also have to remember that there are still some aircraft that the electronics can't see.
 
farangutan said:
Remember that ads-b traffic has a delay. Just as the weather has a delay. You may start a turn to avoid traffic on the iPad but end up turning into the traffic. Something to keep in mind.
Click to expand...

That delay is minimal with the right equipment. I was taxiing on the parallel yesterday and there was landing traffic. When it was at my 3 o clock with my eyes, it was 3 o clock on the ADS-B.
 
^^^ OMG! ads-b for traffic avoidance while taxiing? You've gone too far my friend.
 
drummer4468 said:
Hmm. The way it was explained to me, way back when, was that i was supposed to wait until i was within 20 miles to call unless i wanted flight following. i.e. don't key up and request landing while i'm still 40miles out unless i want flight following or need something. Maybe that's not the right interpretation?
Click to expand...

That is not true. You can call them earlier but service beyond the outer area is "basic radar service" instead of "Class C service" (the main difference being no VFR to IFR separation) and is on a workload-permitting basis. Ref. AIM 3-2-4.d.3.

Additionally reception and radar coverage may or may not be adequate and you might actually be in a different facility's airspace, you can check the chart supplement A/FD for the closest airport for the correct frequency for radar service.
 
The only time I call a Charlie is when I'm landing there or if I need to transit the controlled airspace, which does happen from time to time. Other than that I go on my merry.
 
farangutan said:
Remember that ads-b traffic has a delay. Just as the weather has a delay. You may start a turn to avoid traffic on the iPad but end up turning into the traffic. Something to keep in mind.
Click to expand...

EdFred said:
That delay is minimal with the right equipment. I was taxiing on the parallel yesterday and there was landing traffic. When it was at my 3 o clock with my eyes, it was 3 o clock on the ADS-B.
Click to expand...

I've heard of ADS-B weather having a delay. Maybe that's what he was thinking of.
 
That's right, the weather information delay is much longer. The weather delay is in minutes for processing and other number crunching. And the traffic position request is refreshed periodically 5-12 seconds. Most of the time it's not a big deal. It matters most when up close with faster planes that can cover quite a bit of space in 12 seconds. Plus whatever time it will take for you to pull your eyes off your tablet and out to scan the sky.

https://www.faa.gov/nextgen/equipadsb/capabilities/ins_outs/

Edit: well I definitely read that too fast. The 5-12 seconds is for radar not ads-b. Carry on, oops.

This link explains they designed the system to keep the traffic delay to less than 3.5 seconds.
So probably no big deal to most of us.
https://www.ifr-magazine.com/avionics/tis-b-the-ads-b-bridge/
 
Last edited:
You must log in or register to reply here.
Back
Top