A handful of navigation questions

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radioguy01

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radioguy01
Hi all,

This is a screen capture of a nearby airport (KLCH). It's class D airspace.
I have a few questions:

1. Class D airspace - in all the textbooks they show it as a straight up and down column of space, but on the map, it appears to have that "inverted cone" appearance that they show class B airspace having. I can clearly see the expanding concentric rings with different bottom altitudes. Does the column shape the textbooks show mean anything?

2. I can see the VOR off to the east of the airport. I don't know why, but it strikes me as odd that an airport doesn't have a VOR itself. How wonderful would it be to just tune to an airports VOR and fly right to it. Now, I haven't really done the VOR navigating part of my training yet. But, it would seem that you would just draw a radial out from the VOR, and then tune your OBS to that radial (something like 170') and "fly to it." But how would you do this if you were completely lost? Lets say you had autopilot on, no GPS, and you blacked out for 20 minutes. (I know, that's stupid.) So you wake up, assume you're somewhere near KLCH, and you tune that VOR that you know is east of the airport. You tune the radial that should bring you right over the airport. Would you just fly until the "TO" changed to "FROM" (or vice versa), which would tell you that you passed over the VOR tower, and then turn around and look for the airport? (Or would you tune the airport and ask them to vector you in?)

3. If you look at the bottom of the picture, the dark colored rings. Is that denoting a column of class E airspace? If so, why are those areas class E? I don't see anything in them other than a couple of towers and lakes. And does that mean anything outside of the D and the little shaded rings of E is class G airspace?

4. I think this is a great example of how cluttered these maps are. It took me several minutes to realize the VOR information for the VOR east of KLCH is actually up above and to the left of the whole area, well out of the way (it's not even pictured on this screen capture.) They definitely should have obstacles, private airports, etc, all on different "layers" that smart software (ForeFlight, Garmin Pilot, etc) can switch on and off to get the detail you want.
 

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1. That's a TRSA, which provides radar service in the zones, and yes it looks like a class B.

2. The location of VORs are one of life's great mysteries. Co-locating a VOR on a field has it's own foibles having to do with the radiated power of the VOR, and interference with other potential ground radio waves like a glideslope, radar, etc. Sometimes a VOR serves more than one approach(I think that is the case here) so the location is for mulitple things, not just the final fix for a single airport, or runway.

3. If you are referring to the gray rings, that is the TRSA boundary. See item 1.

4. Maps are cluttered. Flying is not for the simple minded. As for the software vendors de-clutter, I'm guessing you can advise the vendors, but once they make any kind of change to an NOAA or other type of flight nav chart, they then own that change, and all the liability that goes with the alteration of the display: "I crashed because Foreflight didn't show the XYZ on their modification of the federally published NOAA chart, dated mmddyyy". Doubt you'll make any progress with that.
 
radioguy01 said:
Hi all,

This is a screen capture of a nearby airport (KLCH). It's class D airspace.
I have a few questions:

1. Class D airspace - in all the textbooks they show it as a straight up and down column of space, but on the map, it appears to have that "inverted cone" appearance that they show class B airspace having. I can clearly see the expanding concentric rings with different bottom altitudes. Does the column shape the textbooks show mean anything?

2. I can see the VOR off to the east of the airport. I don't know why, but it strikes me as odd that an airport doesn't have a VOR itself. How wonderful would it be to just tune to an airports VOR and fly right to it. Now, I haven't really done the VOR navigating part of my training yet. But, it would seem that you would just draw a radial out from the VOR, and then tune your OBS to that radial (something like 170') and "fly to it." But how would you do this if you were completely lost? Lets say you had autopilot on, no GPS, and you blacked out for 20 minutes. (I know, that's stupid.) So you wake up, assume you're somewhere near KLCH, and you tune that VOR that you know is east of the airport. You tune the radial that should bring you right over the airport. Would you just fly until the "TO" changed to "FROM" (or vice versa), which would tell you that you passed over the VOR tower, and then turn around and look for the airport? (Or would you tune the airport and ask them to vector you in?)

3. If you look at the bottom of the picture, the dark colored rings. Is that denoting a column of class E airspace? If so, why are those areas class E? I don't see anything in them other than a couple of towers and lakes. And does that mean anything outside of the D and the little shaded rings of E is class G airspace?

4. I think this is a great example of how cluttered these maps are. It took me several minutes to realize the VOR information for the VOR east of KLCH is actually up above and to the left of the whole area, well out of the way (it's not even pictured on this screen capture.) They definitely should have obstacles, private airports, etc, all on different "layers" that smart software (ForeFlight, Garmin Pilot, etc) can switch on and off to get the detail you want.
Click to expand...

Doc covered most of it, but on number 4, TrueFlight does that.
 
radioguy01 said:
Hi all,

This is a screen capture of a nearby airport (KLCH). It's class D airspace.
I have a few questions:

1. Class D airspace - in all the textbooks they show it as a straight up and down column of space, but on the map, it appears to have that "inverted cone" appearance that they show class B airspace having. I can clearly see the expanding concentric rings with different bottom altitudes. Does the column shape the textbooks show mean anything?

2. I can see the VOR off to the east of the airport. I don't know why, but it strikes me as odd that an airport doesn't have a VOR itself. How wonderful would it be to just tune to an airports VOR and fly right to it. Now, I haven't really done the VOR navigating part of my training yet. But, it would seem that you would just draw a radial out from the VOR, and then tune your OBS to that radial (something like 170') and "fly to it." But how would you do this if you were completely lost? Lets say you had autopilot on, no GPS, and you blacked out for 20 minutes. (I know, that's stupid.) So you wake up, assume you're somewhere near KLCH, and you tune that VOR that you know is east of the airport. You tune the radial that should bring you right over the airport. Would you just fly until the "TO" changed to "FROM" (or vice versa), which would tell you that you passed over the VOR tower, and then turn around and look for the airport? (Or would you tune the airport and ask them to vector you in?)

3. If you look at the bottom of the picture, the dark colored rings. Is that denoting a column of class E airspace? If so, why are those areas class E? I don't see anything in them other than a couple of towers and lakes. And does that mean anything outside of the D and the little shaded rings of E is class G airspace?

4. I think this is a great example of how cluttered these maps are. It took me several minutes to realize the VOR information for the VOR east of KLCH is actually up above and to the left of the whole area, well out of the way (it's not even pictured on this screen capture.) They definitely should have obstacles, private airports, etc, all on different "layers" that smart software (ForeFlight, Garmin Pilot, etc) can switch on and off to get the detail you want.
Click to expand...

random pretty much nailed it. The circles at the bottom indicate where the floor of controlled airspace (Class E) is 700' agl; below that altitude the airspace is G. The airspace classification has nothing to do with obstructions.

Bob Gardner
 
radioguy01 said:
But how would you do this if you were completely lost? Lets say you had autopilot on, no GPS, and you blacked out for 20 minutes. (I know, that's stupid.) So you wake up, assume you're somewhere near KLCH, and you tune that VOR that you know is east of the airport. You tune the radial that should bring you right over the airport. Would you just fly until the "TO" changed to "FROM" (or vice versa), which would tell you that you passed over the VOR tower, and then turn around and look for the airport? (Or would you tune the airport and ask them to vector you in?)
Click to expand...

Lost, but you think you are in range of xxx VOR - you tune it in and turn the knob until you center the needle then you know that you are yyy degrees to or from that VOR. Draw a line on your chart. Pick another VOR somewhere off to one side or the other of that VOR. Tune it in (listen to the identifier to make sure it is really what you think - just like you did the first time.) Turn the knob again to center the needle and draw your second line - you are somewhere near where the two lines cross. (Account for the fact that you have kept moving since you found the first line.)

Once you know where you are, you can pick the appropriate airport and figure out how to get there.
 
If I were lost and wanted to get to KLCH using the VOR I would select 080 degrees on the OBS. This would tell me if I was North or South of the VOR. If the OBS said TO then I was also West of the field. If the OBS said FROM then I was East of the field.

I would then head North or South to intercept the 080 radial (or 260 radial if I was East of the VOR). From there you would intercept that radial and fly towards the VOR. Then you would either pass over the VOR or the field itself and should be able to proceed from there. DME would obviously be a huge help as would another VOR but I'm assuming you want to do this mental experiment with only one VOR.

A less precise but faster and likely easier way would be to turn the OBS until you had the needle centered and a FROM flag. Draw a line from the VOR on the charted compass rose and then compare the landmarks on the chart to the landmarks outside the window. You should eventually figure out where you were and could use dead-reckoning to make your way to KLCH.
 
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KRFD airspace is TRSA and I just treat it like a class C, although if I remember correctly participation isn't mandatory... but IMO it would be smart if the radar service is there.

As for VORs... I just center the needle up with a "to" indication, this gives me the bearing to the station. A turn to that heading will put you in the right direction before correcting for wind and variation/deviation.

Watch out for reverse sensing if you're trying to intercept a given radial, even though it's a misnomer IMO. Fly the heading, not left/right towards the needle... and you'll intercept the radial.

Of course, I only do this for fun and practice in case of a GPS failure, as a Dual 160 and ipad with foreflight give me the same information:)

As far as the clutter, that doesn't look too bad to me. Study the chart for any given area before a flight and it becomes clear. Now socal airspace, THAT shot looks like it might be confusin:eek:
 
bobmrg said:
random pretty much nailed it. The circles at the bottom indicate where the floor of controlled airspace (Class E) is 700' agl; below that altitude the airspace is G. The airspace classification has nothing to do with obstructions.

Bob Gardner
Click to expand...

I believe you are correct sir. I was misreading the rings for the boundary of the TRSA, but I think the OP meant the class E circles.

As for it's reason, I'm going to go out on a limb and say that the lower class of airspace restriction has to do with the instrument approaches into an airport, but could be for other reasons as well. Pretty much every airport with some kind of instrument approach has the lower class airspace around it, but - they are for other reasons that I have never been able to figure out.
 
I agree with that. Most of the 700' floor class E areas encircle the airport and have straight sections extending out that are aligned with approach paths to the runway(s). And there are probably secondary reasons as well.
 
docmirror said:
2. The location of VORs are one of life's great mysteries. Co-locating a VOR on a field has it's own foibles having to do with the radiated power of the VOR, and interference with other potential ground radio waves like a glideslope, radar, etc. Sometimes a VOR serves more than one approach(I think that is the case here) so the location is for mulitple things, not just the final fix for a single airport, or runway.
Click to expand...
The FAA moved the VOR/DME that was co-located with my home base and sitting fairly close to the intersection of the E/W parallel runways and the N/S one. It's now sitting in a field about half a mile from the east end of those same runways but it hasn't worked very well since it was moved. When it was in the original location it provided guidance for approaches to an E/W and N/S runway with very little offset. Now the approach to the N/S runway has a pretty big angle between the FAC and the runway. The reason was moved is that per the FAA's latest runway environment safety requirements it was too close to the runways. So in the name of safety and at significant expense they took a well functioning and very useful VOR and made it into a poorly functioning much less useful VOR that will likely be decommissioned in a few years.
 
Thank you guys for the answers. Very, very helpful. I also re-read Machado's chapter on airspace and it really helped.

Another question: and I'm purposefully using "baby" terms to make sure I understand. Before you enter any of class B, you get on the radio and talk to tower. Does class b have approach/departure? As for class D, when I've done a couple of short cross countries with my CFI, on the way back I talk to approach, and then they hand me off to tower. So, when I'm in the TRSA I talk to app/dep, and if I need to actually enter class d then I talk to tower. But I could technically fly through the surrounding trsa without talking to anyone (as foolish as that may be.)
 
radioguy01 said:
Another question: and I'm purposefully using "baby" terms to make sure I understand. Before you enter any of class B, you get on the radio and talk to tower. Does class b have approach/departure? As for class D, when I've done a couple of short cross countries with my CFI, on the way back I talk to approach, and then they hand me off to tower. So, when I'm in the TRSA I talk to app/dep, and if I need to actually enter class d then I talk to tower. But I could technically fly through the surrounding trsa without talking to anyone (as foolish as that may be.)
Click to expand...

Before you enter 'B', you have to get clearance to enter, generally from approach.

Before you enter 'C', you have to be talking to ATC, generally approach. (In practice this is fairly similar to 'B', as most 'C' approach controllers will greet you with a friendly 'stay clear of the charlie' until they radar identify you and allow you in.)

Before you enter 'D', you have to be talking to ATC, generally the tower if it's an isolated 'D'. However, if there are big 'B's or 'C's around, their approach controllers will generally take care of moving you through the 'D' until they tell you to contact tower.

In short, it's not about who specifically you're talking to; it's about what they say. Before you enter any 'B', make sure ATC says "cleared into the Bravo." As far as entering 'C' and 'D', it doesn't matter who you're talking to (so long as it's a competent ATC controller). As long as they know where you are and you're talking to them (and not violating any other instructions they give you), you can go ahead into the 'C's or 'D's.

Treat the TRSA like an 'optional C'. They will have an approach controller. If you want to participate (and, like you said, there's no reason not to), call them up before you enter the airspace. They will tell you when it's time to switch over to the tower frequency that controls the 'D'. It might or might not be before you physically enter the 'D', depending on their ATC letters of agreement, etc., that you really don't need to worry about.

If you choose not to participate in the TRSA, just pretend it's not there at all, and make sure you're talking to the 'D' tower frequency before you enter the 'D'.
 
radioguy01 said:
Thank you guys for the answers. Very, very helpful. I also re-read Machado's chapter on airspace and it really helped.

Another question: and I'm purposefully using "baby" terms to make sure I understand. Before you enter any of class B, you get on the radio and talk to tower. Does class b have approach/departure? As for class D, when I've done a couple of short cross countries with my CFI, on the way back I talk to approach, and then they hand me off to tower. So, when I'm in the TRSA I talk to app/dep, and if I need to actually enter class d then I talk to tower. But I could technically fly through the surrounding trsa without talking to anyone (as foolish as that may be.)
Click to expand...

Class B you are actually calling a radar facility, approach/departure, for a clearence to enter the Class B. if you do not hear the magic words, "cleared into Class B", do not enter.

Class D you are talking to tower, establish communication, if the respond to your radio call, continue, unless they specifically state to remain clear of the class D. There may be an emergency in progress or some other issue.
 
For class B, you have to talk to the ATC providing services. That's usually Approach (see the blue/white boxes on the sectional), but it can be Tower for the surface area. If you call the wrong one you'll get handed off, but don't enter the airspace before cleared.
 
A VOR located a few miles from the airport is actually more useful for an instrument approach as you can have a better defined final segment and lower minimums.
 
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