Approach Plate Question

[luvflyin]

That's right. We often Cliff Note it as "published segment of the approach," but the actual language in 91.175(i) is, "established on a segment of a published route or instrument approach procedure." I talked about it in an IFR Magazine article that is still available without the firewall, Gettin' Down.

Thanks for that. On the lighter side of “how low can you go”

 

[Larry in TN]

IFR student here.

You're making this too complicated and that's because you're an IFR student. You have a misconception over how the national airspace system, and instrument flight rules, is built.

Those who learn to fly today are trained in a world where low altitude radar service is the norm. Everything is vectors, RNAV, and directs. While radar is very nice, increasing both efficiency and system capacity, it is a shortcut. It is not the base upon which the IFR system is built.

The system was built based on ground navaids, airways, and pilot nav. The system is there so that you can navigate from takeoff to touchdown without any help from ATC. ATC was added, it wasn't there when we started flying IFR, to provide separation when IFR traffic increased to the point where the "Big Sky Theory" started failing with some dramatic results. That was a time when, if you weren't on an airway or very close to an airport, you were likely in uncontrolled airspace.

When you look at an approach plate, if it doesn't have a note saying that radar is required, it is designed so that you can navigate to it, from the enroute structure, and fly the approach without any navigation help from ATC or RNAV. This is still the fall back if ATC were to go offline (ATC Zero) or during comm failure.

This specific note is there because of the sharp angle of the turn that would be required to make the prohibited transition from the airway to the approach. The radius of that turn would be too wide and would result in you straying outside of the protected airspace.

While under radar contact, the controller can take you outside of the protected airspace, as provided by the approach procedure, using his minimum vectoring altitude by providing both terrain/obstruction separation as well as IFR separation.

 

[luvflyin]

You're making this too complicated and that's because you're an IFR student. You have a misconception over how the national airspace system, and instrument flight rules, is built.

Those who learn to fly today are trained in a world where low altitude radar service is the norm. Everything is vectors, RNAV, and directs. While radar is very nice, increasing both efficiency and system capacity, it is a shortcut. It is not the base upon which the IFR system is built.

The system was built based on ground navaids, airways, and pilot nav. The system is there so that you can navigate from takeoff to touchdown without any help from ATC. ATC was added, it wasn't there when we started flying IFR, to provide separation when IFR traffic increased to the point where the "Big Sky Theory" started failing with some dramatic results. That was a time when, if you weren't on an airway or very close to an airport, you were likely in uncontrolled airspace.

When you look at an approach plate, if it doesn't have a note saying that radar is required, it is designed so that you can navigate to it, from the enroute structure, and fly the approach without any navigation help from ATC or RNAV. This is still the fall back if ATC were to go offline (ATC Zero) or during comm failure.

This specific note is there because of the sharp angle of the turn that would be required to make the prohibited transition from the airway to the approach. The radius of that turn would be too wide and would result in you straying outside of the protected airspace.

While under radar contact, the controller can take you outside of the protected airspace, as provided by the approach procedure, using his minimum vectoring altitude by providing both terrain/obstruction separation as well as IFR separation.

 

[RussR]

2. Assigned an altitude to maintain until the aircraft is established on a segment of a published route or

It could work like this. ATC clears you to KSLE via V165 UBG V287 MCCOY maintain [altitude]. Once you are established on the airway, they can simply say Cleared for the RNAV RWY 13 Approach. You don’t have to be on a “…published segment of the approach…”. Victor Airways are published routes. When cleared, you can descend to 4000 if still on V165 and then 3600 on V287.

7110.65BB 4-8-1 b. 2.
2. Assigned an altitude to maintain until the aircraft is established on a segment of a published route or instrument approach procedure.

I probably wasn't very clear. The question becomes "if you are doing this trick, when you are between UBG and MCCOY, can you descend to 3600 (the airway MEA), or 3100 (the approach procedure minimum altitude)?"

 

[RussR]

When you look at an approach plate, if it doesn't have a note saying that radar is required, it is designed so that you can navigate to it, from the enroute structure, and fly the approach without any navigation help from ATC or RNAV.

This is no longer necessarily true. Some years ago, RADAR REQUIRED (in any location on the chart or format) was removed from RNAV procedures, even if they didn't connect to the enroute structure. This was a reflection of reality of direct-to navigation. I'd have to search to find the reference for this, but you can see this in many examples, one would be the MDW RNAV (GPS) Z RWY 13L. No connection to enroute, and no radar required note.

Application of this is inconsistent, depending on when the procedure was last amended.

 

[Clip4]

Same as any time you have a lost comms in a vector situation. You fly the highest of what you were assigned, filed??,told to expect, or the minimum instrument altitude (you can punt and use the OROCA/MSAs or you can whip out your sectional and figure out what the highest obstacle within 4 NM. Once you get back on an airway or on a published part of the approach, you can follow the rules there.

2) Altitude. At the highest of the following altitudes or flight levels for the route segment being flown:

(i) The altitude or flight level assigned in the last ATC clearance received;

(ii) The minimum altitude (converted, if appropriate, to minimum flight level as prescribed in § 91.121(c)) for IFR operations; or

(iii) The altitude or flight level ATC has advised may be expected in a further clearance.

 

[midlifeflyer]

You're making this too complicated and that's because you're an IFR student.

I disagree it because he's a student. Making things too complicated is the standard for instrument training. Look at what we do with holds and DME arcs (although the latter are in the process of disappearing from a practical standpoint).

 

[luvflyin]

I probably wasn't very clear. The question becomes "if you are doing this trick, when you are between UBG and MCCOY, can you descend to 3600 (the airway MEA), or 3100 (the approach procedure minimum altitude)?"

I’d say 3600 because that’s the MEA of the segment you are cleared on. That you are coincidently over an Initial Approach Segment should not change that.