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Chart question

rvdave

Well Known Member
Hey all, have a question regarding a local ils chart in my area with what looks like an acronym that I or no one I’ve asked has an explanation. It’s CFBTW on this ils approach into tvc. Any takers on an answer?

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Link to larger version: https://flightaware.com/resources/airport/TVC/IAP/ILS+OR+LOC+RWY+28/pdf
 
Last edited by a moderator:
Looks like then it is a fix and it?s use is CNF which means Computer Navigation Fix. What does that mean? I?m a new instrument trainee trying to learn something.
 
Looks like then it is a fix and it?s use is CNF which means Computer Navigation Fix. What does that mean? I?m a new instrument trainee trying to learn something.

I have been flying instrument for some time and I had no idea. See this document for some government clarity. Maybe you will walk away with more clarity than I did. Basically it is just clutter unless you fly with a system that provides pilots situational awareness using CNFs.

https://www.faa.gov/about/office_or...afs420/acfipg/media/closed/Hist_12-02-303.pdf
 
A Computer Navigation Fix (CNF) is also a point defined by a latitude/longitude coordinate and is required to support Performance−Based Navigation (PBN) operations. The GPS receiver uses CNFs in conjunction with waypoints to navigate from point to point. However, CNFs are not recognized by ATC. ? CNFs that do appear on aeronautical charts allow pilots increased situational awareness by identifying points in the aircraft database route of flight with points on the aeronautical chart. CNFs are random five-letter identifiers, not pronounceable like waypoints and placed in parenthesis. Eventually, all CNFs will begin with the letters ?CF? followed by three consonants (for example, CFWBG).
 
The Aeronautical Information Manual is the source document for questions like this.

The AIM "is designed to provide the aviation community with basic flight information and ATC procedures for use in the National Airspace System (NAS) of the United States."

"This manual contains the fundamentals required in order to fly in the United States NAS."

Information on the Computer Nav Fix is located on page 1-1-26.
 
As others have noted it is a Computer Navigational Fix. Basically useless to pilots. Maybe accessible in high-end FMSes, for the FMSes use.

Full explanation in the AIM Section 1-1-17 (5)(i)(2).

George
 
FMS

Ha, "high end" FMS's. I got a chuckle out of that.

I fly into that airport fairly often for work. The "high end FMS" I get to use is in the B-717, and I have used that fix...

The chuckle is because virtually every RV with EFIS has a higher end system than the 717's...and the 717 has some of the better equipment...:D
 
The approach chart shows a charted holding pattern rather than a the standard procedure turn used for course reveral.
A IFR GPS can have the ILS in the database which you can use to enter the approach and also navigate the missed approach.
In this case the GPS can navigate the holding pattern for course reversal. This puts you on the Localizer inbound course. At that point you you select ILS and complete the approach.
The intersection you?re referring to is used in the GPS data base dealing with that data base.
If you?re not using a GPS just navigate the holding pattern using the Localizer and one minute turns for your course reversal. The entersection in this case will not be used.
 
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