Vectors To Final

I did an IPC yesterday which went well. However, it highlighted an ongoing frustration I have with the VTF function.

On both my IFD 540 and CNX 80 activating VTF makes many (most?) of the fixes disappear which is problematic.

My CFII tells me that other units now will allow one to activate VTF but the various fixes remain (which is most helpful).

Can that be changed on the IFD?

Because the bulk of my flying is done in a radar environment I rarely fly a procedure as published. 99% of the time we're getting radar vectors.

I've gone to a standard procedure of loading the full approach in both boxes, but extensive vectoring has confused the logic in both boxes on more than one occasion.

I understand the fly leg option as well, but I really don't understand why VTF feature can't leave the other fixes in place and allow us to join the approach where ATC places us. This really begs to be fixed.

???

Jim

It's annoying for sure and that's why I use activate leg exclusively on the 430W.  Gonna be the same drill on the 540

I understand the Fly Leg procedure.

Honestly it's simply extra work for the PIC that really shouldn't be required.

I can see no viable reason for the VTF feature to disable all fixes on the extended final approach course.

I can provide numerous real world examples involving vectoring back and forth over the approach course that have given my IFD 540 fits. It's as if those who devised the VTF logic in these boxes haven't been vectored back and forth over final 2 or 3 times on the same approach. Out here it happens.

Sometimes it's easier to simply "dumb down" the box and go into ILS mode and fly it the old fashioned way. ATC treats many approaches that way.

I dislike losing those fixes.

I dislike having to reprogram the box to Fly Leg when I'm being given multiple heading and altitude changes.

Can I do it? Of course.

Seems like we can make a smarter box, though. That's my request.

I understand that as pilots we can do extra work to make up for shortcomings in box programming. Why should we have to do that?

This happened to me recently.  I'd been told to expect vectors to final, was flying a heading of 350 and had VTF loaded up.  ATC then told me 'turn right direct AWALT, cleared RNAV 15'.  You guessed it, AWALT was not on my IFD.  Learning experience.  Aside from loading the full approach and activating a leg I don't think you can do much about this.  

If you already have VTF loaded, then reselect and  reload the approach, and select the IAF then Direct to the IAF.