VOR/DME approach with IAF well off inbound victor airway?

S

slough

Well-Known Member
Billings VOR/DME 28R
http://204.108.4.16/d-tpp/1107/00048VD28R.PDF


The feeder radial-252 depicted on the west edge of the chart is actually the inbound victor airway with a mea of 6000. Whats confusing me is the VOR is not an IAF, so how do you get to either of the 16 mile arc IAF north or south of the VOR if you dont initially fly to the VOR? The 6000 mea is lower than the msa altitudes. Also the radials leading to those IAF fixes from the VOR are lead radials without altitudes and not flyable. My only thought is that those IAF fixes are unavailable to traffic from the west, and you must fly to the VOR and outbound to the MUSTY IAF and do the procedure turn.

One other question on the actual approach plate is what does the D outlined by a black box in the airport diagram in the bottom right section of the approach plate signify? The airspace is charlie.
 
Re: VOR/DME approach with IAF well off inbound victor airway

Newly instrument rated guy here, but I think:
The R-252 depicted is the for the hold after the missed approach. It's not a feeder route. To get to NELWN or the unnamed IAF on R-333 from the enroute structure non-radar, you have to be on V611 or V187. So if you're inbound from the west on V2-86, first go to BIL and then outbound on one of those airways to get to an IAF, then fly the DME arc.
MUSTY is also depicted as an IAF. That does have a feeder route depicted, at 6000ft (the arrow leading east from the VOR). So if you were inbound from the west on V2-86 you could also go to BIL, fly outbound on the 082 radial at 6000 until you hit MUSTY at 10 DME, then descend to 5700 and do the procedure turn.

The D indicates runway declared distance information is available in the AF/D. Legend
 
Re: VOR/DME approach with IAF well off inbound victor airway

Yeah, you would go from the VOR to musty and do a procedure turn. No idea about the big D.
 
Re: VOR/DME approach with IAF well off inbound victor airway

How about this ILS into Bozeman, same question here, except there are no victor airways leading to the to IAF's at the extremes ends of the DME arc. How would you get to either of those IAF's without feeder routes leading to them. Maybe fly backwards on the DME arc then turn around.j/k Pretty confusing approach plate.

http://204.108.4.16/d-tpp/1107/00059IL12.PDF
 
Re: VOR/DME approach with IAF well off inbound victor airway

KICDO is on V365-536. BRIGR is useful as an IAF because it's also the hold fix for the missed approach, so if you wanted to try the approach again you can go right into the arc from there.

Keep 'em coming! :D

The ILS Z 11 at Ketchikan, AK is also an interesting one. What equipment do you need to fly it?
 
Re: VOR/DME approach with IAF well off inbound victor airway

Check the front of your approach plates for the "D" symbol definition. IIRC it has something to do with declared runway distances. Don't have any plates with me so I cant look it up.
 
Re: VOR/DME approach with IAF well off inbound victor airway

A D symbol is shown to indicate runway declared distance information available, see appropriate A/FD, Alaska or Pacific Supplement for distance information.

...whatever that means.....:-)
 
Re: VOR/DME approach with IAF well off inbound victor airway

You have altitude information and course guidance from the VOR to the IAF, so you could fly to the VOR, fly the radial outbound to the IAF, then begin the approach.

As far as the arcs are concerned, you don't have to begin them at the IAF. They can be intercepted at any point between the IAF and where they terminate at the final approach course. If you were on a direct route to Billings VOR that crosses over the arcs from the east, you could intercept the arc at that point and fly it in, or be given a vector to intercept the arc.
 
Re: VOR/DME approach with IAF well off inbound victor airway

slough said:
Billings VOR/DME 28R
http://204.108.4.16/d-tpp/1107/00048VD28R.PDF


The feeder radial-252 depicted on the west edge of the chart is actually the inbound victor airway with a mea of 6000. Whats confusing me is the VOR is not an IAF, so how do you get to either of the 16 mile arc IAF north or south of the VOR if you dont initially fly to the VOR? The 6000 mea is lower than the msa altitudes. Also the radials leading to those IAF fixes from the VOR are lead radials without altitudes and not flyable. My only thought is that those IAF fixes are unavailable to traffic from the west, and you must fly to the VOR and outbound to the MUSTY IAF and do the procedure turn.
Click to expand...
You are correct. The 5,148'± obstruction on the south side (for instance) might have something to do with that, but I'm not a TERPS genius, so I'll withhold comment on that. Neither radial that forms the distance-direction fixes for the start of the DME arcs is to be used as a terminal route.

The only authorized terminal route from the Billings VOR is outbound on R-082 at or above 6,000', depicted by the slightly offset arrow outbound from Billings.

How about this ILS into Bozeman, same question here, except there are no victor airways leading to the to IAF's at the extremes ends of the DME arc. How would you get to either of those IAF's without feeder routes leading to them.
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RNAV direct at or above the minimum off route altitude, or radar vectors at or above the MVA. Or there's a STAR that terminates at those fixes (no there's not, I looked, nevermind)

Both Bozeman and Whitehall VORs are on the low altitude enroute structure, so if you're non-radar you're going to BZN or HIA to commence the approach.
 
Re: VOR/DME approach with IAF well off inbound victor airway

Barty said:
You have altitude information and course guidance from the VOR to the IAF, so you could fly to the VOR, fly the radial outbound to the IAF, then begin the approach.

QUOTE]

The radials from the vor leading to IAF at the extreme edges of the vor/dme arc are thin lined and don't have altitudes assigned to them. They are depicted like that because they are only susposed to be used to identify the fixes not fly to them. I think they are called "lead radials". If you were flying the mea in from the west and flew off on those radials you would be below the msa altitudes for the areas those lead radials occupy.
Click to expand...
 
Re: VOR/DME approach with IAF well off inbound victor airway

slough said:
Barty said:
You have altitude information and course guidance from the VOR to the IAF, so you could fly to the VOR, fly the radial outbound to the IAF, then begin the approach.

QUOTE]

The radials from the vor leading to IAF at the extreme edges of the vor/dme arc are thin lined and don't have altitudes assigned to them. They are depicted like that because they are only susposed to be used to identify the fixes not fly to them. I think they are called "lead radials". If you were flying the mea in from the west and flew off on those radials you would be below the msa altitudes for the areas those lead radials occupy.
Click to expand...

I was referring to the 082 radial to MUSTY.
Click to expand...
 
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