On Thu, 02 Oct 2003 10:47:47 -0500, Don Faulkner
wrote:

Hi folks. I've got a bit of a puzzle here.
First off, I'm a student pilot, so maybe I haven't gotten to this yet.

Take a look at the ILS 18 plate for Springdale, AR (ASG):
http://myairplane.com/databases/appr...l/ASG_ir18.pdf

First, note that the approach is "ILS RWY 18"
---
Next, read in the notes section:
Circling NA east of Rwy 18-36, inoperative table does not apply.
DME from RZC VORTAC
Simultaneous reception of I-ASG and RZC DME required.
---

So, the way I read this, DME is not required, since the approach is ILS
not ILS DME, but it is required since "simultaneous reception ... is
required."

I guess my real question is, "Is this approach authorized for an aircraft
without DME? And if not, why don't they call it ILS-DME?" but read on for
my thinking...


Under the approach naming conventions used by TERPS, DME only appears in
the approach name if it is required in order to fly the FINAL approach
segment. "ILS procedures do not require DME to fly the final approach, even
if a DME fix has been substituted for one of the marker beacons, therefore,
ILS procedures shall not be named ILS/DME. If a procedure requires DME to
fly the final approach, the suffix “DME” shall be added; ..."

And my interpretation of the note is that, indeed, DME is legally required
to fly the approach. It is used to ID two of the IAF's and could be used
to ID the MAP (for the LOC approach) and/or Westy (it's not necessary for
either one). And yes, you could fly the approach without DME by navigating
to NOBBY as the IAF; and using timing if you are using the LOC approach;
and using radials to ID WESTY.

I don't know the requirements for putting a DME required note in the
procedure, when it is possible to fly at least one of the charted
procedures without using DME.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)