IFR Fix: No shaded area

February 19, 2013

It’s the climactic moment of every instrument approach under actual instrument conditions: When will you find the runway—or components likely to lead to it very quickly—and switch over to visual references for landing?

Sometimes the reported weather and the weather you get are identical, but at other times, you just have that feeling that you are in for a surprise.

It feels like that today, so it was wise to review every detail of instrument approach procedures, including the VOR/DME RWY 13 approach, for the East Texas Regional Airport, before dropping in on this proficiency flight.

It’s easy to see why your instructor would select this procedure for your approach: arriving from SKIDI, fly the 10-DME arc, passing another fix marking an altitude stepdown, before intercepting the final approach course.

Established and descending, watch for COWLU at 2.5 DME before the Gregg County VOR. The navaid doesn’t serve as a waypoint but remember that it is the spot where DME numbers begin to increase again as you proceed to a landing, or the missed approach point at 2.4 DME. The miss requires an intersection hold on a VOR radial.

Fly the procedures correctly and you will demonstrate a wide range of skills.

One helpful symbol along the approach course is the visual descent point (VDP) at 1 DME after the VOR. At your CFII’s request you recite the textbook definition: “The visual descent point (VDP) is a defined point on the final approach course of a nonprecision straight-in approach procedure. A normal descent from the MDA to the runway touchdown point may be commenced, provided visual reference is established.”

The CFII hands you an IAP for another airport and invites you to compare the depictions of the two VDPs. Issuing from that VDP is a shaded descending line not found on the IAP you will be flying.

“Why?”

Checking the chart legend, you rediscover that below the minimum altitude, the visual segment is clear of obstacles on a 34:1 slope, unless the shaded area is absent (as on yours).

That’s good info to keep in mind as you fly the 1.4 miles between the VDP and the runway—and serves as a strong reminder to maintain a moderate descent despite any optical illusions or anxiousness arising from landing at an unfamiliar airport.