When briefing an approach, we might not care what a given “obstacle” actually is. But they do come in all shapes and sizes; the chart symbols indicate as much. So it’s a good idea, especially in unfamiliar areas with lots of obstacles, to know what’s down there, be it metal, dirt, rocks or trees. The Aeronautical Chart User’s Guide and other pubs have lots of information about how and when they’re depicted. However, the actual obstacles around an airport and its terminal area don’t all appear in one place. They’re scattered around and can pop up in unexpected places, much like the real thing.
Trees or Towers?
Such is the case flying to Deer Park, Washington, elevation 2211 feet. North of Spokane, Deer Park is known for its seasonal fun, so you pack the plane for a long weekend in the great outdoors. With just some mild IFR weather for the Friday arrival, you’ll figure on one easy approach (still filing Spokane as an alternate) and good VFR for departure on Monday. Winds at the noon ETA will be 200 degrees at a steady 15 knots; visibility 3 SM, broken ceiling 1600 feet. Plan on the RNAV (GPS) 16 approach, an LNAV procedure with two MDAs: 2640 feet for the straight-in and 2670 feet for circling to 34.
