"Steven P. McNicoll" wrote in message
nk.net...

Uh... What the hell is an SDF? I don't think I have one in my plane.

I'll bet you don't have a localizer in your plane either, or an NDB or a
VOR.

An SDF is a Simplified Directional Facility, it's similar to a localizer.
You'll find a description in the AIM.

Well, you're right. I've got a KX155, a KNS80 and an M3 GPS. Are SDFs more
prevelant out East? I've flown an LDA, but never an SDF.