Why are non precision approaches not lined up?

"Greg Farris" wrote in message
...
The title just about says it - I've always wondered WHY many
non-precision approaches (not talking about LOC only here, but VOR,
VOR/DME, NDB etc) are not lined up with the runway heading. Sometimes it
looks as though the approach desginers have gone out of their way to
make sure the non-precision approach is just a few degrees off - as if
to say - "look stupid - this is not a precision approach . . ." But if
this were so, then we would have to wonder why SOME of these approaches
ARE lined up and straight-in. I'm surev there's a simple explanation
that will be pointed out here.

thanks,
G Faris



There are numerous reasons. Off field navaids often serve serveral roles in
both the enroute and approach environment for several airports. On field
navaids may not be straight in as the approach coarse must lead to the
runway, and unless the navaid is at the end of a runway, the course would
either be parallel to the extended centerline of the runway, or offset to
intersect with the runway or runway threshold. Finally, obstructions along
the approach path or missed approach may be a fact in offsetting the
approach course. Lastly, air traffic considerations may be a factor,
especially with smaller airports situated close to busy airports.