Thursday, April 18, 2013

Routes to Nowhere

Even professionals do silly things sometimes. Take a look at this approach plate for Nashville Tennessee.
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The other day I saw a route from MDW to this airport that was something like

   CARYN2 CARYN J73 BNA

It seemed ok, pretty simple. I remember a controller telling me once, you don't want a clearance to an airport, you want a clearance to your approach, especially in the radar environment.

Look at the plate again, BNA! that is a VOR on the airport, but it isn't an initial approach fix (IAF). The FIDDS intersection is the IAF for this approach. Even from the North to the 20's runways, BNA isn't an IAF. 

So this poor pilot was cleared to a VOR. What should the pilot do if he looses communication? Assuming this was a ICAO flight plan, the destination airport was in field 16, no big deal. ATC should know where you want to end up. But what should this pilot do when they get to the BNA VOR in the soup? (assuming they have ILS or VOR receivers but no COM, it could happen).

Even if the pilot had good radios, and was planning on the ILS 2L, what should the controller tell this poor pilot? Well he has to figure out a way to this approach. Using the 2's, no big deal, since BNA is mostly on the way to FIDDY. Imagine though, the pilot wanted to go to the 20's. The IAF for the ILS 20R is HIKRY. HIKRY is 20 miles to the north. The pilot still gets to fly 40 miles more than needed to plus two huge turns. It isn't that far, but the pilot is still in the airport traffic area and has the controller guessing what to  do with this aircraft, to keep the pilot out of the way of all the other aircraft.

If the flight plan were filed to the IAF, or better yet, to a transition point on a STAR, so the sequencing can be done easier. The controllers like to know where you are going as far out as practical. The controllers like more time to think, and plan ahead, knowing what is planned, things go smoother.

Probably the proper route would be (ICAO format):
     CARYN2 CARYN J73 PXV DCT FIDDS

Getting off of J73 at PXV is safe and about as direct as you can get. It is 128 miles and gets the aircraft on the ILS 2L without any questions. The controller can assume the aircraft is going on the ILS, assuming ATIS says ILS 2L approach is in use.

I am hoping this helps. Any other thoughts?





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