As I told you a few days ago, I’m excited to be planning my first instrument flight this weekend to Macomb, IL (KMQB). Flying instrument opens up a lot of possibilities for completing missions that otherwise wouldn’t get flown, but it also adds another layer of complexity.
At a high level the planning process is to look at preferred procedures out of your departure area, preferred procedures into your destination and the route in between wherever those leave you off. For this flight it’s pretty easy to get that mapped out. We fly west out of the O’Hare (KORD) airspace then south to Peoria (PIA) and finally west again into Macomb.
The next thing to check is what approaches are available into Macomb. The prevailing winds in the midwest are from the west and Peoria is east of the field, so it looks like LOC 27 will be a good choice.
The approach starts at PIA and continues southwest until capturing the localizer and turning inbound to Macomb. We can descend to 1900 feet once on the localizer and before we get to our final approach fix at JZY.
But wait, JZY is an NDB (Non-Directional Beacon). And, looking at the header it says “ADF REQUIRED”. Well, that’s no good. The airplane I have on Saturday doesn’t have an ADF (Automatic Direction Finder), the receiver for an NDB signal, so we can’t use this one.
The next approach to look at then becomes GPS 27. The course then gets adjusted to add LOGOS to the flight plan. Ok, good to go again. LOGOS is our feeder into the GPS approach, that keeps us in victor airways until close to Macomb, and then we fly to ZUPOK and the rest of the approach.
Unfortunately, we again run into trouble because I’ve forgotten that the same downgrade in aircraft that took us into one without an ADF also means that we’ve lost GPS. So, this approach is completely out of the question.
The problem with losing those approaches is that they are the ones that get us down to 300 feet above the ground. If we lose them then we do still have one option. This one only gets us 600 feet above the ground, a difference that can be significant in many IFR circumstances. The only other option is to fly VFR, which is a heck of a lot worse.
That final approach is a VOR/DME-A or an approach into the area for circling rather than to a specific runway. Once you get to a certain altitude (573 feet above the ground in this case) you can’t go any lower because the procedure covers a wide area and has to give you protection from obstacles the whole way. So in this case you fly to BRL thence southeast for 12 miles. Once 12 miles away from BRL it’s safe to descend to 1280 above sea level (573 above the ground) and hope you are out of the clouds.
At this point, finally I catch a break and after initially thinking the plane I’ve got reserved doesn’t have a DME I get word that it really does. Looks like we’re good to go!