Wednesday, May 13, 2009


The weather was just perfect. Very few clouds in the sky and mild temperatures made it a perfect day for flying. I got to the airport on time and spent a few minutes with the CFII to go over the last flight. (VFR entry and pattern altitudes, where documented,, not necessarily in the Airport/Facility Directory.)

Ground work went fine. I took my time setting up the radios on the ramp and was introduced to pulling up charts on the MFD suing the select function rather then loading them from the GNS430. It is pretty much the same method of selecting letters by scrolling through the alphabet. The rest of ground procedures including run up, copying simulated clearance and take off all went well. I engaged the Nav function too soon on departure (still on vectors so should have stayed in HDG mode) but the rest of the air work was OK.

Objectives: Terminal Procedures. The LOC 28 approach at Pottstown is pretty straight forward. Holding pattern in lieu of a procedural turn, Googl Intersection is the Initial and Final Approach Fix and is defined by the final approach course (276) and a radial (160) from the East Texas VOR (ETX).Missed approach is a climbing right turn heading 090 until intercepting the ETX 160 then back to Googl to hold. No tricks involved, all in all as simple as they come.

So if this was so easy how did I end up with this spaghetti?
It all has to do with with interaction of the GNS430, and understanding of the reference points it uses and how it tells the autopilot to fly the various aspects of the approach. The last time I was IFR current I used a GNS430 along with with two CDIs and one with a glide slope. (Also had an ADF that I never used.) My transition is to take the knowledge I had then and apply it to what I have some cases that can't be done.

First Attempt: Late transition, and used too shallow a descent on the autopilot (-500) so never had a chance to get down to the MDA. Executed the published Missed Approach. ETX is in the VLOC2 so I look for my #2 CDI. Don't have one. So I stumble figuring out that I can use the Bearing indicator and wait for the tail to fall to 160. OR, better method would be to switch the source for the CDI to VLOC 2 while flying the HDG of 090.

Once on the 160 Radial then what? Let's go direct to Googl. So, I open the FPL on GPS1, find GOOGL and punch direct. AHAH! Which GOOGL? It makes a difference for the logic of the system. So it took me some time to understand the differences and how it would effect the track the autopilot would choose to fly.

Another Attempt. There is a subtlety setting up the source and switching from VLOC1 to GPS1. You must insure that you GPS is selected prior to initiating NAV GPSS mode, otherwise it generated a "Fail" message. I also asked about timing. There is a timer incorporated under the function button on the transponder. The GNS430 can also be used to provide time to the fix. In all attempts I forgot to use either one.

Final attempt: resulted in a full stop landing.

Next I set up to return to KLOM. Used the Menu button on the GNS430 to reverse the flight plan and planned for the GPS 6 circle to land 24. I copied Radar Vectors, took some heading changes and briefed the approach. My setup was slow, slightly overflying the final approach course. I did get all of the correct indications and understood what the system was presenting and knew it was correct. However I lowered flaps too soon and allowed the airplane to slide above the glide slope as I prepared for the pattern entry. The landing was good, although to much speed on final forced a long roll out.

Fantastic learning session.

Time = 2.0 hours


  1. Good to see you again Dave. We did the GPS 6 circle to land 24 as well on the way back, just ahead of you. Not satisfied with his landing, Lee went around again and we took off before you turned base, otherwise, I could have gotten a photo of you on approach.

    Great night to be out flying. Sounds like that plane may still be getting ahead of you with all the fancy gizmos and gagets (IFR anyway). Best of luck! I was behind on the G1000 too, so much information there and I wanted to look for standard guages.

  2. Information overload! Sounds like a good learning time type lesson. It's hard at times staying ahead of the plane let alone all those extra knobs, buttons, bells and whistles! :) Sounds like by the last approach you had things working smoothly, it will all fall into place.

    Great write up, it's nice to read someone else describe flying the same approaches I shoot, a neat perspective.