step down instrument approach

fieldbaren

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Apr 25, 2020
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19
Can somebody give me a step by step sequencing when using the Dynon Auto Pilot for a step down LP approach assuming I'm at the IAF (WUBEB) at the published altitude. The example I'll give is Calaveras County Airport, KCPU (California) So I'm at 5200ft msl, I have the next altitude 3700ft msl and -800ft/min set in the PDF, so what is recommended to initiate the descent? And for the remaining step downs??
fieldbaren
 

DBRV10

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Jun 15, 2008
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Brisbane, Qld. Australia
You need VS mode, with EXPERT selected as your AP.

The AP works by a simple "Where do I want to go" and a "How do I get there" process. So for climb, set an altitude (where) and then use IAS mode (how) and away it goes. For descents use VS mode, or VNAV if the approach has vertical guidance (must start below or on the profile).

Does that help?
 

fieldbaren

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Apr 25, 2020
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19
yes and no..
Let's assume the approach is activated, I'm in GPSS mode, altitude hold with VS and altitude armed and just completed the procedure turm in bound to the FAF. so you are saying if I understand correctly, when I cross the FAF all I have to do is hit the VS button and that will activate the descent. It seems with multiple step downs there has to be a faster and easier way!
fieldbaren
 

DBRV10

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Jun 15, 2008
Messages
925
Location
Brisbane, Qld. Australia
If you are stepping down, you would be say at 6000' inbound, and for the discussion say the two steps are 4500 and 3000' and 5+ mile spacings.
When inbound at 6000' you would be in GPSS and ALT mode, with the 6000 captured.
Dial in the next step, which is 4500' and wait. When you hit the descent point, hit DOWN button (puts in VS mode and nose down at your default VS rate) and adjust for a 3 deg profile of half your GS plus a zero, so say 120 knots and 600'/min.
Once that is under way the next step is 3000, so you can either determine that you will meet the sector minimum and it is safe to dial down further, or once the 4500 is captured (listen and watch for that) then dial in the 3000 and wait until you pass the next descent point and hit DOWN again and adjust for the profile you want.
Obviously if you want to dive harder and level out you can.
 

fieldbaren

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Joined
Apr 25, 2020
Messages
19
THANKS DBRV10.
That make sense. I will try that later this week and report back.
FIELDBAREN RV6
 
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