VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 10-04-2017, 11:45 AM
Dorfie Dorfie is offline
 
Join Date: Aug 2009
Location: Lexington, KY
Posts: 408
Default Difference between coupled ILS and GPS approaches

In case it helps anyone else, this is what I have learned.

ILS (land based approach):
There are TWO things you have to do during ILS approach that is NOT needed during GPS approach:
1. Once the ILS approach is selected and loaded, the ILS frequency is put into the standby window. You have to switch this to the active window The needles should turn to green on the HSI.
2. On the go around using the TO/GA button, the command bars is pitched up (5 degrees in my setting), the plane will pitch up to follow the command bars. Here is the catch. At the same time the the NAV function is deactivated. YOU HAVE TO PUSH THE NAV BUTTON to make it follow the missed approach. The missed approach on an ILS is GPS driven.

Any altitudes that is shown in the missed approach sequencing will be followed by the AP. The final altitude is not shown and should be set in pre-select window.

On both types of approaches, once the GS (ILS) or GP (GPS) is armed, the altitude pre-select window at the top of the altitude tape can be set to the missed approach altitude.

Setting the DA or DH (touch center of HSI or push MENU once) into the Baro MIN window also sets a pointer (CYAN) on the altitude tape that will come into view from the bottom of altitude tape as that altitude approaches. This a very handy tool to show DA approaching without number crunching. There is also an audio "minimums", but I am not sure if this is driven by the Baro MIN setting or from the published minimum.

Hope it helps someone.

Johan
__________________
Dorfie
RV10
2017 dues paid with a smile
Reply With Quote
  #12  
Old 10-04-2017, 12:13 PM
humptybump's Avatar
humptybump humptybump is offline
 
Join Date: Feb 2011
Location: Eastern Shore of Virginia
Posts: 2,960
Default

Quote:
Originally Posted by Dorfie View Post
Setting the DA or DH (touch center of HSI or push MENU once) into the Baro MIN window also sets a pointer (CYAN) on the altitude tape that will come into view from the bottom of altitude tape as that altitude approaches. This a very handy tool to show DA approaching without number crunching. There is also an audio "minimums", but I am not sure if this is driven by the Baro MIN setting or from the published minimum.
Once the "Baro Minimums" is set, the audio alert will occur when descending to/through the selected altitude independent of any active approach.

This allows to you to (1) use the feature as a reminder in any phase of flight; and (2) allows the feature to be used to set the DA for a non-precision or circling-to-land even when using a precision approach.
__________________
- Glen, ESVA
RV-8 FP IFR | Track my RV-8 | 53VG
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 09:52 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.