Timothy wrote:
We have discussed this before. It is not correct. Both Garmin and Avidyne have (I assume independently) written a simple algorithm to produce a slope from FAF to MAP. I will try to find the last time I told you that, standby…
Garmin uses the Glidepath Angle field in the (Jepp) database. I don’t see why Avidyne wouldn’t do the same.
I didn’t know that. I wonder if it’s new, because they originally described it as “synthesised” from the FAF and MAP. Have Jepp introduced that field more recently, or have Garmin started to use it more recently?
Jeppesen uses the VDA if it is published for the LNAV. The Avidyne and GTN series both support providing advisory vertical guidance for LNAV (+V) inside or outside the WAAS service volume. Support for LNAV/VNAV is only available inside the SBAS service volume.
NCYankee wrote:
Support for LNAV/VNAV is only available inside the SBAS service volume.
Unless you are using Baro-VNAV.
Do you confirm +V advisory for LNAV is available outside SBAS ?
PetitCessnaVoyageur wrote:
Do you confirm +V advisory for LNAV is available outside SBAS ?
I believe that this is a relatively new feature, possibly as recent as v6.41 of the GTN software.
I believe that this is a relatively new feature, possibly as recent as v6.41 of the GTN software.
Yes, it apparently is. No +V advisory in South America on the GTN, SW not updated within the last year.
If technically possible, i can always dream to see my non WAAS G1000 updated to provide +V to LNAV :-)
I wonder what are the conditions which made +V available outside SBAS, whereas it was not initially.
PetitCessnaVoyageur wrote:
Do you have an example of approach where LNAV/VNAV has lower minima that LPV, according to the differences you explained in obstacle clearance computation ?
Straubing EDMS.
Regarding the lower minima on LNAV/VNAV than LPV approaches in Germany I also heard, that it was due to using the data from the last calibration flights/obstacle surveys which where not specifically for LPV and hence had to use some conversion methods which result in a penalty. It was also said, that with the next calibration/obstacle survey the LPV minima will probably change.
JasonC wrote:
Unless you are using Baro-VNAV.
Yes, that comment was only referring to the Avidyne and GTN.
