Planning an RNAV (GPS) Approach

[JesC 88]

I have been surprised when flying some GPS approaches to discover they have no vertical guidance in the simulator. The published approach seems to indicate LNAV capability, but no vertical is displayed in the sim during the approach.

My question is if there is if some way to determine if VNAV capability exists for the anticipated approach at the sim airport during preflight planning. (I guess I just don't like surprises during an approach. 😧 )

I am using the RXP GNS 530/430 in P3Dv5.

Thanks for any help or suggestions.

Jesse

 

Edited November 5, 2022 by JesC

[C2615 319]

IRL you'll find it on AFM, but it's more complicated in sim.

If the weather is not that critical, use the higher minimum of LNAV only, plan for both, and if VNAV turns out to work, then use it, I even do this on 737 as the FMC do sometime go haywire, especially in training condition you might not have full route setup.

[BerndB 349]

18 hours ago, JesC said:

I have been surprised when flying some GPS approaches to discover they have no vertical guidance in the simulator. The published approach seems to indicate LNAV capability, but no vertical is displayed in the sim during the approach.

My question is if there is if some way to determine if VNAV capability exists for the anticipated approach at the sim airport during preflight planning. (I guess I just don't like surprises during an approach. 😧 )

I am using the RXP GNS 530/430 in P3Dv5.

Thanks for any help or suggestions.

Jesse

 

Jesse, not sure what you mean with "VNAV capability at the Sim airport"

Bear in mind that GPS RNav is not based on terrestrial facilities at the airport like ILS. It works with virtual waypoints which are defined in the database of the RNAV instrument or FMGS of the aircraft you use. So it seems yor GNS doesn' t contain some VNAV capability. This is the case in real world too, which means in that case you just wouldn't be authorized for VNAV approach. This is the case in the real world aswell unless your aircraft has the needed capability within the GPS equipment.

Edited November 6, 2022 by BerndB

[JesC 88]

@C2615 and @BerndB

Thanks for the input. This has clarified the dilemma for me quite a bit. It seems to mostly be an issue of an aging GPS database (Not to mention the occasional operator error). There doesn't seem to be any way of reliably predicting the anomalies. So its just a matter of being prepared for a lack of vertical guidance as suggested.

Thanks again,

Jesse