The current implementation of RNAV approaches is not suitable for correct IFR navigation. Two glaring omissions are currently present.
Firstly, there are no missed approach legs for RNAV approaches. Non. These are included in the navdata, so there is no excuse for their omission. This single missing item is a deal breaker when it come to simulating IFR correctly.
Secondly, the CDI scale does not dynamically change scale from enroute mode, through terminal mode, to approach mode. All IFR approach capable GPS units are required to change the CDI scaling from 5nm (ENR) to 1nm (TERM) to 0.3n (APR) at the appropriate location. This simply does not happen.
The is how these scale transitions are required to work.
These two missing items are not “nice to have”, or “advanced” features. They are basic, core requirements of RNAV approach operation. Their omission is an oversight that needs to be amended if MSFS is to be seen a realistic IFR capable simulator.
Friend, in my personal case the RNAV and ILS approaches are failing me, when I create the flight plan the plane is not going in the right direction, do you know what it can be?
I 100% agree with you. If it wasn’t for FlyByWire constantly fixing Asobos shortcomings of quality control for the A320 it would be a very disappointing experience. It just baffles me how every single update they have put forth has brought cascading faults with it that I’m like " Di’d they not see this isn’t functioning correctly". While they do bring amazing scenery to the sim forefront, they are highly lacking in their aircraft development department.
You’d think it would be a straightforward load of navdata into the database. Why would some information be there and other information be missing? I wonder what the technical holdup is.
I can speak to this issue, as the Working Title CJ4 will have RNAV simulated in the upcoming version and I am working on it presently.
The navdata that is available from the sim API does have the name of the approach (e.g. ILS 21 or RNAV 21 Y), but the specific approach minimums and minimums type (i.e. is it LPV, LNAV/VNAV, just LNAV, etc) is not available in the data coming from the API. So, we will allow LPV to be flown for any RNAV, and the plane will change to the appropriate sensitivities, including switching to angular sensitivity when in approach mode and 2NM or less from the FAF.
Because the way RNAV is handled is specific to each instrument/nav system (some switch sensitivity instantly, some transition over some distance, etc), there isn’t a universal system built into the sim for this. So, each system will need code to address this issue. We will also be porting this functionality (and our overhauled flight management, LNAV and VNAV solutions) to our Garmin units once we finish rolling it out for the CJ4. So, there is some light at the end of the tunnel.
Sorry, I totally forgot to talk about missed approach.
Presently, the in-sim flight plan system, which is based on fs9gps, doesn’t have the ability to track a missed approach plan segment. Therefore no planes have this ability at current. Any plane using the built in flight plan system will not be able to have missed approach legs at the moment. The built in system is a bit strange, as it actually treats the approach as a totally different flight plan, with different limitations, including the inability to add or delete any legs.
Our overhauled flight plan system has missed approach segment support, although usage of it will not appear right away in the initial version, but likely shortly thereafter.