FSX:SE GPS APPROACH APPROACH TYPE

[delivery guy]

Does this variable work? When testing we show value of zero. Does it work with other GPS addons like Flight 1 GTN750? Is there a way to detect the type of GPS approach?
We want to detect linear and angular but the list below does not even have LNAV or LPV. Does anyone know the difference between GPS and RNAV in the list below?
(A:GPS APPROACH APPROACH TYPE, Enum)
Approach type :
0 = None
1 = GPS
2 = VOR
3 = NDB
4 = ILS
5 = Localizer
6 = SDF
7 = LDA
8 = VOR/DME
9 = NDB/DME
10 = RNAV
11 = Backcourse

 

[Roy Holmes]

Those are all types of approach that might be a feature of a particular airfield and are not airplane related as such.
GPS was the original of its type and has evolved into RNAV of which LNAV and LPV are characteristics.
Roy

 

[WarpD]

LNAV/VNAV, LPV, etc... weren't in use when this GPS code was written. I believe the first WAAS was in 2008? As for GPS versus RNAV, the primary difference is that an RNAV approach has an accuracy requirement, called an RNP (which was typically 0.3 (three tenths of a nautical mile)). This accuracy requirement meant that specialized avionics certification was required to fly an RNAV approach. A GPS approach had no such restrictions. GPS approaches are being phased out for the more accurate RNAV approaches since newer GPS systems conform to the RNP certification.

 

[rpmc]

Does this variable work? When testing we show value of zero.

(A:GPS APPROACH APPROACH TYPE, Enum) works fine.

It is analogous to the gps variable C:fs9gps:FlightPlanApproachType, although the approach types are listed in different orders for each variable so the numbers returned aren't the same. (A:GPS APPROACH APPROACH TYPE, Enum) will return zero until an approach and transition are selected and loaded. The approach doesn't have to be active, just loaded.

Does it work with other GPS addons like Flight 1 GTN750?

Yes, it should

Is there a way to detect the type of GPS approach?

LNAV and LPV approach types are not included in the gps module (a slightly longer list of approaches can be found here). Furthermore, as far as I know, the gps module does not include approaches for every type in that list. For example, I have found no SDF approaches. But, it has to be on the list to be 'detected'. My comments pertain to the gps.dll module shipped with FSX. LM have upgraded the module since they have been in control by adding capability such as arrival and departure procedures, but I don't know if they have expanded the approach type capability.

We want to detect linear and angular but the list below does not even have LNAV or LPV.

No idea what you mean by this. Would you please explain further?

It sounds as if you are opening the door to the gps module’s world. If so, welcome. Make a pot of coffee and prepare for study and much testing. There’s a lot in there, but anyone with good xml skills and persistence can get it.

Bob