I would love to be able to modify SIDs and STARs during flight planning with Navigraph Charts. For example, today I am using a route published in FlightAware.com from KDCA to KORD that uses the WATSN4 STAR arrival transitioning to ILS RW 27C via the VOGLR waypoint. When you look at this route you see that WATSN4 ends at CENAK which is a considerable distance beyond VOGLR. The obvious answer is to delete CENAK and connect to VOGLR via DWEEB, the prior waypoint. However this is not possible in Navigraph Charts. Even though the app displays all of the waypoints included in a STAR, the overall patterns are fixed. You cannot delete an individual waypoint or add a new one. The solution is to go ahead and export the route as is and then modify it within the aircraft FMC. I find this awkward and would prefer to be able to set up my route as I want it within Navigraph Charts so when I import it into the aircraft FMC it does not require any modification. I realize many will find this suggestion superflous as most flights are guided by ATC. However I find ATC guidance in XPlane to be poorly implemented and prefer to just fly a route that I plan and excute myself. I’m sure there are many who share that view. So being able to make changes to an established pattern, while not technically “authorized”, would be a very handy addition for desktop sim operators like me.
Another good way around this would be to take the FINAL transition for ILS RWY 27C instead of the transition. Removing a part of the procedure is not possible due to many reasons, but here are a few:
No pilot, be it a virtual or a real-world one, can change a published procedure to their liking during the planning phase. The point of having a published procedure is to improve safety by making sure that all operators stick to the same route unless otherwise instructed. This is and will always be the case in Navigraph Charts too - if you want to remove part of a procedure then you are no longer flying that procedure and you need to plan your approach manually waypoint by waypoint.
The approach chart mentions “Radar required for procedure entry”, so like you mentioned it is very likely that this approach would be handled by ATC.
“Radar Required” appears in the plan view of an instrument approach chart when there’s no way to navigate from the en route structure (a.k.a. airways) to any initial approach fix (IAF) without the help of a kindly controller. The most common reason for this is that the approach has no IAF. Such approaches require ATC vectors to the intermediate fix (IF) or onto the final approach course. Radar Required Approaches Explained - Plane & Pilot Magazine
The WATSN4 arrival is not only used for approaches to RWY 27C - it is used for the other runways as well. Even opposite runways, at least according to the arrival chart which states:
LANDING EAST: EXPECT RADAR vectors to final approach course
In this case, flying all the way to CENAK kind of makes sense for those landing on 22L/R. In the real world, you would be guided by ATC but as you already mentioned, that is not always the case in simulators.
File formats for exported flightplans do not necessarily support partial procedures. Many require you to specify the procedure separately, making modification impossible. The X-Plane .fms format is one example that works like this, here is the flight in question for example:
I
1100 Version
CYCLE 2313
ADEP KDCA
ADES KORD
DESRWY RW27C
STAR WATSN4
STARTRANS ZANLA
APP I27C
NUMENR 3
1 KDCA ADEP 14.000000 38.851400 -77.037700
11 ZANLA DRCT 0.000000 41.189722 -84.846389
1 KORD ADES 680.000000 41.976900 -87.908200
As you can tell, there are many reasons why Navigraph Charts behave the way it does today. I hope I was able to clarify some of them, and that you understand why we can’t fulfil this request.