Intercepting LOC/ILS Question..

ErnieBall

Is it correct operation of the AP in the STARSHIP to steer the aircraft towards the Localizer immediately it senses the LOC when in APR mode??

"Normally" in all aircraft i believe, when selecting approach mode when way out of the beam centre, and the CDI is all the way out to the right or left, it should not "capture" until the CDI needle starts moving towards centre.

For me in the Starship, it turns immediately towards the runway and the intercept to established gets vary late in best case. Does not seem to matter if I am in HDG or NAV mode when selecting approach mode on the AP.

Should it be this way?

Thanks! / Dave.

Black Square

This comes up from time to time with all my aircraft when astute observers notice it. This is just the behavior of the native MSFS autopilot implementation in approach mode, I'm afraid. Some 3rd part avionics developers have undertaken the substantial effort of developing their own completely independent autopilot can avoid this shortcoming. Starship would be an ideal candidate, if I was ever going to explore doing this, because my other aircraft are hamstrung by 3rd party avionics support and interoperability.

ErnieBall

Ok. Just for info, I have tested the exact approaches with my other beloved BKSQ aircraft last night, including the Caravan Pro. They all seem to behave in this respect. I even did a "brute" intercept angle of 90 deg off and about 5-10 nm out from the LOC course, and it activates nicely, sensing the LOC & waiting for the course path to get closer to turn up onto.
-just my observations

Black Square

@ErnieBall Which avionics selection were you using during these tests? Some GPS addons carry their own autopilots, which may behave differently. The Working Title GNS 530/430 has its own autopilot, and the PMS50 GTN, I believe also does not exhibit this problem. The TDS GTNxi used to use the native autopilot, but I'm not up-to-date on its current capabilities in that respect.

ErnieBall

The Pro series of Bonanza, Baron and Caravan. King Air - Analog.
Yes in those tests I used The GTN750 with the KX-155 as well. I also used the GNS430 with the Bonanza.

Additional info:
I did not use the GNS option for the Starship though, and after your post here i just tried to switch over to haing the FMS1 "driven " by the 430.
At first during flight plan loading the way you stated in the manual, by "SEND TO AVIONICS", the plan showed up completely in the CDU, but in the 430 there was a strange gap in the flightplan when i visually looked at the 430 map. I Then edited the flightplan, adding another waypoint (Instead of directly going to my approach FF), and the the plan showed nicely, and the same in the CDU flight plan page.

With this flight plan, using the GNS430 as Nav Source, it flew the legs as it should, And also, Happily, it did not Turn onto the airport direction - kinda.. - But kept its course according to my set Heading bug. Then at the correct point, it captured the LOC and turned onto final course perfectly.
Dont know if this was a "One Off" but will try several more later.

Some more info reg AP flying an FMS flightplan with the snags I mentioned (In case you can see any logic in this..) :

APR mode could drop out for no reason even after established
LOC would sometimes not capture at all, But the GS could then Arm/Capt and lower the nose, even though the aircraft was way out of the LOC Course.
Back CRS could show on the PFD & ND for no reason, even though i was heading in the correct direction TO the Runway, and not 110 deg off! (as per manual)
One more thing.. When I activated appr mode (From NAV or HDG) it directly switched to APR, Turned to an approx 45 deg angle to the LOC, and after that just kept adjusting the course mor and more towards the Runway, So when it fainally came onto LOC course, i was 2-4 NM out. I had good other data as speed & config etc.

Thanks for taking time Nick. I will also do some more flights with the GNS430 as nav source to see what i get out of it. !
Dave.