IAP: Accuracy outbound from LOM
This question is about an instrument approach (in the US if it makes any odds), where a NDB is located at the outer marker.
The procedure shows the NDB is tracked inbound, from a nearby VOR with a prescribed course from the VOR. Due to the angle of intercept to the final approach and the proximity to the runway, an outbound turn is required at the LOM, followed by a procedure turn back to the final approach course.
With no DME available from the VOR to the outer marker the way to know you have reached it will be the swing of the ADF. So as it starts to move, you make a turn to track outbound. Given that this won't be all that precise one would likely end up slightly off the exact reciprocal of the final approach course.
My question is, to what extent is it necessary to establish the exact outbound course, which would involve figuring out which side of it you're on (not hard) and manoeuvring accordingly? In a way it doesn't much matter, because the procedure turn (a somewhat imprecise manoeuvre itself) comes at a self-determined point (within 10 miles of the marker, as per the approach plate) and you then have the guidance of the approach for the exact inbound course.
If there is a difference, which I assume theoretically there would not be, I'm interested to hear views on both a real-world scenario and that of an IR flight test.
For anyone with US plates available, the particular case I'm wondering about is ILS 27L to South Bend, Indiana.