NavList:

The running fix, certainly if other fact are know, they should be used.
Estimates are not of certain, so should be closely monitored.
I would use both TRF & ERF and DR., but pick the one closer to danger to watch.
If course, speed or distance is known use it.
An old way to find course, when three LOP’S are plotted from one NAVAID with out a change of speed or course (BRG. Time must be the same for each LOP.)
Let’s use an idea known to all. This is the BOW-BEAM & QUARTER. This will work with any RFIX.
WE don’t know it but we are heading NORTH or this could be relative brgs.
Off the STBD bow @ 045 We plot 1st LOP.
Off the beam will plot 2nd 090 LOP?
Off the Quarter we plot 3rd 135 LOP.
I think we all know the answer is distance run between bearings is distance off NAVAID at 090 Beam.
No set and drift for this can problem. If we used a TRF we would have a tree pointer at LOP 135.
Using the tree LOP’s, Let us find the course, we are on.
We set the dividers at any spread larger than the distance between LOP 1 and LOP 2.
We mark the LOP1 at the point of the divider (A) at LOP 2 we mark the other point (B).
Using the same spread and parallel to (A&B) we place the dividers between LOP2 (C) & LOP3 (D.)
A line drawn from A to D is your course. Your speed and distance is the only part left.