If you don't have a perfect track log, say you need to stitch
together two track logs because there was a glitch in the flight recorder, you
can cure the problem in FS with manual scoring, or by manually stitching flights
together. Super scorekeeper, Evgeniya Laritskaya, tells us how:

There are at least two ways to fix the problem.

First, yes, manually entering the right flight parameters. Like this:

And then:

Enter times and distance there. That's it.

Second, scorer may modify the track, combining two igc tracklogs in one.

For that, scorer has to open both igc tracks in any text editor (Notepad, for
instance). He will see something like this:

Each igc file consists of header lines, flight itself and footer lines. Each
flight point like starts from time in UTC format.

All scorer has to do is to copy FLIGHT POINTS (without header and footer) from
second IGC file and paste them between flight points and footer of the first igc
file. Watch the times. Then save the new file. Most likely, FS will score it
properly afterwards. Little more technical work, but don't need to do any manual
measurements this way.

By the way, we often use SeeYou to help us make any manual
measurements if we need to do that.