I'm struggling to see why this SCA method is simpler than what fudgy has been taught.
It seems as though the pilot must fix her position and then use two numbers: the number of miles off track, and the number of degrees off track (drift error). She then applies the SCA for the number miles off track, and the drift error correction for the number of degrees off track. Once back on track, she applies just the drift error correction to maintain track. Two angles, one distance, one time. That feels like a lot of numbers to mix up.
By contrast, fudgy's instructor's method involves evaluating the number of degrees off track at a given elapsed time. She doubles it and turn back that amount towards track for the same elapsed time. Once back on track, she applies just the single drift error correction to maintain track. One angle, one time. It's also likely to be a great deal more operationally expedient, as the drift error will usually result in a much smaller closing angle than 40 degrees. For the same reason it's less susceptible to gross errors if the pilot gets distracted while closing the track.
Each one to his goat, I guess.
