Linear pattern = RLLK RLRL LKRL RLLK | RLKR LKRL K*RL*RL RLRL
This is a really fun linear fill that incorporates a crossover with the hands. The fill is played as 16th notes over the duration of two bars. There is a Herta (hybrid rudiment) that starts on the 'e' of beat three in bar two, this is played as a short burst of two 32nd notes followed by two sixteenth notes.
Download the PDF transcription here: Linear Crossover Fill.