We introduce a modification procedure for Engel structures that is reminiscent of the Lutz twist in –dimensional contact topology. This notion allows us to define what an Engel overtwisted disc is, and to prove a complete –principle for overtwisted Engel structures with fixed overtwisted disc.
"The Engel–Lutz twist and overtwisted Engel structures." Geom. Topol. 24 (5) 2471 - 2546, 2020. https://doi.org/10.2140/gt.2020.24.2471