Complex sentence: The aircraft has adjustable leading-edge vortex controller (LEVCONs) designed to control vortices generated by the leading edge root extensions for trim as well as improved behaviour at high angle of attack; the LEVCONs also allow quick stall recovery if the thrust vectoring system fails.
Split into simpler sentences: The aircraft has adjustable leading-edge vortex controllers (LEVCONs) designed to control vortices generated by the leading edge root extensions. The LEVCONs can be used for trim and improving high angle of attack behaviour, as well as allowing quick stall recovery if the thrust vectoring system fails.