Complex sentence: In the difficult southwest sector he employed an inexperienced 3rd class controller, 20-year-old Nikolai Zhukovsky, under the supervision of 1st Class controller, 28-year-old Vladimir Alexandrovich Sumy.
Split into simpler sentences: In the difficult Southwest sector he installed an inexperienced 3rd class controler, 20-year-old Nikolai Zhukovsky. Supervising the work of Zhukovsky was a 1st Class controler, 28-year-old Vladimir Alexandrovich Sumy.