MUHAMMAD FAHMI UMAR; SRI RAHAYU SURTININGTYAS; WISNU DARJONO TU. RANCANGAN SEKTOR GROUND CONTROL PADA UNIT AERODROME CONTROL TOWER (TWR) DI PERUM LPPNPI CABANG SEMARANG. Langit Biru: Jurnal Ilmiah Aviasi, v. 12, n. 3, p. 83-90, 6 Oct. 2019.