TY - Acta Aeronautica et Astronautica Sinica A1 - WAN Haoyun, HAN Dong, ZHANG Yuhang T1 - Performance improvement of variable speed tail rotors by passively extendable chord Y1 - JF - ACTA AERONAUTICAET ASTRONAUTICA SINICA JO - Acta Aeronautica et Astronautica Sinica SP - 224981 EP - 224981 VL - 43 IS - 2 UR - https://hkxb.buaa.edu.cn N1 - 10.7527/S1000-6893.2021.24981 ER -