起降
6.The LZ was setup and maintained in a perfectly safe and secure manner, with a textbook 4-point LZ perimeter.
7.Landing Zone was set up with five FF, excellent procedures and location.
8.The development survey of world VTOL power plant for the past half century is presented and VTOL power plant type, evolution and further development prospect are discussed in this paper.
10.A helicopter-landing zone (LZ) was established in an appropriate area approximately 400 ft from the transportation site.

