What is a requirement for the hydraulic landing unit?

The requirement concerning the hydraulic landing unit specifies that it must be constructed using materials that can withstand the stresses experienced during operation. Using a pole made of schedule 80 PVC pipe or a similarly rated carbon fiber ensures that the structure is both strong and capable of handling the hydraulic pressure exerted during landing operations. Schedule 80 PVC is known for its high strength and durability compared to standard PVC, making it suitable for applications in which safety is paramount. Similarly, carbon fiber offers an excellent strength-to-weight ratio, increasing the safety and efficiency of the landing system.

Other options, while they may seem relevant, do not align with the specific requirement regarding the material and construction of the hydraulic unit. For example, height restrictions or built-in sensors do not directly pertain to the structural integrity and durability mandated for the hydraulic landing unit. It's essential for the materials used to meet the safety and performance criteria set forth in operational guidelines.