Quasi-Steady Maneuvering of Pendant Dual Lift Systems
Abstract
The US army flight research group at Moffett Field (CCDC AvMC ADD-A) undertook a dual lift project in which the load is carried in a pendant two-cable suspension. Work on simulation, feedback control, wind tunnel testing and a flight test with two RMAX helicopters has previously been published. This report analyses configuration management of the system to maintain the prescribed loading ratio for the two helicopters in general quasi-steady maneuvering flight. For equal cable lengths, equal loading is obtained by maintaining the hook-to-hook line segment perpendicular to the total load to be supported by the helicopter. The system can be flown with any formation angle. It was found that the side-by-side formation had general advantages in terms of simplicity of the required configuration management activity and insensitivity to load drag. Sensitivities of the cable tensions to configuration variables indicate that cable tensions are readily controlled by adjusting the vertical position of one helicopter relative to the other and that this sensitivity is nearly invariant with airspeed, formation angle and maneuvering. A study of a system of two UH-60s indicated that load drag and airframe aerodynamics have significant effects on helicopter thrust and attitude requirements in forward flight, depending on formation angle.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2019
- Accession Number
- AD1080150
Entities
People
- Luigi S. Cicolani
Organizations
- San José State University