AN EVALUATION OF THE HEIGHT VELOCITY DIAGRAM OF A LIGHTWEIGHT, LOW ROTOR INERTIA, SINGLE ENGINE HELICOPTER
Abstract
A series of flight tests was conducted at three selected altitudes (sea level, 5000 feet, 7000 feet) to determine the effects of altitude and weight on the height-velocity (H-V) diagram of a small, lightweight, low rotor inertia, medium disk loading, single rotor, single engine helicopter. Two gross weights of the helicopter were used. Quantitative and qualitative test data were collected to determine how the H-V diagram varies with density altitude and aircraft gross weight. An investigation was made into the effects on the diagram of a delayed collective pitch application response. Results disclosed a family of curves showing that increases in density altitude and/or gross weight enlarged the H-V diagram required for a safe power-off landing. Analysis of the results revealed that the key points (V sub cr, h sub min, and h sub max), which partially define the curves, could be determined by the solution of a set of linear equations. These results were identical to those reported in FAA technical Report ADS-1 except for the constants of the linear equations and the location of the critical height. The critical height indicated a slight increase as weight, altitude and collective pitch reduction time delay were increased. An average value for the critical height can be selected without upsetting the family of curves.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1965
- Accession Number
- AD0624045
Entities
People
- Gilbert De Vore
- William J. Hanley
Organizations
- Federal Aviation Administration