Accession Number : AD0754420

Title :   Air Density and Helicopter Lift.

Descriptive Note : Final rept.,

Corporate Author : NATIONAL BUREAU OF STANDARDS WASHINGTON D C

Personal Author(s) : Jones,Frank E.

Report Date : JAN 1973

Pagination or Media Count : 57

Abstract : An analysis has been made of ideal and real gas equations as they apply to the calculation of air density in the region of interest for helicopter flight. The uncertainties in calculated air density due to uncertainties in measurements of temperature, pressure and humidity have been investigated and estimates have been made of measurement accuracies which would be required to enable calculation of air density with a desired relative uncertainty. A reference system has been assembled to provide measurements of temperature, pressure and dew-point temperature aboard a helicopter. This system is to be used in making calculations of reference air density for flight tests of a system for computing hover lift margin and several devices for measuring air density.

Descriptors :   (*HELICOPTERS, *LIFT), (*ATMOSPHERES, AERODYNAMIC CHARACTERISTICS), DENSITY, EQUATIONS OF MOTION, MATHEMATICAL MODELS, HOVERING, UNCERTAINTY

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE