A laser nephelometer developed for airborne measurements of polar scattering diagrams of atmospheric aerosols was flown on the NCAR Sabreliner aircraft to obtain data on light-scattering paramters for stratospheric aerosol particles over Alaska during July 1979. Observed values of the angular variation of scattered-light intensity were compared with those calculated for different values of the asymmetry paramter g in the Henyey--Greenstein phase function. Our observations indicate that, for the time and location of the experiments, the Henyey--Greenstein phase function could be used to calculate polar scattering diagrams to within experimental errors for an asymmetry parameter value of 0.49¿0.07.