[Reports] / Amer.inst.of aeronautics and astronautics. N 89-1142 : Acoustic characteristics of counterrotating fans from model scale tests : Rep. presented at the AIAA 12 aeroacoustics conf., Apr.10-12, 1989, San Antonio(Tx) / B.A.Janardan,P.R.Gliebe, 1989. - 13 p. - Текст : непосредственный.