Temperature of gas and electric intensity of a glow discharge in a longitudinal stream of air are explored experimentally. The bivariate distribution of a reduced field gradient E/N in a gas-discharge tube is received. The numerical examinations of a kinetics of plasma of dry air are carried out. The ionization coefficients, adherence and separation of electrons are calculated. On the basis of comparison experimental and calculation dates the model contraction of a glow discharge with adherence mechanism of instability is offered.