RSFSR. Ordinary air mail letter sent from Moscow on August 17, 1923.

Cover of ordinary ail mail letter sent from Moscow to Rostov-on-Don on August 17, 1923. It was received on August 22, 1923.
Letter paid by air mail tax, overpayment is 3 rubles. Air mail postmark of arrival: "Received by air mail" on the front side of the envelope. Very rare. Folded cover, right edge is cut. With certificate of Mandrovskiy N.F.