Air Mail cover 1930 (Sept.) Russia flight cover addressed to Moscow, franked at 1g.27½c. and showing special red cachet; 1930 (Sept.) Vogtland flight cover addressed to Cottbus, franked at 1g.33½c. and showing special cachet in red; 1931 (24 June) Polar flight cover addressed to New York, franked at 2g.32½c., showing Friedrichshafen and "Malygin" d.s. and special cachet in red. (Sieger 84, 90, 119C)