Air Mail cover 1930 (31 Aug.) Vaduz-St. Gallen first flight cover, bearing 1930 Air set of six plus 1930 30r. and 50r., all cancelled by special boxed cachets in red; 1930 (Sept.) Ostsee flight cover addressed to Vienna, bearing 1930 Air 25r., 45r. and 1f. pair, showing special cachet in green with Tallinn c.d.s. on reverse; 1930 (16 Nov.) Sachsen flight cover, bearing 1930 Air 25r., 45r. and 1f. pair, and showing special red cachet; 1931 (29 Aug.) First South American flight cover, bearing 1930 Pictorial 40r., 2f. (2) and Air 1f., showing special green cachet with Rio c.d.s. on reverse. (Sieger 88B, 100A, 124C)