Air Mail cover CRASH COVERS: 1936-74 collection with 1936 Scipio crash off Crete envelope from Hong Kong, 1937 Cygnus crash at Brindisi envelope from Hankow, 1953 Comet crash at Calcutta envelopes from Hong Kong (3), 1954 Singapore crash registered cover to Hong Kong, 1970 envelope from Kowloon to London with boxed "DAMAGED BY SEA/WATER", 1971 (c.) envelope from New York to Hong Kong with bilingual cachet "DAMAGE DUE TO MISADVENTURE/TO CONVEYING AIRCRAFT" and 1974 local cover endorsed "RECEIVED IN WET SUCH CONDITION"