First Day of Issue = March 15, 1933
Size: 26.00 mm x 33.00 mm
Quantity printed = 12,620
Perforated 10.00 x 11.50
Print method: Lithography

Stamp shows Icarus Falling. The surtax was for wounded Latvian aviators.

Watermark



Catalog numbers
Scott CB14
Michel LV 215A

For more information check out the links below
Latvian airmail semipostal stamps
Latvian aviation
The myth of Icarus