Otto Nielsen Biography
The Artist name is Otto Nielson he was Danish he was painting for SAS 1946-1993 he use the sign  with the initials:  

Otto Nielsen (1916-2000) was born in Aarhus, Denmark where he was educated at Gustavus Bach's Character College in 1934-35. He loved to travel, and  he started work with the airline DDL in 1946 prior to moving to SAS
airlines, his work was reproduced on SAS calendars and travel posters from 1954 to 1976.

Otto Nielsen worked as an illustrator for a variety of authors' works including 1001 Nights in New translations 1976-80 with 1600 drawings.  He wrote and illustrated many books,including travel books. In 1973 and 1993
he made posters for the Tivoli Gardens.  He also provided artwork for several magazines and his artwork grace - the lounge at Idlewild Airport in New York.

Otto Nielsen's artwork has been exhibited at the Musee des Baux Arts in  Liege, Moderna Museet in Stockholm, Decorative Art, Museum of Vilanowie in  Poland.  In addition Otto Nielsen's works are represented at the Museum of  Decorative Art, the Museum of Danish cartoonists, Danish Revy Museum,  Danish Poster Museum, Arts Museum, the Moderna Museet and Bryn Artiyn Library in Pennsylvania.

The Otto Nielson trade mark small airplane in the sky.

The airline was founded on August 1, 1946.
In 1954, SAS became the first airline in the world to operate a trans-polar route.
In 1957, SAS was the first airline to offer "round the world service over the North Pole" via the North Pole shortcut, Copenhagen-Anchorage-Tokyo.