Today in Postal History

This airmail cover requested service via German airpost (Par poste aerienne | allemande.).
It went into the mail in Jablonec nad Nisou about 85 km northeast of Prague where it was posted with three CDS.
Note that the CDS and the return address on the reverse uses the German name Gablonz an der Niesse.
The Germanic culture of the area (Sudetenland*) certainly suggests the conflicts leading to the subsequent occupation by Germany.

Note the red German Luftpost service mark.
The cover had most unusual and ingenious handling.
The cover is a catapult flight cover sent by the 251st flight by the German airline Lufthansa
from Stuttgart, Germany, via Sevilla, Spain, and Bathurst (now Banjul), Gambia to the German ship S/S Westfalen
which was waiting in the Atlantic Ocean between Africa and South America.
Here the plane landed in the water, was hoisted on board the ship, refueled and catapulted into the air.
The next stop was Natal, Brazil, and from there to São Paulo.*

It arrived in São Paulo June 13 as indicated by the receiver on the back.
This seems to me to have been quite good service for the period.
Note this was before São Paulo was the capital.
It was still a rather remote interior center at this time.

The cover is franked with stamps from the 1936 pictorials:
one 2 Koruna dark blue green Castle at Zvikov,
three 5 Koruna green Town Square at Olomouc,
and one 10 Koruna blue Castle Ruins at Bratislava (Scott 220, 225, and 226).

*Thanks so much to Knud-Erik A. for his additions concerning the handling of this cover.  Makes a wonderful story!
He adds the following concerning the history of the S/S Westfalen:

"The S/S Westfalen was taken over by the German Airforce for use
as a supplyship in February, 1940, and used during the invasion of Norway in April, 1940.

In September, 1944, en route from Oslo, Norway, it ran into a mine near Gothenborg, Sweden and sank.
About 220 drowned, most of them Prisoners of War. "

The following history was found here:
The Westfalen was "taken over by the Luftwaffe in 1940, and
was stationed at Seefliegerhorst Hörnum/Sylt; 1.5.41 to Trondheim;
1942 to Altafjord and 1943 back to Trondheim;
Hit a mine 7.9.44 in Skagerrak (near Stora Pölsan), and sank, 150 dead."
The number of people lost seems to have been understated.