Cancel Of Riga / Lettonia - Details?

I already posted this topic incorrectly in the US - now here it is again:

Hello all,
I just got this loose stamp and am wondering, what the cancel is saying.
I read RIGA-LIDPAS??? ; the complete word probably ist LIDPASTS. But does it just mean airmail or airfield of possibly both?
Thank you for any comments.
Heinrich

Hi Heinz,

This has been an interesting puzzle. I'm pretty sure now it means "airmail", not "airport".

I was surprised you were suggesting LIDPASTS with such confidence until I found quite a number of RIGA-LIDPASTS postmarks on the internet from the 1930s.

Surprisingly, online translation for Lidpasts hasn't been as easy as I expected but there were lots of hints suggesting it meant Airmail in Google.

In particular, I saw a cover with a simple two-line PAR AVION / LIDPASTS etiquette.

Finally I found "Lidpasts" translated into a Japanese word meaning airmail.:)

I hope this helps.

Hi Nigel,
it surely helps. Thanks a lot! Why did I post at all? Well, it was the hyphen between Riga and Lidpas..
though I know that mail in Lettonian is Pasts I still was not sure.
I also tried the google translater which in this case was no great help.
Regars
Heinz