Lentojoukkojen teknillinen koulu, it means something like the Air Force Aviation Technology College, actually.
During the war it moved several times, to Kauhava only in 1945.
I don't know where you got this idea but IMHO this is much less plausible than my earlier explanation which was based on a 1930s document which, as I mentioned, included all such abbreviations.
Here is a link to another document listing the organization of the Finnish Army
On page 80 you will find LAs 6 which is also listed here as Lentoasema 6, Airbase 6. From 1934-36 it was Viipuri and 1937-38 Immola.
Lentojoukkojen teknillinen koulu is listed right after that, the official abbreviation is Le.Tekn.Koulu. Also "LAS" wouldn't make much sense as there is no letter "a" in the whole name...