The first pneumatic machine I ever worked on was a Link Trainer.
I grew up on the local airport in the Texas panhandle.  We had a Link
used for instrument training.  I 'flew' it every spare minute when in
high school.  I accumulated over 400 hours in the thing by the time
I was 18 (1956).

It gave very little trouble, requiring only minor adjustments done by
a WW2 tech and the airport 'kids'.

Jon Guy
Arnett, OK