I am a private pilot with an instrument rating.  I remember my first
instructor telling me that early flight simulators were pneumatic.
A quick read of Wikipedia on flight simulators gets us to some
information on the "Link Trainer":

  http://www.nationalmuseum.af.mil/factsheets/factsheet_print.asp?fsID=3371 

From that web page:

     Edwin A. Link provided a giant step forward when in 1931 he received
     a patent on his "pilot maker" training device.  He had perfected his
     design in the basement of his father's piano and organ factory in
     Binghamton, New York.  Organ bellows and a motor provided the means for
     the trainer, mounted on a pedestal, to pitch, roll, dive and climb as
     the student "flew" it.

Robbie, can you dig up anything else?

Jody Kravitz - MMDigest

 [ At http://www.mechanicalmusicpress.com/registry/link/link.htm  --
 [
 [   This history of Automatic Musical Company and Link is abbreviated
 [   from the much more detailed history in the forthcoming "Guide Book
 [   of Coin-Operated American Pianos and Orchestrions" by Reblitz and
 [   Bowers.
 [
 [ A short article about Link Piano and Organ Company is at
 [   http://en.wikipedia.org/wiki/Link_Piano_and_Organ_Company 
 [ The restoration of a Link pneumatic trainer is described at
 [ The Link Trainer
 [   http://www.starksravings.com/linktrainer/linktrainer.htm 
 [
 [ Two videos about the Link trainer are at YouTube:
 [ Link Trainer
 [   https://www.youtube.com/watch?v=MEKkVg9NqGM
 
 [ Video Documentary "Link: the Quiet Genius"
 [   https://www.youtube.com/watch?v=RmuBgntYiI0
 
 [
 [ See these related MMD articles:
 [ Video Documentary "Link: the Quiet Genius"
 [   http://www.mmdigest.com/Archives/Digests/200202/2002.02.13.02.html 
 [ "Ed Link & Link Aviation Trainer"
 [   http://www.mmdigest.com/Archives/Digests/199805/1998.05.01.12.html 
 [ Other MMD articles about Link and Link instruments are indexed at
 [   http://www.mmdigest.com/Archives/KWIC/L/link.html 
 [
 [ -- Robbie