Find the movie of this MOC on youtube:
https://youtu.be/n9sv_GWcd4c

This model was a prototype of an aircraft cargo loading platform inspired by
60k used in the US Air Force.

It was a test to operate 4 pneumatic V2 large cylinder simultaneously instead 
of PF linear actuator.

There is 4 motor used:
- 1 PF-Servo for the steering (axle 1-2-4-5)
- 2 PF-L for the propulsion (on axle 3)
- 1 PF-M used as autovalve for the pneumatic system.

If you look at the video you will see that front and aft arm can't synchronise
due, I think, to the copression of air, as a consequence the platform 
does not remain horizontal.
On a next version i will try to use two AFT/FWD separated pneumatic system.