E- east

W- west

N- north

S- south

So, as told in the title above, flying machines can be weird. I designed a flying machine and its behaviour is strange - pistons don't always fire at the same time when you try to launch it, but worse problem is that they work differently when facing E-W compared to N-S.

What happens is, after machine succesfully takes off in N-S direction, it doesn't stop or change direction. That is not the case for E-W.

My phone is ZTE Axon 7, running ArrowOS Android 9.0, however this happens on other Minecraft clients as well. 

*second picture shows it in action when facing N-S, sadly the slime block got invisible