As an engineer looking at the 170B/172 from a mechanical design
standpoint, I particularily admire the roller-track system for the
flaps. Notice how the track etc system is arranged so that the flap
extends with a single pushrod (on each side of the A/C) yet is fully
restrained in the yaw direction.

Another feature that was new then was the centered and locked nosewheel
when the nose strut is extended.