Quote :
WHEN LANDING GEAR IS DOWN
FLAPS 3 ...........................................ORDER
FLAPS 3 ............................................SELECT
Check Airman : I don’t read that as “wait for three greens to move the flaps”.
Are you sure ? "WHEN" seems fairly clearly to be a conditional clearance, relying on something else having finished first, in this case the landing gear being down. i.e. you wait until the landing gear is down before moving the flaps further. How do you know the landing gear is down? = you have three/four green lights on the Gear panel and/or at least three/four green triangles on the Wheels page.