I thought an absolute rule was that if you are two or more notches below the glideslope (or two notches left or right of the glidepath) on the approach, you mus

I thought an absolute rule was that if you are two or more notches below the glideslope (or two notches left or right of the glidepath) on the approach, you must perform a go-around and try again. Maybe this is only for ILS approaches though (this was a visual approach) and maybe this is only a "rule" in quotes and not an actual rule. In any case the other posts are absolutely correct, monitoring your airspeed on the approach is arguably priority one for a pilot flying an approach. Even if the autopilot is selected and even if airspeed is being controlled by autothrottle, monitoring the airspeed is supposed to be one of the key things to check on the routine "scan" of the instruments as you come in on your approach. It's inconceivable to me that both the pilot AND the right-hand-seat instructor both missed the drop in airspeed. Also raising the nose is the wrong thing to do in response to being to low. In fact increasing power (engine thrust) is the thing one is supposed to do in order to increase altitude. Raising the nose is what you do in order to decrease airspeed. It's actually a rookie mistake that beginning private pilots flying single-engine cessnas make. They think throttle = airspeed and elevators (nose up/down) = altitude. The opposite is what you're supposed to do for stable flight.