We have been taught as student pilots to aim for the numbers while on final for landing.
Aiming for the numbers (or other aim point) is good advice, since it is one way of ensuring we stay on glide slope. However, it is often what we are not explicitly told that becomes the bane of successful execution of a maneuver, whether in flying or other activity. Namely, when is aiming for the numbers no longer a good idea? Knowing when to break off aiming for the numbers can help alleviate the problems many students seem to have in the final moments before touchdown. After flying a consistently stable approach, they still manage to slam the aircraft onto the runway somewhere between the traditional roundout and the flare.
Let us first examine why aiming for the numbers is good advice.
We know, either intuitively or through experience, that a stabilized approach is key to a good landing. A stabilized approach means that the aircraft is:
a. in the recommended landing configuration – gear down and flaps extended as recommended in the POH
b. aligned to runway centerline at airspeed recommended in the POH
c. on the correct glide-slope to the runway
Aiming for the numbers is a mechanism to keep the aircraft on glide slope. Essentially, aiming at a fixed point on the runway means that we do not let that point move up or down in relation to another imaginary fixed point on the aircraft windshield. (Instructors sometimes advise marking a cross on the windshield with a soft pencil and keeping that mark and the aim point aligned at all times).
If the aim point seems to be drifting up on our windshield, we are sinking below the glide slope; if it drifts below, we are rising above. (For the more sharp-eyed readers: Yes, the mere fact that the aim point and the imaginary cross on the windshield are aligned does not mean we are on the correct glide slope. All that the drift can tell us is that we are sinking below or rising above an arbitrary slope. In effect what we really do is that we rely on experience to recognize the runway picture of the glide slope (3, 4 or 5 degrees; power-on approach assumed), acquire that glide slope as our arbitrary slope, and then use the aligning technique to maintain that glide slope).
So why does this seemingly useful technique cause so much grief?
The fault lies not in the technique, but in not knowing when to break out of this rule. Students religiously follow the glide slope almost down to the runway, and then try to execute fairly abrupt roundout and flare by attempting to yank the aircraft level parallel to the ground. This, more often than not, results in abrupt ‘arrivals’ rather than landings as the yanking is invariably too late and the aircraft still carries considerable downward momentum and more or less 'impacts' the ground.
When must one break off aiming for the aiming point?
Aiming for the numbers does not mean that one must almost reach the numbers before one can flare. Keep coming down the glide slope while aiming for the numbers, but, at between 30 and 50 feet above, start pulling gently on the yoke so that the roundout starts very gently and the runway starts leveling out. This will cause your aiming point to drift below the imaginary point on your windshield. This is normal and desirable at this point. Keep practicing this (with your instructor carefully guarding the controls) till you can get to the point where you can fly almost level parallel to the runway and may be 10 to 20 feet from the threshold, while being about 5 feet up. You may elect to cut the power now, or even at an earlier point during the maneuver if you felt you were too high for the "about 5 feet up" to be accomplished at the right time. This will come with judgment developed by practice.
Hold that attitude (do not release control pressure) and look straight ahead at the far end of the runway. It will appear to be not rising or falling with respect to your line of sight. Keep watching and you will see a rise begin (meaning your airplane is dipping). The moment you perceive your airplane begin to dip, smoothly increase elevator pressure (no jerking -- and, BTW, this is flare; the earlier leveling out was the roundout) and continue to increase backpressure (do not ever stop), till the main wheels touch the runway. Then, gently relax backpressure (no abrupt letting go) till the nose wheel touches.
Breaking off from aiming for the numbers is essential to proper roundout and flare – and, consequently, to good landings.
