At altitude, a pilot can get away with inaccuracy and lack of precision. Not desirable but not life-threatening. However, when it comes to landing, it’s got to be spot on every time. The return to earth is the ‘bit that counts’.
Let’s start with the approach. No doubt your instructor said a hundred times that a good landing starts with an accurate approach. So make a habit of flying an accurate speed on approach. Control speed via the pitch attitude and rate of descent with thrust. You can reduce your workload by carefully trimming the plane in pitch. Most light aircraft are pitch stable. This just means that left to its own devices, your plane will hold its trimmed speed. If you don’t have faith in the designer, just relax your grip on the stick and low and behold, the plane maintains its speed. If you did nothing else and descended into the wind, the plane would arrive and you would stand a sporting chance of walking away.
However, it is far more desirable to find a runway. Following the traffic pattern should lead the pilot to the extended centreline for the approach. Success with the ‘bit that counts’ is far more likely if you line up accurately. Low-level corrections to gain the centreline complicate the procedure and should be avoided. Bear in mind that in any crosswind, the crosswind component will change as you descend. Usually, it will reduce until almost non-existent at flare height. Remember that the airfield anemometer is located at 10m (33ft). If you are doing it right, you will flare well below this level! Note that corrections to the extended centreline are achieved with the coordinated use of aileron and rudder. The nose will rarely point straight down the runway due to a crosswind component.
However, the main issue is still to improve on the ‘arrival’ described earlier. Given that the typical light aircraft weighs around 750kg and approaches at 55kts with a rate of descent of 500 feet per minute, it’s clear that the pilot must take some further action to turn an arrival into a landing.
It is pretty obvious that in the final seconds of the approach, the pilot must pitch the nose up to fly just above the runway. Bringing the rate of descent to zero at the right moment is the bit that counts. As the nose pitches up, the angle of attack and drag increase. This will cause the speed to fall. Assuming that you were carrying a small margin over the stall speed (1.3 x Vso dependant on conditions), the plane will initially float just above the runway. Inevitably with the throttle closed, it will sink and as it does, the pilot should try to prevent it from landing by pitching the nose up. Don’t give up until the stick hits the backstop. Despite your best efforts, gravity always wins in the end.
‘THE PILOT SHOULD TRY TO PREVENT THE PLANE FROM LANDING’
That’s the theory. In practice, there are many variables to be taken into account.
Firstly, there is always a wind gradient such that wind strength decreases as you descend. This is particularly the case through the last 100 feet. Surface friction is at the root of the issue. The wind direction also often varies due to local terrain and this means that the ‘headwind’ component also varies. Add into this the fact that the proximity of the ground makes any change in the rate of descent or attitude very obvious to the pilot and this means that as you descend through the last 100 feet, the speed will fall, followed by the nose dropping. This is the planes built in pitch stability kicking in and if there was sufficient height it would regain its trimmed speed. Unfortunately at 100 feet ….. Well, it’s obvious. There isn’t and it won’t.
As the plane sinks, it is very tempting to haul back on the stick. After all the ground is coming up to meet you. However, back pressure on the stick will simply increase the angle of attack and drag. The aiming point disappears under the nose. The plane levels out well above the normal flare height for a few seconds followed by an uncontrollable sink. The wing has reached the stalling angle of attack. Result ….. Heavy landing that at best bounces or pitches from main wheels to nose wheel/tailwheel and back. At worst an arrival rather than a landing ranging from expensive rectification to write off.
So what to do? Well, anticipation is the name of the game. By gently relaxing some of the back pressure on the stick as the plane descends through the last stage of the approach (approx. 100 feet) the plane accelerates under the force of gravity at the same rate as speed would be falling due to the drop in headwind component. The speed remains constant. Job done ……. well, job started because there’s more to do.
Judging whether or not there is a wind gradient or wind shear often starts before you get into the plane. It’s always a good idea to watch the windsock for a while before going anywhere near the plane. In the air, you can often sense or feel a sudden sink due to the reduction in ‘g’ force. A bit like driving over a humpback bridge. This is reinforced by the visual reference due to the proximity of the ground. However as mentioned earlier, knowledge and anticipation are the key elements.
The next point to consider is the judgment of the round out or flare. This will be easier to judge if you have a visual reference or aiming point over or around the nose of the plane. The runway threshold markings (Piano keys or threshold bar) are ideal for this. Do not aim for the airfield boundary ditch where the runway extends up to it. This gives away your margin for error. Even the ‘Ace of the base’ will occasionally need that margin. Attempting to land further into the runway without a good reference risks rounding out too high. It also reduces the available runway length for landing. A good tip to judge the right moment to round out is to watch for the runway to appear to get wider. It also helps to imagine a set of goal posts over the threshold with the aim of passing under the crossbar ….. Every time. This means that there comes a point during the approach when the emphasis swings from pitch to control speed, to pitch to control the glide path down to the threshold. If the trimmed speed has been held from 500ft down to 100ft, there is a good chance it will hold down to the threshold.
Once safely in the hold off phase, the main issues become holding a steady height above the ground and keeping straight. Key points are to vary your visual reference point to judge height and direction and be prepared to move the controls enthusiastically. They are less effective at low speed. Rudder keeps the fuselage aligned with the runway centreline. Independently the ailerons keep the wings level or establish a low bank angle to prevent sideways drift. This means you may require ‘crossed controls’. If you encounter a gust the elevator can be used aggressively to reduce the angle of attack and prevent a balloon. However always be prepared to ‘GO AROUND’.
Now that we are landing rather than arriving, don’t forget that practice makes perfect. When you return from a cross-country flight, why not do a touch and go and get in a second landing.