Ground Rush. (Part Four)

Hit the Spot.

As we fly down our final approach we are always assessing our aim point. That imaginary spot on the runway where we project our flight path will lead us to connect with the runway. A stable approach sees that aim point sitting steadily upon the same point in our windscreen as we drive towards it at the nominated approach speed. Unfortunately, that spot can sometimes wander up and down the windscreen.

‘Nailing’ that aim point is more commonly referred to as aim point retention. A frequent scenario sees the aim point move further down the runway in the latter stages of the approach. Sometimes this is because in the heat of battle the pilot loses a degree of discipline in focussing on the specific point, lost in the looming runway. Occasionally, it results from trepidation on the part of the pilot manifesting in unwarranted back pressure on the control column, raising the nose. In either case, the touchdown point will occur much further down the runway, just as if excessive speed had been carried into the flare.

Equally, ‘target fascination’ with the aim point can result in the pilot arriving at the correct point, but driving it into that point rather than flaring. In the worst case the nosewheel can actually touchdown first, causing damage or a potential ‘wheel-barrowing’ situation; neither are advisable. This issue can be particularly significant at night as the landing lights illuminating the runway almost transfix the pilot’s line of sight to the tarmac at the very time that the eyes should start to look ahead. The goal is to retain the aim point until we arrive at that wonderfully vague point in space where flight down to the runway transforms into the landing manoeuvre known as the flare. Hold onto the aim point for too long and the aircraft will most certainly make an arrival rather than a landing.

Just as with speed, aim point retention or lack thereof, can be a contributing factor in the ‘where’ and ‘how’ of an aircraft’s landing. Often aim points can wander or become hypnotic when pilots are tired and the end of a long day, or a session of circuits. Be aware of where you are looking and work at flying there, but also be ready to release the point when the flare dictates.

Showing Some Flare.

At that point when the approach becomes the landing, the pilot’s eyes should release the aim point and rise towards the runways end. At this point the ground will rise in the peripheral vision and assist in judging the rate of closure while the focal point ahead will offer cues for maintaining directional control. The pilot is now endeavouring to bleed the energy from the aircraft by reducing power and increasing the angle of attack with back pressure. Lift is still being generated, but without adequate energy, level flight is replaced by a controlled descent to the runway. Occasionally, the reduction in power is not complete and the aircraft may elect to continue flying in ground effect, so make sure that when it is time to land, the thrust is reduced fully.

Playing it Straight.

The need to be aligned with the runway at touchdown has been previously emphasised. It avoids directional control issues during the ground roll and undue trauma to the undercarriage. The most obvious challenge to this objective is the crosswind and instructors and students continue to battle this fiend using a variety of techniques from the ‘side-slip’ to the ‘crabbed’ approach where the aircraft is aligned in the flare.

Yet at times, the wind does not need to be abeam for runway alignment to wander. On final, pilots develop a ‘wing walk’ where they oscillate aileron, or occasionally rudder, inputs with a resultant rolling or yawing motion. Presenting as gentle S-Turns as the pilot chases the centreline, it is often merely a case of P-I-O; (Pilot Induced Oscillation). PIO can occur with the use of elevator as well and results in a lot of effort for no benefit. If centreline management is proving a struggle on final, then relax all control inputs and see if the aircraft is actually trimmed and flying well. The problem may simply be over-controlling, which if carried into the flare can cause all sorts of confusion.

A Thought on Short.

A short field landing is achieved by flying a standard approach at a slightly lower speed and achieving the desired touchdown point with precision. It is NOT achieved by a very low speed/high thrust undershoot approach, dropped onto the near end of the runway and followed by excessive braking. This latter technique has more holes in it than Swiss cheese as it doesn’t account for obstacles on approach, avail adequate thrust and airspeed to conduct a missed approach and runs a high risk of flat-spotting a tyre. And yet you will see it time and again.

Short field landings are more than ever about a stable approach, flown at a minimum safe margin speed over the stall. The standard approach perspective means that no major adjustments in technique are called for and those trees on final are not a threat. Aim point retention is doubly important as these approaches are generally necessitated by length critical airstrips. At a lower speed, there will be less energy to dissipate, so the landing flare is initiated a fraction later. This assists in achieving the aim point and avoiding an unwanted float down the runway. Fly the book figures as they appear in the Flight Manual and always verify the field length is adequate from the ‘P-Charts’. And check that adequate length exists to depart again before committing to a landing is always well advised.

Airmanship and Away!

In all landings, AVIATE-NAVIGATE-COMMUNICATE. In a tight traffic environment, don’t succumb to subtle pressure from ATC to expedite clearance of the runway. As an aviator, airmanship dictates that you won’t dawdle unnecessarily on the runway after landing. Jumping on the brakes and blowing a tyre or snapping a nose-gear won’t help anybody. You are the pilot in command, fly the aircraft to the best of your ability and if inadequate separation has been provided with the following aircraft then they can go-around. Similarly, these requests can be made as the aircraft is rolling out and should not be acknowledged unless the aircraft is well and truly decelerated and under control.

In all cases, on approach, in the flare, or after a bounce, if the pilot is not happy with the situation then conduct a missed approach. As the saying goes, “If in doubt. BUG OUT!” Generally, the earlier a poor situation is abandoned, the simpler the extraction. Time affords a more organised abandonment of the approach in an unrushed manner. For this reason, the go-around should be practised at various stages of the approach and landing throughout a pilot’s career. It is a manoeuvre that can be called for at any time and requires the correct sequence of actions and the management of trim that can prove awkward. A prudent, competent missed approach is a strong weapon in a pilot’s arsenal.

For all of the variables that the aircraft and environment can provide, it will always be impossible to detail them all in the written word. Similarly, nothing can substitute the positive input from a proficient instructor for both the student pilot and the qualified aviator who is lacking currency. What the 'Ground Rush' has sought to emphasise is the common traps that plague the landing phase and to reassure one and all that the landing is not the ‘make or break’ of a pilot.

The landing is merely the arrival at the end of a flight that has called for all manner of skills enroute. Highly rated and unfairly judged, the landing will continue to be the secret nemesis of many pilots. However, in its most basic components it is about being on speed, on aim point, on slope and aligned with the runway. When the ground rush is sensed and the earth moves up to meet the wheels, it is all about safety........finesse will come with time.

Missed the story so far?

CLICK HERE to begin 'Ground Rush' at PART ONE.

Ground Rush. (Part Two) 

An Aviation Training Blog

by Owen Zupp.

Be Consistent.

It always pays to have a consistent set of terms of reference. The environment and the aircraft can introduce enough variables, so it is important that we endeavour to keep our methods constant.

One of the first items we can attend to for landing occurs even before engine start; seat position. Logically, seat position determines our ‘eye position’ which is critical in the process of perspective and judgement. Some aircraft provide a series of markings or guides for the best eye position, though the majority leave seat position up to the individual. Internally, the seat must be far enough forward to comfortably access all controls and switches while permitting full and free movement of the control column at its aft-most travel. For those aircraft with fixed seats and adjustable pedals, the same effect can be achieved through the use of cushions. The position should also permit a clear view of all instruments and annunciators without being obscured by the instrument panel coaming. (This can sometimes be a challenge with ageing, drooping coamings and another reason they need to be maintained.)

For the view outside, the positioning of the seat should permit a clear view ahead above the instrument panel. Commonly, pilots can sit a little low, but ideally they should have a view along a tangent down the nose. This will ensure an adequate forward field of vision in low visibility operations. This seat position is best assessed on the ground just before engine start. To do it any earlier may result in having to repeat the process after you move the seat to access a jacket on the back seat, or close a door.

Scan the instrument panel, exercise the controls fully and look well ahead to visualise the landing perspective. The perspective will be different on approach, but selection of flap will lower the nose further and enhance the outlook. If flying the same aircraft day after day, this exercise may come naturally, but take a little more time and effort when moving between aircraft. On approach with the seat adjusted correctly, remember to sit up straight and the eye position will offer a relatively consistent perspective on each approach. It is worth noting that if the seat position doesn’t feel quite correct coming in to land; LEAVE IT ALONE! Do not adjust seats on approach as the potential catastrophe from a seat sliding back is not worth the attempt.

It is often said that a good landing results from a good approach. This is fundamentally because a good approach involves being configured in a timely fashion, with correct speeds being flown and a stable rate of descent. It may be flown from a base leg or a straight in approach, so the perspective can change. What remains consistent is that the approach is unrushed and the pilot is able to focus on the approach and landing without being distracted by gross adjustments of airspeed and/or attitude late in the approach. Should these occur the safest option is generally to go-around and attempt another approach to land.

If new to a particular aircraft type, not overly current, or even just a little uncomfortable; establish the aircraft into its landing configuration of gear and flap setting early. It will result in slowing down early and powering up against the extended drag, but it allows the aircraft and the pilot to be established in the landing ‘mode’ without being rushed. With the landing checklist complete, there are no other tasks to distract for the primary one of flying the approach. There should be no further major changes in attitude or trim and the ‘picture’ out the front should remain fairly consistent down to the flare.

Once stable and configured on final approach, the aim point should be clearly selected. If not marked by a painted stripe, it may be abeam a group of trees or a darker patch of dirt. Whatever it may be, the pilot should pick the spot and keep it steady in the windscreen by whichever technique they have been instructed. However, the eyes should not be obsessed with the aim point. There must be scanning cycle that assesses the approach perspective, or ‘slope’, the track relative to the centerline and even a brief glance back inside to verify the airspeed. A mental repeating mantra of something like; ‘aim point-slope- centerline-speed’ may remind the pilot to continually assess the various aspects of the approach. Importantly, if something is not correct, fix it before moving onto the next point, always being aware that adjusting one element may impact upon others. As the approach gets closer to the ground, the adjustments should become progressively more subtle, notwithstanding that wind shear and the likes call for significant action regardless of the aircraft’s location.

Correctly flown, a stable approach flown with a consistent, cyclic scan will bring the aircraft over the fence in a healthy state to commence the flare. A ‘last look’ inside may be stolen to indicate whether the speed is a little fast or slow or trending, but otherwise the eyes are outside. The subsequent transition to the flare calls for the pilot to look ahead and release the rigid eye-line to the aim point.

Ground Rush.

The runway is now just below the wheels and the flare is about to commence. Much of the hard work has actually already been completed, so what can go wrong now? How can a stable approach be complicated at the last moment, or in some cases much earlier? Next blog, a number of variables will be discussed from over-controlling to cross-winds. When the wheels approach the earth some of the challenges are of the pilot’s making and others are most definitely not.