WHY PILOT’S DON’T ABORT UNSTABILISED APPROACHES?

 

 

WHY PILOT’S DON’T ABORT UNSTABILISED APPROACHES?

1.         The approach speed was significantly high.  It was raining and I sighted the runway very late but continued with the landing. I rounded off on the threshold and floated for a significant time landing and stopping barely inches short of the runway end. Why did I continue the approach in spite of the excess speed of 50kmph?  Why did I hesitate to go round? Why I did not go round? A survey by Flight Safety Organization says that ‘the lack of go-around decision is the leading risk factor in approach and landing accidents and is the primary cause of runway excursions during landing.’ Yet only less than 3% of all un-stabilized approaches lead to a go around.  In-spite of plethora of advisories, guide lines and benefits of going around as also assurances of immunity to pilots against any punitive action, go-around remains rare. Why is there such reluctance to go around, conscious or subconscious, even when there is enough evidence in front of the pilot that the approach is un-stabilized? Let us dwell into some psychological reasons that inhibit the GO-AROUND DECISIONS:

            -The first phenomenon called COGNITIVE LOCK UP is akin to fixation and can be defined as human tendency to deal with tasks sequentially i.e. one after the other. Under its effect pilots are inclined to focus on the current task and are reluctant to switch to another task, even if that task becomes of a higher priority for the overall outcome of the task.  Switching between tasks needs mental reconfiguration, time and effort which the brain would like to avoid as it prefers to do things sequentially by completing the present task before coming on to the new task. While continuing to land is the present task a go-around would be a new task. The switching of the task could also be effected by the perceived benefits as well as mental frame work of the pilot where he has seen approaches being salvaged from such instability. Eastern Airline Flight 401 is the perfect example of cognitive lock up where not only the Captain but the entire crew got LOCKED UP with the minor onboard emergency that of unsafe undercarriage indication. The LOCK UP was so complete that no one noticed any other parameters when the aircraft gradually descended and impacted with the ground killing all on board.

            -The next phenomenon connected and responsible for this is the COGNITIVE DISSONANCE. When we initially consider a situation we could look at both pros and cons but once a decision is made to follow a particular plan seeing both sides becomes difficult. The tendency to stick by a decision, closing oneself with any dissenting view in front or from others is what cognitive dissonance is all about. It can also be explained as the tendency to hold on to an erroneous belief in the face of overwhelming contradictory evidence. It is the disparity between aspiration and reality during the conduct of a task. There is that we humans harbor a compelling desire to complete a task once we have commenced it. This can be so compelling that we may press on although all of the indications our instincts and may be even our own colleagues telling us to stop and rethink the strategy. This is what leads a pilot to continue with an unstable approach and execute a landing. They become so focused on achieving the goal that they ignore evidence suggesting that it is not working out. In this fixated and tunneling the advisories of other crew is unheard or ignored.           

            -THE BARN DOOR EFFECT. The analogy is taken with reference to horses when they are close to the bran. Mostly the horses obey the riders wherever he is taking him however close to the barn or when he sees the gate to his house he turns into different personality and now he just wants to romp home. May be compared with get home its or pressuriitis. Perhaps the lure of just being one step away from your destination is a little too much for the horses to resist. This is what is happening to the pilot when he smells the gate and sees it. There is a special urge to mark completion of the task. In an experiment it was found that the pilots are fairly well acceptable to give wide berth to weather en-route but were more inclined to enter weather and take chances  when closer to destination. The closeness to home and inante desire to tick task completion makes go around a difficult decision.

            -THE ZEIGARNIK EFFECT is a little known psychological phenomenon that says that we are more motivated to complete interrupted and incomplete task than we are to start new ones. This cognitive bias was discovered by Prof Zeigarnik while observing the waiters taking orders from customers. He noticed that waiters would remember the exact orders of customers who had not paid than who had paid. The conclusion of this study was that we have inbuilt desire to complete an assigned task. Or our brain does not like things being incomplete. Continuing the approach and landing is akin to an unfinished task whereas a missed approach is like a new task. The mental faculties would be more tuned to complete the unfinished tasks before coming on the next task.

            -PLAN CONTINUATION BIAS is a recognized and subtle cognitive bias that tends to force the continuation of an existing plan or course of action even in the face of changing conditions. This bias becomes stronger and stronger as the task approaches the culmination point as is the case in the later stages of approach. The bias also obscures subtle clues indicating that initial conditions and assumptions have changed.  

            -MULTI TASKING is a myth. Our mind cannot simply carry out two independent cognitive tasks simultaneously. While making a difficult approach and trying to balance out parameters to regain normalcy the mind is already occupied to full and during this time to add a new unknown task would prove to be too much for the brain to handle which can fully devote to one task at a time. Hence there would be a strong heuristic telling brain to avoid the new task and continue with the present task at hand.

            -LOSS AVERSION BIAS       More applicable to the commercial world where every overshoot would entail a significant cost to the operator as also the loss of on- time status of the airline. However even the organization like IAF where the pilots are not any pressure to save fuel or time this could be seen as a perceived wastage of all the effort that has been carried out till then.

            -VALENCE EFFECT Also called wishful thinking or optimism bias.  It is the tendency of the people to overestimate good things happening and underestimating bad or negative things. So here the chances are that the pilot might be tempted to continue the approach thinking that he will be able to salvage the approach and everything will turn out just fine. It would also be accentuated by the fact that in his memory there are remnants of the fact that the approach can be salvaged.

           

2.         It is important to understand the influence of prevalent culture of the organization. Military pilots have exaggerated ego and a keen sense of competitive spirit which many times becomes one up man ship with the sole aim of being seen as better than others. A soul searching need to carried out by all especially supervisors/ seniors/Commanding Officers as to how many times they have gone-around when the approach was un-stabilized, as also how many times they have made obvious errors and accepted them publicly? The general tendency is to salvage the approach as it is seen as a personal failure and ego starts dominating. The human limitation has to be understood in correct sense and accepted. It is human to make mistake and errors will always be part of us. The supervisors need to be in the forefront to teach this fundamental truth and remove the stigma associated with a go around by accepting their own vulnerabilities and setting examples of going around.  We all must realize that making errors is not a weakness but acceptability of us as being human and human limitations has nothing to do with piloting skills .The quote by Jeromme Lederer  is as true today as it was made in 1952could serve as a shining light in seeing the human limitations : “…the average man has only one head, two hands, two feet, his response to demands cannot be guaranteed within plus or minus five percent; his temperature control cannot be allowed to vary more than a few degrees; his pump must operate at constant speed and pressure; his hydraulic system is accustomed to relatively stable conditions; his pressure containers, both hydraulic and pneumatic, have limited capacity; his controls are subject to fatigue, illness, anger, inattention, glee, complacency and impatience. This mechanism was originally designed to operate in Stone Age. It has not since been improved. The problem consists of permitting this ancient mechanism designed to function within narrow tolerances to control its destiny in a strange environment of very wide ranges in operating conditions”. There is no sortie in my 9000hrs of flying where I can say that I had not made multiple errors. It is written all over that we err, that’s why there is a runway controller who checks the position of undercarriage in-spite of having multiple checks, warnings and indications. Why do we behave as if we do not make mistakes or why do we hide our mistakes or why do we think it is wrong to make mistakes? In my humble opinion the only way to avoid is to accept it whole heartedly and talk about it in a frank and open atmosphere. I can only give an example from my experience of long distance running that I am always competing against myself and not against anyone else. We must remember that social relationships influence decisions. People tend to behave in accordance with the perceived expectation of others. Young pilots behave like old/senior pilot who takes risks. He thinks this type of behavior is expected in this organization and he tries to adapt himself to that. The worst example a senior can give is to pull out an unauthorized maneuver or salvage a difficult app against SOP and cautions that he should not attempt it. His ego has been activated and challenged and he will do it. The seed of dissonance to the SOPs has been planted.

 

3.         Yet another reason could be non existence of any hard specified criteria for a go round on approach unlike as we have during takeoff where GO/NO-GO are clearly defined by V1. The pilots would tend to skirt if the criteria are not well articulated. Many operators follow the concept of assigning GATES where the progress of the approach can be assessed and permitted to pass beyond them only if parameters are within the tolerance for that GATE. These gates can be kept as per the requirements like at 1000 AGL, 500 AGL and at Threshold. At each gate the crucial parameters need to be monitored through the criterion of must, should and recommended. The primary criterion in visual approach would be perspective and alignment whereas in Instrument approaches the glide slope and localizer deviation. In addition following parameters are to be monitored on approaching these gates:   

            (a)       Altitude

            (b)       ROD

            (c)       Air Speed

            (d)       Configuration

            (e)       Power setting

            (f)        Briefings and checks

As an example we can take an aircraft making an instrument approach on ILS at an approach speed of 120 knots. The gates he has to pass are 1000’, 500’, DH and Crossing threshold. At all these gates he checks the progress of his approach on a scale RECOMMENDED, SHOULD and MUST. Like at 500 feet he MUST be on ILS (+-1/2 dot), Speed +10kts -0, ROD 600 fpm+-100, power +-10%of calculated, aircraft in correct configuration for landing and all checks and briefing carried out. The same can be tweaked a little at 1000 feet ( like speed +15-0kts, ROD +-200feet) making sure that the deviation can be corrected so as to arrive at the next gate in correct parameters. Organization can decide on their own gates and criteria for a stable approach. At every gate the pilot will have an objective idea on the progress of his approach and level of instability providing him with an easy reference, like V1 on takeoff roll, for continuing the approach or aborting it in favor of go around. Like after V1 on takeoff the pilot become ‘go minded’ similarly at these gates on approach he could become ‘go-around minded’ if parameters are not as defined for the gate.

4.         However go around are not without any risks. One in ten go-around reports record a potentially hazardous outcome, including exceeding aircraft performance limits or fuel endurance. A go around require multiple changes in aircraft flight path including configuration. Any mistake could lead to loss of control or abnormal contact with the runway as well as CFIT. A go around procedure require precise and tight tracks due to proximity of runway and other aircrafts which would be converging on to the runway for landing or take off. There are issues height restrictions as well as wake turbulence. In-spite of obvious advantage a go around is a relatively rare maneuver for most pilots. Hence there is a need to practice more and pilots should be encouraged to go around when conditions warrant.

5.         We cannot combat cognitive biases as they exist in our subconscious but knowing about them is half the battle won as it would remind us of our vulnerabilities and limitations. One method I read long back in an article (not able to remember the book or the author) was “I always make an approach with the premise that at DH I would not be able to sight the runway necessitating a go around and diversion to the planned diversion airfield as per procedure. However if at DH I sight the runway and meets all criteria of a stable approach I would continue and land.” Makes sense as hesitation and indecisiveness stems from lack of concrete plan which makes it difficult for the mental mode to switch on to go around mode.