How might our understanding of perception, different categories of attention, and arousal help us understand common causes of aviation incidents?
Human error plays a pivotal role in aviation incidents, it accounts for over 70 percent of aircrafts damaged beyond economic repair. Within the Human Information Processing (HIP) system perception, attention and arousal (P.A.A) all require a sophisticated cognitive process in order to comprehend and take action to distinct and contrasting stimuli a pilot encounters everyday. On a normal flight the pilots have a set checklist of workload that needs to be carried out and are trained meticulously, so performance tends to be very high because it’s a task that is carried out vey often. As the difficulty of the task increases, as such in an emergency situation the workload and task difficulty is increased unexpectedly but the time taken to deal with it is decreased.
Perception, attention and arousal (P.A.A) all play a crucial role in the way we understand the world around us and our understanding of HIP can help us how to prevent future incidents, however within this essay the breakdown within the HIP system is going to be examined and further investigation on how HIP played a catastrophic role within British Midland flight 072.
Flight BD 072 (G0BME) was operated by British Midland and flew from London Heathrow (LHR) to Belfast International Airport (BFS). In this particular incident the flight took of from LHR with 126 passengers onboard, as the aircraft proceeded to climb through 28,300ft the aircraft began to shake.
While ascending the cabin began filling with smoke, from previous training the pilots knew that the most probable cause was an engine fire.
Air Traffic Control instructed the pilots to divert to the closest airport, which was East Midlands, to deal with the contaminated air being pumped through the cabin the pilot shut down the starboard engine. The shaking and the fumes stopped temporally but on final approach a higher power setting was required and in an attempt to land the Boeing 737 the aircraft plummeted out of control crashing into the embankment.
Within this accident there were numerous failures by the aircrew, passengers and the airline itself which all accounted towards the crash.
All complex systems have barriers and safeguards in place, but all have a latent weakness. This model is known as the Swiss cheese model, the way in which the model works is the events that cause you from getting from where you are to hazardous risk accruing is blocked, the layers of cheese don’t line up. So at any point one of the barriers would be effective and prevents a hazardous situation from happening.
The problem then arises when all of the layers/weaknesses line up causing an accident; within the G0BME accident there were a number of latent weaknesses that were highlighted within the accident report:
- Aircraft Design
Human Information Processing
Information processing model proposes that our brain is similar to that of a computer in that we get:
- Input – Environment
- Process – Cognitive Process
- Output – Decision
We are not able to attend to every stimulus that our senses receive because we have a limited cognitive resource so the HIP system filters through our senses and depending on what activity is being carried out focuses our senses on those signals. An important element of HIP is that you don’t have to have a memory of every situation in order for your brain to predict the outcome of an activity; we can use previous experiences and assumptions in order to forecast situations.
Perception is the operation where the brain can organize and interpret stimuli from the sensory registry in order for us to understand the environment around and put it into context.
Perception played a vital role within flight BD 072 crash, on the older models of the Boeing 737 the compressor on the right hand engine was used for Environmental Control System (ECS), this system controls the aircraft pressurization air-conditioning and air supply to the cabin, using pervious knowledge of this aircraft type the first officer came to the conclusion that the right engine was at fault and as a result shut it down.
The top down approach to perception can be used to explain how this fatal error was made, Gregory claims “the visual information available to us is not always of a high enough quality and therefore the brain needs to fill in the gaps by using prior knowledge, memories and similar experiences to understand what is around us” (Gibson,J). This top-down theory is hypothesized as a primitive reflex when it came to hunting food and is incredible when put within a situation in which you need to improvise, but when in a emergency situation where the workload is elevated and your not particularly familiar with the upgraded aircraft model can lead to flight BD 072.
You can only attend to a small of the sensations around us and only a small part of what we attend to can be remembered; in essence attention can be thought of as a filtering process. Attention is a limited resource and a pilot cannot focus on everything within the cockpit at once, but how he filters out the unimportant information and decides when to shift his attention to something new is fundamental. .
Within the cockpit of flight BD 072 the pilot and first officer had numerous things to attend to, but there primary task was to stop the smoke entering the cockpit and rerouting to East Midlands airport.
- Selective attention – It concerns with signals we choose to focus on rather than others, so the pilot would be focused on altimeter and his speed. In an attempt to reroute and land the aircraft as quick as possible, only the essential tasks would get attending to.
- Focused attention – Knowing that the aircraft is incapable of continuing the route and having to reroute the pilot would no longer be focused on fuel levels and instead thrust, so ignoring some stimuli and instead choosing to pay attention to others.
- Divided attention – The pilots attention would have been divided between the flashing lights and aural cautions on the instrument panel and the smoke within the cockpit, while manually flying the aircraft in an attempt to land it.
- Sustained Attention – Before the emergency occurred the attention o f the pilot would have been sustained on the Head Up Display (HUD), which gives the pilot all critical flight information.
Attention helps us understand how this accident could of occurred because from the flight deck the pilots could not see the engine and had to rely on an engine vibration gauge, but from previous experience the pilots believed the readings were unreliable and consequently disregarded it. If their selective attention attended to this gauge the accident would have been avoided.
Arousal leads to a release of adrenaline within the brain, an increased blood pressure/heart rate and a condition of sensory alertness. It is essentially apart of our primitive state in which we are ready to (fight or flight) when we feel threatened or in danger, it’s our readiness to respond.
The aircraft encountered a emergency situation, the pilots onboard would have been overwhelm attempting to deal with the issues at hand, the arousal system would have been important element because that release of adrenaline is needed when your in a emergency situation and scared.
Arousal and attention are closely associated because if your bored and lose attention your arousal decreases, inversely in an emergency situation both would be heightened, an optimum level of arousal for performance exists, and too little or too much arousal can adversely affect task performance.
Shortly after terminating thrust the captain of the aircraft made an announcement on the public announcement system stating that there was an engine fire and the right hand engine was shut down.
There were 118 passengers and 3 crewmembers that heard the announcement and could clearly see flames ravaging the left hand engine yet no one decided to tell the flight deck that they had turned off the wrong engine.
An individual is less inclined to take action because of the presence of others; there are a number of examples of why no one said anything:
- Experience of the pilot
- Passengers would think the cabin crew would have said something
- The pilot simply misspoke
- The pilot would have known
Diffusion of responsibility theory, when individuals are in the presence of others they feel less personal responsibility and are less likely to take action, the bystander affect is amplified by the number of people in a group, so because there are 121 people the less inclined each passenger felt to take action.
The P.A.A systems play a vital role within aviation incidents, having an understanding of these key contributors can help to minimize accidents reoccurring.
The air disaster of flight 072 has cemented how important P.A.A. is with the industry a number of regulatory changes have been made to ensure
- It is now mandatory for crewmembers to report any findings to the pilot that may affect the flight.
- Retraining pilots in order to have knowledge of the upgraded senser on this new model of aircraft.
- The CAA in conjunction with the engine manufacturer increased the frequency of engine inspections and health monitoring on the Boeing 737-400.
- Gibson, J. (n.d.) Perception Psychology – How We Understand Our World [online]available from <https://owlcation.com/social-sciences/Perception-in-Psychology> [12 November 2018]
- Resilience.har-el.com. (2018). ESCM – Extended Swiss Cheese Model. [online] Available at: http://resilience.har-el.com/Guide/Models/ESCM/index.htm [Accessed 8 Nov. 2018].
- Gibson, J. J. (1966). The senses considered as perceptual systems. Oxford, England: Houghton Mifflin