The Loss of Control-In-flight Accident report by IATA analyzes the 38 LOC-I accidents that occurred during the reported period 2011-14 and caused 1,242 fatalities and contributing factors. LOC-I accidents like the 2014 Air Asia often have catastrophic results with very few, if any, survivors. Reducing the number of LOC-I accidents is an ICAO priority, and ICAO has developed harmonized training requirements for flight crews that address and mitigate LOC-I events.
The industry has spent a whooping 1,000 million USD on training pilots and trainers. Does it ensure that LOC-I accident will be eliminated like they did with the introduction of the Ground Proximity Warning System?
Upset recovery training for prevention of LOC-I is collated into an integrated approach which identifies the training resources — academic, on aeroplane, and Flight simulator-based — and the associated elements of training required to provide pilots with the necessary knowledge, skills and attitudes (KSA) to reduce the probability of an upset encounter and to maximize their ability to recover from such an event.
The training aims at accurate and early recognition of all available aural, visual and tactile alerts to both an approaching stall and, with due consideration to maintaining adequate safety margins, an aerodynamic stall. Particular attention is given to aeroplane stall characteristics in the absence of a stall warning indication.
Background information on stall
The lift of an airfoil depends on its aerodynamic coefficient (Cl) and the square of the speed of the airflow. The aerodynamic coefficient increases with the angle of attack (noted as alpha) up to a maximum value, after which it decreases when the angle of attack continues to increase. This tipping point, where the aerodynamic coefficient is at maximum is the marker, from an aerodynamic point of view, for the stall. The angle of attack at which the Cz is at a maximum is thus the stall angle of attack (alphamax).
The aerodynamic characteristics of an aerofoil, thus the evolution of the Cl = f (alpha) curve, are different between the lower layers (low Mach, subsonic airflow, incompressible air) and the high altitudes (higher Mach, airflow close to trans-sonic, influence of the compressibility of the air).
Recovery from an impending stall or after a stall requires the pilot to unload the wing or reduce the angle of attack. If for e.g. the aircraft nose drops after a stall, the pilot would instinctively pull the control column back to get the nose back up because this is what they do day in and out. In this scenario, the pilot will push the stick to fly the nose down and reduce the angle of attack.
How long does it take to form a new habit?
Stall recovery is a counterintuitive maneuver. Skill is learnt through repetition till it forms a habit and becomes automatic. Maxwell Maltz was a plastic surgeon in the 1950s when he began noticing a strange pattern among his patients. When Dr. Maltz would perform an operation — like a nose job, for example — he found that it would take the patient about 21 days to get used to seeing their new face. Similarly, when a patient had an arm or a leg amputated, Maltz noticed that the patient would sense a phantom limb for about 21 days before adjusting to the new situation. These experiences prompted Maltz to think about his own adjustment period to changes and new behaviors, and he noticed that it also took himself about 21 days to form a new habit. Maltz wrote about these experiences and said, “These, and many other commonly observed phenomena tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell.”
Phillippa Lally is a health psychology researcher at University College London. In a study published in the European Journal of Social Psychology, Lally and her research team decided to figure out just how long it actually takes to form a habit. On average, it takes more than two months before a new behavior becomes automatic — 66 days to be exact. And how long it takes a new habit to form can vary widely depending on the behavior, the person, and the circumstances. In Lally’s study, it took anywhere from 18 days to 254 days for people to form a new habit.
The current duration of training is grossly inadequate for the pilot behaviour to becoming automatic for an approach to stall/stall recovery.
Ebbinghaus forgetting curve describes the decrease in ability of the brain to retain memory over time. The issue was hypothesized by Hermann Ebbinghaus in 1885, which is why it’s called Ebbinghaus forgetting curve. The theory is that humans start losing the memory of learned knowledge over time, in a matter of days or weeks, unless the learned knowledge is consciously reviewed time and again. A related concept to the forgetting curve is strength of memory, which states that the time period up to which a person can recall any memory is based on the strength of the particular memory.
Ebbinghaus found the forgetting curve to be exponential in nature. Memory retention is 100% at the time of learning any particular piece of information. However, it drops rapidly to 40% within the first dew days. After which, the declination of memory retention slows down again.
In simple words, forgetting curve is exponential because memory loss is rapid and huge within the first few days of learning. But, the rate of memory loss decreases and the rate of much forgetting are much slower from then on.
Ebbinghaus also discovered another phenomenon called overlearning during his study on forgetting curve. The basic idea is that if you practiced something more than what is usually required to memorize it, the effect of overlearning takes place. This means that the information is now stored much more strongly and thus the effects of forgetting curve for overlearned information is shallower.