Good Morning and welcome to a new look for the Monday blog. Each Monday I will alternate between my articles on “Aviation Wisdom From the Past” and an article on aviation safety. This week I want to showcase an article from the Flight Safety Foundation that will help each of us rationalize how to deal with sensory overload on the flight deck.
A pilot from the pioneering days of aviation, who flew with little more than a compass for flight information, would no doubt be delighted — and overwhelmed — by the array of instruments on today’s flight decks. More displays mean that pilots have more information — and that leads to improved decision making and enhanced flight safety.
However, cognitive scientists warn that providing more and more information has its limitations, increases workload and actually can negatively influence the amount of information pilots can absorb and act upon. This concern may be most important in emergency situations when multiple, simultaneous warning displays activate, overwhelming pilots with information.
This warning has not gone unheeded, as many cockpits have a declutter mode, allowing pilots to greatly reduce the number of instrument displays vying for their attention. When a declutter mode is not available, pilots often simply turn off the instruments they consider unnecessary or distracting.
The first step in avoiding the potential problem of information overload is understanding the balance between information requirements (how much information is needed) and availability (how much information is being presented or is quickly accessible).1 How much information is required is ever-changing and depends on flight task, aircraft type and phase of flight. Information availability also depends on the cockpit instrument panel design — that is, the number and location of instruments, the types of displays and the modes of information presentation.
Equally important is the human at the controls. Pilots use multiple senses — especially sight and hearing — to gather information about their aircraft and its relationship to the outside world (i.e., situational awareness).
Although the first aviation displays were entirely visual in nature, many modern displays have both visual and auditory modalities; this is especially true of displays presenting caution and warning information.
Visual displays primarily present information using intensity (brightness), size and color characteristics. Auditory displays use intensity (loudness) and frequency (tone). Both visual and auditory displays often incorporate a pulsating characteristic, such as a flashing light or a beeping tone.
Displays can be considered as having two functional modes. The first, and most obvious, is to present current status information for various aircraft performance parameters such as airspeed and angle of climb, and to have this information always available. This is especially true for visual displays. An example is an altitude indicator. There is no need for pilots to continuously monitor this parameter, but the information is always there, for example, for timely awareness of deviation from clearances.
In a second functional mode, a display may serve as a caution or warning indicator. In this mode, the display moves from a passive to an active function. Based on certain predetermined criteria, the display alerts pilots that the current status of some flight parameter requires monitoring or immediate action. Communications systems, which are a type of auditory display, fall within this mode, as air traffic control communications regarding altitude changes or the presence of nearby aircraft require acknowledgement and possible action. Stall warning indicators are another example.
While all flight displays should be monitored at appropriate intervals, pilots generally interface most with the displays used during takeoff and landing and during emergency situations. During the en route phase of flight, the use of autopilot is customary, with the interface adapted for monitoring.
During takeoffs and landings, pilots use scanning techniques to systematically and purposefully direct their attention to the important and relevant task-defined displays. During these flight phases, pilots must monitor hundreds of sources of information within the cockpit, as well as attend to additional inputs from outside the aircraft. In general, pilots can select when and where to direct attention during most, if not all, phases of flight.
In an emergency scenario, multiple caution and warning displays generate new visual or auditory stimuli, such as red flashing lights or sirens, which are intended to capture pilots’ attention. In such situations, there is a sudden shift in how pilots interact with the displays, which compete to capture pilots’ urgent and full attention.
Have a good week and thanks for letting the 3DB be a part of your routine. Fly safe/be safe.
March 7, 2014