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Situational awareness is the accurate perception and understanding of all the factors and conditions within the four fundamental risk elements that affect safety before, during, and after the flight. Maintaining situational awareness requires an understanding of the relative significance of these factors and their future impact on the flight. When situationally aware, the pilot has an overview of the total operation and is not fixated on one perceived significant factor. Some of the
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Warning Signs of Fatigue
Eyes going in and out of focusHead bobs involuntarilyPersistent yawningSpotty short-term memoryWandering or poorly organized thoughtsMissed or erroneous performance of routine procedures Degradation of control accuracy
Figure 9-5. Fatigue is a threat to aviation safety because it impairs alertness and performance.
Long naps (3–4 hours*) can restore aler
tness for 12–15 hoursShort power naps (10–30 minutes*) can restore alertness for 3–4 hoursEat high-protein mealsDrink plenty of fluids, especially waterRotate flight tasks and converse with other crew members or passengersKeep the flight deck temperature coolMove/stretch in the seat, and periodically get up to walk around the aircraft, if possible* Allow 15–20 minutes after awakening to become fully alert before assuming aircrew duties.Countermeasures90807060504030
Figure 9-6. Countermeasures for coping with fatigue.
elements inside the aircraft to be considered are the status of aircraft systems, pilot, and passengers. In addition, an awareness of the environmental conditions of the flight, such as spatial orientation of the aircraft and its relationship to terrain, traffic, weather, and airspace must be maintained.
To maintain situational awareness, all of the skills involved in ADM are used. For example, an accurate perception of the pilot’s fitness can be achieved through self-assessment and recognition of hazardous attitudes. A clear assessment of the status of navigation equipment can be obtained through workload management, and establishing a productive relationship with ATC can be accomplished by effective resource use.Obstacles to Maintaining Situational Awareness
Many obstacles exist that can interfere with a pilot’s ability to maintain situational awareness. For example, fatigue, stress, or work overload can cause the pilot to fixate on a single perceived important item rather than maintaining an overall awareness of the flight situation. A contributing factor in many accidents is a distraction, which diverts the pilot’s attention from monitoring the instruments or scanning outside the aircraft. Many flight deck distractions begin as a minor problem, such as a gauge that is not reading correctly, but result in accidents as the pilot diverts attention to the perceived problem and neglects to properly control the aircraft.
Fatigue, discussed as an obstacle to learning, is also an obstacle to maintaining situational awareness. It is a threat to aviation safety because it impairs alertness and performance. [Figure 9-5] The term is used to describe a range of experiences from sleepy, or tired, to exhausted. Two major physiological phenomena create fatigue: sleep loss and circadian rhythm disruption.
Fatigue is a normal response to many conditions common to flight operations because characteristics of the flight deck environment, such as low barometric pressure, humidity, noise, and vibration, make pilots susceptible to fatigue. The only effective treatment for fatigue is adequate sleep. As fatigue progresses, it is responsible for increased errors of omission, followed by errors of commission, and microsleeps, or involuntary sleep lapses lasting from a few seconds to a few minutes. For obvious reasons, errors caused by these short absences can have significant hazardous consequences in the aviation environment.
Sleep-deprived pilots may not notice sleepiness or other fatigue symptoms during preflight and departure flight operations. Once underway and established on altitude and heading, sleepiness and other fatigue symptoms tend to manifest themselves. Extreme fatigue can cause uncontrolled and involuntary shutdown of the brain. Regardless of motivation, professionalism, or training, an individual who is extremely sleepy can lapse into sleep at any time, despite the potential consequences of inattention. There are a number of countermeasures for coping with fatigue, as shown in Figure 9-6.
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Complacency presents another obstacle to maintaining situational awareness. Defined as overconfidence from repeated experience on a specific activity, complacency has been implicated as a contributing factor in numerous aviation accidents and incidents. Like fatigue, complacency reduces the pilot’s effectiveness in the flight deck. However, complacency is harder to recognize than fatigue, since everything is perceived to be progressing smoothly. Highly reliable automation has been shown to induce overconfidence and complacency. This can result in a pilot following the instructions of the automation even when common sense suggests otherwise. If the pilot assumes the autopilot is doing its job, he or she does not crosscheck the instruments or the aircraft’s position frequently. If the autopilot fails, the pilot may not be mentally prepared to fly the aircraft manually. Instructors should be especially alert to complacency in students with significant flight experience. For example, a pilot receiving a flight review in a familiar aircraft may be prone to complacency.
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Aviation Instructor’s Handbook下(82)
