Warning Signs of Fatigue z z z Vision going in and out of focus Head bobbing involuntarily Persistent yawning Spotty short-term memory Wandering or poorly organized thoughts Missed or erroneous performance of routine procedures  Degradation of control accuracy Figure 13-7. Warning signs of  fatigue  according to the FAA Civil Aerospace Medical Institute (CAMI) .  Figure 13-8. Countermeasures to fatigue according to the FAA  Civil Aerospace Medical Institute (CAMI) .  Long naps (3–4 hours*) can restore alertness  for 12–15 hours. Short power naps (10–30 minutes*) can restore alertness for 3–4 hours. Eat high-protein meals. Drink plenty of fluids, especially water. Rotate flight tasks and converse with other  crew members or passengers. Keep the flight deck temperature cool. Move/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. Countermeasures 90 80 70 60 50 40 30 may be flying a day flight Monday and then at night on  Tuesday. Your awareness of how your body and mind  react to this variation in schedule is vital to safety. This  disruptive pattern may result in degradation of attention  and concentration, impaired coordination, and decreased  ability to communicate.  Since complacency seems to creep into our routine without  notice, ask what has changed. The minor changes that go  unnoticed can be associated with the four fundamental risks  we previously discussed: pilot, aircraft, environment, and  external pressures.  As a pilot, am I still using checklists or have I become reliant  on memory to complete my checks? Do I check (Notices to  Airmen) NOTAMs before every flight or only when I think  it is necessary? And the aircraft: did I feel that vibration  before or is it new? Was there a log book entry for it? If so,  Physical fatigue results from sleep loss, exercise, or physical  work. Factors such as stress and prolonged performance of  cognitive work result in mental fatigue. Consecutive days of  flying the maximum allowable flight time can fatigue a pilot,  mentally and physically. It is important to take breaks within  the workday, as well as days off when possible. When you find  yourself in this situation, take an objective, honest assessment  of your state of mind. If necessary, use rest periods to allow  rejuvenation of the mind and body.  [Figure 13-8] Fatigue also occurs under circumstances in which there is  anticipation of flight followed by inactivity. For instance,  a pilot is given a task requiring a specific takeoff time. In  anticipation of the flight, the pilot’s adrenaline kicks in and  SA is elevated. After a delay (weather, maintenance, or any  other unforeseen delay), the pilot feels a letdown, in effect,  becoming fatigued. Then, upon resuming the flight, the pilot  does not have that same level of attention. Complacency presents another obstacle to maintaining  SA. Defined as overconfidence from repeated experience  with a specific activity, complacency has been implicated  as a contributing factor in numerous aviation accidents  and incidents. When activities become routine, a pilot may  have a tendency to relax and not put as much effort into  performance. Like fatigue, complacency reduces a pilot’s  effectiveness on the flight deck. However, complacency is  more difficult to recognize than fatigue, since everything  seems to be progressing smoothly.  13-14