Adequate rest best way to battle fatigue Published April 7, 2010 99 Air Base Wing Safety Office NELLIS AIR FORCE BASE, Nev. -- Many people have driven to work tired and tried to stay alert by drinking coffee or energy drinks. Though caffeine may help for a short while, it does not compare to getting adequate rest; the human body needs seven to eight hours of sleep a day to function properly. Recently, a driver was towing small missiles from the flightline back to the munitions storage area just before 4 a.m. Fighting a losing battle against fatigue, he felt his eyelids close for what seemed like a single blink. Suddenly, the vehicle bucked beneath him as it jumped the curb. He jerked the steering wheel to get back on the road, but it was too late. The impact against the concrete edge was hard enough that it blew a tire and tipped the vehicle dangerously. More seriously, the jolt ignited the rocket motors aboard the tow trailer. Rocket bodies shot forward, deflecting off the truck and landing in a nearby field. The driver had succumbed to a micro-sleep event. Fortunately, his experience and skill were enough to keep the trailer from flipping; but the mishap still resulted in $37,000 in damage. Had the trailer overturned, far more destruction would have occurred. Only good luck prevented the driver's death. Wing Safety's investigation revealed that in the 72 hours prior to the mishap, the driver was awake for approximately 53 hours. In those three days, he had an 8-hour sleep, a 6-hour sleep and a 4-hour nap. This may seem like a decent amount of sleep, perhaps even a typical amount for an adult, but hindsight shows it was not enough because the driver's normal sleep pattern had been affected. The driver normally worked the mid-shift and slept during the day, but his regular sleep pattern had been thrown off due to working nine hours at an event the previous Sunday. Those hours he was working cut into his normal sleep time, triggering a disruption to his circadian rhythm, the "internal clock" that regulates the body's daily cycle. He tried to reverse his sleep schedule the next day, but was only able to get a short nap in the afternoon prior to his next shift because he had slept through the night after working the event. He returned to his normal sleep pattern on the third day, but the schedule change had already taken its toll. He reported to work feeling tired the night of the mishap. Wing Safety used the Fatigue Avoidance Scheduling Tool (FAST) program, a computer tool that measures the effects of fatigue, to evaluate the driver's rest cycle. The tool takes into account both sleep time and schedule. Fatigue had reduced the driver's cognitive performance to just 67.5 percent by the time of the mishap. This performance level is the same as someone with a blood alcohol content rating of 0.10 (a BAC of 0.08 is enough for an arrest due to driving under the influence). The FAST analysis also showed the driver was at the low point of his circadian rhythm, making him about the same as a person who has just been woken up in the middle of the night. Since many Airmen work long hours, it is important to remember the body needs a consistent schedule. Failing to get seven to eight hours of sleep each day can create serious, sometimes fatal, risks.
