Relay-Version: B 2.11 6/12/87; site scorn Path: uunet!cs.utexas.edu!sdd.hp.com!elroy.jpl.nasa.gov!ames!trident.arc.nasa.gov!yee From: yee@trident.arc.nasa.gov (Peter E. Yee) Newsgroups: rec.aviation Subject: Controlled rest periods shown to improve pilot alertness (Forwarded) Message-ID: <52972@ames.arc.nasa.gov> Date: Mon, 02 Jul 90 12:39:21 PDT Sender: usenet@ames.arc.nasa.gov Reply-To: yee@trident.arc.nasa.gov (Peter E. Yee) Organization: NASA Ames Research Center, Moffett Field, CA Lines: 110 Mary Sandy Headquarters, Washington, D.C. July 2, 1990 (Phone: 202/453-2754) Donald G. James Ames Research Center, Mountain View, Calif. (Phone: 415/604-3935) RELEASE: 90-90 CONTROLLED REST PERIODS SHOWN TO IMPROVE PILOT ALERTNESS Rest during long-haul flights improves pilot alertness. This is the conclusion of a recently completed study at NASA's Ames Research Center, Mountain View, Calif., providing the first concrete evidence that there may be substantial safety benefits from allowing pilots to obtain limited rest in the cockpit during long-haul, international flights. "These findings confirm our previous studies that showed international flight crews often experience considerable fatigue and sleep loss. We now have direct scientific evidence that short, carefully controlled rest periods can act as a 'safety valve' to reduce fatigue and improve alertness during the most important phases of flight such as descent and landing," said Dr. R. Curtis Graeber, principal investigator of the study and Chief of the Flight Human Factors Branch at Ames. Incident and accident reports indicate that good flight crew performance is especially important near the end of any flight when workload increases and the crew must often deal with air traffic control problems, uncooperative weather and potentially unfamiliar airports. "Unfortunately, this is also the time when they are most likely to be the most tired after a long trip crossing several time zones," said Graeber. Consequently, measures that can help the crew perform better when the job requires the best performance have significant implications for reducing pilot error and enhancing safety. The research project, co-sponsored by the Federal Aviation Administration (FAA), was carried out with the cooperation of Northwest Airlines and United Airlines during regularly scheduled trans-Pacific flights. The scientists examined the levels of alertness in three-person flight crews during long-haul flights, the pilots' ability to obtain quality rest in the cockpit environment and the effectiveness of preplanned, cockpit rest periods to improve pilot alertness and performance. A total of ten volunteer Boeing-747 crews were placed in one of two groups: a preplanned rest group and a non-rest control group. Crew members in the rest group were allowed to rest one- at-a-time on a preplanned rotation basis during the cruise portion of four successive flights. Two crew members monitored and maintained control of the plane while the other pilot had a 40-minute opportunity to rest. The control group of pilots operated its four flights as usual with no preplanned rest. To document changes in fatigue and alertness, researchers took a variety of measurements: Laboratory-type performance tests evaluated pilot vigilance and sustained attention; wrist monitors provided a 24-hour measure of activity level; subjective reports of mood and other factors were recorded in a log book. Also, continuous measurement of brain activity (i.e., electroencephalogram -- EEG), by a portable unit adapted especially for NASA, was used to determine physiological levels of alertness. Two NASA researchers observed and monitored all of the volunteer crews on the flight deck. The researchers found that when given the opportunity to rest in their seats, the pilots generally were able to fall asleep easily and sleep well. Later, these crew members demonstrated significantly higher levels of vigilance than their no-rest counterparts. These differences between the two groups were especially dramatic near the end of the cruise phase of flight, just before the pilot starts the descent for landing. Also, pilots who could rest were less adversely affected by consecutive flight segments and night flights. This study is a part of an on-going NASA/FAA collaborative research program to study fatigue, sleep loss and circadian rhythm disruptions (i.e., jet lag) in commercial and military aviation and, most recently, the role of these factors in the manned space program. Previous research with long-haul crews has shown that repeated time zone crossings often result in poor sleep patterns during hotel layovers, particularly after eastward flights. While pilots sometimes sleep well, their ability to do so varies both among individuals and at different times. Experienced crew members were found to be poor predictors of their own sleepiness when compared with objective measurements. The overall impact of these findings is that there is often at least one crew member who is not optimally rested to perform flight duties. The current results demonstrate that preplanned rest periods during low workload phases of flight may provide a safety valve for the sleep loss and fatigue experienced by crews during long- haul flights. Planned cockpit rest periods may possibly prevent excessive fatigue and improve alertness and performance during critical phases of flight. Cockpit rest currently is allowed among military transport crews and among airline crews in some other countries. The FAA is now reviewing the NASA-Ames research results. Collaborators on this study included researchers from Stanford University, the University of Pennsylvania and the University of California, San Diego.