By Chuck Crinnian, MD
The crew on the Impact Airlines flight was making their last approach of the day at 03:00 into their home airport. They had configured the aircraft and engaged the autopilot for a coupled ILS. When they flew over the outer marker, the beeping on the audio panel suddenly awakened the captain. He looked over at the co-pilot who was also asleep. A tragedy was avoided, by luck. The worst possible time for our bodies and their daily circadian rhythm is about 03:00.
Fatigue can be a major safety issue in aviation. In addition to circadian rhythm, travel across time zones, poor sleep, poor diet, and pushing the fatigue envelope all will catch up to you in time, with potentially deadly results. The FAA has drafted a notice of proposed rule making on pilot flight duty and rest. It is expected to come out later this year. For us flying under part 91, you need to set your own rest and sleep limits. Know that fatigue is cumulative and coupled with night time, poor nutrition, lack of exercise, and general state of health, the development of the spectrum of inattention to deep sleep can creep up on you. Flying an aircraft is not the time to be “Asleep at the Wheel”.
Another well documented medical issue that we see in the pilot population is Obstructive Sleep Apnea (OSA). This affects 7-8% of the general population. It is most linked to body mass index, in other words, obesity. If you are male, the more obese you are, the higher chance for you to have OSA. A push by the FAA is underway for Aviation Medical Examiners to screen for this issue.
High risk criteria for OSA are new onset hypertension (high blood pressure) or hypertension that required two or more medications. Also type II diabetes. Loud snoring is an indicator for OSA. OSA is a major cause of fatigue and daytime sleepiness. It is also linked to heart attack and stroke.
OSA can be effectively treated. In addition to effective weight loss programs, special breathing apparatus can be employed at night. Also, there are some surgical procedures that modify the airway which may eliminate OSA.
Your AME will be screening for OSA in the near future. The FAA medical evaluation system will do so by utilizing a Body Mass Index calculator and asking screening questions to help identify high risk individuals. It is possible that identifying this sleeping killer will prevent the next accident.