Inside the European Community, new Flight and Duty Time Limitations and Rest Requirements for Flight Crew and Cabin Crew are currently being prepared on several levels. In the discussion about the harmonization of national regulations , aero-medical results are to be taken into account. Because of this, examinations on 50 pilots of two-man flight crews on several transmeridian and transequatorial long-distance routes were conducted during normal passenger flights as a part of the research program of the DLR - Institute of Aerospace Medicine.For the duration of the examinations Sleep, work load, stress and fatigue were registered during the respective operations by measurements of EEG, EOG, EKG and by subjective estimations.
During the transmeridian round trips (Düsseldorf (DUS) - Atlanta (ATL), Hamburg (HAM)/Frankfurt (FRA) - Los Angeles (LAX)/San Franzisko SFO)), the average sleep deficit was 8.2 hours - the return flight being carried out at night. On the Seychelles (SEZ) route, the deficit amounted to 9,3 hours, with both the outgoing and the return flight being accomplished at night and the intermediate stay on Seychelles lasting only 14 hours. The subjective work performance was low during the transatlantic flights, while it was of medium level on the north-south flights. The fatigue increased with the duration of the flight. Towards the end of the longer day flights to the American West Coast and during all nocturnal flights, an increased state of fatigue that has to be seen as critical was observed with some pilots. The subjective statements on fatigue were confirmed by the objective measurements of the EEG and EOG (occurrence of micro-sleep) and by the ECG, which all showed an increased drowsiness and a decreased vigilance.The results lead to the conclusion that extremely long flights by day (like the route HAM-LAX) and particularly night flights in succession (like the route FRA-SEZ) reach the limits of physiological and psychical capacity.The results are important to the legal fixation of the Flight and Duty Time Limitations and Rest Requirements for Flight Crew and Cabin Crew and contribute significantly to the further discussion of these regulations on a European level.
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