As the frequently life-preserving and thus medically necessary operations of helicopter pilots in the air rescue services utilize the complete period of daylight, longer hours of duty and shortened times of rest may occur for helicopter pilots during the summer months. This leads inevitably to conflicts with the legal provisions, since the regulations for periods of flight duty and rest of the 2nd DVOLuftBO do not take the special circumstances of the air rescue service into consideration. In order to solve this conflict by formulating a special authorization, the DLR-Institute of Aerospace Medicine was entrusted by BMV (German Ministry of Transportation) with the execution of medical studies during the service of air rescue helicopter pilots in co-operation with the ADAC (Allgemeiner Deutscher AutomibilClub - the German automobile association). The results of this study were: (1) The schedule for operations for air rescue helicopter pilots was altered (2) New regulations that take the needs of the air rescue service into consideration for periods of flight, flight duty and rest were developed that are to be valid in Germany independent of the 2nd DVOLuftBO. In order to test this new regulation, the DLR - Institute of Aerospace Medicine was entrusted with another study on helicopter pilots by BMV.
7 helicopter pilots and one flight engineer of the ADAC air rescue services (of the locations Berlin, Munich and Siegen) took part in this study during the summer months of 1995/96. The examination time for each pilot was a period of duty of 3 and/or 4 days as well as two days before and after these periods for control examinations. In order to determine strain and stress, the ECG as recorded continuously. The concentration of cortisol in the saliva was - when possible - registered hourly during the period of waking. Questionnaires concerning the current state of wakefulness / fatigue and the personal condition were also filled in every hour. Duration and quality of sleep were recorded using sleep logs and measurements of activity. Additionally, computer supported performance tests (10 minutes) for the objective assessment of the performance were conducted every evening.
The strain on pilots was essentially shaped by the shortened sleep duration and the associated sleep deficit. The objective strain measurements show increased reactions during operations. However, this increase is - compared to results from other areas - not to be classified as higher than normal to moderately severe. The daily average values of the cortisol concentration increased in the course of the service period. In the performance tests conducted in the evenings, no deterioration caused by work strain and/or fatigue could be established.
The new regulation for periods of flight, flight duty and rest for helicopter pilots in the air rescue services constitutes a sensible compromise. It can be seen as a basis for a harmonization on a European level.
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