Author(s): OJANEN, T., KOIVURANTA, J., KYRÖLÄINEN, H., HONKANEN, T., Institution: FINNISH DEFENCE RESEARCH AGENCY, Country: FINLAND, Abstract-ID: 1598

INTRODUCTION:
The workload of helicopter loadmasters can be physically and mentally demanding. The workload has been studied mostly with questionnaires instead of objective measures. The purpose of this study was to find out the amount of physical and mental load on the loadmasters before the flight (PRE), during the immediate flight activities (WALK), during the actual flight (FLIGHT), and after (POST/POST2) the flight.
METHODS:
A total of 16 (age 34±6 yrs., height 180±5 cm, and body mass 82±5 kg) male loadmasters voluntarily participated in the study. Data on the occupational load of loadmasters was collected through objective and subjective measurements. As objective measurements, heart rate and heart rate variability, saliva biomarkers, and isometric and dynamic force production tests were used. The aim of the objective measurements was to obtain information on the functioning of the cardiovascular, autonomic nervous, and excretory systems at PRE, WALK, FLIGHT, and POST/POST2 time points. A diary was used as a subjective method, with which the loadmasters evaluated the load caused by the flight and the other activities on the day of the flight.
RESULTS:
The maximum heart rate of the loadmasters during the flight was significantly higher compared to other measurement periods (FLIGHT = 173±14 bpm vs. PRE = 133±21 bpm, p<0.01, WALK = 153±16 bpm, p<0.05 & POST = 145±20 bpm, p<0.05), but heart rate variability was significantly lower during WALK than during POST (SDNN = 47±14 ms vs. 58±15 ms, p<0.01; RMSSD = 39±17 ms vs. 51±17 ms, p<0.05). Based on the cortisol levels, the load of the loadmasters was significantly higher PRE than POST or POST2 (PRE = 8.35±3.79 nmol/l vs. POST = 5.57±3 .79 nmol/l, p<0.05 & POST2 = 5.12±3.03 nmol/l, p<0.05). The saliva alpha-amylase concentration was significantly higher after POST compared to POST2 (150.23±99.94 U/ml vs. 87.62±69.18 U/ml, p<0.01). No statistically significant differences were observed in the results of the physical tests. Based on the subjective assessment collected from the subjects, the load caused by helicopter flights on a scale of 1–10 was a 6.
CONCLUSION:
According to the present study, the physical load on loadmasters during the flight is momentarily intense but not long-lasting. In addition, standing still during the flight seems to enable the activation and recovery of the parasympathetic nervous system of loadmasters, further reducing the overall physical load caused by the flight. In addition, good muscle endurance and maximal strength may have a more significant effect than aerobic endurance in reducing the load of the flight tasks. In the future, it will be important to study more in detail the load exerted by different load-bearing components during a flight.