Noise, vibration and changes in wakefulness during helicopter flight

Area of Science:

• Aviation Physiology
• Occupational Health
• Human Factors Engineering

Background:

• Helicopter operations involve significant environmental stressors.
• Understanding pilot physiological responses is crucial for flight safety and performance.
• Previous research has explored various flight factors, but a comprehensive analysis of noise, vibration, and wakefulness in specific helicopter types is needed.

Purpose of the Study:

• To investigate the correlation between helicopter flight parameters and pilot physiological responses.
• To quantify the impact of noise and vibration on pilot wakefulness and weariness.
• To analyze how different flight durations and events influence pilot stress levels.

Main Methods:

• Measurements of noise and vibration exposure in Hkp 3 and Hkp 6 helicopters.
• Analysis of electroencephalogram (EEG) and electrocardiogram (EKG) recordings to assess wakefulness.
• Correlation analysis between flight events (take-offs, landings, unexpected events) and physiological data.

Main Results:

• Noise and vibration exposures were primarily linked to main rotor energy and frequencies below 10 Hz.
• Pilot wakefulness levels increased with flight stress, particularly during take-offs, landings, and unexpected events.
• Longer flights (approx. 4 hours) and shorter flights (less than 2 hours) showed varying correlations with weariness and wakefulness.

Conclusions:

• Low-frequency noise and vibrations are significant factors influencing helicopter pilot's state of wakefulness.
• Flight stress, characterized by dynamic events, directly correlates with increased pilot alertness and subsequent fatigue.
• The study highlights the interplay between environmental factors, flight characteristics, and pilot physiological responses, informing potential mitigation strategies.