Identify Ways to Reduce Noise Pollution in Aircraft Hangars

The noise pollution produced by various aircraft systems, including hydraulic, pneumatic, electrical systems and auxiliary aircraft equipment inside the aircraft hangars, generally cause hearing impairment and mental disorder of shift and office personnel. Identifying hangar noise pollutants can lead to find solutions and methods to deal with the contaminants in the aviation industry. In the first phase of the research, the sound study in each specified region of the hangar, the required measurements and frequency analysis are done to determine the type of sound control appropriate for the hangar. Measurements in this study were conducted in accordance with standards, and the results of the measurements and equilibrium calculations after recording were compared with the permissible exposure limits in accordance with the Occupational Exposure Limit values. The results show that the highest sound pressure level corresponds to sheet metal activities (128 dBC) and thereafter respectively, pneumatic systems (112 dBC), hydraulic pumps (104 dBC) and electrical systems (86 dBA), and found that noise pollution of the hangar during the specified time for shift and office personnel is higher than the permissible limits, and this exposure is harmful to the physical and mental health of the staff. In the second phase of the research, by the results of statistical analysis of the questionnaires, there was a significant relationship between the result of estimating noise intensity and the extent of its annoyance by shift and office personnel, which most people in the hangar believe that this level of noise pollution is very annoying.