Noise exposure during ambulance flights and repatriation operations

Area of Science:

• Occupational health
• Aviation safety
• Audiology

Background:

• Ambulance flights for international patient repatriation are common, yet data on crew noise exposure is lacking.
• This absence of data hinders the development of specific preventive advice and guidelines for noise protection.

Purpose of the Study:

• To investigate and quantify noise exposure levels for flight crews operating in ambulance flight organizations.
• To gather data for establishing specific guidelines concerning noise protection in this occupational setting.

Main Methods:

• Noise levels were measured inside a Learjet 35A, a common aircraft for repatriation, at crew workstations.
• Measurements were conducted during actual repatriation flights using a Class 1 sound level meter, with results adjusted for real-world conditions (~3% error).
• Occupationally encountered equivalent noise levels were calculated based on measured data and crew flight hours, adhering to DIN 45645-2 standards.

Main Results:

• Measured noise levels within the aircraft cabin remained below the 85 dB(A) threshold, indicating a low risk of permanent hearing threshold shifts.
• Engine noise levels outside the cabin significantly exceed the 85 dB(A) threshold.
• The study highlights the importance of keeping aircraft doors closed during engine operation.

Conclusions:

• While in-cabin noise is generally safe, crews must use hearing protection during activities involving open aircraft doors with engines running.
• Adherence to noise protection measures is crucial, especially considering external engine noise levels.
• The European Union's noise directive mandates the provision of hearing protection for aircrew, although its use is not compulsory.