Multi-Axis Vibration Mitigation and Habitability Improvement for Seated Occupants

Propeller-driven aircraft produce vibrations that have deleterious and potentially harmful effects on crew members exposed to their operational environment for extended mission durations. The E-2C/D aircraft has a high vibration environment and a seat that passes these environments on unmitigated to the crew members maximizing discomfort, especially during the long duration missions that are standard for the E-2 aircraft. Exposure to these environments are even producing physiological damage and injury to crew members. A new propeller design has been marginally successful at reducing the blade passage frequency vibrations, but the propeller rotation frequency vibrations transmitted to the occupant and seat remain unacceptable. Under a previous Phase II SBIR contract a seat with an integrated magnetorheological (MR) vibration isolation system was developed, vibration tested and proven to be effective in isolating seat occupants from the vibration environment. The objective of this proposed Phase II program is to evaluate the ability of a seat with integrated magnetorheological (MR) vibration isolation to reduce the physiological problems of discomfort and pain experienced by the pilots of these E-2 aircraft. The approach is to conduct flight tests initially using the test residue/seat from the previously completed Phase II SBIR program.