John Hall, M.S., CCC-A
DOD personnel are exposed to hazardous acoustic noise degrading hearing/communication. F/A-22 and legacy AF and Navy fighter aircraft generate up to 150 dB at key ground crew positions (same expected for the Joint Strike Fighter). Current hearing protection (30 years old) is inadequate, offering only 25-30 dB of protection; AF and Navy aviation ground crew members wearing current protection are often overexposed in seconds or minutes. OUSD and the Congressional Defense Committees are concerned over magnitude of the problem and directed initiation of Defense Technology Objective (DTO) HS-33 “Improved Aviation Personnel Hearing Protection”.
The joint effort targets 50 dB of overall protection. To date there has been successful field demonstrations with F/A-22 maintainers wearing improved deep insert custom passive earphones called the Attenuating Custom Communications Earphone System (ACCES) developed by the Air Force Research Laboratory (AFRL). ACCES demonstrated 40 dB overall protection under standard flightline communication muffs. The F/A-22 CTF reports improved attenuation and clear communication in 150 dB jet noise with ACCES. Recent performance on a contract to add ANR to ACCES have demonstrated 47dB attenuation performance in the ear canal under a passive muff.
A flight helmet version of ACCES was developed by AFRL at the request of the Aeronautical Systems Center. This system has been evaluated in-flight by the F/A-22 Raptor at the Air Force Flight Test Center, Edwards AFB, CA. To date, ACCES has logged over 300 flight hours in the F/A-22 by numerous pilots with high marks on performance. Test sorties have been up to 4 hours in duration, with maneuvers including 9 G accelerations, aerial refueling, and multiple ship formations. The F/A-22 Program Office has requested AFRL and the 311th Human Systems Wing deliver 2 sets of ACCES to each Raptor pilot at every F/A-22 squadron.
This presentation will compare and contrast emerging intra-canal acoustic technologies with legacy system performance and provide a status update on AFRL’s activity in this technology area.