Director, Naval Aerospace Medical Research Laboratory

In 2008 he returned to the Navy as a civilian staff scientist at Naval Aerospace Medical Research Laboratory (NAMRL), NAS Pensacola, FL. He was promoted to Acting Scientific Director in 2009 and Scientific Director in 2010. His research at NAMRL included work in aviation personnel selection and fatigue countermeasures. As Scientific Director he was responsible for execution of NAMRL’s research mission, spanning a range of aeromedical and aviation human factors topics such as motion sickness countermeasures, spatial orientation, fatigue effects and countermeasures, altitude effects, vision sciences, personnel selection and aeromedical standards. 
In 2011 he relocated with the laboratory, as directed by the Base Realignment and Closure Act of 2005, to Wright-Patterson AFB, OH, since which time he has continued to direct the activities of the aeromedical lab at NAMRU-Dayton. 
Dr. Arnold is an active member of the Aerospace Medical Association and the Department of Defense (DoD) Human Factors Engineering Technical Advisory Group.  He serves on numerous DoD and non-DoD boards and panels, including member (current) and chair (2015-2020) of the JPC-5 Aviation Mishap Prevention Working Group, NAMRU-Dayton representative to the Ohio Federal Research Network since 2016, and NAMRU-Dayton representative on the DoD/FAA Aeromedical Research, Alignment and Coordination (AMRAC) Working Group since 2014.  He served as 2018 Chair of the DoD Human Factors Engineering Technical Advisory Group.