After leading the National Transportation Safety Board for four and a half years, Mark V. Rosenker has announced that he will resign his position as acting chairman and member. He submitted his letter of resignation to President Obama yesterday, according to an NTSB press statement.

Rosenker said he will delay his departure until a new chairman and an additional board member are confirmed to ensure a quorum remains at the Board.

In his letter to the President, Rosenker said that the opportunity to serve in and lead the NTSB "has been the highlight of my entire 40-year professional life. It is an agency that truly makes a positive difference every day, saving lives by preventing accidents, not only in our great Nation, but around the world."

Rosenker became a member and the vice chairman of the NTSB in March 2003 and became acting chairman two years later. He was sworn in as the 11th chairman of the Safety Board in August 2006, and was renominated by President Bush for a second term as chairman in October 2007.

Before joining the Board, Rosenker was Deputy Assistant to the President and Director of the White House Military Office under President George W. Bush. In that capacity, he was traveling with President Bush onboard Air Force One during the events of September 11, 2001. He also held several other federal government and private sector positions during a 40-year career, including 23 years as Vice President, Public Affairs for the Electronic Industries Alliance.

During his Chairmanship of the Board, the agency marked a number of major transportation safety achievements. Three significant items were removed from the NTSB's Most Wanted List of Transportation Safety Improvements. The Board removed Airliner Fuel Tank Flammability when the Federal Aviation Administration announced a new requirement for inerting fuel systems in newly manufactured airliners. With Congressional passage of the Rail Safety Act of 2008, two rail items were removed from the list: Positive Train Control, designed to prevent collisions if engineers fail to operate their trains in accordance with signal indications, and Rail Fatigue, whereby hours of service rules will be revised to set work hour limits based on fatigue research, circadian rhythms and sleep and rest requirements.

Under his leadership, the Safety Board added important issues to the Most Wanted list to reflect new safety priorities, including Emergency Medical Helicopter Safety, Cell Phone Use by Bus Drivers, Highway Vehicle Anti- collision Technology, On-board Highway Vehicle Recorders, and School Bus Passenger Safety.

Chairman Rosenker also improved the Safety Board's financial posture. Among fiscal improvements, he ensured that the NTSB Training Center — which was renamed from the previous NTSB Academy to better reflect the internal training mission of the facility — reduce the operational cost burden to the taxpayer through course fees, short-term rentals and long- term subleases.

Rosenker is a retired Major General in the Air Force Reserve. He intends to pursue opportunities in the private sector.