Cessna O-2A Super Skymaster 67-21363Photographed at the Museum of Flight Restoration Center, Paine Field, Washington State, USA on 13 June 2007.
Now registered N18BB, c/n 337M-0069. This is a Vietnam War combat veteran, with over 3,000 hours as a Forward Air Controller - note the warning "Don't Shoot" on top of the wing.
This aircraft was airworthy in 2009, and may still be.
Picture added on 21 February 2012 at 15:07