Airman Alicia Guenther, Airmen First Class Raphael Jacobs and Nicholas Caines, 30th Airlift Squadron maintenance people, Yokota Air Base, Japan, give a C-9 Nightingale a good scrub Nov. 22, 1999. A paint safe detergent is used to wash the aircraft once every quarter, the wash also prevents corrosion. The C-9 is a twin-engine, T-tailed, medium-range, swept-wing jet aircraft used primarily for Air Mobility Command's aeromedical evacuation mission. The Nightingale is a modified version of the McDonnell Douglas Aircraft Corporation's DC-9. It is the only aircraft in the inventory specifically designed for the movement of litter and ambulatory patients. The C-9A's airlift capability to carry 40 litter patients, 40 ambulatory and four litter patients, or various combinations thereof, provides the flexibility for Air Mobility Command's worldwide aeromedical evacuation role.