The FAA-LED team continues the development of a highly efficient LED airport approach lighting system to replace presently-used incandescent lamps. The improved system uses photodiodes and temperature sensors in a closed-loop system to compensate light levels for snow, rain, dirt and LED aging. Visual acquisition of the airport is improved with an innovative LED configuration and computer-controlled strobe sequences. Fuel cells are evaluated for use as backup power and a detailed economic analysis of the LED system is also performed.