The Continuous Lower Energy, Emissions and Noise (CLEEN) program is a NextGen effort to accelerate development and commercial deployment of environmentally promising aircraft technologies and sustainable alternative fuels. The aircraft technologies focus on reduction in aircraft noise, emissions, and fuel burn.

Under this program, FAA has awarded five-year agreements to Boeing, General Electric, Honeywell, Pratt & Whitney, and Rolls-Royce. These companies will match or exceed the awards in this cost-sharing program. The total federal investment is expected to be $125 million over five years.

Specifically, CLEEN goals include developing and demonstrating:

  • Timeframe for Introduction into MarketCertifiable aircraft technology that reduces noise levels by 32 dB cumulative, relative to the Stage 4 standard;
  • Certifiable engine technology that reduces landing and takeoff cycle (LTO) nitrogen oxide emissions by 60 percent below the International Civil Aviation Organization (ICAO) standard adopted in 2004;
  • Certifiable aircraft technology that reduces aircraft fuel burn by 33 percent relative to current subsonic aircraft technology, and which reduces energy consumption and greenhouse gas emissions;
  • Use of "drop in" sustainable alternative jet fuels in aircraft systems and quantifying benefits
  • Suitability of new technology for engine and aircraft retrofit to accelerate penetration into the commercial fleet

A complementary piece of the CLEEN Program to the technology and fuel development activities is an independent technology assessment. This effort will:

  • Independently assess the CLEEN funded technologies across five generic aircraft classes using the Environmental Design Space (EDS) modeling tool developed by Georgia Tech
  • Identify synergistic technology combinations
  • Compare results with CLEEN company estimates

To learn more about the CLEEN program, please visit the links below:

For information and materials on CLEEN II Industry Day: