Continuous Lower Energy, Emissions, and Noise (CLEEN) Program
Pursuant to 49 U.S.C. § 47511, the Continuous Lower Energy, Emissions and Noise (CLEEN) Program is an FAA effort to evaluate innovative aircraft technologies with improved performance and safety. Through the CLEEN Program, the FAA partners with aerospace manufacturers via a cost-sharing approach to support the development and integration of these advanced technologies into current and future aircraft.
About CLEEN
Through the public-private partnership of the CLEEN Program, the FAA and industry are working together to test and develop technologies that will enable manufacturers to create aircraft and engines with reduced fuel burn, less noise, and other benefits. The work of CLEEN can also help inform the development of FAA airframe and engine environmental standards and environmental review of rulemaking and other actions.
In 2010 the FAA initiated the first phase of the CLEEN Program, entering into five-year agreements with Boeing, General Electric (GE), Honeywell, Pratt & Whitney (P&W), and Rolls-Royce.
Based on the success of this program, the second phase of CLEEN was initiated in 2015 for a five-year term. Under the CLEEN Phase II program, FAA awarded five-year agreements to Aurora Flight Sciences, Boeing, Collins Aerospace, America's Phenix/Delta TechOps/MDS Coating Technologies, General Electric, Honeywell, Pratt & Whitney, and Rolls-Royce.
Following subsequent successes under the second phase, the third phase of the CLEEN Program was launched in 2021 with research and development activities planned to run through 2026. Under the CLEEN Phase III program, FAA awarded five-year agreements to GE Aerospace, Boeing, Collins Aerospace, America's Phenix/Delta TechOps/MDS Coating Technologies/GKN Aerospace, Honeywell Aerospace, Pratt & Whitney, Rolls-Royce, and Safran Nacelles.
CLEEN Phase IV
The FAA is in the process of initiating a fourth phase of the CLEEN Program. A Screening Information Request (SIR) for CLEEN Phase IV was posted to SAM.gov on March 30, 2026. Proposals are due no later than 12:00pm (noon) EDT on Monday, May 18, 2026.
CLEEN Reports
- Boeing CLEEN Phase I Aircraft Technologies Report
- GE CLEEN Phase I Aircraft Technologies Report
- Honeywell CLEEN Phase I Aircraft Technologies Report
- Pratt and Whitney CLEEN Phase I Aircraft Technologies Report
- Rolls-Royce CLEEN Phase I Aircraft Technologies Report
- Boeing CLEEN Phase I Fuels Report
- Pratt and Whitney CLEEN Phase I Fuels Report
- GE CLEEN Phase II Aircraft Technologies Report
- Pratt and Whitney CLEEN Phase II Aircraft Technologies Report
- Rolls-Royce CLEEN Phase II Aircraft Technologies Report
- Boeing CLEEN Phase II Aircraft Technologies Report
- Collins CLEEN Phase II Aircraft Technologies Report
- GE CLEEN Phase II Fuels Report
- Rolls-Royce CLEEN Phase II Fuels Report