GE Aerospace and NASA are partnering for a series of test flights that will deepen the aviation industry’s understanding of contrail formation and persistence. The flights will be conducted off the US east coast using GE’s highly-modified 747-400 Propulsion Test Platform and NASA’s Gulfstream C-20A (GIII) as part of the Contrail Optical Depth Experiment (CODEX). The NASA aircraft will closely follow the GE 747 and scan the aircraft’s wake with Light Detection and Ranging (LiDAR) technology.
What is the purpose of the study?
Contrails are clouds of ice crystals that form in the wake of aircraft at high altitudes when hot exhaust gases mix with cold, humid air. Research suggests that persistent contrails have a warming impact on Earth’s climate. This series of test flights is designed to advance the understanding of contrails and to aid in the development of new technology to reduce non-CO₂ emissions.
The use of LiDAR during the flight tests will generate three-dimensional imagery, which according to GE and NASA will “better characterize how contrails form and how they behave over time.”
Arjan Hegeman, general manager of future of flight technology for GE Aerospace notes, “Understanding how contrails act in-flight with the latest detection technology is how we move innovation forward. These tests will provide critical insight to advance next generation aircraft engine technologies for a step change in efficiency and emissions.”
GE plans to use these tests as a baseline for approaching new engine technology, including the CFM Revolutionary Innovation for Sustainable Engines (RISE) open rotor concept.
How to follow the flight tests
The GE Aerospace 747 flying test bed can be followed by searching N747GF. The NASA C-20A can be followed by searching N520NA or by searching NASA520 beginning 18 November and running through the end of the week.
Flightradar24 will also be onboard one of the test flights (tentatively scheduled for 21 November) and we’ll bring you exclusive access to the GE Aerospace 747 on the ground and in the air. Follow along on your preferred social channel (X (formerly Twitter), BlueSky, Facebook, Instagram) this week and check out or YouTube channel soon for a full behind the scenes look at the flight tests.
![An example full flight summary response from the Flightradar24 API: { "data": [ { "fr24_id": "0987654321", "flight": "SK1415", "callsign": "SAS1415", "operated_as": "SAS", "painted_as": "SAS", "type": "A20N", "reg": "SE-DOY", "orig_icao": "ESSA", "orig_iata": "ARN", "datetime_takeoff": "2023-01-27T05:15:22", "runway_takeoff": "12R", "dest_icao": "EKCH", "dest_iata": "CPH", "dest_icao_actual": "EPWA", "dest_iata_actual": "WAW", "datetime_landed": "2023-01-27T06:15:10", "runway_landed": "27L", "flight_time": 3600, "actual_distance": 1007.74, "circle_distance": 6245, "category": "Passenger", "hex": "4A91F9", "first_seen": "2023-01-27T05:06:22", "last_seen": "2023-01-27T06:18:10", "flight_ended": "true" } ] }](https://www.flightradar24.com/blog/wp-content/uploads/2025/04/Flight-summary-API-cover-300x148.jpg)
