[6] In 2018 a new design of engine inlet liner was flight tested in a successor program, Quiet Technology Demonstrator 3 (QTD3), using acoustic arrays at Moses Lake, Washington.

[13] The NASA-designed inlet was installed in the right-hand nacelle of one of Boeing's two 737 MAX 7 prototypes,[14] powered by CFM International LEAP 1B engines.

The testing is usually done in collaboration with many industry partners, including NASA, the FAA, airlines, makers of engines, equipment and software, and academic institutions.

Technologies explored included: This airliner had served Air China since 2001 before Boeing purchased it to join the ecoDemonstrator program.

Among the 50 projects trialled were: This new aircraft for Etihad Airways was used for just a few weeks between August and October 2020,[35] with testing mainly carried out at Boeing's Glasgow Industrial Airport, Montana.

[40] In October 2021 the aircraft flew from Seattle to Glasgow, Scotland, for the United Nations COP26 Climate Change Conference, bringing executives from Boeing and Alaska Airlines and fuelled by a 50% SAF fuel blend.

[27] The testing program included: The aircraft was originally delivered to Singapore Airlines in 2002, and flew most recently for Surinam Airways.

[17] The company stated that the six-month 2022 program would demonstrate 30 new technologies,[45] among which were: In April 2023 Boeing announced that the 777-200ER would be testing 19 technologies during the year, including: Between 25 June and 29 June 2023 the aircraft operated from London Stansted Airport,[49] performing flights over The Netherlands, Belgium, Germany and the Czech Republic, subsequently returning to its base at Seattle.

In December 2023, in cooperation with Nav Canada, the aircraft taxied from stand to runway at Vancouver International Airport using only digital communications via the EFB, with no voice contact with ATC.

[50] Most information from Planespotters.net[56] All aircraft apart from the 2022 777 had ecoDemonstrator stickers applied to the fuselage or engine nacelles, at least one retaining them for some time after its participation in the program ended.

Boeing's chief pilot for product development stated that the TBO system, using technologies already in use aboard many modern airliners, allows pilots and air traffic controllers to make trial route change requests to see the cascading effects of the change on their, and other aircraft's flights, all the way through to airport gate availability, to see if they are likely to be approved.

[63] In October 2023 it was announced that the ANSPs of China, Indonesia, Japan, New Zealand, the Philippines, Singapore, Thailand, and the USA would create a Pathfinder project to demonstrate TBO across the region within four years.

Registered N27602, it made its first flight on 14 September 2023 and wore a special livery with "ecoDemonstrator EXPLORER" titles and "The Future is SAF" markings on the nacelles.

The emissions from the CFM International LEAP 1B engines were sampled by the NASA Douglas DC-8 Airborne Science Lab, registered N817NA, which flew behind the test aircraft.

At the end of the final test flight on 1 November, the Explorer aircraft returned to Everett while the DC-8 flew back to Plant 42, Palmdale, California.