Just over 20 years ago, Rolls-Royce and Boeing partnered together to develop quieter aircraft engines in what they called the “ecoDemonstrator program.” In 2001, an American Airlines Boeing 777-200 with Rolls-Royce Trent 800 engines was used for test flights at a Boeing Flight Test Facility at Glasgow Industrial Airport in Montana. The test results were better than expected and led to Boeing redesigning the de-icing holes on the leading edge of the aircraft’s wings to eliminate a whistling noise.