It’s easy to imagine how things like wind and weight affect aircraft fuel consumption, but it's harder to comprehend how insect residue on aircraft wings and fuselage could be a contributing factor to fuel efficiency. However, the experts at NASA can, and have begun testing non-stick wing coatings designed to minimize insect residue to help reduce aircraft fuel consumption.
Over the next two weeks in Shreveport, Louisiana, NASA will be testing the coating using its Boeing ecoDemonstrator 757.
During planned ecoDemonstrator flights, NASA's Environmentally Responsible Aviation Project will evaluate how five different coatings prevent insect remains from sticking to the 757's wings.
A spokesperson for NASA's Langley Research Center in Hampton, Virginia, says bug residue is "a nuisance on cars, but on some aircraft designs it is also a drag - literally."
Research shows that keeping the flow smooth, or laminar, over a wing can save up to six percent of fuel consumption, adding even something as small as a bug on an aircraft's leading edge can cause turbulent wedges that "interrupt laminar flow, resulting in an increase in drag and fuel use."
With the help of Boeing, the University of California's Davis team, and the U.S. Department of Transportation (Volpe), the Research Center developed and tested several non-stick coatings on an jet wing in a small wind tunnel and from these selected the best candidates to test during actual flights.
The team needed an area with a large bug population for the tests and from a list of 90 bug heavy airports, they chose Shreveport, based on runway length, temperature, humidity, weather, the ability to handle a 757 aircraft, and thunderstorm frequency.
The researchers from Langley will work with pilots and engineers from Boeing to test the coatings during the Louisiana flights. The team will establish a "bug baseline by using uncoated surfaces to capture insect accumulation rates." The aircraft’s other untreated wing will be the control sample.
NASA's goals are not only to determine which coating is best in decreasing the amount of bug residue collected, but also to provide data that will "allow engineers to measure how reducing the size and specific locations of bug strikes affect laminar flow and help improve fuel efficiency.”
According to Boeing, the ecoDemonstrator Program plays a major role in the "company’s environmental strategy by testing and accelerating new technologies that can reduce fuel use, carbon emissions and noise.”
In 2014, the company tested 25 different technologies on the aircraft.