When it comes to commercial aviation, even the smallest improvements in fuel efficiency mean millions of dollars saved and fewer harmful emissions in our atmosphere. That's why NASA is looking everywhere for ways to improve fuel efficiency. Two of its most promising projects — a bug-repellant coating and a new technology for smaller vertical tails — are now ready to be tested in the real world.
Bugs splattered across the surface of a commercial jet might seem pretty insignificant, but NASA researchers say they can decrease fuel efficiency by as much as six percent. When those dead bugs collect on aerodynamically sensitive elements like the leading edge of wings, they disturb the airflow over the surface. That causes turbulent air and drag — which ultimately reduces efficiency. So NASA's testing five different nonstick coatings on Boeing's "ecoDemonstrator" 757 aircraft over a number of 15 different flights at a particularly buggy airport, located in Shreveport, Louisiana. Researchers will not only test to see how many fewer bugs stick to the surface, but also whether the coatings can withstand the rigors of commercial aviation.
It's all about reducing drag
NASA is also testing a novel way to cut down the size of the vertical tail on commercial airliners — reducing weight and fuel use in the process. According to the agency, the only reason the tails are so large is to assist with airplane stability at low speeds during landing and take off. It's also seen as a safety measure should an aircraft suffer an engine failure. But the large tails only weigh down planes while they cruise. So NASA worked with Boeing to try to make smaller, lighter tails that could behave like the old, bigger tails when needed.
The solution? Thirty-one tiny jets along the edge of the tail that can selectively blow air over the surface and generate the same stabilizing forces with a tail 17 percent smaller than the ones in use today. The agency worked with Boeing to develop the technology, and will test it this year in nine separate flights with a 757 test aircraft. The testing will include simulated engine failures, and researchers expect the development of smaller tails to cut back on half of one percent of fuel usage.
Should testing go as planned, the developments made by NASA and Boeing will become available to the public, and hopefully implemented in future aircraft retrofits and designs.