We asked three influential thinkers in the aerospace industry the same question: What’s next?
To understand their responses, a short glossary might be helpful:
Blended Wing Body: Unlike tube-and-wing designs, a blended wing body (or hybrid wing body) airplane blends the wing into the fuselage. That creates a wedge-shaped aircraft that holds promise for substantially improved fuel efficiency and other benefits.
Boundary Layer Ingestion: As an airplane passes through the air, it disturbs it, creating a thin layer of distorted air between the plane and the undisturbed air flow. Researchers are working to find out whether funneling this air into engines could greatly increase fuel economy.
Scramjet: Traditional rockets carry fuel and oxygen, which are burned together to create thrust. Hauling more weight or traveling farther requires bigger fuel loads, which limits rockets’ uses. Scramjets draw oxygen from the air around them, significantly reducing the amount of fuel they need to carry. This may result in the ability to carry heavier payloads into space, or a tremendous increase in speed when flying within Earth’s atmosphere. While no one is going to use rockets to go places quickly in Earth’s atmosphere, scramjets have that potential.
Anywhere in the world in two hours
Boeing’s chief scientist for hypersonics
Imagine getting anywhere in the world in two hours or less, barely enough time to watch a movie or take a nap. It’s all thanks to hypersonic technology, allowing airplanes to fly Mach 5 — five times faster than the speed of sound.
Hypersonic technology is nothing new. In 1949, the first man-made object flew at hypersonic speed. Soon after, a piloted rocket-powered aircraft reached Mach 6.7. More recently, space capsules and the space shuttle reached hypersonic speeds re-entering the atmosphere.
The opportunity for practical hypersonic flight changed dramatically over the last decade with flight demonstrations of air-breathing hypersonic engines called scramjets. As scramjet technology matured, so, too, did high-temperature materials and hypersonic vehicle design capability.
Given this demonstrated capability, what about a hypersonic passenger airplane? The potential for hypersonic aircraft in the future will require further advances in several technology areas, as well as market demand.
While Boeing is not developing a hypersonic airliner and does not see a near-term demand for the product, we continue to research many advanced hypersonic concepts and technologies, so we are prepared if there is a business case for such vehicles. While we can’t say when hypersonic flight for global travel will be a reality, it could be feasible looking 50 years into the future.
Reshaping airplanes for a cleaner world
Aurora Flight Sciences research engineer
Environmental impacts are an existential threat to the continued growth and prosperity of the aviation industry. Primary among these are local air quality impacts, community noise and long-term climate effects due to increasing fuel consumption. I believe the foreseeable future of aircraft development will focus on continuing to improve cost performance while simultaneously reducing environmental impacts in a substantial way.
Any discussion of aviation and the environment would be lacking without emphasizing the technological miracle that is a modern jet aircraft. The aviation industry has been improving the performance of aircraft continuously since the dawn of the commercial jet age, with breathtaking results. Today’s aircraft have environmental and cost performance that is in some ways better than their ancestors by orders of magnitude. Depending on your metric of interest, aircraft have fuel performance equal to or better than our best automobiles.
Unfortunately, these improvements have been outstripped by the rapid and sustained increase in demand for commercial air travel. Despite huge gains in aircraft fuel efficiency, net emissions continue to rise.
The rapid growth of aviation and a renewed understanding of environmental damage due to noise and emissions have challenged the industry to improve even faster than the already impressive historical rate. Traditionally, this improvement rate has been driven largely by incremental progression in propulsion systems. There have been some beneficial changes to the aerodynamic shaping of the aircraft; however, even a casual observer will notice a stark similarity in the silhouette of a 1960s-era jet and the jets that are flying today.
One way to disrupt the historical rate of progression is to rethink the classical tube-and-wing silhouette by re-configuring the aircraft. These new aircraft shapes, or “configurations,” will allow for more symbiotic integration of the major aircraft components. Decades of research by NASA, academia and industry have proven that treating the aircraft system as a more fully integrated machine — rather than a combination of optimized sub-systems — can put the industry on a path towards meeting aggressive performance goals.
Disruptive innovation due to highly integrated airframes and engines will drive a paradigm shift in environmental performance. My vision — and Aurora’s vision for the future of commercial aviation — is the D8 aircraft, which integrates engines into the fuselage to improve the overall efficiency of the aircraft. This concept leverages Boundary Layer Ingestion (BLI), which essentially means consuming the disturbed air behind the aircraft and doing useful work with it. There are some technical barriers remaining. Most notably, engine operability in the presence of disturbed air needs to be demonstrated, but these are solvable in a relatively short timeline.
Regardless of the eventual silhouette of the dominant aircraft configuration that emerges in the coming decades, I believe a combination of BLI and advanced composite manufacturing — to efficiently make new aircraft shapes — will be the defining characteristics of the future global air transportation industry.