Opinion: Why It Is Time For The Blended Wing Body

JetZero Concept
Credit: JetZero Concept

The protests at last month’s European Business Aviation Convention and Exhibition in Geneva remind us of the need for aviation to accelerate its decarbonization progress (page 30). Sustainable aviation fuel is the only realistic near-term option for long-range jetliners but will be lucky to reach 15% penetration by the mid-2030s. Hydrogen has significant promise but is decades away as a potential solution. Aviation needs a game changer. Paradoxically, that could be a design concept that has been around for 100 years: the blended wing body. 

The BWB’s key advantage is fuel efficiency. Its airfoil-shaped body allows the entire aircraft to generate lift, reducing fuel consumption at least 30-40%. When coupled with sustainable aviation fuel (SAF), carbon emissions could fall more than 80%. There are other advantages. The empennage is eliminated, and top-mounted engines reduce aircraft noise by 15 dB or more. BWBs offer improved survivability with lower radar and infrared signatures in military applications. And there is ample space for cylindrical hydrogen fuel tanks, which are not particularly compatible with tube-and-wing aircraft designs.

The BWB does have downsides. Moving away from the load-efficient cylindrical fuselage can add weight and complexity to the structure. Passengers would need to adapt to a dearth of windows and a new cabin format. Then there is inertia: The aerospace ecosystem has utilized tube-and-wing designs since the beginning. How would the industry transition? How would BWBs be certified?

Three notable BWB concepts were introduced in recent years. The first, a 200-passenger design powered by hybrid-hydrogen turbofan engines, was introduced by Airbus in 2020 as part of its ZEROe initiative. Airbus also flew a small-scale demonstrator aircraft.

The second recent BWB concept, revealed last year, is the Bombardier EcoJet. After flying a small-scale demonstrator, the OEM believes it could reduce aircraft emissions by up to 50% through a combination of aerodynamic and propulsion enhancements. It also sees the potential for an enhanced passenger experience.

The most intriguing design was unveiled recently by California startup JetZero. Its Z5 (see image) is designed to carry up to 250 passengers over a range of more than 5,000 nm. JetZero says the aircraft’s structure is lighter per passenger than comparable conventional aircraft. The Z5 is aimed squarely at the New Midmarket Airplane (NMA) category, and rather than 50,000-60,000-lb.-thrust engines required for tube-and-wing aircraft, JetZero expects to be able to use conventional CFM International Leap or Pratt & Whitney geared turbofan engines with perhaps 35,000 lb. thrust. The result is an estimated 50% reduction in emissions. 

Why could JetZero succeed in entering the jetliner business with an unconventional design when every new entrant has failed over the last 50 years except for Embraer? There are several reasons.

First, the Pentagon is interested in leveraging BWB advantages for a tanker or transport aircraft. The design could expand fuel-carrying capacity, increase range and offer improved survivability—all critical for emerging mission requirements in the Asia-Pacific region. JetZero is in a down-select phase for a public-private, full-scale U.S. Air Force BWB demonstrator program.

JetZero has impressive partners, including Northrop Grumman and Scaled Composites. Among its leaders are Tom O’Leary, a former Tesla and Beta Technologies executive; Mark Page, a McDonnell Douglas BWB veteran; and John Vassberg, Boeing’s former chief aerodynamicist. The company’s advisory board is a who’s who of aerospace.

Another reason for optimism is that the pressure for tangible emissions reductions will only increase. The BWB offers a step-function improvement with the ability to use SAF and transition to green hydrogen. 

JetZero also benefits from timing. The Z5 offers the potential of a rare “troika” of enhanced national security, sustainability and economic benefit—all priorities in Washington. With interest from both civil and military customers, the Z5 could follow the path of the Boeing KC-135 and 707, where the Pentagon funded much of the aircraft’s development costs before commercializing.

Finally, the target NMA market segment is wide open. Boeing does not plan a new aircraft until the mid-2030s, and the strong sales of the A321neo demonstrate the magnitude of the opportunity.

It remains to be seen if JetZero can challenge the Airbus-Boeing duopoly, but its entry could spur incumbents to innovate much like Tesla and SpaceX did in their respective industries.

Former Airbus Americas President and CEO Barry Eccleston is on JetZero’s board of advisors. When asked why he’s a supporter, he stated: “The industry deserves it and doesn’t do well when it stops innovating.”

Kevin Michaels

Contributing columnist Kevin Michaels is managing director of AeroDynamic Advisory in Ann Arbor, Michigan.


Well thought out and written. I'd like to hear your take on how in the world the FAA is going to take this on.....I don't have high hopes.
The performance benefits of the blended wing are well documented. Let's leave aside the argument of how much wing vs. body (the image is not highly blended).

Previous discussions of passenger implementation have focused on a different set of problems. Instead of the usual tube and wing technical issues of lift/drag, range/payload, there is another significant issue that becomes a major sticking point. The self-loading cargo (passengers).

A partial list:
• How do you load and unload? If you place the boarding doors on the forward edge of the wing you have issues with airflow, anti-ice, lift enhancement (slats), etc. On the underside? Stairs or ramps, lifts for the disabled? All are less than desirable. Tail works for cargo, but people, who are panicking?

• Given the requirement to evacuate in under 90 seconds how do you get people out? See above for leading edge exits in addition to fact that they will likely be obstructed by whatever the aircraft might’ve dug itself into coming in. Underside exits are non-starters for the same reason. Overhead exits? E-seats?

• This one really gave pause to the Engineers in the room: “Tumble through”. Given the placement of the engines, the fuselage crown is going to have to be tough enough to prevent an engine that’s broken loose from plowing into the passenger compartment on impact. Not a big threat if the engines are hung out on the wing but that negatively impacts the efficiency target you are after.

• Human Factors Engineers had determined the flying public wasn’t really ready for a live forward view. In many weather conditions where visibility is an issue, the passengers are better off not knowing what it looks like to the front. From human factors engineer: “Can you imagine the number of lawyers lining up for the inevitable "They scared the xx#@! out of me lawsuits?” Giving people a view from a camera on their seatback monitors is sufficiently detached from reality most people can deal with it and the captain can always disable the feed. Suddenly dimming the windows will have a negative effect as well. "What happened? Why did it suddenly go dark? Are we going to crash?" As we've seen with the COVID recovery, passengers can be fickle creatures.

• Passengers like windows. This design offers few if any. As above, HFE determined if you have to have them, make them look to the side not forward. For an alternative, HFE found that the view created by projection systems to create a synthetic outside view just were not up to the task and the additional power requirement above the existing generation load was prohibitive. Projectors have certainly improved since the discussion being referenced. Power loading…not so much. Increased use of passenger mobile electronics is straining the already heavily loaded engine driven generators.

• On a positive note it was felt that the great expanse of upper surface area could permit addition of overhead “skylights” to provide better natural lighting to passengers making for a better experience on ultra-long range routes. Even brought out a few comments about tennis courts etc. However…”tumble through”.

Cool concept. Still a lot of issues that need a solution.
I seriously doubt the statement that, "The BWB’s key advantage is fuel efficiency. Its airfoil-shaped body allows the entire aircraft to generate lift, reducing fuel consumption". Lift costs fuel, regardless of its source.