This is the last story in our “Grist for the Mill” series – the IATA Technology Roadmap.
The following web story will cover the development of a demonstrator with the Hybrid or Blended Wing Body (BWB), which is the last part specified in IATA’s Technology Roadmap.
The risks and expectations are slightly higher in this last TRM In-Flight instance as demonstrators are specified, compared to other cases where an article with a Technology Readiness Level 9 is the final output. As one can expect, the price points for demonstrators of new technologies are somewhat higher, while revenues are not yet evident. Two projects are part of the last story in Grist for the Mill -Part 6. The first is the US government’s support for a demonstrator project which uses the Blended Wing Body. The second project is the EcoJet, which Bombardier is proposing for executive jet travel.
US Air Force BWB
The US Air Force has indicated to its sponsors that the BWB design would serve as a critical component of the USAF climate action plan. There are many other reasons and features that flow from these choices when moving to the BWB, and these will be outlined in the following narrative.
The Blended Wing Body name is derived from the design choices that have been made regarding the jet’s wings and fuselage, which are now blended together. This resultant design for the BWB shows no clean break (see the following Figures 1 and 2) between the wing and fuselage elements of the airplane.
This departure from the tube and wing design is a concept that has existed for several decades but has not been acted on until recently. One previous subscale BWB demonstrator that was tested was Boeing’s X-48, which was built in partnership with NASA. Figure 1 shows a picture of the X-28 BWB circa 2007.
Figure 1: Boeing – NASA X-48C Hybrid Wing Body aircraft flies over Rogers Dry Lake at Edwards Air Force Base, California
Since then, the 48C BWB has completed its service and been retired. The US government, through the DOD, has recently re-initiated plans to move forward from that earlier sub-scale model.
The next step in the evolution of the BWB airplane concept will be a full-scale project. DOD has recently completed a competition in this matter and has awarded JetZero a substantial contract to proceed with that design. Figure 2 shows the artist’s concept for this new BWB aircraft.
JetZero company representatives refer to this project as a “public-private partnership” and add that they will also invest in the airplane’s development. As a result, their resources will be coupled with the Pentagon’s $235 million award.
DOD’s recent award (April 23) has many implications for climate change, as well as furthering commercial and government interests. Firstly, the aircraft design will be able to reduce emissions by up to 50%[1]. Next, the aircraft passenger configuration has a significant potential as a large aircraft. The passenger configuration remains open to design elements but could range from 450 – 800 passengers. Furthermore, once this aircraft is proven, it can be considered as a commercial passenger replacement for the Airbus 320 NEO.
DOD’s interest in this project is both as a tanker and a freighter. The BWB, like any new airframe, can bring new materials and capabilities to the flight line, which is vital to the defence sector as it considers future challenges and needs.
Two critical limitations of the BWB are found, which are unique to its design. Compared to the tube and wing project, passenger seating in the BWB will be theatre-style. Focus group testing in the early days of the airplane’s development indicated that the customers did not appreciate this style. However, in the intervening 20+ years, several wide-body aircraft (with two passenger aisles) were successfully introduced. Each of these had a wider middle section. Current wide-body aircraft now all have theatre seating elements, and some middle rows have as many as five seats! The second limit to the BWB is that once an aircraft has been configured, its designs are locked in. Unlike the current tube and wing design, taking a BWB design and making it longer, broader, etc, will not work. Any new size requirement for the BWB aircraft requires an entire redesign. Obviously, these new designs would be similar, but they will not be scaled versions of one another.
Figure 2 JetZero Design Concept – a full-scale BWB
The reimagined BWB-JetZero aircraft is set to launch in 2030 and will have 100% SAF compatibility. Additionally, it will have an appropriate internal volume (i.e. space) to accommodate zero-carbon hydrogen.
The engines selected for this project are indicated to be provided by Pratt & Whitney.
Currently, JetZero is focused on a 1:8-scale BWB model named Pathfinder. This aircraft recently received FAA certification, allowing JetZero to commence its test flight program. In scaling up from the current size to the full-scale prototype, JetZero will work with Northrop Grumman, the developer of the B2 Stealth Bomber, which is also a BWB-type aircraft.
The Bombardier EcoJet
Bombardier has made considerable innovations in the aerospace sector in the past decades. Since 2009, this company has been developing the EcoJet aircraft to support the executive business travel market. The Bombardier product line already has four classes of business jets, to which the EcoJet will be added. Figure 3 shows an artist’s concept of the Ecojet.
Figure 3 – Artists Concept of Bombardier’s EcoJet
The first drone variant of this scaled-down aircraft was flown in 2017, and Bombardier is now prepared to proceed with its second phase of development. The Phase Two article will fly faster, higher and longer. These subsequent test programs will allow test program engineers and managers to examine flight control matters and how the BWB’s unconventional shape affects its flight.
Like all aircraft developments now, the EcoJet also aims to reduce emissions. Up to a 50% reduction in emissions is also anticipated for this airplane.
Some reasons that the BWB design is of high interest to aerospace aircraft designers are that the fuselage generates lift while the wingspan has a lower drag. The BWB fuselage is also relatively flat compared to the tube designs of current aircraft in service. This flat fuselage generates lift, so with the fuselage contributing to lift, the wingspan’s configuration can now be redesigned to provide less drag to the entire aircraft structure yet still serve its purpose. In effect, the wings become relatively smaller in any BWB structure.
The current EcoJet test vehicle is an 18’ wide BWB drone. Several test campaigns are being proposed to be held over the coming years. These tests are aimed at generating real-world data in representative
environments. Company officials offer that there will be a Phase 3 program at the conclusion of the current Phase 2 exercises.
The following is a YouTube video describing the EcoJet, along with an interview with Bombardier’s VP of Engineering and Chief of Aircraft Design and Development. Additionally, our website hosted an earlier story which described the Phase 1 testing regime for Bombardier’s EcoJet.The full-scale EcoJet has no set date for arrival but completes the IATA TRM for in-flight developments.
EnviroTREC first mentioned the Blended Wing Body program in a recent web story: IATA Technology Roadmap 2023, Grist for the Mill, Part-4.
[1] R. H. Liebeck Published Online: 22 May 2012 https://doi.org/10.2514/1.9084