How JetZero's MASSIVE 'Flying Wing' ENGINE Will Be Built

Conventional aircraft hang their engines below the fuselage because that surface is not generating lift. On a blended wing body, every surface generates lift. There is no neutral place to mount an engine, [music] and that is where the engineering nightmare begins. Jet Zero is trying to build the first commercial blended wing body airliner. An aircraft where the passenger cabin, wings, and [music] fuselage are merged into a single continuous lifting surface. Their aircraft is called the Z4. Jet Zero claims the aircraft will deliver up to 50% lower fuel burn and carbon emissions compared to conventional tube and wing aircraft. >> [music] >> The Z4 is a fundamentally different shape of aircraft, and fitting engines onto it changes almost everything. So, here's the question. What do you think is the hardest part of making that work? Is it finding the right engine for an airframe that has never flown at this scale, building the structure that holds it in place above a surface that generates lift, or getting a configuration no regulator has ever certified [music] or approved for passengers? Drop your answer in the comments. We'll come back to it at the end. On March 6th, 2025, Pratt & Whitney announced it would integrate the PW2040 engine on the Z4 demonstrator. The PW2040 is the same turbofan that powers the Boeing 757. [music] It received FAA certification in 1987 and entered service with UPS Airlines nearly four decades before the aircraft it will now help prove. It produces around 40,000 lb of thrust, roughly equivalent to what a narrow-body commercial airliner needs to get off the ground. [music] Jet Zero did not choose the PW2040 because it is the best engine for the Z4. They chose it because it is the right size and it exists. No engine manufacturer has publicly committed [music] to developing a new engine in the thrust class the commercial Z4 will require. So, Jet Zero is building a demonstrator to prove an airframe. But that airframe at commercial size will need an engine in a thrust class no manufacturer has publicly committed to developing. That missing engine matters. Jet Zero is constructing its airframe, securing airline partners, building its factory, and planning its certification program, all without a confirmed production engine. On a conventional aircraft, the engines hang below the wings on pylons with plenty of clearance between the engine and the ground. A BWB has none of that. The whole aircraft is one continuous surface. Put an engine below it and you disrupt the airflow generating lift. So, the engines move to the only place that works. Above the aircraft, mounted at the rear. Being positioned in the back, the air has been traveling across the entire upper surface. By the time it reaches the engines, it has slowed down significantly. With a conventional aircraft, the engine that hangs below a wing gets clean and fast-moving air. These engines get slow, thick air that has dragged along the body for the entire length of the aircraft. >> [music] >> That sounds like a problem, but NASA research found it can actually be an advantage. If the engine is designed to work with that slow air rather than against it, it does less work to generate the same thrust. NASA's modeling projected around 5.5% better fuel efficiency compared to a conventional underwing installation. The part of the engine system that has to manage all of that is the nacelle. Get the nacelle design wrong and the efficiency advantage disappears. And nobody has ever built one for this. Jet Zero handed that problem to Collins Aerospace. >> [music] >> The same division that built the nacelles for the 787 and the A350. Even with that experience, they are starting from scratch on this new design. Jet Zero places the Z4's engines above the center body. On a conventional aircraft, the pylon carries the full engine weight and thrust load below the wing, requiring a heavy reinforced attachment that adds significant weight. Jet Zero states that placing engines above the center body reduces structural complexity compared to a conventional underwing pylon attachment and [music] keeps the wing surface clear. Mounting the engines on top puts the aircraft body between the engines and the ground. On takeoff and approach, that body blocks a significant portion of the noise before it reaches the people below. Jet Zero is also shaping the engine openings to push the noise further in that direction. The inlets and nozzles are cut at an angle rather than straight, which directs noise away from the ground. But the position creates a problem, too. The slow, thick air the engine sit in increases noise at the source. The body shielding offsets some of that, but whether the Z4 ends up quieter at ground level than a conventional aircraft depends on how well the final design manages that balance. Those tradeoffs are still being calculated, but the engine itself has already been built. A PW2040 from the 757 starts as raw titanium and steel. The fan blades are pressed and hollowed out at the center to keep them as light as possible without sacrificing strength. Each blade has to withstand the force of spinning at thousands of revolutions per minute while pulling enormous volumes of air into the engine. Fan blade structural integrity is a certification critical requirement. Under FAA regulations, every turbofan must pass tests demonstrating it can contain a blade failure without releasing hazardous fragments. That containment requirement is part of why manufacturing tolerances are measured in thousands of an inch. The turbine discs, which spin at extreme speed inside the hottest part of the engine, are built by compressing metal powder under intense heat until it fuses into a solid that is dense enough to survive temperatures no conventional casting could handle. The combustion chamber and compressor blades are both cast from alloy. Each component is inspected individually before it gets anywhere near the assembly line. The engine is assembled in sequence around a central shaft. Fan at the front, compressor behind it, combustion chamber next, turbine at the rear. The tolerances between rotating and stationary parts are fractions of a millimeter. Before it leaves the factory, the engine is bolted to a [music] test stand and runs at full power. Engineers measure thrust output, fuel consumption, temperature at every stage, vibration, and oil pressure. The engine must hit every number before it is cleared. Only then is it shipped. On a conventional aircraft, installing that engine follows a process refined over decades. It is hoisted from below, bolted to its mounts, then connected through a series of fuel lines, air ducts, and electrical harnesses in an order the workforce has run hundreds of times. On the Z4, the installation approach has to change. With engines mounted above the body, the standard procedure of hoisting from below does not apply. No published commercial installation procedure exists for this configuration. The wiring presents its own challenge. A modern turbofan runs on a computer called a fadec, which controls [music] fuel flow, monitors engine health, and communicates with the cockpit in real time. On a conventional aircraft, the cables connecting that computer to the rest of the aircraft run through the pylon and down into the wing. On the Z4, those cables must route from the top of the aircraft through a composite structure not optimized for conventional cable runs. It is a routing challenge with no commercial precedent. The PW2040 itself is unchanged. Everything around it is new. Jet Zero completed its critical design review on May 29th, 2025. Assembly is underway at Mojave, with the main center body section expected to be complete in the fourth quarter of 2026. Jet Zero's subscale demonstrator with a 23-ft wingspan received an experimental category FAA airworthiness certificate in March 2024. That certification covers a small unpressurized test vehicle. It does not apply to a passenger aircraft, a pressurized [music] cabin, or a full-scale composite airframe. Ground testing of the full-scale Z4 is expected to begin in April 2027. [music] Every data point from those tests will be new. The FAA has not published specific certification standards for this [music] engine configuration on a passenger airframe. The central fact of the BWB engine program is this. >> [music] >> The demonstrator engine exists and has a nearly 40-year track record. The engine that will power the full-scale aircraft does not exist yet. And about that question from earlier, what is the hardest part of making the Z4's engines work? Is it finding the right engine, building the structure that holds it in place, or getting it certified? The evidence points to the engine selection itself. No manufacturer has committed to building one in the power range the full-scale Z4 will need. Jet Zero is constructing a factory, signing up airlines, and targeting deliveries in the early 2030s, all without knowing what will actually [music] power the full-scale aircraft. The radical new shape, the fuel savings, the passenger capacity, blended wing body aircraft are getting a lot of attention right now. What nobody is talking about is what happens when one of these tries to land at an airport designed for tube aircraft. The tube and wing formula has defined commercial aviation for more than 60 years. A cylindrical fuselage carries passengers and separate wings generate lift. Every airport was built around that arrangement. A blended wing body merges the fuselage and wings into a single integrated lifting surface. [music] Lift is generated across the entire planform. Two funded commercial programs are now developing blended wing body aircraft for passengers. Jet Zero's Zeed four carries approximately 250 passengers with a wingspan of [music] around 55 m, placing it in wide body territory. The Natilus Alerion Evo carries up to 250 passengers [music] with a wingspan of 118 ft or 36 m. Natilus designates this as gate class C4, a company classification rather than an official category, placing it in the same gate footprint as a Boeing 737 or Airbus A320. Two blended wing body programs, the same passenger count. One company designed its aircraft to fit existing airports by keeping the wingspan small. The other built the more ambitious shape and argues airports [music] will manage. Understanding why requires understanding what airports are actually built around. Airports were designed around cylindrical aircraft because every commercial [music] plane was. The layout used at most major airports is to park planes nose first into the terminal. Jet bridges extend from fixed terminal positions to aircraft doors on a cylindrical fuselage at predictable heights and positions. Gate spacing is calibrated to the known ratio between wingspan and fuselage width. Baggage systems route cargo to a hold accessed beneath a recognizable fuselage floor. A blended wing body changes every one of those relationships. There is no conventional nose. There is no cylindrical fuselage spine. Door positions occur at heights and angles that no existing jet bridge was designed to reach. The ground footprint is wider and flatter than the gate geometry anticipates. The aircraft is not a bigger cylinder. It is a different shape. So, do you think a blended wing body aircraft will ever reach a commercial gate or will the airport problem kill it before it gets there? Let us know your thoughts in the comments. The last time airports had to adapt to a genuinely new aircraft shape, it cost nearly a billion dollars in the US alone. That aircraft was the Airbus A380. And the A380 was just a bigger cylinder. The 18 US airports identified as making changes estimated they would spend approximately 927 million dollars in completed, ongoing, or planned infrastructure projects. About 83% of those costs were for runway or taxiway work. FAA standards required 200-ft wide runways and 100-ft wide taxiways, where most airports had built to smaller dimensions. Amsterdam expanded [music] its terminal infrastructure with costs exceeding 650 million dollars. Lufthansa constructed a dedicated maintenance facility at Frankfurt between 2006 and 2015 [music] at a cost of over 150 million euros. Every euro of that was spent adapting infrastructure to an aircraft that was otherwise completely familiar. The A380's doors [music] were in standard positions. Its tail was taller. Its wheels were heavier. The shape was the same. A blended wing body changes the shape completely. Jet Zero CEO Tom O'Leary has argued that airports will need only minor adjustments. You might have to adjust the line markings on the ground and reposition the passenger boarding bridges, but it will all be done using the same terminal. That claim has not been independently verified. No airport has tested it. A standard passenger boarding bridge adjusts in height, angle, and extension, but every adjustment assumes a door at a predictable location behind a conventional nose. A blended wing body has no fuselage spine to reference. Entry points sit at different heights and angles. The Jet Zero Z-4 has six separate passenger bays spread across the aircraft. So, instead of two doors on the side of a tube, you potentially have entry points distributed across the entire [music] wing-shaped body. The bridge configuration that reaches one door will not reach the others without separate repositioning. A 250-passenger aircraft also requires multiple boarding points to achieve commercially viable turnaround times. Klaus Zimmer of MTU Aero Engines stated it directly, "Keeping to today's turnaround times on the ground is also a challenge for BWB's and a key consideration for airlines." The A380 required at least two jet bridges for efficient boarding. Airports that could not provide that found the aircraft could not be effectively operated. A blended wing body carries the same boarding complexity inside a geometry that makes multi-bridge configuration significantly harder. The gate problem is visible and discussed. The hangar problem is a different story. Conventional commercial hangars are built for a specific geometry, tall and narrow with door heights calibrated to clear a vertical tail fin reaching 60 to 80 ft. A blended wing body aircraft has no conventional vertical tail. Its profile is wide and low. The hangar geometry it requires is the inverse of what every commercial maintenance facility was built to provide. No cost estimate for a commercial BWB maintenance hangar has been published. When Lufthansa took delivery of the A380, their existing hangars couldn't fit it. So, they built a new one from scratch. It took 9 years and cost over 150 million euros for one aircraft type at one airport. That was for a cylinder that fit a hangar shape the industry understood. No commercial BWB maintenance hangar has ever been built. No public estimate exists for what one may cost. Jet Zero built the more aerodynamically ambitious aircraft and argues airports will adapt. Natilus made the opposite choice. Their aircraft, the Horizon Evo, is a blended wing body designed to carry up to 250 passengers in the same gate footprint as a narrow-body like the Boeing 737 or Airbus A320. By constraining the wingspan to 118 ft, Natilus kept the Horizon Evo within what it designates as gate class C4, a company classification that maps to the same ICAO gate footprint as today's single-aisle aircraft. An airport that handles narrow-body traffic today would require no gate modifications to receive it. Natilus didn't stop at the gate footprint. The Horizon [music] Evo's dual-deck configuration allows passengers to board from the upper deck while cargo loads from the lower, which would improve turnaround time. Multiple aisles across the cabin reduce boarding time further. These are not comfort features. They are economic. Every extra minute at the gate erodes the fuel efficiency advantage earned in the air. Both Jet Zero and Natilus are betting that a fundamentally new aircraft shape is worth the risk. But the strongest argument against both of them isn't the airport problem. It's the plane sitting at the gates already. The Boeing 787 and Airbus A350 deliver meaningful fuel savings through advanced composite structures and high-bypass engines [music] without requiring a single airport modification. Both aircraft are certified, commercially operational, and use existing infrastructure [music] worldwide. In March 2026, the Leeham News BWB analysis drew this response. It is easier to keep the wing and fuselage structure and get 15 to 20% better fuel consumption from the engines than spending years and billions getting a BWB through FAA certification for a 5% fuel reduction. That is the decision airport planners and airline teams are weighing right now. Neither Jet Zero nor Natilus has completed a full-scale flight. Neither aircraft holds FAA certification. No airport has published a BWB [music] infrastructure plan. Both companies assert their aircraft will require minimal modifications to existing infrastructure. Both assertions rest on design intent, not operational evidence. Jet Zero targets a full-scale demonstrator flight by the end of 2027. What airport modifications would actually be required will not be answerable from manufacturer specifications. It will be answerable from the first airport that has to prepare a real gate for a real aircraft. The A380 was just a bigger cylinder, and 18 US airports estimated nearly $1 billion in modifications to receive it. A blended wing body changes the shape. The gate problem, the bridge problem, the hangar problem, and the turnaround problem have each been identified by engineers and analysts, but none has been solved at full scale yet. If you want to see more on where aviation is actually heading, give us a like and subscribe. And let us know if a blended wing body reaches commercial service, would you pay a premium to board one knowing you might sit in a windowless center bay and feel the turns differently than you do now? Or would you stick with a tube and wing structure? Drop your answer in the comments. We will see you in the next video.