The End of the Runway

A Realistic VTOL Architecture that Obsoletes Horizontal Takeoff and Landing

The idea of a Vertical Takeoff and Landing (VTOL) aircraft has long been dismissed as heavier, more complex, and less fuel-efficient than its runway-dependent counterparts. The primary culprit has always been the engine. Attempting to modify a turbofan for VTOL only compounds its inherent flaws. I have solved this by eliminating the turbofan entirely. I see turbofans as the bulky CRTs of the past; my design is the slim LED display. Just as LEDs outperformed CRTs in every metric, this unified combustion engine resolves the weight and complexity issues of traditional aviation. By shifting the technology, I have opened new horizons where VTOL isn't just a feature—it's a 'no-brainer' that beats horizontal takeoff in every aspect.

The heart of this design is a unified combustion engine fueled by liquid methane and liquid oxygen. These chemicals yield ideal thrust compared to bulky air-breathing engines. While such a system might seem unfeasible for long-duration flight, the key lies in air augmentation and the afterburner effect. To make this work, attaining a very high bypass ratio is a must.

Most aircraft are drawn as artistic models with engines tacked on as an afterthought. My planes are designed around the engine to maximize its efficiency. This philosophy led to my successful subsonic and hypersonic VTOL designs. When you possess compact, lightweight engines with an extreme Thrust-to-Weight ratio, you gain total design flexibility. You can distribute multiple units to serve dedicated roles for VTOL or horizontal flight. This unified engine—essentially integrated Tesla valves, a flat combustion chamber, and a slit exhaust—can be parametrically designed with high-surface-area regenerative heat exchange canals and 3D printed in one piece. The efficiency of the engine allows it to be integrated directly into the structural elements of the aircraft, essentially making the engine a part of the airframe itself.

The VTOL engines I propose are located at the belly of the aircraft, surrounded by Actuated Skirt Doors and a carbon fiber fabric shroud. This formation serves a double purpose: it acts as the landing legs and forms a plenum for thrust augmentation and air entrainment. By utilizing the ground-effect "skirt," we reduce the immense fuel consumption typically associated with VTOL by up to 30% with minimal weight. It is important to remember that traditional planes carry massive hydraulic landing gears, complex wheel assemblies, heavy brakes, and intricate flap systems. This is all dead weight for 99% of the flight. It costs fuel to lift, fuel to carry, and compromises the aerodynamics of the airframe for the entire mission. The weight penalty associated with my VTOL architecture is a mere fraction of these legacy systems. While vertical takeoff requires high propellant consumption for a short duration, that weight is consumed immediately and presents no penalty for the remainder of the flight. During landing, the considerably lighter plane requires even less fuel for its final descent. Furthermore, because this is a winged aircraft, it transitions to horizontal flight quickly as it ascends. It approaches the landing pad with helical movements—similar to a traditional plane—and only hovers vertically at the last minute. As a result, the aircraft only requires gradual vertical thrust bursts, thanks to the low stall speeds of the tandem bi-plane design.

Even though my VTOL carries some of the oxygen needed for the flight, it remains more fuel-efficient than a traditional aircraft. The horizontal thrust engine is embedded inside a long, featureless duct. This duct allows fuel-rich exhaust gas to be fully combusted with ambient oxygen, creating a very-high bypass effect where air is accelerated by the exhaust gas. This significantly improves the Iₛₚ compared to a classical rocket engine. Additionally, this clean duct induces much less drag than a standard turbofan housing. The heat exchangers forming the duct walls pre-pressurize the propellant while keeping the fuselage cool. The lightweight, simple structure of the duct allows it to be much longer than a turbofan casing, facilitating a better mixture of hot and cold gases and further improving overall efficiency.

Utilizing ambient air as a primary oxidizer requires heavy fans, compressors, and gas turbines—all dead weight that must be carried throughout the entire flight. In contrast, Liquid Oxygen (LOX) is a consumable weight; the aircraft becomes progressively lighter as it flies. Furthermore, ambient oxygen is still utilized as an afterburner, reducing the total LOX requirement.

Carrying the necessary components for combustion on board ensures that engine thrust remains stable regardless of external conditions. If ambient oxygen levels drop, LOX consumption can be increased to maintain the desired thrust. In my design, air quality does not dictate thrust levels—a critical safety criterion for powered flight. Instead, air quality only affects fuel economy. This reduced dependency on ambient oxygen allows the aircraft to fly at significantly higher altitudes, aided by the high lift capacity of the tandem bi-plane design. At these altitudes, the aircraft experiences less drag while still benefiting from augmented air flow.

Removing engines from beneath the wings "cleans" the airframe. By eliminating horizontal takeoff equipment—such as heavy flaps and landing gear—and storing the fuel below the passenger cabin, we remove the structural burden from the wings. This allows the aircraft to utilize tandem bi-plane wings joined by vertical supports to form a closed-box structure. This configuration offers higher structural strength with significantly reduced wing thickness. One major benefit of these vertical supports is that they eliminate the need for a large vertical stabilizer at the back of the plane, further cleaning up the airframe and reducing weight. Furthermore, this setup enables high-aspect-ratio wings that maximize the Lift-to-Drag ratio compared to traditional aircraft. Even though my design features more wing surface than a conventional plane, its optimized cross-section results in less total drag. The result is a much lower stall speed, which shortens the VTOL duration, provides higher lift at high altitudes, and requires less fuel to keep the aircraft airborne.

Finally, the design features a removable aft cargo bay coupled with six boarding doors to allow for rapid deployment (the simultaneous loading/unloading of cargo and boarding of passengers). This efficiency is made possible by specially designed VTOL-only airports. I have detailed the operation of these airports of the future in separate articles, but they are the final piece of the "No-Brainer" puzzle: a world where the runway is replaced by a streamlined, vertical-flow terminal.