True F35 VTOL

The F-35B represents a deeply compromised short take-off and vertical landing (STOVL) design. To achieve sub-optimal vertical capability, it relies on immense mechanical compromises: a massive shaft-driven lift fan, heavy friction clutches. During high-speed supersonic transit or combat maneuvering, this entire vertical lift apparatus becomes parasitic dead weight that degrades the jet’s range, fuel capacity, and agility. The problem lies on insisting the use of classical turbofan engines to achieve VTOL capability. A perfect solution on the other hand lies on a new engine design. Like the one I proposed on my previous article, Hybrid Turbofan Engine.

Aerodynamic and Thermodynamic Mechanics

Upper-Fuselage Induced Lift: By moving the primary air intake completely to the upper fuselage and pairing it with a broad, flat-belly undercarriage, the distributed BLDC fans create a massive, high-velocity intake zone across the top of the aircraft. This creates a severe static pressure differential—suction on top, high pressure below—generating active aerodynamic lift even at zero horizontal airspeeds.

High Bypass with a Slender Profile: Conventional fighter engines are trapped at low bypass ratios (around 0.57:1) because a larger frontal fan would increase engine diameter and cause catastrophic supersonic drag. This architecture bypasses the diameter limitation entirely. The core engine remains ultra-slender in the tail cone to minimize drag, while the multiple upper-fuselage BLDC fans ingest a massive volume of air. This achieves an unprecedentedly high bypass ratio for a fighter airframe, radically extending its flight range with zero mass or agility penalties.

Zero-Parasitic-Mass Thrust Vectoring: Instead of a heavy mechanical lift fan embedded in the center of the airframe, vertical lift is achieved by vectoring the slender, aft-mounted hybrid engine exhaust downward. Pitch and yaw stabilization during hover are managed via a compact, high-thrust bipropellant rocket engine positioned in the nose cone.

The Structural Mass Advantage: Operating a nose rocket for brief takeoff and landing windows requires minimal propellant weight. The combined mass of the nose rocket and its fuel is a fraction of the weight of the F-35B's mechanical lift fan, clutches, and heavy runway-landing gear assemblies. This eliminates parasitic cruise weight entirely.

Combat and Operational Implications

Omnidirectional Speed Efficiency: Fighter jets operate in highly dynamic environments where constant cruise speeds are impossible. By decoupling the intake face velocity from the core shaft via the hybrid electrical bus, the engine maintains peak thermodynamic efficiency across a vastly broader flight envelope, drastically extending combat radius.

Low Stall Speeds and High Altitude Ceiling: The active lift generated by the upper-fuselage suction plenum drastically lowers the airframe's stall speed. In combat scenarios, this allows for ultra-tight, low-speed turning radii or high-altitude operations where the air is traditionally too thin to support standard wing profiles.

Unrestricted Strategic Deployment: This hybrid propulsion layout can be scaled uniformly across an entire air wing—from stealth fighter jets to heavy cargo transports and bombers. By removing traditional runway dependencies without paying a mechanical weight penalty, a completely self-sustaining, distributed VTOL air wing can operate from austere, unprepared clearings independent of vulnerable, fixed airfield infrastructure.