AVIATION'S NEW ERA
Figure 8. VTOL aircraft that transitions to vehicle configured for improved cruising.
Chapter 6 Vertical Takeoff Aircraft
Air Taxi applications will use vertical takeoff versions of the Towed Platform Configuration.
Vertical takeoff and landing (“VTOL”) aircraft are even less efficient than airliners. Quadcopters have a cruising L/D of about 5:1 versus about 16:1 for typical airliners. This translates to Towed Platform aircraft having efficiencies of 9X to 18X the L/V of contemporary VTOL aircraft. Increasing the efficiency of VTOL aircraft is particularly important when making the transition to battery powered aircraft which have simpler and lower cost designs and can operate from direct solar power.
VTOL aircraft rely primarily on their rotating wings for lift, which provide for easy vertical take-offs. At best, rotating wings are not very efficient; however when designed to provide both thrust and lift, the lift is further compromised (hence a L/D around 5:1). Furthermore, most quadcopters and many VTOL cruise at a nose-down configuration resulting in much of the fuselage’s surfaces producing negative lift.
U.S. Patent 10,589,838 B1 is the first of a series of patents, and patent applications, on instant technology. The allowed claim is for a plurality of surfaces that are oriented for good air flow for vertical takeoff that transition to a flat plate airfoil over the length of the vehicle. Some schematics to the to the aligned surfaces as a “liftpath,” with this category of aircraft referred to as transitioning VTOL (Vertical Take-off and Landing).
Figure 8 illustrates an early version of a transitioning VTOL where the front tiltwing includes passive actuation to the cruising configuration; more specifically, when moving forward, the impacting air rotates the front tiltwing from a primarily lift-generating position to a thrust-generating position. Later versions transform to a configuration similar to that of Figure 6 with a single towed platform.
The Figure 8 aircraft was a working prototype that made about a 70% transition to a lift path for cruising. Other versions of the prototype had a front tiltwing capable of full transition, but all lacked the upgrade in control technology for full transition. A decision at that point directed research and development to ramp takeoff aircraft that only had leading edge thrusters; and that path of innovation led to the Towed Platform aircraft and the innovations discussed in Chapter 7.
A 50:1 L/D identifies that the cruising thrust is only 2% of the vehicle weight. Therefore, only part of the lift generation for take-off needs to convert to thrust generation. This is illustrated by Figure 8 where only the front two blades transition.
Highly efficient cruising design and solar panel incorporation enable purely electric aircraft for most applications of transitioning VTOL; alleviating the weight concerns and complexity of fuel-based aviation. As electric motors become lighter in weight and lower in costs, a series of electric blades can be incorporated into the body of the aircraft for VTOL without the need for those blades to transition for cruising. As cost and weight for these electric VTOL blades become less, VTOL will begin to dominate the aviation market because the efficiency advantages of traditional fixed wing aircraft become increasingly less.
Advantages of electric VTOL are: a) lower-cost maintenance infrastructure (e.g. no need for liquid fuel storage or supply), b) high reliability at low cost, c) ability to fully or partially use direct solar power for transit, and d) ability to configure a VTROL for redundant failsafe landing modes and do not require airport runways. The weight and cost of the VTOL blades will be offset by the reduced weight and cost of landing gear.
Due to these advantages, VTOL aircraft will become the safest lowest-cost aviation option. They will dominate air transit, and the strategic technology to make that happen is the transitioning to towed platform airframes.
Air Taxi applications will use vertical takeoff versions of the Towed Platform Configuration.
Vertical takeoff and landing (“VTOL”) aircraft are even less efficient than airliners. Quadcopters have a cruising L/D of about 5:1 versus about 16:1 for typical airliners. This translates to Towed Platform aircraft having efficiencies of 9X to 18X the L/V of contemporary VTOL aircraft. Increasing the efficiency of VTOL aircraft is particularly important when making the transition to battery powered aircraft which have simpler and lower cost designs and can operate from direct solar power.
VTOL aircraft rely primarily on their rotating wings for lift, which provide for easy vertical take-offs. At best, rotating wings are not very efficient; however when designed to provide both thrust and lift, the lift is further compromised (hence a L/D around 5:1). Furthermore, most quadcopters and many VTOL cruise at a nose-down configuration resulting in much of the fuselage’s surfaces producing negative lift.
U.S. Patent 10,589,838 B1 is the first of a series of patents, and patent applications, on instant technology. The allowed claim is for a plurality of surfaces that are oriented for good air flow for vertical takeoff that transition to a flat plate airfoil over the length of the vehicle. Some schematics to the to the aligned surfaces as a “liftpath,” with this category of aircraft referred to as transitioning VTOL (Vertical Take-off and Landing).
Figure 8 illustrates an early version of a transitioning VTOL where the front tiltwing includes passive actuation to the cruising configuration; more specifically, when moving forward, the impacting air rotates the front tiltwing from a primarily lift-generating position to a thrust-generating position. Later versions transform to a configuration similar to that of Figure 6 with a single towed platform.
The Figure 8 aircraft was a working prototype that made about a 70% transition to a lift path for cruising. Other versions of the prototype had a front tiltwing capable of full transition, but all lacked the upgrade in control technology for full transition. A decision at that point directed research and development to ramp takeoff aircraft that only had leading edge thrusters; and that path of innovation led to the Towed Platform aircraft and the innovations discussed in Chapter 7.
A 50:1 L/D identifies that the cruising thrust is only 2% of the vehicle weight. Therefore, only part of the lift generation for take-off needs to convert to thrust generation. This is illustrated by Figure 8 where only the front two blades transition.
Highly efficient cruising design and solar panel incorporation enable purely electric aircraft for most applications of transitioning VTOL; alleviating the weight concerns and complexity of fuel-based aviation. As electric motors become lighter in weight and lower in costs, a series of electric blades can be incorporated into the body of the aircraft for VTOL without the need for those blades to transition for cruising. As cost and weight for these electric VTOL blades become less, VTOL will begin to dominate the aviation market because the efficiency advantages of traditional fixed wing aircraft become increasingly less.
Advantages of electric VTOL are: a) lower-cost maintenance infrastructure (e.g. no need for liquid fuel storage or supply), b) high reliability at low cost, c) ability to fully or partially use direct solar power for transit, and d) ability to configure a VTROL for redundant failsafe landing modes and do not require airport runways. The weight and cost of the VTOL blades will be offset by the reduced weight and cost of landing gear.
Due to these advantages, VTOL aircraft will become the safest lowest-cost aviation option. They will dominate air transit, and the strategic technology to make that happen is the transitioning to towed platform airframes.