US 12,351,303 B2
System and method for operating air vehicle
Danny Abramov, Lod (IL); and Shai Alexandroni, Lod (IL)
Assigned to Israel Aerospace Industries Ltd., Lod (IL)
Appl. No. 18/722,145
Filed by Israel Aerospace Industries Ltd., Lod (IL)
PCT Filed Dec. 22, 2022, PCT No. PCT/IL2022/051373
§ 371(c)(1), (2) Date Jun. 20, 2024,
PCT Pub. No. WO2023/126919, PCT Pub. Date Jul. 6, 2023.
Claims priority of application No. 289487 (IL), filed on Dec. 28, 2021.
Prior Publication US 2025/0083806 A1, Mar. 13, 2025
Int. Cl. B64C 27/26 (2006.01); B64C 29/00 (2006.01); B64U 10/25 (2023.01)
CPC B64C 29/0025 (2013.01) [B64C 27/26 (2013.01); B64U 10/25 (2023.01)] 22 Claims
OG exemplary drawing
 
1. A method for transitioning an air vehicle from a forward speed mode to a hover mode via a transition mode, the method comprising:
(a) providing the air vehicle, wherein the air vehicle is a VTOL-type fixed wing air vehicle, comprising a first propulsion system, a second propulsion system and a fixed wing arrangement, wherein:
said first propulsion system is configured for providing a first thrust to the air vehicle at a first thrust vector, the first thrust being sufficient for enabling powered aerodynamic flight to the air vehicle at least in said forward speed mode;
said second propulsion system is configured for providing a second thrust to the air vehicle at a second thrust vector, the second thrust being at least sufficient for enabling vectored thrust flight to the air vehicle at least in said hover mode, wherein said second thrust vector is spatially fixed with respect to the air vehicle at a first fixed spatial position that is unchanged at least during said transition mode; and
said fixed wing arrangement comprises high lift, mild stall wings;
(b) causing the air vehicle to follow a transient path in said transition mode from said forward speed mode to said hover mode, wherein said transient path comprises manipulating a first magnitude of angle of attack of the air vehicle and a second magnitude of forward speed of the air vehicle during said transition mode to provide a corresponding aerodynamic lift component, and concurrently manipulating a third magnitude of said second thrust during said transition mode to provide a vertical vectored thrust component corresponding to said first magnitude of angle of attack, such that a summation of said aerodynamic lift component and said vertical vectored thrust component is sufficient for enabling the air vehicle to remain in controlled flight in said transition mode between conditions corresponding to said forward speed mode wherein said vertical vectored thrust component is zero, and conditions corresponding to said hover mode wherein said aerodynamic lift component is zero, and wherein a stall plateau of the high lift, mild stall wings enables said step of manipulating the first magnitude of angle of attack of the air vehicle and the second magnitude of forward speed of the air vehicle to provide said first magnitude of angle of attack corresponding to a high angle of attack, thereby enabling the spatially fixed second thrust vector to provide an aft braking force during said transition mode.