A blended wing body aircraft having an interior cabin with a usable volume of at most 4500 ft.sup.3 and a cabin aspect ratio of at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.7 and at most 2.8. Also, a blended wing body aircraft having an interior cabin with a usable volume of at least 1500 ft.sup.3 and at most 4500 ft.sup.3 and a cabin aspect ratio of at least 2 and at most 4, wherein a combination of the wings and center body has a wetted aspect ratio of at least 1.9 and at most 2.7. Also, a blended wing body aircraft wherein at least each profile section having normalized half-span values from 0 to 0.3 has a leading edge having a normalized height having a nominal value within the range set forth in Table 4.

A propeller includes a hub coaxially surrounding a longitudinal axis. A ring shroud coaxially surrounds the longitudinal axis and is spaced radially from the hub. At least one propeller blade is fixedly attached to both the hub and ring shroud and extends radially therebetween for mutual rotation therewith. At least one stub blade has a first stub end radially spaced from a second stub end. The first stub end is fixedly attached to a selected one of the hub and ring shroud. The second stub end is cantilevered from the first stub end and is radially interposed between the first stub end and the selected one of the hub and ring shroud.

A spoiler assembly is provided that is engageable to a UAV that defines a body, an outer surface and an inner surface. The spoiler assembly comprises a spoiler, translatably connected to the UAV inner surface adjacent a first portion of the spoiler aperture. The spoiler defines an upper surface and an outer surface, the upper surface being substantially the same size and shape as the spoiler aperture. A spoiler shroud is connected to the UAV inner surface and extends within the UAV body about at least a portion of the spoiler aperture. A spoiler activating mechanism is secured to the UAV inner surface and connected the spoiler lower surface. The mechanism is operative to translate the spoiler between a first position wherein the spoiler upper surface is substantially flush with the UAV outer surface, and second a position, wherein the spoiler upper surface is disposed substantially within the UAV body.

In one embodiment, an aircraft includes a blended wing body (BWB) and a cargo bay having a polygonal shape. A longitudinal centerline of the aircraft intersects a vertex of the polygonal shape and an interior angle of the vertex.

Aspects relate to airplanes having a blended wing body. A blended wing body may include a fuselage and a port wing and a starboard wing continuously coupled to the fuselage and a nose section. A midship control surface may be disposed on a trailing edge of the blended wing body and centered between the port wing and the starboard wing.

Technologies are described herein for a drag recovery scheme using a boundary layer bypass duct system. In some examples, boundary layer air is routed around the intake of one or more of the engines and reintroduced aft of the engine fan in the nozzle duct in a mixer-ejector scheme. Mixer-ejectors mix the boundary layer flow to increase mass flow.

The invention relates to a propulsion system concept that is a propulsion system that is integrated in the hull of an aerial vehicle (1), which propulsion concept comprises at least one differential velocity fan (4), which is arranged on a shaft driven by one or more power units (2). The propulsion concept is intended to provide short takeoff and landing distances, high flight speed (high subsonic to transsonic) and to be able to provide low IR signature, low radar signature, a small cross section and low air resistance. The propulsion concept is called HPVO (High Performance Optimized Versatile propulsion). The invention is useful both for air vehicles of the type for conventional takeoff and landing, “CTOL” (Conventional Take Off and Landing), “Chair” and for vertical takeoff and landing, “V (t) OL” (Vertical (Take) Off and Landing’) and the flying wing (blended-body). The concept is applicable to both large and small aircraft, manned as well as unmanned aerial vehicles.

An aircraft of flying wing or blended wing body type comprising, for access to a pressurized housing, a non-pressurized door in the trailing edge of the aircraft and a pressurized door on the pressurized housing. The distance between the center of the pressurized door and a plane of symmetry of the aircraft is less than or equal to the distance between the center of the non-pressurized door and the plane of symmetry, and the pressurized door is outside a rear wall of the pressurized housing or upstream of a rear extremum point of the housing in the absence of any such rear wall. This aircraft has optimum aerodynamic performance and the circulation of passengers between the pressurized housing and the exterior of the aircraft may be fluid.

Technologies are described herein for a drag recovery scheme using a boundary layer bypass duct system. In some examples, boundary layer air is routed around the intake of one or more of the engines and reintroduced aft of the engine fan in the nozzle duct in a mixer-ejector scheme. Mixer-ejectors mix the boundary layer flow to increase mass flow.

An aircraft (2) comprises at least first and second gas turbine engines (10a, 10b) arranged in a line extending generally normally to an aircraft longitudinal axis (A), each engine (10a, 10b) comprising at least one compressor or turbine rotor disc (32-42) defining a respective rotational plane (D.sub.32-D.sub.42). The rotational plane (D.sub.32-D.sub.42) of at least one of the rotors (32-42) of at least one of the engines (10a, 10b) is angled relative to the aircraft longitudinal line (A) such that a burst disc plane of the respective engine (10a, 10b) is nonintersecting with another engine (10a, 10b).