LONG-RANGE AIRCRAFT WITH HIGH FORWARD SPEED IN CRUISING FLIGHT

• US 20110114798A1
• Filed: 11/16/2010
• Published: 05/19/2011
• Est. Priority Date: 11/17/2009
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Gemmati, Bernard
• Granted Patent: US 8,540,184 B2
• Time in Patent Office: Days
• US Class Current: 244/7.R
• CPC Class Codes: B64C 27/26 characterised by provision of fixed wings

Abstract

The present invention relates to an aircraft (1) comprising an airframe (2) provided with a fuselage (10) and fixed wings (20), a rotary wing (30), at least two propellers (41, 42), and a power plant suitable for driving said rotary wing (30) and said propellers (41, 42) into rotation. The fixed wings (20) comprise a front wing (21) arranged in the high portion (15) of the front portion (11) of the fuselage (10), and a rear wing (22) arranged in the rear portion (13) of said fuselage (10), said front and rear wings (21 and 22) each extending transversely on either side of the fuselage (10), said front wing (21) having a first front half-wing (21′) and a second front half-wing (21″), at least one of said propellers (41) being mounted on said first front half-wing (21′) and at least one of said propellers (42) being mounted on said second front half-wing (21″), said rotary wing (30) being arranged in the central portion (12) so that an axis of rotation (AX) of the rotor (31) of said rotary wing (30) is located between said front and rear wings (21 and 22).

Claims

1. An aircraft with a long-range and with high forward speed, the aircraft comprising:

an airframe provided with a fuselage extending along a longitudinal direction (X) from a front portion towards a rear portion and passing via a central portion, and in a vertical direction (Z) from a low portion to a high portion;

fixed wings secured to the fuselage;

a rotary wing above said fuselage;

at least two propellers for enhancing advance of said aircraft; and

a power plant suitable for driving said rotary wing and said propellers into rotation;

wherein said fixed wings comprise a front wing arranged in the high portion of the front portion of the fuselage and a rear wing arranged in the rear portion of said fuselage, said front and rear wings each extending transversely on either side of the fuselage, said front wing having a first front half-wing extending transversely from the fuselage in a first front traverse direction (Y1) and a second front half-wing extending transversely from the fuselage in a second front transverse direction (Y2), at least one of said propellers being mounted on said first front half-wing and at least one of said propellers being mounted on said second front half-wing (21″

), said rotary wing being arranged in the central portion so that the axis of rotation (AX) of a rotor of said rotary wing lies between said front and rear wings.

2. An aircraft according to claim 1, wherein said rear wing has a first rear half-wing (22′

) extending transversely from the fuselage in a first rear transverse direction (Y3) and a second rear half-wing (22″

) extending transversely from the fuselage in a second rear transverse direction (Y4), said aircraft including landing gear provided with a first wheel set fastened to the front portion of the fuselage, a second wheel set fastened to the first rear half-wing (22′

), and a third wheel set fastened to the second rear half-wing (22″

).

3. An aircraft according to claim 1, wherein said rear wing is located in the low portion of the rear portion of said fuselage.

4. An aircraft according to claim 1, wherein each propeller forms part of a propulsion engine unit provided with a streamlined nacelle fairing an engine of said power plant, said nacelle being mounted on the top (21′

″

) of a front half-wing (21′

, 21″

).

5. An aircraft according to claim 1, wherein said power plant has a plurality of propulsion engine units, said aircraft including a mechanical interconnection system between said propulsion engine units and said rotary wing.

6. An aircraft according to claim 1, including declutching means for declutching said rotary wing so that said power plant no longer drives said rotary wing in rotation during certain stages of flight.

7. An aircraft according to claim 1, wherein a front wing area of the front wing is equal to a rear wing area of the rear wing.

8. An aircraft according to claim 1, wherein the fixed wings present a total wing area equal to the sum of a front wing area of the front wing and a rear wing area of the rear wing, said aircraft being suitable for flying at a speed going from zero speed to a maximum speed and passing via a mean speed equal to half the maximum speed, said total wing area generating lift equal to the weight of said aircraft:

under a load factor equal to the acceleration due to gravity, and at a forward speed equal to the mean speed; and

under a load factor equal to four times the acceleration due to gravity, and at a forward speed equal to the maximum speed.

9. An aircraft according to claim 1, including stabilization and control surfaces, namely:

first flaps for controlling pitching and roll arranged at the trailing edge of each wing of the fixed wings; and

a fin provided with at least one second flap (91) for yaw control.

10. An aircraft according to claim 1, wherein said rotary wing is provided with a rotor having a plurality of blades rotating about an axis of rotation (AX), and the center of gravity of the aircraft moves within a centering range as a function of the loading of the aircraft, a mean center of gravity (Cgmoy) being placed at the center of said centering range, and said axis of rotation (AX) being located in a transverse plane (P2) of the aircraft containing the center of gravity of the aircraft.

11. An aircraft according to claim 1, wherein a first aspect ratio (k1) of the front wing is greater than a second aspect ratio (X2) of the rear wing.