Convertible aircraft operating method

• US 7,918,415 B2
• Filed: 02/28/2005
• Issued: 04/05/2011
• Est. Priority Date: 03/05/2004
• Status: Expired due to Fees

• Current Assignee: Glaxo Group Limited (GSK plc), Industria Helicat Y ALAS Giratorias SL
• Original Assignee: Industria Helicat Y ALAS Giratorias SL
• Inventors: de la Cierva Hoces, Juan
• Primary Examiner(s): Dinh; Tien
• Assistant Examiner(s): Green; Richard R
• Application Number:
  US10/598,592
• Publication Number:
  US 20070170307A1
• Time in Patent Office: 2,227 Days
• Field of Search: 244/2, 244/7.R, 244/7.A, 244/7.C, 244/8, 244/17.11
• US Class Current: 244/7.00R
• CPC Class Codes: B64C 27/24 with rotor blades fixed in flight to act as lifting surfaces
• CPC Class Codes: B64C 27/26 characterised by provision of fixed wings

Abstract

The invention relates to a convertible aircraft operating method. According to the invention, the aircraft comprises: a fuselage, standard fixed wings which are equipped with ailerons, a tail unit with flight-control surfaces, engines, a rotor with blades, a transmission which is placed between the engines and the rotor and which is equipped with rotor clutch and braking means, a landing gear, means for transition from helicopter mode to autogyro mode and vice versa, and means for direct or reverse transition from autogyro/helicopter mode to aeroplane mode. The lift for a range of low speeds is produced by means of the rotor, while the lift for a range of high speeds is produced by means of the wings. In addition, the lift for a range of intermediate speeds can be produced using the wings and the rotor in autogyro mode simultaneously, and take-off and landing can be performed in autogyro mode or in helicopter mode with the engines coupled to the rotor. The aircraft comprises a hybrid helicopter/autogyro/aeroplane aircraft and, as such, can perform the direct or reverse transition to aeroplane mode from both helicopter mode and autogyro mode.

Claims

1. Operating method for a convertible aircraft (1), equipped with a fuselage (2), standard fixed wings (3) with ailerons, a tail unit (4) with rudders (20), propulsion engines (5), a rotor (6) with blades (7, 8) located at approximately the center of the fuselage in between the wings, a transmission between the engines and the rotor equipped with a brake and a clutch, and a landing gear (9), the method comprises direct and reverse transitions from a helicopter mode to an autogyro mode and from an autogyro-helicopter mode to an aeroplane mode, the direct transition from the helicopter mode to the autogyro mode comprising the following step:

declutching the rotor from the propulsion engines;

the direct transition from the autogyro-helicopter mode to the aeroplane mode comprising the following steps;

adjusting the collective and cyclic pitches of the blades (7, 8) of the rotor (6) to essentially zero degrees, in such a way that they cease to lift and control the aircraft (1) and the latter is lifted by the standard fixed wings and controlled by the ailerons and the rudders (20);

quickly reducing the rotational velocity of the rotor (6) using a brake (24) thereof;

characterized in that the method also comprises

stopping the rotor in a transverse position of at least two of its blades (7, 8) in a position essentially transverse to the direction of flight;

retracting the rotor blades towards a stern of the aircraft, until their longitudinal axes are parallel to the fuselage (2) of the aircraft;

rotating the blade which had a reverse air flow when the blades were stopped transversely to the direction of the flight to approximately 180°

on its pitch axis;

deploying the rotating blades, independently from one another, to an azimuthal position determined by a pre-determined range of angles;

adjusting the angle of attack of the deployed blades until the blades are deployed in a position parallel to the fixed wings; and

the reverse of each of these transitions accomplished by executing each of the above steps in reverse sequence.

2. Method, according to claim 1, characterised in that said step of adjusting the angle of attack of the deployed rotating blades (7, 8) such that each blade is parallel to one of the fixed wings and traverse to a forward direction of the aircraft thus transitioning into a biplane wherein the rotor blades now form upper wings and the fixed wings form the lower wings.

3. Convertible aircraft (1), of the type that comprises a fuselage (2), fixed wings (3) with ailerons, a tail unit (4) with rudders (20), propulsion engines (5), a rotor (6) with blades (7, 8) located at approximately the center of the fuselage in between the wings, landing gear, the aircraft comprising:

a means to transition from helicopter mode to autogyro mode;

a means for the direct transition from autogyro-helicopter mode to aeroplane mode, including;

a second servo-engine (18) for the regulation of the collective and cyclic pitches of the blades (7, 8) of the rotor (6) to essentially zero degrees, in such a way that they cease to lift and control the aircraft (1) and the latter is lifted and controlled by the ailerons and the rudders (20);

a means to stop the rotors (24);

a first servo-engine (17) to retract and deploy the rotor blades both towards and away from the stern of the aircraft, to position the blades essentially perpendicular to the fixed wings and when needed parallel to the fixed wings, and to deploy the blades to an azimuthal position determined by a pre-determined range of angles; and

to rotate at least one of the rotor blades to approximately 180°

on its pitch axis;

when needed to rotate the blades such that each blade now form upper wings and the fixed wings form the lower wings.

4. Convertible aircraft (1), according to claim 3, characterised in that the blades (7, 8) of the rotor (6) are designed in such a way that the chord at the root is greater than the chord at the tips.

5. Convertible aircraft (1), according to claim 3, characterised in that said propulsion engines (5) are engines with propellers (11).

6. Convertible aircraft (1), according to claim 5, characterised in that the propellers (11) are placed astern of the fixed wings (3).

7. Convertible aircraft (1), according to claim 5, characterised in that said propellers (11) have a variable pitch.

8. Convertible aircraft (1), according to claim 3, characterised in that said propulsion engines (5) are piston, gas turbine or jet engines.

9. Convertible aircraft according to claim 3 further comprising:

wherein the means to transition from helicopter mode to autogyro mode are also—

a means to transition from autogyro mode to helicopter mode; and

wherein the means for the direct transition from autogyro-helicopter mode to aeroplane mode are also—

a means to transition from aeroplane mode to autogyro-helicopter mode.