Aircraft with dual flight regimes

• US 8,690,096 B2
• Filed: 05/29/2010
• Issued: 04/08/2014
• Est. Priority Date: 06/04/2009
• Status: Expired due to Fees

• Current Assignee: Alvarez-Calderon F. Alberto
• Original Assignee: Alvarez-Calderon F. Alberto
• Inventors: Alvarez Calderon F., Alberto
• Primary Examiner(s): Collins, Timothy D
• Assistant Examiner(s): Badawi, Medhat
• Application Number:
  US12/802,104
• Publication Number:
  US 20110031355A1
• Time in Patent Office: 1,410 Days
• Field of Search: 244/7.A, 244/7.C, 244/8, 244/17.11, 244/17.21, 244/17.23, 244/17.25, 244/17.27, 244/45.R, 244/129.5, 244/132, 492/78
• US Class Current: 244/6
• CPC Class Codes: B64C 29/0025 the propellers being fixed relative to the fuselage
• CPC Class Codes: B64C 29/0033 the propellers being tiltable relative to the fuselage
• CPC Class Codes: B64C 3/10 Shape of wings
• CPC Class Codes: B64C 39/08 having multiple wings
• CPC Class Codes: Y02T 50/10 Drag reduction

Abstract

The aircraft is capable of two distinct fuel-efficient flight regimes: one is a vertical flight regime supported by two large two-bladed rotors with low disc loading located on right and left longitudinal booms. The booms extend between outboard regions of a front wing and inboard regions of a rear wing that has a larger span an area than the front wing. The other flight regime is high speed up to high subsonic Mach number with the aircraft supported by wing lift with high wing loading, and with the rotors stopped and faired with minimal local drag contiguous to the booms. The longitudinal location of the aircrafts center of gravity, aerodynamic center and the center of the rotors are in close proximity. The front wing is preferably swept back, and the rear wing is preferably of W planform.

Claims

1. An aircraft capable of rotor sustained vertical flight and wing sustained horizontal flight, said aircraft comprising:

a front wing with a planform area, a wing span, and backward sweep;

a rear wing featuring

a wing span

a W-shaped leading edge and a W-shaped trailing edge, said leading edge and trailing edge defining a W-shaped plan form,

wherein area of the W-shaped plan form is larger than the area of said plan form of the front wing, a wing span that is larger than the wing span of the front wing,

wherein the wing span of the rear wing is larger than the wing span of the front wing;

a first streamlined body that (a) is longitudinally oriented between the front and rear wings and (b) supports a first rotor;

a second streamlined body that (a) is longitudinally oriented between the front and rear wings and (b) supports a second rotor;

said first and second stream lined bodies located on lateral portions of said front and back wings; and

,

said first and second streamlined bodies having a longitudinal length between said front and back wings, wherein said first and second rotors feature a diameter approximately equal to the longitudinal length of said first and second streamlined bodies.

2. The aircraft of claim 1 wherein:

said front wing is swept forward;

said rear wing is swept backwards; and

,

the planform area of the front wing is substantially smaller than the planform area of the rear wing.

3. The aircraft of claim 1 further comprising a central fuselage between said streamlined bodies, and wherein the lift sustained by each of said rotors during vertical flight is approximately half of the weight of said aircraft.

4. The aircraft of claim 3 wherein the planform area of said rear wing is substantially larger than the planform area of the front wing, and wherein the longitudinal positions of (i) the center of gravity of said aircraft, (ii) the aerodynamic center of said aircraft, (iii) the axis of rotation of said first rotor, and the axis of rotation of said second rotor are in close proximity to alignment.

5. The structure of claim 3 further characterized in having blades of said first and second rotors with fixed pitch and free of articulations.

6. The aircraft of claim 1 further characterized in that said streamlined bodies have longitudinal structural beams that support large lift forces of said rotors, with external fairing surfaces hinged at the bottom surface of said beam and adapted to be moved from a first position clear of the path of said rotors when in operation in vertical flight regime, and a second position enclosing said rotors when stopped in a low drag disposition in high speed regime.

7. The aircraft of claim 2 with a front portion of said first and second streamlined bodies being attached to said front wings adjacent to different tips of said front wings, and with a rear portion of said streamlined bodies attached to different portions of said rear wings at a locations adjacent the changes of sweep of the W planform of said rear wing.

8. The aircraft of claim 2, further wherein portions of said wings in planform and portions of said central fuselage in planform form a circular ring portion with lips that are contiguous to portions of the circular paths of the tip of said rotors, with the radius of said circular ring portion and said lips being substantially equal to the radius of said rotors for minimal gap there between, said ring portion and lips being free of rectilinear segments in planform, to induce lifting forces by extending the low pressures inherent in top of the rotors when in vertical flight on said contiguous lips and on part of the surfaces of said wings and said fuselage, which are adjacent to said lips, and to the top surface of said aircraft between said rotors.

9. An aircraft capable of operating in rotor sustained vertical flight and in wing sustained high speed horizontal flight, said aircraft comprising:

a front wing with a front wing span;

a rear wing with a span that is larger than said front wing span;

two longitudinal streamlined bodies attached to lateral portions of said wings, said streamlined bodies having a longitudinal length between said wings, with each of said longitudinal bodies supporting a rotor, and with the diameters of said rotors being approximately equal to said longitudinal length of said streamlined bodies between said wings;

wherein each of said rotors having two blades that are adapted to be permanently stopped during high speed wing-sustained flight with their long dimension parallel and in close proximity to, and aerodynamically faired with said longitudinal bodies in a low drag disposition;

wherein said front wing features backward sweep, and said rear wing features a trailing edge and a leading edge each having a W shaped planform with a rear wing area larger than the area of said front wing; and

,

wherein said aircraft center of gravity, an aerodynamic center, and axis of rotation of each of said rotors with longitudinal positions that are in close proximity to alignment.