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US4538779A Expired / Lapsed US ⏱️ 0.0 years remaining

Caster type empennage assembly for aircraft

Assignee: Boeing Co

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Filing: 1982-09-30

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Granted: 1985-09-03

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Expires: 2002-09-30

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Abstract

Abstract An empennage assembly for supersonic aircraft includes longitudinally and rearwardly extending booms (12) mounted upon the wings (16) or fuselage of the aircraft. The booms (12) include aft rotatable sections (22) upon which are mounted larger (18) and smaller (20) tail surfaces. The boom sections (22) are angularly rotated through angular displacements θ such that the dispositions of the tail surfaces (18, 20) are interchanged between their dispositions during low subsonic and high supersonic flight conditions. In this manner, the directional and longitudinal aerodynamic static stability components of the aircraft are rendered substantially constant at an optimum low or near-neutral level of stability in order to enhance the flight maneuverability capabilities of the aircraft throughout the subsonic, transonic, and high supersonic speed ranges. The empennage (10) is also advantageously employed for enhancing the directional stability characteristics of all aircraft under varied angle of attack conditions, and still further, can likewise enhance the lift characteristics of STOL aircraft employing vectored thrust. In connection with the use of the present invention empennage system upon supersonic aircraft, the rotational orientation of the empennage system (10) and its associated boom sections (22) is automatically programmed by suitable feed-back control means (23) in response to sensed changes in Mach number. In a similar manner, the rotational orientation of the empennage system (10) and its associated boom sections (22) would also be automatically programmed by the feed-back control means (23) as a function of angle of attack.

Inventors

👤 Sidney E. Goldstein

Bibliographic Details

Application Number —

Jurisdiction US

Data Source google_patents

Last Synchronized 2026-11-04 21:24

CPC Classifications

B; B64; B64C; B64C5/00; B64C5/10

Claims Analysis

Total Claims: 24

Claim 1

Independent Claim 162 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stablizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer for imparting to said aircraft substantially constant directional static stability throughout the subsonic, transonic, and high supersonic speed ranges as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 2

Dependent Claim 162 words

Claim 3

Dependent Claim 222 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer and thereby effectively counteract the tendency of the composite aerodynamic center of said aircraft, as defined by said aerodynamic center of said fuselage-wing means and said aerodynamic centers of said vertical and horizontal stabilizers, to shift its longitudinal location in the longitudinal direction of said aircraft as said aircraft traverses the subsonic, transonic, and high supersonic speed ranges so as to impart to said aircraft substantially constant longitudinal static stability throughout said subsonic, transonic, and high supersonic speed ranges as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 4

Dependent Claim 222 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer and thereby effectively counteract the tendency of the composite aerodynamic center of said aircraft, as defined by said aerodynamic center of said fuselage-wing means and said aerodynamic centers of said vertical and horizontal stabilizers, to shift its longitudinal location in the longitudinal direction of said aircraft as said aircraft traverses the subsonic, transonic, and high supersonic speed ranges so as to impart to said aircraft substantially constant longitudinal static stability throughout said subsonic, transonic, and high supersonic speed ranges as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 5

Dependent Claim 165 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer for simultaneously imparting to said aircraft substantially constant directional and longitudinal static stability throughout the subsonic, transonic, and high supersonic speed ranges as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 6

Dependent Claim 165 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer for simultaneously imparting to said aircraft substantially constant directional and longitudinal static stability throughout the subsonic, transonic, and high supersonic speed ranges as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 7

Dependent Claim 164 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer for imparting to said aircraft substantially constant directional static stability throughout an angle of attack range of at least between 0°-15° as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 8

Dependent Claim 164 words

An empennage assembly for aircraft, comprising: a fuselage; wing means secured to said fuselage for defining therewith an aerodynamic center; empennage means, including a vertical stabilizer having an aerodynamic center, and a horizontal stabilizer having an aerodynamic center; and boom means, upon which said empennage means are mounted, secured to at least one of said fuselage or wing means and extending longitudinally rearwardly of said aircraft for defining moment arms between said aerodynamic centers of said vertical and horizontal stabilizers and said aerodynamic center of said fuselage-wing means, said empennage means being rotatably secured to said boom means about the longitudinal axis of said boom means so as to alter the positions of said vertical and horizontal stabilizers relative to a horizontal plane which normally includes said horizontal stabilizer for imparting to said aircraft substantially constant directional static stability throughout an angle of attack range of at least between 0°-15° as a result of said vertical and horizontal stabilizers acting through said moment arms.

Claim 9

Dependent Claim 154 words

An empennage assembly as set forth in claim 3, wherein: said empennage means comprises at least two substantially different sized tail surfaces disposed mutually perpendicular with respect to each other; said boom means includes a first fixed section secured to said at least one of said fuselage or wing means, and a second section rotatable relative to said first fixed section and said fuselage or wing means and upon which said empennage tail surfaces are mounted; and means for rotating said second section of said boom means and said empennage tail surfaces as a function of Mach number such that during said subsonic speed range, the larger one of said tail surfaces will be disposed substantially horizontally while said smaller tail surface will be disposed substantially vertically, while during said supersonic speed range, the larger one of said tail surfaces will be disposed substantially vertically and said smaller tail surface will be disposed horizontally.

Claim 10

Dependent Claim 158 words

An empennage assembly as set forth in claim 4, wherein: said empennage means comprises at least two substantially different sized tail surfaces disposed mutually perpendicular with respect to each other; said boom means comprises a first fixed section secured to said at least one of said fuselage or wing means, and a second section rotatable relative to said first fixed section and said fuselage or wing means and upon which said empennage tail surfaces are mounted; and means for rotating said second section of said boom means and said empennage tail surfaces as a function of angle of attack such that during low angle of attack modes, the larger one of said tail surfaces will be disposed substantially horizontally while said smaller tail surface will be disposed substantially vertically, while during high angle of attack modes, said larger one of said tail surfaces will be disposed substantially vertically and said smaller tail surface will be disposed substantially horizontally.

Claim 11

Dependent Claim 70 words

An empennage system as set forth in claim 5, wherein: said means for rotating said boom means and said empennage tail surfaces rotates said boom means and said empennage tail surfaces in a smooth and continuous manner as a function of said Mach number such that during said transonic speed range, said larger and smaller tail surfaces will be disposed at predetermined angles relative to said horizontal and vertical planes.

Claim 12

Dependent Claim 72 words

An empennage system as set forth in claim 6, wherein: said means for rotating said boom means and said empennage tail surfaces rotates said boom means and said empennage tail surfaces in a smooth and continuous manner as a function of said angle of attack such that during intermediate angle of attack modes, said larger and smaller tail surfaces will be disposed at predetermined angles relative to said horizontal and vertical planes.

Claim 13

Dependent Claim 56 words

An empennage assembly as set forth in claim 6, wherein: during said high angle of attack modes, said larger one of said tail surfaces will be disposed vertically downwardly beneath said wing plane so as to fluidically interact with the high energy air flow passing beneath said wing means during said high angle of attack modes.

Claim 14

Dependent Claim 22 words

An empennage assembly as set forth in claim 3, wherein: said boom means are secured to the tips of said wing means.

Claim 15

Dependent Claim 23 words

An empennage assembly as set forth in claim 3, wherein: said boom means are secured to the trailing edges of said wing means.

Claim 16

Dependent Claim 34 words

An empennage assembly as set forth in claim 3, wherein: said boom means are secured to said fuselage; and said empennage means comprises two sets of mutually perpendicular tail surfaces of substantially different size.

Claim 17

Dependent Claim 18 words

An empennage assembly as set forth in claim 10, wherein: said aircraft additionally comprises aft horizontal stabilizer means.

Claim 18

Dependent Claim 17 words

An empennage assembly as set forth in claim 10, wherein: said aircraft additionally comprises canard surface means.

Claim 19

Dependent Claim 53 words

An empennage assembly as set forth in claim 5, wherein: said boom means are secured to the tips of said wing means; and said horizontally disposed tail surfaces of said empennage means are disposed outboard of said aircraft so as to fluidically interact with the upwash flow region generated by said wing means.

Claim 20

Dependent Claim 109 words

An empennage assembly as set forth in claim 6, wherein: said empennage means is disposed upon a vectored thrust STOL aircraft; and during said high angle of attack modes, said larger one of said tail surfaces will be disposed vertically downwardly beneath said wing plane so as to fluidically interact with the high energy air flow passing beneath said wing means during said high angle of attack mode, while said smaller tail surface is disposed within said horizontal plane so as to shift the aerodynamic center of said aircraft forwardly and thereby increase the lift characteristics of said aircraft to balance the force and moments of said vectored thrust.

Claim 21

Dependent Claim 177 words

An empennage assembly as set forth in claim 4, wherein: said empennage means comprises at least two substantially different sized tail surfaces disposed mutually perpendicular with respect to each other; said boom means comprises a first fixed section secured to said at least one of said fuselage or wing means, and a second section rotatable relative to said first fixed section and said fuselage or wing means and upon which said empennage tail surfaces are mounted; and means for rotating said second section of said boom means and said empennage tail surfaces as a function of angle of attack such that during subsonic low angle of attack modes, the larger one of said tail surfaces will be disposed substantially horizontally while said smaller tail surface will be disposed substantially vertically upwardly, while during subsonic high angle of attack modes, said larger one of said tail surfaces will be disposed substantially horizontally 180° out of phase with respect to its position during said low angle of attack mode while said smaller tail surface will be disposed vertically downwardly.

Claim 22

Dependent Claim 114 words

An empennage assembly as set forth in claim 17, wherein: said empennage means is disposed upon a vectored thrust STOL aircraft; and during said high angle of attack modes, said larger one of said tail surfaces will be disposed within the downwash regions of said aircraft wing means so as to shift the aerodynamic center of said aircraft forwardly and thereby increase the lift characteristics of said aircraft to balance the force and moments of said vectored thrust, while said smaller tail surface is disposed vertically downwardly beneath said wing plane so as to fluidically interact with the high energy air flow passing beneath said wing means during said high angle of attack mode.

Claim 23

Dependent Claim 155 words

An empennage assembly as set forth in claim 1, wherein: said empennage means comprises at least two substantially different sized tail surfaces disposed mutually perpendicular with respect to each other; said boom means includes a first fixed section secured to said at least one of said fuselage or wing means, and a second section rotatable relative to said first fixed section and said fuselage or wing means and upon which said empennage tail surfaces are mounted; and means for rotating said second section of said boom means and said empennage tail surfaces as a function of Mach number such that during said subsonic speed range, the larger one of said tail surfaces will be disposed substantially horizontally while said smaller tail surface will be disposed substantially vertically, while during said supersonic speed range, the larger one of said tail surfaces will be disposed substantially vertically and said smaller tail surface will be disposed substantially horizontally.

Claim 24

Dependent Claim 155 words

An empennage assembly as set forth in claim 2, wherein: said empennage means comprises at least two substantially different sized tail surfaces disposed mutually perpendicular with respect to each other; said boom means includes a first fixed section secured to said at least one of said fuselage or wing means, and a second section rotatable relative to said first fixed section and said fuselage or wing means and upon which said empennage tail surfaces are mounted; and means for rotating said second section of said boom means and said empennage tail surfaces as a function of Mach number such that during said subsonic speed range, the larger one of said tail surfaces will be disposed substantially horizontally while said smaller tail surface will be disposed substantially vertically, while during said supersonic speed range, the larger one of said tail surfaces will be disposed substantially vertically and said smaller tail surface will be disposed substantially horizontally.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-09-02	1989-03-04	1989-09-03	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-09-02	1993-03-04	1993-09-03	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-09-02	1997-03-04	1997-09-03	$7700.00	Window Closed / Lapsed

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