# US 10,479,495 B2 · Aircraft tail with cross-flow fan systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,479,495 B2 - Document ID: US10479495B2 - Status: Granted - Kind: B2 - Application number: 15/483,652 - Filed: 2017-04-10 - Published: 2018-02-15 - Granted: 2019-11-19 - Earliest claimed: 2016-08-10 - Assignees: Bell Helicopter Textron Inc. - Applicants: Bell Helicopter Textron Inc. - Inventors: Kirk L. Groninga; Daniel B. Robertson; Matthew E. Louis - Web page: https://patentgrep.com/patent/US10479495B2 ## CPC - B64C 27/82: characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft - B64C 11/006: {Paddle wheels} - B64C 23/02: by means of rotating members of cylindrical or similar form - B64C 27/06: with single rotor - B64C 39/006: {about a vertical axis} - F04D 17/04: of transverse-flow type - F04D 25/166: {using fans} - F04D 27/002: {by varying geometry within the pumps, e.g. by adjusting vanes} - F04D 29/4226: {Fan casings} - B64C 2027/8218: {wherein the rotor or the jet axis is inclined with respect to the longitudinal horizontal or vertical plane of the helicopter} - B64C 2027/8227: {comprising more than one rotor} - B64C 2027/8254: {Shrouded tail rotors, e.g. "Fenestron" fans} - B64C: AEROPLANES; HELICOPTERS - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract In one aspect, there is provided an aircraft, including a fuselage having a longitudinal axis extending from a front portion through an aft portion; first and second tail members extending from the aft portion; a first cross-flow fan system rotatably mounted to the first tail member; and a second cross-flow fan system rotatably mounted to the second tail member. The first and second cross-flow fan systems are configured to provide a forward thrust vector and an anti-torque vector on the aircraft. The first and second cross-flow fan systems can have a rotational axis oriented generally vertically. In another aspect, there is an aircraft including a fuselage having a front portion and a tail portion; and a cross-flow fan system supported by the tail portion. Embodiments include a cross-flow fan system retrofittable onto an aircraft and methods for retrofitting an aircraft with a cross-flow fan system. ## Claims ### Claim 1 An aircraft, comprising: a fuselage having a longitudinal axis extending from a front portion through an aft portion; a tailboom extending from the aft portion of the fuselage; first and second horizontal tail members extending from the tailboom; a first cross-flow fan system rotatably mounted and oriented generally vertically on the first horizontal tail member, the first cross-flow fan system rotates about a first rotation axis, the first cross-flow fan system includes a first rotatable shroud rotatable about the first rotation axis; and a second cross-flow fan system rotatably mounted and oriented generally vertically on the second horizontal tail member, the second cross-flow fan system rotates about a second rotation axis, the second cross-flow fan system includes a second rotatable shroud rotatable about the second rotation axis; wherein the first and the second rotation axes are generally parallel. ### Claim 2 (depends on 1) The aircraft according to claim 1, wherein the first and second cross-flow fan systems are configured to provide a forward thrust vector on the aircraft. ### Claim 3 (depends on 1) The aircraft according to claim 1, wherein the first and second cross-flow fan systems are configured to provide yaw control for the aircraft. ### Claim 4 (depends on 1) The aircraft according to claim 1, wherein the first and second cross-flow fan systems are configured to provide an anti-torque vector on the aircraft. ### Claim 5 (depends on 1) The aircraft according to claim 1, wherein the first and second rotational axes are disposed on a distal end of the respective first and second horizontal tail member. ### Claim 6 (depends on 5) The aircraft according to claim 5, wherein the rotational axis is generally perpendicular to the longitudinal axis of the fuselage. ### Claim 7 (depends on 5) The aircraft according to claim 5, wherein the first and second rotatable shrouds are selectively and independently rotated. ### Claim 8 (depends on 1) The aircraft according to claim 1, wherein the first and second cross-flow fan systems each comprise a variable thrust cross-flow fan assembly associated the respective rotatable shroud. ### Claim 9 (depends on 8) The aircraft according to claim 8, wherein the variable thrust cross-flow fan assembly comprises at least one variable thrust cross-flow fan assembly unit. ### Claim 10 (depends on 9) The aircraft according to claim 9, wherein the variable thrust cross-flow fan assembly unit having a longitudinal axis and including a first and second driver plates having a plurality of blades rotatably mounted therebetween, the plurality of blades disposed radially outwardly from the longitudinal axis such that the plurality of blades have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis, the plurality of blades moveable between a plurality of pitch angle configurations, and a control assembly coupled to the plurality of blades, the control assembly operable to change the pitch angle configuration of the plurality of blades to generate a variable thrust. ### Claim 11 (depends on 10) The aircraft according to claim 10, wherein the control assembly further comprises a control cam that is operable to rotate relative to the first and second driver plates. ### Claim 12 (depends on 10) The aircraft according to claim 10, wherein the control assembly further comprises a control cam that is substantially non-rotatable relative to the first and second driver plates. ### Claim 13 (depends on 10) The aircraft according to claim 10, wherein the longitudinal axis of the variable thrust cross-flow fan assembly is perpendicular to the longitudinal axis of the fuselage. ### Claim 14 (depends on 8) The aircraft according to claim 8, wherein the longitudinal axis of the variable thrust cross-flow fan assembly intersects a plane transverse of the fuselage longitudinal axis. ### Claim 15 (depends on 8) The aircraft according to claim 8, wherein the first and second rotatable shrouds each comprise an outer housing and an inner housing, each of the outer housing and the inner housing having an exterior aerodynamic surface, each of the outer housing and inner housing are arranged concentric to the respective first rotational axis and second rotational axis. ### Claim 16 An aircraft, comprising: a fuselage having a longitudinal axis extending from a front portion through an aft portion; first and second horizontal tail members extending from the aft portion; a first cross-flow fan system rotatably mounted and oriented generally vertically on the first horizontal tail member; and a second cross-flow fan system rotatably mounted and oriented generally vertically on the second horizontal tail member; wherein the first and second cross-flow fan systems each comprise a variable thrust cross-flow fan assembly associated with a shroud, the variable thrust cross-flow fan assembly comprises at least one variable thrust cross-flow fan assembly unit; wherein the variable thrust cross-flow fan assembly unit having a longitudinal axis and including a first and second driver plates having a plurality of blades rotatably mounted therebetween, the plurality of blades disposed radially outwardly from the longitudinal axis such that the plurality of blades have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis, the plurality of blades moveable between a plurality of pitch angle configurations, and a control assembly coupled to the plurality of blades, the control assembly operable to change the pitch angle configuration of the plurality of blades to generate a variable thrust, the control assembly further comprises a control cam that is operable to rotate relative to the first and second driver plates. ### Claim 17 (depends on 16) The aircraft according to claim 16, wherein the first and second cross-flow fan systems are configured to provide a forward thrust vector on the aircraft. ### Claim 18 (depends on 16) The aircraft according to claim 16, wherein the first and second cross-flow fan systems are configured to provide yaw control for the aircraft. ### Claim 19 (depends on 16) The aircraft according to claim 16, wherein the first and second cross-flow fan systems are configured to provide an anti-torque vector on the aircraft. ### Claim 20 (depends on 16) The aircraft according to claim 16, wherein the first and second cross-flow fan systems are each configured to rotate about a rotational axis that is generally perpendicular to the longitudinal axis of the fuselage. ### Claim 21 (depends on 16) The aircraft according to claim 16, wherein the first and second cross-flow fan systems each comprise the variable thrust cross-flow fan assembly associated with a first and second rotatable shroud, respectively. ### Claim 22 (depends on 21) The aircraft according to claim 21, wherein the first and second rotatable shrouds are selectively and independently rotated. ### Claim 23 (depends on 21) The aircraft according to claim 21, wherein the first and second rotatable shrouds each comprise an outer housing and an inner housing, each of the outer housing and the inner housing having an exterior aerodynamic surface, each of the outer housing and inner housing are arranged concentric to the respective first rotational axis and second rotational axis.