Tandem Wing Aircraft With Variable Lift And Enhanced Safety

Abstract

A tandem wing aircraft having a fore wing, an aft wing, and a middle wing, attached relative to the aircraft and each other such that the middle wing provides a substantial portion of the total lift at landing speeds, and a minimal portion of the total lift at cruise speeds. At cruise speeds, induced drag is minimized, permitting higher speeds, greater fuel efficiency, and/or greater payload. Advantageously, the wing loading at cruise speeds is higher providing better passenger comfort while still providing controllability and safety at landing speeds.

1 - 20 . (canceled) 
     
     
         21 . A tandem wing aircraft, comprising:
 a fore wing mounted to the aircraft at an Angle of Incidence (AOI) F;   an aft wing mounted to the aircraft at an AOI of A;   a middle wing mounted to the aircraft at an AOI of M; and   a respective mechanical device attached to each of the fore wing, the middle wing, and the aft wing to independently change a respective AOI of each of the fore wing, the middle wing, and the aft wing.   
     
     
         22 . The aircraft of  claim 21 , wherein the respective mechanical device attached to the middle wing is configured to independently change the middle wing AOI such that the lift generated by the middle wing is greater than, equal to, or less than the lift generated by the fore wing or the aft wing. 
     
     
         23 . The aircraft of  claim 21 , wherein the respective mechanical device attached to the middle wing is configured to independently change the middle wing AOI during flight such that the AOI of M is less than the AOI of F and the AOI of M is greater than, equal to, or less than the AOI of A. 
     
     
         24 . The aircraft of  claim 21 , wherein the respective mechanical device attached to the fore wing is configured to independently change the fore wing AOI during flight such that the AOI of F is less than the AOI of A and/or the AOI of M. 
     
     
         25 . The aircraft of  claim 21 , wherein the respective mechanical device attached to the aft wing is configured to independently change the aft wing AOI during flight such that the AOI of A is less than the AOI of F and/or the AOI of M. 
     
     
         26 . The aircraft of  claim 21 , wherein at least one of the fore wing, the middle wing, or the aft wing is configured to retract, fold and/or pivot. 
     
     
         27 . The aircraft of  claim 21 , further comprising at least one of water skis, pontoons, or floats. 
     
     
         28 . A tandem wing aircraft having one or more zero lift line(s) at a cruise speed, comprising:
 a fore wing with a wingspan of WF mounted to the aircraft at an Angle of Incidence (AOI) F;   an aft wing with a wingspan WA mounted to the aircraft at an AOI of A;   a middle wing with a wingspan of WM mounted to the aircraft at an AOI of M; and   a mechanical device attached to the middle wing to independently change the middle wing AOI during flight with an AOI of M, which is less than F and A, such that the middle wing AOI of M is approximately parallel to the zero lift line at said cruise speed and is different from F and A.   
     
     
         29 . The aircraft of  claim 28 , further comprising one or more mechanical devices attached to the fore wing and/or the aft wing to independently change the AOI of the fore wing and/or the aft wing during flight. 
     
     
         30 . The aircraft of  claim 28 , further comprising at least one Angle of Attack (AOA) sensor attached to at least one of the fore wing, the middle wing, or the aft wing. 
     
     
         31 . The aircraft of  claim 28 , wherein the middle wing is a lifting wing body. 
     
     
         32 . The aircraft of  claim 28 , further comprising an emergency descent system. 
     
     
         33 . The aircraft of  claim 28 , wherein at least one of the fore wing, the middle wing, and the aft wing comprises an internal volume. 
     
     
         34 . The aircraft of  claim 33 , wherein at least a portion of the internal volume is configured to be maintained near atmospheric pressure. 
     
     
         35 . The aircraft of  claim 28 , wherein the aircraft is designed to substantially maximize the internal volume for the wingspans WF, WA, and WM. 
     
     
         36 . The aircraft of  claim 28 , wherein the mechanical device attached to the middle wing is configured to change the middle wing AOI during flight to minimize drag. 
     
     
         37 . The aircraft of  claim 28 , wherein the AOI of F is approximately 2 degrees, the AOI of M is approximately 0 degrees, and the AOI of A is approximately 0.5 degrees. 
     
     
         38 . The aircraft of  claim 28 , wherein at least one of the fore wing, the middle wing, and the aft wing is configured to retract, fold and/or pivot. 
     
     
         39 . The aircraft of  claim 28 , further comprising at least one of water skis, pontoons, or floats. 
     
     
         40 . A tandem wing aircraft, comprising:
 a fore wing mounted to the aircraft at an Angle of Incidence (AOI) F;   an aft wing mounted to the aircraft at an AOI of A;   a middle wing mounted to the aircraft at an AOI of M; and   a mechanical device attached to the middle wing selectable to change the middle wing AOI during flight to generate lift, wherein at landing configuration speeds lift is generated by the fore wing, the middle wing, and the aft wing, and wherein the lift generated by the middle wing is greater than the lift generated by the fore wing or the aft wing.