Fuselage tail jet engine thrust reverser and method

Abstract

Production of a downwardly and forwardly directed reverse thrust discharged from a reverse-thrust duct is controlled .Iadd.during landing .Iaddend.by a door in the rearward-discharge duct having its rearward portion pivotally mounted for swinging of its forward portion between a position lodged in a recess in the side of the rearward-discharge duct and a position in which the forward edge of the door is spaced from the recess and the door is inclined to deflect jet exhaust from the rearward-discharge duct into the reverse-thrust duct branching from the rearward-discharge duct. The discharge end of the reverse-thrust duct can be closed by a second door and actuating .[.means.]. .Iadd.mechanism .Iaddend.interconnecting the two doors can move them simultaneously through proportionate degrees of movement.

I claim: .[. 
     
       1.  In an airplane fuselage power plant installation including a jet engine buried in the aft portion of the airplane fuselage and having a rearward-discharge duct opening in the tail of the fuselage, the improvement comprising reverse-thrust duct means branching from the rearward-discharge duct and constituting the sole reverse-thrust duct means, said reverse-thrust duct means opening through the bottom of the fuselage and being directed only downwardly and forwardly for discharge of jet exhaust producing thrust having a rearward component and an upward component, and control means for selectively proportioning jet exhaust discharge between the rearward-discharge duct and said sole reverse-thrust duct means ..]. .[.2. In the airplane fuselage power plant installation defined in claim 1, and acoustical lining means lining the bottom and opposite upright sides of the rearward-discharge duct..]. .[.3. In the airplane power plant installation defined in claim 1, a vent door, and fixed pivot means at the rearward side of the discharge end of the reverse-thrust duct means supporting the rear portion of said vent door for swinging of said vent door between a position closing the reverse-thrust duct means and a position projecting substantially entirely outwardly beyond the surface of the airplane and inclined forwardly and downwardly from the rearward side of the discharge end of the reverse-thrust duct means..]. .[.4. In the airplane power plant installation defined in claim 1, the control means forming constricting means in the rearward-discharge duct when the control means is in position closing the reverse-thrust means..]. .Iadd. 5. In an airplane designed for conventional landing at substantial forward speed and having a steerable nose wheel and main landing gear located rearward of the nose wheel, a power plant installation comprising a jet engine mounted in thrust relationship to the aft portion of the airplane and having rearward-discharge duct means for normally directing the exhaust of the jet engine rearward, one and only one reverse-thrust duct means constituting the sole reverse-thrust duct means of such jet engine and having an exhaust intake that opens in the rearward-discharge duct means and an exhaust outlet that opens downward at the aft portion of the airplane, said reverse-thrust duct means being directed only forward and downward from said rearward-discharge duct means for discharge of jet exhaust at the aft portion of the airplane, and control door means selectively movable during landing of the airplane from a normal position closing said exhaust intake of said reverse-thrust duct means for discharge of jet exhaust rearward through the rearward-discharge duct means to a reverse-thrust position opening said exhaust intake and obstructing the rearward-discharge duct means for discharge of at least the major portion of the jet exhaust downward and forward through said reverse-thrust duct means to produce thrust on the aft portion of the airplane having a rearward component tending to retard forward movement of the airplane during the landing ground run and an upward component tending to pitch the nose portion of the airplane downward about a fulcrum located in the vicinity of the main landing gear for increasing the pressure of the nose wheel on the ground and consequently increasing the steering effectiveness of the nose wheel during landing. .Iaddend..Iadd. 6. In the airplane defined in claim 5, the airplane including a fuselage, and the jet engine being buried in the aft portion of said fuselage. .Iaddend. .Iadd. 7. In the airplane defined in claim 6, vent door means selectively movable between a normal position closing the exhaust outlet of the reverse-thrust duct means and a reverse-thrust position opening such outlet. .Iaddend..Iadd. 8. In an airplane designed for conventional landing at substantial forward speed and having a fuselage, a steerable nose wheel and main landing gear located rearward of the nose wheel, a power plant installation comprising a jet engine buried in the aft portion of the airplane fuselage and having a rearward-discharge duct for normally directing the exhaust of said jet engine rearward, one and only one reverse-thrust duct means constituting the sole reverse-thrust duct means of said jet engine and having an exhaust intake that opens in said rearward-discharge duct and an exhaust outlet that opens downward through the bottom of the airplane fuselage, said reverse-thrust duct means being directed only forward and downward from said rearward-discharge duct means for discharge of jet exhaust at the aft portion of the airplane fuselage, control door means selectively movable during landing of the airplane from a normal position closing said exhaust intake of said reverse-thrust duct means for discharge of jet exhaust rearward through said rearward-discharge duct means to a reverse-thrust position opening said exhaust intake and obstructing said rearward-discharge duct means for discharge of jet exhaust downward and forward through said reverse-thrust duct means to produce thrust on the aft portion of the airplane having a rearward component tending to retard forward movement of the airplane during the landing ground run and an upward component tending to pitch the nose portion of the airplane downward about a fulcrum located in the vicinity of the main landing gear for increasing the pressure of the nose wheel on the ground and consequently increasing the steering effectiveness of the nose wheel during the landing ground run, vent door means selectively movable between a normal position closing said exhaust outlet of said reverse-thrust duct means and a reverse-thrust position opening such outlet, and fixed pivot means at the rearward side of said exhaust outlet of said reverse-thrust duct means supporting the rear portion of said vent door means for swinging of said vent door means between its normal position and its reverse-thrust position, said vent door means in its reverse-thrust position projecting substantially entirely outward beyond the surface of the airplane fuselage and inclined forward and downward from the rearward side of said reverse-thrust duct means exhaust outlet. .Iaddend..Iadd. 9. The method of landing an airplane having a steerable nose wheel, main landing gear located rearward of the nose wheel and a jet engine mounted in thrust relationship to the aft portion of the airplane for normally propelling the airplane forward, which comprises effecting conventional approach of the airplane toward the ground at substantial forward speed, effecting touchdown of the airplane by engagement of the main landing gear with the ground, and, during the landing ground run of the airplane after touchdown, diverting at least the major portion of the exhaust of the jet engine from its normal generally rearward direction to only a downward and forward direction for producing thrust on the aft portion of the airplane having a rearward component for retarding forward movement of the airplane and an upward component tending to depress the nose portion of the airplane about a fulcrum located in the vicinity of the main landing gear for increasing the pressure of the nose wheel on the ground and consequently increasing the steering effectiveness of the nose wheel.