Helicopter airborne load systems and composite aircraft configurations

HELICOPTER AIRBORNE LOAD SYSTEMS AND
COMPOSITE AIRCRAFT CONFIGURATIONS

BACKGROUND OF THE INVENTION 5

The concept of a rotary wing-fixed wing composite aircraft system and method of flight was recognized as early as 1958 by Bennett, as set forth in U.S. Pat. No. 2,843,337 which was issued July 15, 1958, and was assigned to Hiller Helicopters. The Bennett patent dis- 10 closed a rotary wing aircraft attached above the longitudinal center of gravity of a fixed wing aircraft with the attachment points being close to the main structure of the fixed wing aircraft and with attachment fittings on the rotary wing aircraft housed in leg fairings of a 15 skid type under carriage. The attachment disclosed effected a rigid connection directly between strong points on the upper and lower aircrafts, with an arrangement in which the attachment point on the fixed wing aircraft could be retracted when released for inde- 20 pendent flight. In a disclosure by E. F. Andrews, as set forth in U.S. Pat. No. 2,797,881 of July 2, 1957, another rotary wing-fixed wing composite aircraft system was described. In both of these disclosures the attachment means on the rotary wing aircraft was neither extend- 25 ible nor maneuverable and was rigidly attached to the rotary wing aircraft structure. In addition the engine thrust of the fixed wing aircraft could not be directed or utilized to help lift or assist in the fixed wing aircraft take-off or landing. 30

Other kinds of composite aircraft such as fixed wing^ fixed wing and dirigible-fixed wing systems have also been previously disclosed.

There preceded Bennett the concept of launching and retrieving a small fixed wing aircraft from the bomb 35 bay of a large fixed wing aircraft, as disclosed by Barkey in U.S. Pat. No. 2,653,777, which was issued Sept. 29, 1953. This patent was directed to the mechanism for achieving that result.

Prior to the Bennett and Barkey disclosures, Richard- 40 son disclosed, in U.S. Pat. No. 1,869,506 which issued Aug. 2, 1932, an arrangement for catching a powered airplane while in flight from another aircraft, and more particularly disclosed apparatus to permit an operator from within a dirigible to catch and temporarily sus- 45 pend an aircraft from the underside of the dirigible. The disclosure of the preferred method derived by Richardson was directed to manual control over the securing or mooring means, since the pilots of the respective components were not considered in position to visually 50 superintend the catching operation.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to helicopter airborne load systems and composite aircraft configurations, and 55 more particularly to means rendering the helicopter useful for handling airborne loads or to be part of a configuration that allows a fixed wing aircraft to take off and land with a minimum of ground run.

It is an object of the present invention to utilize a 60 rotary winged aircraft equipped with a maneuverable probe type attachment means to make contact with a fixed wing aircraft for rendering assitance to it in the take off mode or the landing mode, and to effect a substantially vertical movement thereof or to reduce to a 65 minimum the ground run for the fixed wing aircraft.

It is a further object of the present invention to provide a maneuverable probe type attachment means that

can be moved between retracted or extended positions by an operator or pilot in the rotary winged aircraft to permit unencumbered take-off of the rotary wing aircraft and extension of the probe to effect a hook up or release of the fixed wing aircraft.

It is a further object of the present invention to provide an extendible attachment means that can permit a safe separation between the rotary wing aircraft and its airborne load or safe spacing relative to a fixed wing aircraft.

It is an additional object of the present invention to utilize the propulsive thrust of the fixed wing aircraft directed vertically, or nearly so, as an assist in the takeoff.

Further objects of the present invention will be set forth in the detailed description of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain preferred embodiments of the present composite aircraft will be set forth in the accompanying drawings, wherein:

FIG. 1 is an elevations view of the initial hook up of a rotary winged aircraft and a fixed wing aircraft just prior to initiating take-off;

FIG. 2 is a view similar to FIG. 1, but depicting the lifting of the fixed wing aircraft during take-off;

FIG. 3 is a view similar to FIG. 1, but depicting a supersonic type fixed wing aircraft as a component of the composite aircraft;

FIG. 4 is a view similar to FIG. 3 in which the jet thrust of the fixed wing aircraft is directed generally vertically during the take-off mode of the composite aircraft by pitching the aircraft nose up.

FIG. 5 is a perspective view of a fragmentary portion of the fixed wing aircraft equipped with load bearing means exposed for engagement by the maneuverable probe, a fragmentary portion of which is extended from the rotary wing aircraft;

FIG. 6 is a view similar to FIG. 5 illustrating a more advanced condition in which the principal connection of the maneuverable probe has effected engagement with the load bearing means on the fixed wing aircraft;

FIG. 7 and FIG. 8 are fragmentary sectional views showing the progressive operation of the maneuverable probe in effecting connections with the load bearing means;

FIGS. 9 and 9A are schematic views of the control system for the probe carried by the rotary wing aircraft;

FIG. 10 is a fragmentary perspective view of a modified probe having maneuvering control means, and means to retract or to vary its extended position; and

FIG. 11 is an elevational view of a1 modification in which the helicopter is used as a refueling vehicle by carrying a fuel supply pod for a fixed winged aircraft.

DETAILED DESCRIPTION OF THE
EMBODIMENTS

While a composite aircraft system is not new in view of Bennett or Barkey, supra, the present invention embodies improvements of unique type which are useful in a number of different ways. A fixed wing aircraft normally requires a substantial length of runway for takeoff and landing. On the other hand a composite aircraft using a rotary wing aircraft capable of aiding the fixed wing aircraft can substantially reduce or eliminate the take-off and landing run as will be set forth hereinafter. 4

The improvements comprise a maneuverable and retractable and extendible probe means that is operatively carried by the rotary wing aircraft in position to effect attachment to the fixed wing aircraft or to an object such as a load carrying container or object requiring 5 movement from place to place. The maneuverability of the probe means greatly improves the hookup reliability and the extendibility allows a safe separation between the rotary wing and fixed wing aircraft structure.

Another improvement is the utilization of the propul- 10 sive thrust of the fixed wing aircraft component of the composite aircraft system directed vertically, as an assist in the take-off. This can be accomplished by controlling the direction of the thrust independently of the aircraft or by bodily positioning the aircraft. 15

Turning now to FIGS; 1 and 2, there is shown a helicopter 14 with a multibladed rotor 15 driven by a suitable turboshaft power plant 16. A load sustaining probe 17 is operatively extended from the helicopter 14 so as to assume a generally pendent position for the 20 purpose of connection into load bearing means on a fixed wing aircraft 18. The aircraft 18 is provided with jet engines 19 having exhaust thrust deflectors 20 which can be manipulated by the pilot during take-off or landing of the composite aircraft to direct the exhaust down- 25 ward for additional lift during take-off or during landing.

FIGS. 1 and 2 illustrate a take-off sequence for the aircraft 18 assisted by the helicopter 14. The sequence begins with the helicopter hovering over the stationery 30 fixed wing aircraft 18 so that the load sustaining probe

17 may be maneuvered by an operator 21 (FIG. 1) seated in the helicopter 14 into engagement with suitable load bearing means (later to be disclosed in detail) on the upper surface of the fixed wing aircraft 18. The 35 aircraft 18 will have the thrust deflectors 20 set in the downward position as shown in FIG. 1 so that the jet engine thrust may be used to assist in the take-off. The helicopter 14 after making contact through the probe 17 increases the thrust of its main rotor 15 to lift the fixed 40 wing aircraft 18 substantially vertically off the ground. As shown in FIG. 2 the helicopter 14 has lifted the fixed wing aircraft and can now accelerate with the aircraft

18 generally horizontally up to flight speed prior to release of the probe 17. 45

The landing sequence for the fixed wing aircraft is substantially the reverse of. the take-off sequence. The fixed wing aircraft 18 maneuvers into position beneath the helicopter 14 and the probe 17 is maneuvered into engagement with the load bearing means on the upper 50 surface of the fixed wing aircraft. After attachment of the probe 17 the thrust deflectors 20 on the aircraft 18 can be positioned to direct the exhaust in a downward direction and the helicopter proceeds to lower the aircraft to a substantially vertical landing before discon- 55 necting the probe 17.

Turning now to FIGS. 3 and 4 there is shown a modification of a composite aircraft in which the rotary wing aircraft 14 equipped with the probe 17 is joined to a fixed wing aircraft 22 having a fixed position exhaust 60 nozzle 22A, without thrust deflection means. The takeoff sequence in this composite configuration, after attachment of the probe 17, begins with the helicopter overspeeding its main rotor 15 so as to gain the necessary additional energy to vertically lift the fixed wing 65 aircraft 22 clear of the ground for a sufficiently long period of time and to an elevation to permit the probe 17 to pitch the aircraft 22 into a position such that the

thrust from the jet engine exhaust nozzle 22A may be utilized to assist in the remainder of the take-off sequence and to relieve the helicopter 14 from sustaining the entire weight of the aircraft 22. After reaching a safe altitude, the probe 17, as will appear presently, is operated to allow the aircraft 22 to return to a more normal horizontal flight position so that longitudinal velocity of the composite aircraft can reach a speed necessary for the aircraft 22 to sustain itself in horizontal flight. When this speed is reached the probe 17 is disconnected and the aircraft 22 is then in free flight.

The landing sequence for the composite aircraft of FIGS. 3 and 4 is substantially the reverse of the take-off sequence if the aircraft 22 is too heavy for the helicopter 14 to lower to the ground in a horizontal attitude. The composite aircraft must be at a sufficient elevation to permit the positioning of the aircraft 22 pitched in a nose up attitude with the jet engines running to produce thrust assistance from nozzle 22A until just prior to the point of touchdown when the aircraft 22 would be rotated back to the necessary horizontal attitude for landing. During the critical landing maneuver the main rotor 15 of the helicopter would be overspeeded to provide a burst of power required to sustain the weight of the aircraft 22 after its change of attitude from the nose up pitched position (illustrated in FIG. 4) to the horizontal landing position (illustrated in FIG. 3).

Turning now to FIGS. 5 and 6 there has been illustrated one form of structural arrangement for the probe 17 and one example for the attachment means necessarily provided in the structure of the fixed wing aircraft, whether it is an aircraft 18 as illustrated in FIG. 1 or as shown at 22 in FIG. 3. Other suitable attachment means may be employed, so the following description is given by way of an example. In the present example the fixed wing aircraft fuselage 23 is provided with a receptacle 24 in the upper surface of the fuselage close to the center of gravity, and a second receptacle 25 is provided in a position forward of the receptacle 24. These receptacles are located on the longitudinal center line of the fixed wing aircraft. The probe 17 comprises an elongated streamlined (airfoil configuration when seen in section) body 26, the upper end 27 of which is pivotally connected into the helicopter 14 at suitable attachment assembly 28 (see FIG. 9). The probe 17 in this form needs to be sufficiently longer than the landing gear 14A so there will be a safe separation between the rotary and fixed wing aircrafts when the probe is extended from its retracted position. The lower end of the housing 26 is formed so as to be hingedly connected to a member 29 which houses operating mechanism to be described. The hinge connection includes the hinge pin 30 having its axis substantially parallel to the longitudinal axis of the aircraft fuselage 23 so that the member 29 is capable of pivoting laterally relative to the longitudinal axis. Roll damper device 30A is operatively connected between the members 26 and 29 and is streamlined within member 26.

It can be seen in FIGS. 5 and 7 that the fuselage 23 has the receptacle 24 provided with a crossbar 31, and a second crossbar 32 is located in the receptacle 25. The lower end of the probe member 29 carries attachment means in the form of a pair of jaws 33 which are adapted to engage or effect attachment with the bar 31 as the probe member 29 aligns itself over the receptacle 24. The member 29 is also provided with lateral stabilizing fins 34 for assuring a substantial fixed engagement of the probe member 29 with the fuselage 23. It can be seen