Double hinged access panel for aircraft

An access door assembly includes a door panel located at a door opening and a primary hinge having a primary hinge axis and operably connected to the door panel. A guide track is affixed at the door opening and is operably connected to the door panel to guide rotation of the door panel about the first hinge axis. A secondary hinge having a secondary hinge axis is operably connected to the door panel. The secondary hinge allows for rotation of a first portion of the door panel about the secondary hinge axis, while a second portion of the door panel is stationary.

BACKGROUND

The subject matter disclosed herein generally relates to aircraft structures. More specifically, the subject disclosure relates to access doors for aircraft airframes.

Typical aircraft, such as rotary wing aircraft or helicopters, have one or more doors that, when opened, allow for ingress of articles or passengers into an aircraft compartment, for example, a cargo compartment or a passenger compartment. The doors may also provide for egress of passengers during normal operation of the aircraft. Aircraft further have requirements to provide for emergency egress of passengers in the case of an evacuation. Emergency egress requirements include those that the door must open outwardly, and that the door must be openable manually, without applying power via, for example, a motor.

BRIEF SUMMARY

In one embodiment, an access door assembly includes a door panel located at a door opening and a primary hinge having a primary hinge axis and operably connected to the door panel. A guide track is affixed at the door opening and is operably connected to the door panel to guide rotation of the door panel about the first hinge axis. A secondary hinge having a secondary hinge axis is operably connected to the door panel. The secondary hinge allows for rotation of a first portion of the door panel about the secondary hinge axis, while a second portion of the door panel is stationary.

Alternatively or additionally, in this or other embodiments the door assembly includes a guide pin secured to the door panel and interactive with the guide track to guide movement of the door panel.

Alternatively or additionally, in this or other embodiments the door assembly includes a drive operably connected to the door panel to drive motion of the door panel about the primary hinge axis.

Alternatively or additionally, in this or other embodiments the drive is one of an electric motor or a hydraulic motor.

Alternatively or additionally, in this or other embodiments the door assembly includes a guide stop located at the guide track to limit rotation of the door panel about the primary hinge axis.

Alternatively or additionally, in this or other embodiments the guide track is affixed to a sidewall of the door opening.

Alternatively or additionally, in this or other embodiments the secondary hinge has an operating angle of 180 degrees.

In another embodiment, an aircraft includes an airframe and an access door assembly. The access door assembly includes a door panel located at a door opening of the airframe. A primary hinge having a primary hinge axis is operably connected to the door panel. A guide track is affixed to the airframe and is operably connected to the door panel to guide rotation of the door panel about the first hinge axis. A secondary hinge having a secondary hinge axis is operably connected to the door panel. The secondary hinge allows for rotation of a first portion of the door panel about the secondary hinge axis, while a second portion of the door panel is stationary.

Alternatively or additionally, in this or other embodiments the door assembly includes a guide pin secured to the door panel and interactive with the guide track to guide movement of the door panel.

Alternatively or additionally, in this or other embodiments the door assembly includes a drive operably connected to the door panel to drive motion of the door panel about the primary hinge axis.

Alternatively or additionally, in this or other embodiments the drive is one of an electric motor or a hydraulic motor.

Alternatively or additionally, in this or other embodiments the door assembly includes a guide stop located at the guide track to limit rotation of the door panel about the primary hinge axis.

Alternatively or additionally, in this or other embodiments the guide track is affixed to a sidewall of the door opening.

Alternatively or additionally, in this or other embodiments the secondary hinge has an operating angle of 180 degrees.

DETAILED DESCRIPTION

Shown inFIG. 1is a schematic view of an embodiment of a rotary wing aircraft, in this embodiment a helicopter10. The helicopter10includes an airframe12with an extending tail14. A main rotor assembly18is located at the airframe12and rotates about a main rotor axis20. The main rotor assembly18is driven by a power source, for example, an engine24via a gearbox26about the main rotor axis20. The main rotor assembly18includes a plurality of rotor blades28secured to a rotor hub30, with a main rotor shaft32connected to the rotor hub30and to the gearbox26to transfer rotational energy from the gearbox26to the main rotor assembly18. In some embodiments, the helicopter10further includes a tail rotor16located at the extending tail14to provide yaw control for the helicopter10. The tail rotor16is connected to and driven by the engine24via the gearbox26. While shown as a single rotor, it is understood that aspects of the inventions can be used in coaxial rotorcraft, tilt rotor and tilt wing aircraft, and other rotary winged aircraft. Further, while one engine24is shown inFIG. 1, it is to be appreciated that some embodiments may include two or more engines24.

Referring now toFIG. 2, the helicopter10includes an access door34located in the airframe12for ingress and/or egress of passengers or cargo from a compartment36inside the airframe12. The door34is, for example, an emergency egress door, and may be located at various locations on the airframe12, such as at the extending tail14as shown inFIG. 2.

Referring toFIG. 3, the door34opens outwardly from the airframe12, which in some embodiments is in a downward direction. The door34includes a primary hinge40and a door panel42affixed to the primary hinge40. To move between a closed position, as shown inFIG. 3, and an opened position, the door34rotates about a primary hinge axis38. In some embodiments, the rotation is guided by a guide track44affixed to the airframe12, with a guide pin46affixed to the door34and located in the guide track44. In some embodiments, the guide track44is secured to a sidewall62of the airframe12, with no interface to an upper wall64of the airframe12. The guide pin46and/or the primary hinge40are operably connected to a motor48, in some embodiments a continuous motor or stepper motor, to drive rotation of the door34about the primary hinge axis38when desired, to move the door to an opened position, as shown inFIG. 4. The motor48may be electrically or hydraulically operated. Further, in some conditions, the motor may be disengaged and the door34operated manually. In some embodiments, the guide track44is curvilinear, having an arc length of, for example, 90 degrees. Further, the guide track44includes guide stops50at one or more ends of the guide track44to stop rotation of the door34at the selected opened and/or closed positions. The guide stops50may include sensors, such as proximity sensors or the like, to sense when the guide pin reaches the opened and/or closed position. The sensed information may trigger stoppage of the motor48when the door34reaches the closed position, and may also be communicated as an access door status to an operator of the aircraft10via, for example a cockpit display (not shown).

Referring now toFIG. 5, the door34includes a secondary hinge52allowing for rotation of a first door portion54about a secondary hinge axis56, to an emergency open position illustrated inFIG. 5, while a second door portion58remains stationary. As shown, the secondary hinge axis56is parallel to the primary hinge axis38. Opening the door34by rotating the first door portion54about the primary hinge axis56is useful in situations such as power failure to the motor48, jamming of the guide track44mechanism, or the like, such as in an emergency. Referring toFIG. 6, in some embodiments, the secondary hinge52has an operating angle of up to 180 degrees or more to allow for an additionally wide opening width58compared to a normal opening width60shown inFIG. 4.

Mounting the guide frame44to the sidewall62results in a compact mechanism requiring no overhead support, thus saving interior space for passengers and/or cargo. The dual hinge arrangement, reduces a moment arm and thus reduces force, either via motor or manually, required to open the door34.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. For instance, while described in terms of aircraft, it is understood that aspects could be used in other contexts such as for wind turbines, maritime propulsion, or other technologies in which a rotating element's plan of rotation will vary from perpendicular with the axis of rotation of a shaft driving the rotating element. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.