Abstract:
Assemblies and methods are provided to allow a temporary alternate door (e.g., an observation door for use during search and rescue (SAR) missions) may be placed in a fuselage opening normally closed by a dedicated personnel door. The assembly may be provided with a central support pole attachable to interior structure of the aircraft fuselage so as to be disposed in an upright position within an interior of the aircraft fuselage (e.g., within the aircraft&#39;s cargo hold), and at least one stand-by alternate door (e.g., an observation door) which is sized and configured to be operatively accepted by the aircraft fuselage door opening when the dedicated primary aircraft door is in an opened and stowed condition. Typically a pair of stand-by alternate doors are removably connected to the central support pole so as to be capable of being movably deployed into a position to close the aircraft fuselage opening when disconnected from the central support pole.

Description:
FIELD 
       [0001]    The embodiments described herein relate generally to assemblies and methods by which aircraft doors may be reconfigured for different operations and/or missions, e.g., changing an aircraft personnel door for the ingress/egress of personnel (e.g., paratroopers) into/from the aircraft having relatively limited visibility, to an observation door having greater visibility to more readily permit external observation by aircraft crewmembers. 
       BACKGROUND 
       [0002]    Utility transport (cargo) aircraft operated by civilian transportation companies, governmental agencies and air forces are sometimes required to perform a number of missions, including the transport of personnel and material in addition to providing an airborne search and/or observation platform, e.g., during territorial patrol operations, search and rescue (SAR) operations, emergency patrol missions and the like. The aircraft fuselage doors employed for transport and ingress/egress of personnel are typically dedicated doors that allow the aircraft to be pressurized, yet can be opened during flight at lower altitudes when the aircraft is depressurized to allow personnel (e.g., paratroopers) and/or supplies to be discharged from the aircraft. Dedicated aircraft fuselage doors however are typically unsatisfactory for airborne search and/or observation missions by virtue of their limited range of exterior visibility provided to on-board aircraft personnel. 
         [0003]    Due to the increased field of vision that is provided to on-board aircraft personnel, observation doors (conventionally known as “bubble doors”) are typically employed for aircraft used for SAR and other observation missions. Although various types of aircraft are equipped with dedicated observation doors, it can sometimes be more desirable to provide an aircraft operator with the flexibility to replace a dedicated aircraft personnel door with a temporarily installed observation door when needed. One prior proposal for the temporary replacement of a dedicated aircraft fuselage personnel door with an observation door is disclosed by U.S. 2014/0077034 (the entire content of which is expressly incorporated hereinto by reference). One drawback of such a conventional temporarily installed observation door, however, is that it cannot readily be installed while the aircraft is in-flight and is relatively complex. 
         [0004]    What has been needed in the art, therefore, are assemblies and methods by which a dedicated aircraft personnel door may be replaced temporarily and more readily with an observation door. It would also be especially desirable in terms of maximum mission flexibility if such aircraft door replacement could be achieved while the aircraft is in-flight. It is towards providing solutions to such needs that the embodiments disclosed herein are directed. 
       SUMMARY 
       [0005]    The embodiments disclosed herein are directed towards assemblies and methods whereby a temporary observation door may be placed in a fuselage opening normally closed by a dedicated personnel door so the opening may be reconfigured to adapt the aircraft to an observation mission. According to some embodiments, the assembly is provided with a central support pole attachable to interior structure of the aircraft fuselage so as to be disposed in an upright position within an interior of the aircraft fuselage, and at least one stand-by alternate door (e.g., an observation door) which is sized and configured to be operatively accepted by the aircraft fuselage door opening when the dedicated primary aircraft door is in an opened condition. Typically a pair of stand-by alternate doors are removably connected to the central support pole so as to be capable of being movably deployed into a position to close the aircraft fuselage opening when disconnected from the central support pole. 
         [0006]    The assembly may be provided with upper and lower mounting assemblies. In order to removably mount the stand-by alternate door(s) to the central support pole. According to some embodiments, the lower mounting assembly may comprise at least one lower mounting clip associated with the central support pole and at least one lower mounting arm associated with a lower portion of the door frame of the observation door which is removably connected to the at least one lower mounting clip of the central support pole. The upper mounting assembly may comprise at least one upper mounting arm associated with an upper portion of the door frame, and a mounting carriage slideably coupled to the central support pole for rectilinear movements between raised and lowered positions thereof. The mounting carriage may therefore include at least one upper mounting clip removably connected to the at least one upper mounting arm. 
         [0007]    Certain embodiments will provide the stand-by alternate door(s) with a pair of wheels journally mounted to a lower portion of the door frame for rolling movements along a surface (e.g., along the cargo deck of the aircraft). In such embodiments, the lower portion of the door frame may include a pair of spaced-apart support brackets, whereby each of the wheels is journally mounted to a respective one of the support brackets. 
         [0008]    The central support pole may be adjustable lengthwise to accommodate different vertical heights within an aircraft interior cargo hold. In order to accommodate such lengthwise adjustment, certain embodiments will include a central support pole having a tubular main pole and an extension pole received telescopically within the tubular main pole so as to be extendible relative to the main pole and thereby allow lengthwise extension of the central support pole. 
         [0009]    In use, a fuselage door opening normally closed by a dedicated personnel door may be reconfigured when the personnel door is in an opened condition by removing a stand-by alternate door from the assembly mounted in the interior cargo hold of the aircraft and moveably manipulating the stand-by alternate door into position within the opening. The assembly including a central support pole and one (or preferably pair of) stand-by alternate doors may be brought on-board the aircraft, e.g., as part of an observation (SAR) pallet. The assembly may then be erected adjacent to the dedicated personnel doors of the aircraft while the aircraft is on the ground or while airborne by positioning the central support pole in an upright position within the interior aircraft cargo hold and attaching its opposed ends to aircraft fuselage structure (e.g., cargo tie-down rails or the like). 
         [0010]    When it is desired to reconfigure the aircraft door, the dedicated personnel door may be moved and stowed in an opened condition to thereby expose the door opening. If airborne, the aircraft must be at a sufficient low altitude to allow for depressurization before opening of the dedicated personnel door and the on-board crewmembers must be secured by suitable safety harnesses. Thereafter, a stand-by alternate door may be removed from the support pole and transported to the fuselage door opening. Once the door is moved so as to be adjacent to the door opening, it may be positioned and latched removable to the fuselage while maintaining the dedicated personnel door in an opened condition. 
         [0011]    The stand-by alternate door may be removed from the central support pole by disengaging a lower mounting assembly from a lower portion of the at alternate door so as to allow the lower portion thereof to be moved outwardly away from the central support pole while an upper portion thereof remains connected to the central support pole by an upper mounting assembly. The upper mounting assembly will be allowed to slideably move lower along the support pole while the lower portion of the alternate door is moved outwardly away from the central support pole. 
         [0012]    According to some embodiments, movement of the stand-by alternate door is facilitated by establishing rolling engagement between the wheels and the cargo deck and rolling the lower end of the at least one observation door across the cargo deck by the rolling engagement between the wheels and the cargo deck. Thereafter, the upper mounting assembly may be disengaged from the alternate door so that the upper portion of the alternate door is disconnected from the central support pole. At such, time the entire alternate door may be moved toward the fuselage door opening by on-board crewmembers (i.e., since the alternate door is disconnected from the central support pole) and secured in place. 
         [0013]    The alternate door may be secured in the fuselage door opening by engaging connection claws and respective stationary mounting pins while an upper portion of the at least one observation door is tilted inwardly within the interior cargo hold. Once the claws and mounting pins are engaged, the upper portion of the at least one observation door may be pivoted about the stationary mounting pin until the at alternate door closes the fuselage door opening, at which time is may be securely latched in place. 
         [0014]    These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof. 
     
    
     
       BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS 
         [0015]    The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which: 
           [0016]      FIG. 1  is a rear perspective view of a utility transport aircraft showing an exemplary temporary observation door assembly according to an embodiment of the invention at a stand-by position within the cargo space thereof; 
           [0017]      FIG. 2  is an enlarged interior perspective view of the temporary observation door assembly at the stand-by position within the cargo hold of the aircraft as shown in  FIG. 1  depicted with the dedicated personnel door in a closed condition; 
           [0018]      FIG. 3  is another interior perspective view of the temporary observation door assembly at the stand-by position within the cargo hold of the aircraft similar to  FIG. 2  but shown with the dedicated personnel door in an opened condition; 
           [0019]      FIGS. 4A and 4B  are enlarged perspective views of the upper and lower end regions of the observation doors associated with the temporary observation door assembly in the stand by position particularly depicting the upper and lower mounting assemblies, respectively, to mount the temporary observation doors to the central support pole of the assembly; 
           [0020]      FIG. 5  is an elevational view showing a state in which an exemplary temporary observation door is disconnected from the central support pole of the assembly during a reconfiguration operation; 
           [0021]      FIG. 6  is a greatly enlarged elevational view of the bottom latch system associated with an exemplary temporary observation door; and 
           [0022]      FIG. 7  is a schematic perspective view showing a sequence for the installation of the temporary observation door at the fuselage door opening during a reconfiguration operation. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Accompanying  FIG. 1  is an aft view of a utility transport (cargo) aircraft  10  which is shown with the bulk cargo door ramp  12  in a lowered position while the aircraft is on the ground G thereby exposing the interior aircraft cargo hold  14 . The aircraft  10  is shown as including exemplary port and starboard personnel doors  16   a,    16   b  on the port and starboard sides, respectively, of the aircraft fuselage  10 - 1 . As can be seen in  FIG. 1 , the interior aircraft cargo hold  14  may be provided with a temporary observation door assembly  20  having port and starboard temporary observation doors  22   a,    22   b  that may replace the dedicated personnel doors  16   a,    16   b  and thereby allow reconfiguration of the aircraft  10  to perform an observation, e.g., SAR, mission. 
         [0024]    It is noted that accompanying  FIG. 1  depicts the temporary observation door assembly  20  in a standby and ready position even though the aircraft  10  is shown to be on the ground. Typically, however, the various components of the assembly  20  to be described in greater detail below will be disassembled from one another and loaded aboard the aircraft on a mission pallet (not shown) while the aircraft  10  is on the ground. The aircraft  10  will thus typically be airborne when the flight crewmembers remove the component parts of the assembly  20  from the supplied pallet and erect them in the interior of the aircraft  10  as shown in  FIG. 1 . The assembly  20  of course could likewise be pre-assembled on the ground as depicted if deemed desirable or necessary by the mission operator. 
         [0025]    Accompanying  FIGS. 2 and 3  depict in an enlarged manner the temporary observation door assembly  20  in a stand-by location within the interior cargo hold  14 . As shown, the assembly  20  includes the temporary port and starboard observation doors  22   a,    22   b  which may temporarily be positioned within the fuselage openings when the dedicated personnel doors  16   a,    16   b  are opened. The port fuselage opening  18  is shown in  FIG. 3  with the corresponding dedicated personnel door  16   a  in a stowed opened and locked condition (e.g., by operating conventional onboard door opening hydraulics and/or electrical actuators (not shown) associated with the door  16   a ). 
         [0026]    Each of the temporary observation doors  22   a,    22   b  is removably attached to a central support pole  30  in a manner described hereinbelow. The support pole  30  is elongate and has a lower end removably attached to a conventional cargo hold rail  14 - 2  positioned lengthwise relative to the aircraft fuselage  10 - 2  in the cargo deck  14 - 1 . In a similar manner, the upper end of the support pole  30  may be removably attached to overhead fuselage structure or an overhead cargo hold rail  14 - 3  (see  FIG. 3 ) so that the support pole  30  is positioned substantially vertically upright within the cargo hold  14  adjacent to the doors  16   a,    16   b.  In order to accommodate varying heights within the cargo hold  14 , the support pole  30  may be formed of a tubular main pole member  30 - 1  and an extension pole member  30 - 2  telescopically received within the main pole member  30 - 1 . The extension pole member  30 - 2  may therefore be extended upwardly from the main pole member  30 - 1  and positionally locked to the main pole member  30 - 1  once the desired lengthwise extent is achieved by a suitable locking clamp  32  (see  FIG. 3 ). The central support pole  32  also includes a pair of parallel guide poles  34   a,    34   b  to assist in the mounting and dismounting of the doors  22   a,    22   b,  in a manner to be described in greater detail below. 
         [0027]    The doors  22   a,    22   b  may be provided with respective door frames  24   a,    24   b  such that a relatively large transparent upper observation pane provided with generally hemispherical observation bubble windows  26   a,    26   b  therein. The lower portion of the door frames  24   a,    24   b  may be provided with an outwardly protruding enclosure  28   a,    28   b  having a lower platform  28 - 1   a,    28 - 1   b  to allow on-board personnel to stand near the door so that the observer&#39;s head may be positioned in the observation bubble windows  26   a,    26   b.  The lower platforms  28 - 1   a,    28 - 1   b  of the enclosures  28   a,    28   b,  respectively, may have a portion that is openable to allow on-board personnel to air-drop items from the aircraft  10  (e.g., data marker beacons, visible flares, communication and/or navigation buoys and the like). 
         [0028]    The upper and lower mounting assemblies  40   a,    40   b  and  42   a,    42   b,  respectively, to removably mount the observation doors  22   a,    22   b  to the central support pole  30  of the assembly  20  are shown in greater detail in accompanying  FIGS. 4A and 4B . Specifically, as shown in  FIG. 4A , an upper panel  22 - 1   a,    22 - 1   b  of the doors  22   a,    22   b  is preferably articulated relative to the door frames  24   a,    24   b  by hinges  27   a,    27   b.  The upper panels  22 - 1   a,    22 - 1   b  include outwardly projecting mounting arms  44  having transverse mounting pins  46  removably received within a respective one of the quick-release mounting clips  48   a,    48   b.  Only the mounting arms  44  and pins  46  received within the mounting clip  48   a  which are associated with the upper panel  22 - 1   a  are visible in  FIG. 4A , but it will be understood that such structures are similarly provided in the upper panel  22 - 1   b  so as to be removably received by the mounting clip  48   b.  The mounting clips  48   a,    48   b  are operatively connected with a carriage member  50   a,    50   b  slideably coupled to the guide poles  34   a,    34   b,  respectively, associated with the central support pole  30  so as to be rectilinearly movable between raised and lowered positions along the guide poles  34   a,    34   b  with respect to the cargo deck  14 - 1 . 
         [0029]    The lower mounting assemblies  42   a,    42   b,  like the upper mounting assemblies  40   a,    40   b,  will include outwardly projecting mounting arms  54   a,    54   b  having transverse mounting pins  56   a,    56   b  associated with the lower portion of the door frames  24   a,    24   b.  The mounting pins  56   a,    56   b  are removably received within a respective one of the quick-release mounting clips  58   a,    58   b  connected operatively to the mounting brackets  60   a,    60   b  positionally fixed to a lower end of the central mounting pole  30 . 
         [0030]    As is also visible in  FIG. 4B , the lower portion of the door frames  24   a,    24   b  include a pair of laterally separated support brackets  70   a,    70   b  each of which includes a respective wheel  72   a,    72   b  journally connected thereto so as to allow rolling movements of the door  22   a  across the cargo deck  14 - 1 . The support brackets  70   a,    70   b  also include a connection claw  74   a,    74   b  that is adapted to cooperate with a stationary pin (identified in  FIG. 7  by reference numeral  80 ) to mount the door frames  24   a,    24   b  in a respective fuselage opening  18  when the personnel doors  16   a,    16   b  are in an opened condition. 
         [0031]    The following description will focus on the port side personnel door  16   a  and its associated temporary observation door  22   a,  it being understood that such description is equally applicable to the starboard side personnel door  16   b  and its associated temporary observation door  22   b.    
         [0032]    In use, the opening  18  associated with the personnel door  16   a  is initially provided by moving the door  16   a  into its opened condition. Such a state is shown in  FIG. 3 . The opening of the door  16   a  and the positioning of the temporary observation door  22   a  in the opening  18  may, if desired, be accomplished while the aircraft  10  is in-flight provided that the onboard personnel are equipped with suitable safety straps while the door  16   a  is opened and the aircraft  10  is at a sufficiently low altitude so as to be depressurized. 
         [0033]    The temporary observation door  22   a  is prepared for movement into an occupying position within the opening  18  when the door  16   a  is opened by initially releasing the pins  56   a  associated with the lower mounting assembly  42   a  from their respective engagement with the mounting clips  58   a  while substantially concurrently moving the lower part of the door frame  24   a  outwardly away from the central mounting pole  30  (i.e., in the direction as shown by arrow A 1  in  FIG. 5 ). Such movement of the door frame  22   a  is preferably accomplished manually by onboard crewmembers being positioned on respective opposite sides of the door  22   a.  Movement of the door frame  24   a  outwardly away from the central mounting pole  30  is facilitated by rolling engagement of the wheels  72   a  across the cargo deck  14 - 1  within the cargo hold  14  of the aircraft  10 . Continued movement of the door frame  24   a  outwardly away from the central mounting pole  30  by the crewmembers will also responsively cause the carriage member  50   a  to slideably move downwardly toward the cargo deck  14 - 1  along the guide post  32   a  (i.e., in the direction of arrow A 2  in  FIG. 5 ). 
         [0034]    Once the carriage member  50   a  has been lowered sufficiently, the attending crewmembers will disengage the pins  46  from the mounting clips  48   a  associated with the upper mounting assembly  40   a.  At this time the crewmembers will be physically supporting the door  22   a,  for example by positioning a crewmember on each side of the door  22   a  and holding the door  22   a  by the provided interior handles  80 , while they continue to advance the door  22   a  outwardly away from the central mounting pole  30  and toward the opening  18 . As noted previously, such advancement of the door  22   a  is facilitated by the rolling movement of the wheels  72   a  across the cargo deck  14 - 1  of the aircraft  10 . 
         [0035]    As shown in  FIG. 6 , once the lower part of the door frame  24   a  of the door  22   a  has been positioned immediately adjacent to the opening  18 , the connection claw  74   a  will be aligned with the stationary door mounting pin  82  fixed to the lower part of the door supporting structure  16 - 1   a  of the door  16   a  surrounding the opening  18 . Upon engagement between the connection claw  74   a  and the door mounting pin  82 , the crewmembers may then raise the door  22   a  by pivoting the door frame  24   a  about the pin  82  (i.e., in the direction shown by arrow A 3  in  FIG. 7 ) until the door frame  24   a  is positioned in the opening  18  in engagement with the door supporting structure  16 - 1   a  of the fuselage  10 - 1 . Thereafter, the upper panel  22 - 1   a  may be pivoted so as to be an extension of the door frame  24   a  and close the opening  18 . The thus positioned temporary observation door  22   a  may then be removably fixed to the door supporting structure by engagement with conventional door latches (not shown) associated with the door supporting structure  16 - 1   a.    
         [0036]    The removal of the temporary door  22   a  and placement back into a stand-by ready position whereby the door  22   a  is connected to the central supporting pole  30  may proceed in a manner opposite to that described above. Following removal of the door  22   a  from the opening  18 , the dedicated personnel door  16   a  may be lowered into its closed condition. As previously noted, the reconfiguration of the starboard side personnel door  16   b  to have the temporary observation door  22   b  positioned in its opening may proceed in a similar manner to the operational sequence related to the door  22   a  that was described above. 
         [0037]    Various modifications within the skill of those in the art may be envisioned. Therefore, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.