Translatable outward opening plug-type aircraft door and actuating mechanisms therefor

An inward/outward movable plug-type aircraft passenger door (50) including: (i) a hinge assembly (56) and programming control mechanism (100, 114, 116 and 105, 114, 119) therefor; (ii) a latch/unlatch mechanism (58, 70, 82, 88, 89, 90, 91, 92, 94 and 95) therefor; (iii) a pressure lock gate (69) and actuating mechanism (58, 75, 76, 78, 79, 80, 81, 82 and 84) therefor; and (iv), a deployable emergency evacuation system (59) and actuating linkage (60, 132, 134, 135, 136, 138, 139, 140, 141, 142 and 144); wherein the aircraft door (50) is of the type adapted to be translated between a first fully closed and latched position and a second fully opened position while being maintained essentially parallel to the plane containing the ingress/egress cutout opening (51) in the fuselage (52) at all intermediate door positions--i.e., the aircraft door (51) is not pivoted or rotated about the hinge axis (104 and/or 109) to, in effect, turn the door (51) inside-out, but, rather, is moved with translatory motion outward of the ingress/egress cutout opening (51) in the fuselage (52) to a fully open position where the door's inner skin (66) is in facing relation to the fuselage (52) outer skin.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention relates generally to plug-type aircraft doors; and, 
more particularly, to inwardly/outwardly movable plug-type aircraft doors 
of the type which are adapted to be translated between a first fully 
closed and latched position and a second fully open position while being 
maintained at all times in a plane essentially parallel to the plane 
containing the ingress/egress cutout opening formed in the aircraft 
fuselage--i.e., the aircraft door is not appreciably moved into the 
aircraft interior during any portion of a door opening/closing operation; 
nor is it pivoted or rotated about the hinge axis to, in effect, turn the 
door inside-out when fully open. Rather, aircraft doors embodying the 
features of the present invention are moved with translatory motion about 
a vertical, or near vertical, hinge axis, thus effectively limiting the 
need for imposition of the significant manual forces heretofore required 
to move relatively heavy aircraft doors in an uphill direction during 
significant portions of a door opening and/or closing operation when the 
doors are pivotally or rotationally mounted for movement about an inclined 
hinge axis. Since aircraft doors constructed in accordance with the 
present invention are intended to be operated about a vertical, or near 
vertical, hinge axis, the invention finds particularly advantageous use in 
connection with narrow-bodied commercial passenger aircraft where 
relatively constant fuselage frame cross-sections are available permitting 
mounting of one or more aircraft doors at various fore and/or aft 
locations. 
2. Background Art 
Conventional commercial aircraft are commonly provided with a multiplicity 
of ingress/egress openings in the aircraft fuselage with suitable doors 
being provided for closure of such openings. The doors vary widely in 
terms of their construction and operation. Commonly, such doors are 
plug-type doors which are designed to fit into the ingress/egress openings 
when the doors are closed so as to form a substantially smooth, 
continuous, uninterrupted, exterior skin surface. When such doors are 
opened, they may be moved through any of several different paths, 
dependent upon the particular door design employed. For example, some 
plug-type aircraft doors are of the type which move inwardly into the 
aircraft and slide upwardly along tracks deployed on the interior of the 
fuselage with the door being received within a compartment immediately 
above the ceiling in the passenger cabin. In still other instances, the 
doors are pivoted about the axis of a first torque tube assembly mounted 
in the door and moved slightly inboard, at which point the doors are 
pivoted simultaneously about the axes of both the first door-mounted 
torque tube assembly and a second torque tube assembly mounted in the 
fuselage body structure and to which the door is hingedly connected, with 
the door moving outwardly through the ingress/egress opening, and swinging 
through an arc approximating 180.degree. so that when fully open, the door 
is entirely disposed outside of the aircraft fuselage, lying in a plane 
generally parallel to the aircraft centerline and with the door's outer 
skin surface essentially in face-to-face contact with the outer skin 
surface of the fuselage--i.e., the door is, in effect, turned inside-out. 
In most instances today, doors of the foregoing character are manually 
operated by on-board flight attendants since most commercial aircraft 
carriers are reluctant to rely upon electrical actuating systems which are 
subject to electrical malfunction. As a consequence, and due to the rather 
significant weight of the doors and the limited strength of crew 
attendants, it has been necessary to provide rather sophisticated 
counterbalance systems so as to enable the on-board flight attendant to 
manipulate such doors, particularly when the doors are being moved along 
an uphill path--a necessity when the door's hinge axis is other than 
essentially vertical. 
In recent years, some commercial aircraft have employed ingress/egress 
doors which are capable of translatory motion about a vertical, or near 
vertical, hinge axis, thus permitting the on-board flight attendant (or 
ground crew members located external to the aircraft) to open the door by 
translating the door outwardly with the door, when fully opened, occupying 
a position wherein the interior skin surface of the door is in facing 
relation to the exterior fuselage skin surface. Because the door is moved 
about a vertical, or near vertical, hinge axis, the door is in essentially 
a balance position during all portions of door opening and/or closing 
movement, thus effectively eliminating the need to move the door uphill 
and enabling even those on-board flight attendants having relatively low 
body weights and limited strength to manipulate doors weighing two, three 
or more times the body weight of the flight attendant with relative ease. 
Nevertheless, outwardly opening translatory plug-type doors of conventional 
construction have continued to pose a number of significant problems for 
aircraft designers. One of the more significant of these problems is 
directly related to the requisite hinge mechanism and actuating linkages 
which are needed to interconnect the door to the aircraft fuselage frame 
structure. More specifically, with such constructions, the aircraft door 
is commonly supported in cantilever fashion from one end of a hinge 
assembly coupled to the fuselage frame; and, since the hinge elements and 
other associated operating linkages must, in effect, go around a corner as 
the door is moved towards a fully opened position, they have tended to be 
rather complex and, moreover, they tend to project into the ingress/egress 
cutout opening when the door is fully open, thus effectively reducing the 
size of an unobstructed door opening. Moreover, in some instances, the 
hinge assembly and/or associated actuating linkages limit the degree of 
permissable door opening movement. As a consequence of the foregoing 
problems, and in order to meet the specifications of commercial aircraft 
carriers, it has been necessary to make the cutout opening in the aircraft 
wider to accommodate laterally projecting components and/or somewhat 
higher to accommodate overhead projecting components while maintaining the 
necessary unobstructed ingress/egress opening in the aircraft. Compounding 
the foregoing problems is the requirement that such ingress/egress 
passenger doors in commercial aircraft be provided with deployable 
emergency evacuation systems and their associated actuating linkages. 
As those skilled in the art are well aware, the prior art is replete with 
numerous patent disclosures dealing with the foregoing types of doors and 
their inherent problems. Exemplary patents which are representative of 
plug-type aircraft doors with associated deployable evacuation systems and 
of the type which are adapted to move upwardly along tracks into the 
interior of the aircraft fuselage are those disclosed in U.S. Pat. Nos. 
4,125,235--Fitzgerald et al and 4,470,566--Fitzgerald, both of which are 
assigned to the assignee of the present invention. 
Patents which typify outwardly opening plug-type doors of the type adapted 
to be rotated about either a vertical or an inclined hinge axis and which 
are, in effect, turned inside-out include U.S. Pat. Nos.: 
2,997,751--McPherren; 3,051,280--Bergman et al; 3,791,073--Baker; 
4,199,120--Bergman et al; and, 4,479,623--Maraghe et al. Reference to the 
Bergman et al and Baker patents, all of which are assigned to the assignee 
of the present invention, reveals the nature of the problem inherent with 
hinge mechanisms and associated actuating linkages which project into the 
ingress/egress cutout opening when the door is open; while the Maraghe et 
al patent, also assigned to the assignee of the present invention, is 
illustrative of the types of counterbalance systems that are required with 
such doors to enable on-board flight attendants to manipulate the doors 
along uphill paths. 
Wilmer, U.S. Pat. No. 3,004,303 is of interest for its early disclosure of 
a rather rudimentary type of aircraft door of the type intended to move 
with translatory motion. The patent contemplates the use of a lower main 
hinge and an upper control member, each of which are pivotally connected 
at one end to the aircraft frame adjacent the ingress/egress opening and 
at their other ends to the approximate midpoint of the door, with the 
uppermost control member serving to maintain parallel movement of the door 
as it is translated to and from a fully opened position. It is believed 
that commercial aircraft employing translatory plug-type doors of the 
general type disclosed in the Wilmer patent have, of necessity, employed 
considerably more complex latching and locking mechanisms than shown in 
the patent. 
Heinemann et al, U.S. Pat. No. 2,751,636, a patent assigned to the asignee 
of the present invention, discloses a similar translatory plug-type 
aircraft door construction, here employing upper and lower hinges defining 
an inclined hinge axis about which the door is translated, together with 
an overhead control linkage. The construction is such that when used with 
conventional narrow bodied commercial aircraft of the type presently being 
manufactured, the fuselage curvature prohibits disposition of the hinges 
for rotation about a vertical, or near vertical, hinge axis; and, 
consequently, this arrangement would further require rather sophisticated 
counterbalance systems and, in some instances, power assist systems. 
Yet another patent illustrative of closures for aircraft ingress/egress 
openings which do not rotate is Russian Pat. No. 182,003, wherein a hatch 
closure is provided that is moved out of the ingress/egress opening and 
then moved sidewise along spatial runners. 
Other patents of miscellaneous interest include Linderfelt, U.S. Pat. Nos. 
3,085,297 and Allwright et al, 3,647,169. 
SUMMARY OF THE INVENTION 
An inward/outward movable plug-type aircraft passenger door including: (i) 
a hinge assembly and programming control mechanism therefor; (ii) a 
latch/unlatch mechanism; (iii) a pressure lock gate and actuating 
mechanism therefor; and (iv), a deployable emergency evacuation system and 
actuating linkages; is disclosed wherein the aircraft door is of the type 
adapted to be translated between a first fully closed and latched position 
and a second fully open position while being maintained essentially 
parallel to the plane containing the ingress/egress cutout opening in the 
fuselage at all intermediate door positions--i.e., the aircraft door is 
not pivoted or rotated about the hinge axis to, in effect, turn the door 
inside out, but, rather, is moved with translatory motion outward of the 
ingress/egress cutout opening in the fuselage to a fully open position 
where the door's inner skin is in facing relation to the fuselage outer 
skin. That is, the aircraft door remains in a plane essentially parallel 
to the plane it occupied when fully closed and latched during all portions 
of its movement between fully open and fully closed and latched positions. 
Moreover, the hinge assembly and all actuating mechanisms associated with 
the door are designed to minimize obstruction to the ingress/egress cutout 
opening, thereby permitting door designs which require significantly less 
dedication of fuselage and/or available bulkhead space to meet the 
specifications of commercial aircraft carriers. Indeed, doors manufactured 
in accordance with the present invention can, while permitting 
unobstructed ingress/egress openings of the same width as attainable with 
more conventional translatory door constructions, employ up to about 6 
inches less dedicated fuselage space per door. 
It is a general aim of the present invention to provide outwardly opening, 
plug-type, translatory aircraft doors of the foregoing type which are 
characterized by their simplicity of construction, are compact, are devoid 
of actuating mechanisms interconnecting the door and surrounding fuselage 
frame structure at the upper and lower ends of the door, and which require 
only minimal direct-coupled actuating linkages for latching/unlatching the 
door, lifting the door relative to the ingress/egress cutout opening, 
and/or for deploying door mounted emergency evacuation systems. 
Another important objective of the present invention is the provision of an 
outwardly opening, plug-type, translatory aircraft door which permits of 
usage of a single, centrally located, hinge assembly permitting the door 
to be translated about a vertical, or near vertical, hinge axis, thereby 
minimizing the forces that must be manually imparted by either an on-board 
flight attendant or by externally located ground crew members to move the 
door between a fully closed and latched position and a fully opened 
position. An ancillary objective of the invention is the provision of an 
aircraft door of the foregoing type having a hinge assembly and proramming 
control linkage therefor which permit such tranlatory door movement and 
which, at the same time, are characterized by their ability to support the 
door in cantilever fashion while simultaneously extending around the 
corner of a vertical fuselage frame member adjacent the door cutout 
opening without significantly obstructing the ingress/egress opening when 
the door is fully opened. 
A further objective of the invention is the provision of a translatory, 
outwardly opening, plug-type aircraft door of the foregoing character 
which permits of a simple door structure consisting of continuous edge 
members, beams and skins and which can be utilized in ingress/egress 
cutout openings in the aircraft fuselage which do not require 
irregularities to accommodate either the hinge assembly and/or the 
actuating mechanisms for the door. 
Another and more detailed objective of the invention is the provision of a 
simple, reliable, door construction of the foregoing type which readily 
permits of modification to accommodate power assist systems for aiding 
door opening under emergency evacuation conditions.

While the invention is susceptible of various modifications and alternative 
forms, specific embodiments thereof have been shown by way of example in 
the drawings and will herein be described in detail. It should be 
understood, however, that it is not intended to limit the invention to the 
particular forms disclosed but, on the contrary, the intention is to cover 
all modifications, equivalents and alternatives falling within the spirit 
and scope of the invention as expressed in the appended claims. 
DETAILED DESCRIPTION 
A. General Environment (FIGS. 1, 2, 12 and 13) 
Referring first to FIG. 1, there has been illustrated an outwardly opening, 
translatory, plug-type aircraft door, generally indicated at 50, of the 
type adapted to fit into and close an ingress/egress opening or cutout 51 
formed in the aircraft fuselage 52 between fore and aft frame members 
depicted in broken lines at 54, 55. In the exemplary form of the invention 
depicted in FIG. 1, the door 50 includes a hinge assembly, generally 
indicated at 56, located generally centrally of the door for hingedly 
interconnecting the door to the fuselage frame structure--here, to the 
forward frame member 54--with freedom for translatory motion about a 
vertical, or near vertical, hinge axis. The door 50 further includes an 
interior manually operable handle 58 which can be used to latch/unlatch 
the door and, additionally, to lift the door slightly so as to permit 
opening thereof. As is conventional with aircraft doors of the type here 
illustrated, the door 50 is also provided with a recessed exterior door 
handle (not shown) which is interconnected to handle 58 in such a manner 
as to permit opening and/or closure of the door from either the passenger 
cabin by an on-board flight attendant or from outside the aircraft by 
ground personnel. Finally, and as is common with aircraft doors of the 
type employed in commercial passenger aircraft, the door 50 includes a 
deployable emergency evacuation system, generally indicated at 59, 
comprising a deployable and inflatable escape chute or slide (not shown) 
for permitting evacuation of passengers and crew members from the aircraft 
under emergency conditions. Such emergency evacuation system 59 is either 
Armed or Disarmed by the on-board flight attendant by means of an arming 
lever 60. 
To facilitate an understanding of the present invention, the door 50 and 
surrounding fuselage structure shown in FIG. 1 have been illustrated in 
FIG. 2 with the inner cabin and door bulkheads or skins removed so as to 
expose the interior structure of the door and surrounding frame. Thus, as 
here shown, it will be observed that the door 50 comprises a pair of 
continuous force and aft parallel vertical edge members 61,62 
interconnected by a plurality of transverse beams 64 to which are attached 
an outer skin 65 and an inner skin (not shown in FIG. 2, but illustrated 
at 66 in FIG. 1). The interior manually operable handle 58, as well as the 
exterior operating handle (not shown), are connected through a handle box 
mechanism, generally indicated at 68 in FIG. 2, and a suitable control 
actuating linkage assembly to be described in greater detail below, to a 
pressure lock gate 69 and a latch torque tube 70. The functions and 
operation of the pressure lock gate 69 are described hereinbelow in more 
detail in connection with FIGS. 3 through 6, 9 and 10; while the door 
latch/unlatch mechanism associated with the latch torque tube 70 is 
thereafter described in conjunction with FIGS. 5 through 13. 
In order to properly seat the aircraft door 50 within the ingress/egress 
opening 51 and to permit transfer of pressure loads on the door to the 
aircraft fuselage structure 52 when the door is closed and latched, the 
exemplary structure is provided with a plurality of cooperable mating door 
and fuselage stop fittings 71,72, as best illustrated by reference to 
FIGS. 2 and 12 conjointly. More particularly, a plurality of door stop 
fittings 71 are fixedly mounted on, and project fore and aft from, the 
pair of continuous fore and aft parallel vertical door edge members 
61,62--there being one door stop fitting 71 at each end of each transverse 
beam 64; and, since there are eight (8) such transverse beams 64 in the 
illustrative door structure, there are a total of sixteen (16) door stop 
fittings 71 with eight (8) projecting from the forward edge member 61 
towards the forward frame member 54 and eight (8) projecting rearwardly 
from the aft door edge member 62 towards the aft frame member 55. 
Similarly, eight (8) mating fuselage stop fittings 72 are formed on each 
of the fuselage frame members 54,55 and positioned so as to be in load 
transmissive, cooperable, mated engagement with respective ones of the 
door stop fittings 71 when the aircraft door 50 is closed, fully seated, 
and latched. 
B. Pressure Lock Gate 69 and Operating Mechanism (FIGS. 3-6, 9 and 10) 
The pressure lock gate 69 serves a number of important functions such, for 
example, as: (i) providing a means to permit interior cabin pressurization 
while at the same time permitting equalization of interior and exterior 
cabin pressure in those instances when interior cabin pressure is less 
than ambient pressure; (ii) preventing opening of the aircraft door 
whenever the passenger cabin is pressurized at greater than 1.0 psi; and 
(iii), providing a means for preventing unintentional upward door movement 
during in-flight operations should the door's latch cranks which are 
mounted on the latch torque tube 70 and/or the frame mounted latch tracks 
break. To this end, and as best illustrated by first referring to FIGS. 3, 
4 and 9 conjointly, it will be observed that the pressure lock gate 69 is 
pivotally mounted on the uppermost transverse door beam 64 by means of a 
pair of brackets 74; and, further, the pressure lock gate 69 is coupled to 
the door's main operating handle 58 by means of a first upper control link 
75 having its uppermost end coupled to the gate 69 and its lowermost end 
coupled to one end of a control lever 76 pivotally mounted centrally 
thereof on bracket 78 to a transverse door beam 64 and coupled at its 
opposite end to the uppermost end of a second lower control link 79. As 
best shown in FIG. 9, the lowermost end of the second control link 79 is 
coupled to one end of a bell crank 80 pivotally mounted on the handle box 
assembly 68, while the opposite end of the bell crank 80 is provided with 
a laterally projecting cam roller 81 or follower received within a cam 
groove 82 formed in the handle box assembly 68 and rotatable with the 
handle 58. 
The arrangement is such that when the aircraft door 50 is fully closed and 
latched--i.e., when the door components are in the position shown in FIGS. 
3, 4 and 9--the lower control link 79 is in its lowermost position as 
shown in FIGS. 4 and 9, thus pivoting control lever 76 in a clockwise 
direction as viewed in FIG. 4 and shifting the upper control link 75 to 
its uppermost position so as to pivot the pressure lock gate 69 in a 
counterclockwise direction to its fully closed position. Under these 
conditions, should the passenger cabin be depressurized, a conventional 
spring cartridge assembly 84 associated with the upper control link 75 
serves to permit the pressure lock gate 69 to pivot inwardly and open due 
to higher exterior pressure conditions, thereby insuring that gate 69 
functions as a negative pressure relief door for the passenger cabin. 
Contrasting the relative positions of the pressure lock gate 69 operating 
components as depicted in FIGS. 3, 4 and 9 when the gate 69 is closed with 
their relative positions shown in FIGS. 5, 6 and 10 when the gate is open 
(for reasons other than pressure equalization when the passenger cabin is 
depressurized), it will be observed that during the initial stages of a 
door opening cycle [whether initiated by an on-board flight attendant 
using the manually operable internal door handle 58 or by ground personnel 
actuating the external door handle (not shown)], the operating handle 58 
is manually rotated slightly--about 10.degree.--in a counterclockwise 
direction from the position shown in FIG. 3 to that shown in FIG. 5. As 
the handle 58 is rotated, the cam assembly depicted in FIG. 9 is 
simultaneously rotated about the axis 85 of handle rotation from the 
position shown in FIG. 9 to that depicted in FIG. 10, thus forcing the cam 
roller or follower 81 to move downwardly and to the left towards the axis 
of rotation 85 from the position shown in FIG. 9 to that shown in FIG. 10. 
As a consequence, the bell crank 80 is rotated in a clockwise direction 
about its point of pivotal connection to the handle box assembly 68, thus 
raising the second lower control link 79 and causing the control lever 76 
to pivot in a counterclockwise direction from the position shown in FIG. 4 
to that depicted in FIG. 6. The foregoing action serves to pull the first 
upper control lever 75 downwardly, pivoting the pressure lock gate 69 
inboard about its pivotal connection to the door frame from the closed 
position shown in FIG. 4 to the open position shown in FIG. 6. During this 
entire period of time--i.e., as the main control handle 58 is moved 
approximately 10.degree. from the position shown in FIG. 3 to that shown 
in FIG. 5, the aircraft door 50 remains in its fully seated, closed and 
latched position. 
Referring to FIG. 4, it will be observed that one or more steps 86 are 
fixedly mounted on the aircraft frame structure immediately above the 
pressure lock gate 69 and are positioned so as to prevent upward movement 
of the gate--and, therefore, of the door 50--when the pressure lock gate 
69 is closed. And, while not illustrated in the drawings, those skilled in 
the art will appreciated that suitable and completely conventional limit 
switches may be provided which are coupled to a remote warning light or 
other alarm in the cockpit for indicating when the pressure lock gate 69 
is other than fully closed, thus providing an indication to the cockpit 
when the aircraft door 50 is not closed and latched. 
C. Door Latching/Unlatching Mechanism (FIGS. 5-13) 
In order to latch and/or unlatch the aircraft door 50, the manually 
operable internal door handle 58 (as well as the external handle, not 
shown) is coupled to the transversely extending latch torque tube 70 which 
is journaled for rotation in, and extends through, the fore and aft 
continuous door edge members 61,62 by means of a control link 88 coupled 
at its lower end to a torque tube crank 89 splined or otherwise affixed to 
the latch torque tube 70 for rotationally driving the latter; while the 
control link 88 is coupled at its upper end to one end of a bell crank 90 
(FIGS. 9-11) pivotally mounted on the handle box assembly 68 and having a 
laterally projecting cam roller or follower 91 received within cam groove 
82 generally diametrically opposite the cam roller 81 associated with the 
pressure lock gate operating linkage previously described. Referring to 
FIGS. 9 and 10, it will be noted that during rotation of the control 
handle 58 through the initial portion of its rotating cycle--i.e., 
approximately the first 10.degree. of handle rotation--as the cam roller 
81 is moved downwardly and to the left in groove 82 from the position 
shown in FIG. 9 to that shown in FIG. 10, cam roller 91 remains 
substantially equidistant from the axis 85 of the handle/cam rotation and, 
therefore, dwells with bell crank 90 remaining in the same position. 
However, as the handle 58 is rotated further in a counterclockwise 
direction from the position shown in FIG. 5 (with the pressure lock gate 
69 open and the door 50 latched) to that shown in FIG. 7--i.e., through an 
additional angle of about 170.degree.--the profile of the cam groove 82 is 
such that cam roller 91 is moved downwardly and to the left away from the 
axis 85 of handle/cam rotation, thus rotating bell crank 90 in a clockwise 
direction as viewed in the drawings from the position shown in FIG. 10 to 
that shown in FIG. 11, thereby raising control link 88 and causing 
rotation of the latch torque tube 70 in a counterclockwise direction from 
the position shown in FIG. 6 to that shown in FIG. 8. Moreover, during the 
latter portion of door handle 58 movement from the position shown in FIG. 
5 to that shown in FIG. 7, the profile of the cam groove 82 is such that 
the cam roller 81 associated with the pressure lock gate actuating linkage 
remains substantially equidistant from the axis 85 of handle/cam rotation 
and, consequently, dwells with the bell crank 80 remaining stationary as 
the camming mechanism shifts from the position shown in FIG. 10 to that 
depicted in FIG. 11. As a consequence, the pressure lock gate 69 remains 
open. 
While the exemplary form of the invention has herein been illustrated and 
described in conjunction with a camming mechanism having a single cam 
groove 82 and a pair of cam rollers 81,91 received therein, those skilled 
in the art will appreciate that other arrangements can be provided. For 
example, the single cam groove 82 can be replaced with independent cam 
grooves or tracks, each of which can be selectively and independently 
profiled to produce the desired sequential actuation of: (i) the pressure 
lock gate 69; and (ii), the latching/unlatching mechanism. Alternatively, 
the bell cranks 80,90 can be formed with cam tracks which are 
cooperatively engaged with cam followers on the rotatable portions of the 
handle box 68. 
Referring to FIGS. 5 and 12 which depict the aircraft door 50 in the fully 
seated, closed and latched condition, it will be observed that the free 
extremities of the latch torque tube 70 journaled in and extending through 
the continuous door edge members 61,62 have nonrotatably mounted thereon a 
pair of latch cranks 92, each of which include a latch roller 94 received 
in respective ones of fore and aft latch tracks 95 respectively mounted on 
the fore and aft fuselage frame members 54,55. Thus, the arrangement is 
such that as the door handle 58 is moved from the position shown in FIG. 5 
to that shown in FIG. 7, the counterclockwise rotation imparted to the 
latch torque tube 70 serves to rotate the latch cranks 92 in a 
counterclockwise direction from the position shown in FIG. 12 to that 
shown in FIG. 13. Since the latch rollers 94 are mounted in latch tracks 
95 which are fixed to the vertical frame members 54,55 at the fore and aft 
ends of the ingress/egress door openings 51, it will be appreciated that 
as the latch torque tube 70 is rotated, the door 50 will be raised by a 
distance substantially equal to the effective length of the latch cranks 
92--in a practical situation, by a distance of approximately 2 inches. 
Such upward door movement is, of course, permitted because at this point 
in a door opening cycle, the pressure lock gate 69 is open and free to 
move upwardly within the ingress/egress opening from the position shown in 
FIG. 6 to that shown in FIG. 8. Moreover, it has been found that the 
tremendous mechanical advantage available from the linkage described above 
will readily permit opening of iced-over doors 50 by either ground 
personnel or on-board flight attendants having only limited physical 
strength. 
In carrying out the present invention, and as best illustrated in FIG. 12, 
it will be noted that when the aircraft door 50 is fully seated, closed 
and latched, the latch cranks 92 are positioned such that the latch 
rollers 94 are approximately 10.degree. over-center with respect to the 
axis of the latch torque tube 70--i.e., the latch cranks 92, rather than 
extending upwardly along a true vertical, project slightly inboard. As a 
consequence, in the event that any forces attempt to displace the aircraft 
door 50 in an upward direction off the mutually engaged door and fuselage 
pressure stop fittings 71,72, interaction between the over-center latch 
rollers 94 and the upper surface of the latch tracks 95 will--in the 
absence of intentional door unlatching as a result of rotation of handle 
58 and latch torque tube 70 in the manner previously described--serve, via 
cranks 92, to bias the latch torque tube 70 in a clockwise direction as 
viewed in FIG. 12, thus biasing the door 50 in a downward direction into 
its fully seated, closed and latched condition with the door and fuselage 
pressure stop fittings, 71,72 mutually engaged. Althrough not illustrated 
in the drawings, those skilled in the art will appreciated that suitable 
and completely conventional over-travel stops may be provided for limiting 
rotation of the latch torque tube 70 by more than a preselected 
amount--say, for example, approximately 5.degree.--beyond the fully 
latched and fully unlatched positions shown in FIGS. 12 and 13, 
respectively. As a consequence of the foregoing arrangement, together with 
the pressure lock gate system previously described, the aircraft door 50 
of the present invention is provided with an essentially "fail-safe" 
locking system which insures that the door will not come off of its 
mutually engaged door and fuselage pressure stop fittings 71,72 during 
normal in-flight conditions. 
As will be best observed by reference to FIGS. 5, 7, 12 and 13 conjointly, 
it will be noted that the door 50 is provided with lower and upper, fore 
and aft projecting latch pins 96 which are received within inverted, 
generally L-shaped guide tracks 98 and which serve to permit releasable 
latching of the aircraft door 50. Thus, when the door is in a fully seated 
and latched condition such as depicted in FIGS. 5, 6 and 12, the latch 
pins 96 are retained captive within the lower ends of the inverted 
L-shaped guide tracks 98, thereby preventing opening of the door. On the 
other hand, as the door handle 58 is rotated from the position shown in 
FIG. 5 to that shown in FIG. 7, rotation of the latch torque tube 70 
serves to rotate the latch cranks 92 in the manner previously described 
from the position shown in FIG. 12 to that shown in FIG. 13, thus lifting 
the latch pins 96 to the upper end of the inverted L-shaped guide tracks 
98 from the position shown in FIG. 12 to that depicted in FIG. 13. In this 
position, the door 50 may be freely moved out of the ingress/egress 
opening since the latch rollers 94 and latch pins 96 are free to move out 
of the latch tracks 95 and guide tracks 98, respectively, and since the 
door-mounted pressure stop fittings 71 have been raised approximately 2" 
and will, therefore, clear the fuselage-mounted pressure stop fittings 72. 
D. Hinge Assembly 56 and Controllable Translatory Door Motion (FIGS. 1, 2 
and 14-19) 
Turning now to a specific hinge assembly construction of the type embodying 
features of the present invention and as shown in detail in FIGS. 1, 2 and 
14 through 19, it will be noted that the illustrative hinge assembly 56 
includes a relatively large hinge member 99 which, when viewed in plan as 
shown in FIGS. 14-16, is of generally L-shaped configuration, having: (i) 
a relatively short hinge arm 100 mounted at its free extremities in 
vertically spaced brackets 101,102 (FIG. 1) fixedly secured to the forward 
fuselage frame member 54 for rotation about a fixed vertical, or near 
vertical, hinge axis 104; and (ii), an integral, relatively long hinge arm 
105 mounted at its free extremities on links 106,108 (best shown in FIGS. 
17 and 18) pivotally connected to the aircraft door 50 for rotation about 
a second vertical, or near vertical, hinge axis 109 parallel to hinge axis 
104. Thus, the arrangement is such that while hinge member 99 is 
vertically fixed relative to the fuselage frame structure--e.g., relative 
to forward frame member 54--it is hingedly connected thereto for rotation 
about an essentially vertical hinge axis 104. At the same time, the 
aircraft door 50, while hingedly connected in cantilever fashion to the 
free extremity of the hinge member 99 for rotation about a second 
essentially vertical hinge axis 108, is free to move up and down during 
door unlatching and latching operations. That is, assuming the door 50 is 
in a fully seated, closed and latched position, it will be recognized that 
as the door handle--e.g., inner handle 58--is rotated from the position 
shown in FIG. 5 to that shown in FIG. 7, rotational motion is imparted to 
the latch torque tube 70 which, through cooperative engagement between the 
latch rollers 94 on latch cranks 92 and the latch tracks 95 on the forward 
and aft frame members 54,55, serves to lift the door 50 by a distance of 
approximately 2 inches from the position shown in FIG. 6 to that depicted 
in FIG. 8. As the door 50 moves up from a latched position as shown in 
FIG. 17 to an unlatched position as shown in FIG. 18--i.e., as the latch 
torque tube 70 rotates in a counterclockwise direction as viewed in the 
drawings--such vertical motion is accommodated by the links 106,108 which 
are pivotally connected at one end to the door 50 and at their opposite 
ends to the relatively long hinge arms 105 on hinge member 99. 
It is to be noted that during unlatching of the door 50, the weight of the 
door--which is initially supported only by the latch tracks 95 when the 
door is fully seated and latched (see, FIG. 12)--is supported by both the 
latch tracks 95 (FIG. 13) and a load carrying link 110 (FIG. 17) when the 
door is raised and unlatched but prior to opening thereof by movement out 
of the ingress/egress opening 51. To accomplish this, the load carrying 
link 110 is coupled at its lower end to the latch torque tube 70 and at 
its upper end to link 106. Thereafter, when the door 50 is pushed out of 
the ingress/egress opening 51 and the load is no longer supported in whole 
or in part by the latch tracks 92 (FIGS. 7, 12 and 13), the door is 
prevented from dropping by virtue of link 110 which, through link 106 on 
the hinge assembly 56, serves to support the door diretly from the 
fuselage frame member 54 in an elevated position approximately 2 inches 
above the position of the door when closed and fully latched. As best 
illustrated by reference to FIGS. 17 and 18 conjointly, it will be noted 
that link 110 is coupled to link 106 by means of a pin 111 passing through 
the link 106 and through an elongated slot 112 formed in link 110. Thus, 
when the door 50 is fully seated, closed and latched, as shown in FIG. 17, 
the pin 111 resides in the lower end of slot 112 and, consequently, no 
load is carried by link 110; but, rather, the full weight of the door is 
supported by the latch cranks 92, latch rollers 94 and latch tracks 95. 
However, when the door 50 is unlatched and raised as shown in FIG. 18, the 
pin 111 resides in the upper end of slot 112; and, consequently, a load 
supporting path including link 110 is provided for supporting the entire 
weight of the door 50 from the foreward fuselage frame member 54. 
In carrying out the present invention, provision is made for controlling 
the rotational attitude of the aircraft door 50 as it is being shifted 
between fully opened and fully closed positions. To this end, a 
programming mechanism is provided for maintaining the aircraft door 50 in 
a plane essentially parallel to the plane containing the ingress/egress 
opening 51 at all door positions ranging between the fully closed and the 
fully opened positions--i.e., for imparting translatory motion to the door 
as contrasted with rotational motion. In this connection, and as best 
illustrated in FIG. 15, the exemplary programming mechanism includes: (i) 
a bell crank 114 pivotally secured at 115 to the hinge member 99 at the 
juncture between the short hinge arm 100 and the long hinge arm 105; (ii) 
a first control lik 116 pivotally connected at one end to one end of bell 
crank 114 and at its opposite end to a bracket 118 mounted on the forward 
fuselage frame member 54 immediately above hinge brackets 101; and (iii), 
a second control link 119 pivotally connected at one end to the opposite 
end of bell crank 114 and at its opposite end to a bracket 120 secured to 
the door 50. 
The arrangement is such that the short hinge arm 100, first control link 
116, that portion of the bell crank 104 intermediate the control link 116 
and pivot point 115, and the space between the hinge axis 104 and the 
point of pivotal connection between control link 116 and bracket 118, 
define a first essentially perfect parallelogram, here indicated by the 
dotted line 121, at all positions of the door 50, as best shown in FIG. 14 
where the door is fully closed, FIG. 15 where the door 50 is partially 
open, and FIG. 16 where the door 50 is fully open. Similarly, the long 
hinge arm 105, control link 119, that portion of bell crank 114 
intermediate the link 119 and pivot point 115, and the space between hinge 
axis 109 ad the point of pivotal connection between bracket 120 and link 
119, define a second essentially perfect parallelogram, here identified by 
the dash-dot line 122, at all positions of the door 50 as best shown in 
FIGS. 14-16. 
As previously described, during a door unlatching operation, the aircraft 
door 50 is lifted slightly--about 2"--and moves slightly inboard at its 
lower end (Cf., e.g., FIGS. 17 and 18); while during a door latching 
operation, the door 50 moves downwardly about 2" and its lower end moves 
lightly outwardly. Such essentially vertical door movement relative to a 
vertically fixed hinge element 99 is, as previously indicated, readily 
accommodated by virtue of the pivotal connection between the free 
extremity of long hinge arm 102 and the door frame which is provided by 
links 106,108. However, in order for the programming mechanism defined by 
links 116,119 and bell crank 114 to accommodate such relative movement 
between the door 50 and the hinge member 99, provision is preferably made 
for permitting controlled extension of link 119. To this end, link 119 
includes a conventional extension-type spring cartridge assembly 124 which 
maintains link 119 at an essentially fixed predetermined length when the 
door 50 is in its raised position such that the linkage describes a 
perfect parallelogram as indicated by the dash-dot line 122 in FIGS. 
14-16. However, when the door 50 is closed, fully seated, and latched, the 
spring cartridge assembly 124 permits of slight elongation of link 119; 
and, as a consequence, the parallelogram indicated by the dash-dot line 
122 in FIG. 14 will, in fact, be somewhat imperfect as indicated by the 
slope of link 119 depicted in FIG. 2. The provision of the spring 
cartridge assembly 124 thus serves to reduce prelaods in the programming 
mechanism and the tendency of the aircraft door to rotate within the 
ingress/egress cutout 51 in a clockwise direction (as viewed in FIG. 2) 
during latching of the door 50 and/or in a counterclockwise direction 
during unlatching of the door. 
As a consequence of the foregoing construction, as the aircraft door 50 is 
translated from a fully closed unlatched position to a fully opened 
position--i.e., as it moves progressively from the position shown in FIG. 
14 through that shown in FIG. 15 and to that shown in FIG. 16--the hinge 
assembly 56 readily moves around the corner defined by the forward 
fuselage frame member 54; and, those hinge assembly components defining 
the dotted line parallelogram 121--viz., short hinge arm 100, bell crank 
114 and control link 116--assume a nearly lineal configuration, best shown 
in FIG. 16, closely abutting the fuselage forward frame member 54 and 
projecting out of the ingress/egress opening 51 along a line essentially 
normal thereto. As will be noted upon inspection of FIGS. 16 and 19, the 
foregoing arrangement results in an ingress/egress opening 51 which is 
essentially devoid of hinge elements and actuating and/or control 
mechanisms projecting into the rectilinear boundaries of the opening 51 
when the door is fully open; and, further, there is no need for overhead 
control link assemblies. As depicted in the drawings, the hinge assembly 
56 may be provided with an additional handle 125 which can be used by 
either an on-board flight attendant or by ground personnel to assist in 
initiating door closing movement. 
Moreover, although not illustrated or described herein in considerable 
detail, those skilled in the art will appreciate that aircraft doors used 
for passenger ingress/egress purposes are generally relatively heavy, 
normally weighing up to several hundred pounds or more; and, as a 
consequence, it is generally desirable to provide a snubber mechanism 
which can take any of several well-known conventional forms for retarding 
or braking the movement of the door and preventing damage due to inertial 
movement. For example, as shown diagrammatically in broken lines in FIG. 
15 only, a hydraulic snubber mechanism 126 may be provided having one end 
pivotally connected to a bracket 128 secured to the forward inboard edge 
of the door frame and its opposite end secured to the relatively long 
hinge arm 105. In those instances where the snubber mechanism 126 is 
intended to function solely as a snubber, it will commonly employ a single 
piston (not shown) for transferring hydraulic fluid through a cylinder 
orifice so as to provide a controlled retarding force irrespective of the 
direction of door movement. In those instances where it is desirable to 
employ the snubber mechanism 126 to provide power assist and to aid in 
door opening under emergency conditions, the snubber mechanism 126 may 
include tandem pistons (not shown)--one for snubbing utilizing hydraulic 
fluid flowing through a cylinder orifice; and, one employing compressed 
gas or the like for powering the door to the open position. Such emergency 
power-assist door operation can be initiated in any suitable and/or 
conventional manner which forms no part of the present invention and is 
not, therefore, either illustrated or described in detail herein. Suffice 
it to say that persons skilled in the art will appreciate that a POWER-ON 
switch (not shown) can be provided for permitting electrical activation of 
the power-assist system by an on-board flight attendant; or, since most 
carriers prefer non-electrical mechanical actuation systems which are less 
prone to malfunction, the cam groove 82 (FIGS. 9-11) can be profiled to 
permit an additional 15.degree. movement of the interior door handle 
58--i.e., an additional counterclockwise rotation of handle 58 
approximately 15.degree. beyond the door unlatched position shown in FIG. 
7--without further rotation of the latch torque tube 70. Under normal 
non-emergency operating conditions, an adjustable stop (not shown) would 
be provided for preventing such additional rotation of handle 58 during a 
door opening operation; but, when the arming lever 60 (FIGS. 1 and 2) is 
shifted to the Armed position for activating the emergency evacuation 
system 59, such motion can be used to move the adjustable stop (not 
shown), thereby permitting the on-board flight attendant to rotate the 
interior handle 58 an additional 15.degree. to mechanically initiate a 
power-assist operation through any suitable linkage (not shown) 
interconnecting the handle 58 and tandem piston snubber mechanism 126. 
E. Emergency Evacuation System 59 (FIGS. 20-25) 
In order to comply with both federal regulations and the specifications of 
commercial carriers, aircraft doors 50 of the type utilized to permit 
passenger ingress and/or egress to and/or from commercial aircraft are 
normally required to include a deployable, and generally inflatable, 
emergency evacuation system which can be deployed to permit rapid 
evacuation of the aircraft under emergency conditions. As previously 
indicated, such a system has been generally depicted at 59 in, for 
example, FIGS. 1, 2 and 20-25. As best shown in FIGS. 21 and 22, the 
exemplary emergency evacuation system 59 includes a slide pack 129 which 
is carried by, and releasably secured to, a slide pack board 130 in any 
suitable manner (not shown in the drawings). For example, the slide pack 
129 may be releasably secured to the slide pack board 130 by means of: (i) 
magnets; (ii) fabric fasteners--for example, a male-type fabric fastener 
element secured to one of the slide pack 129 or slide pack board 130, and 
a female-type fabric fastener secured to the other of the two components; 
(iii) bayonet-type fittings; (iv) a load-carrying support flange or lip on 
the lower edge of the slide pack board 130; and/or (v), combinations of 
two or more of the foregoing. 
Basically, the arrangement is such that when the emergency evacuation 
system 59 is Disarmed, the slide pack 129 and slide pack board 130 move as 
a unit with the aircraft door--i.e., as the door 50 is unlatched and 
raised approximately 2" in the manner previously described, the slide pack 
129 and slide pack board 130 are also raised approximately 2"; and, as the 
door 50 is opened and moved from the position shown in FIG. 14 to that 
shown in FIG. 16, the slide pack 129 and slide pack board 130 move out of 
the ingress/egress opening 51 with the door. On the other hand, under 
emergency evacuation conditions when the door 50 is opened while the 
emergency evacuation system 59 is Armed, provision must be made for 
separating the slide pack 129 from the slide pack board 130 as the door 50 
is opened, thereby permitting the slide pack 129 to move outwardly through 
the ingress/egress opening 51 and deployment of the slide 131 carried 
therein as best shown in FIG. 25. 
To this end, and with reference first to FIGS. 20 and 21 conjointly which 
are illustrative in solid lines of operation under Disarmed conditions, it 
wil be noted that the slide pack board 130 (and, therefore, the slide pack 
129) is supported from the door frame structure by a pair of upper links 
132 and a pair of lower links 134, each having one end pivotally secured 
to the slide pack board 130 and its opposite end pivotally secured to the 
door 50. Arming lever 60 is provided with a crank arm 135 (best 
illustrated in FIG. 20) having its free end connected to the upper end of 
an upper control link 136 which, in turn, is connected at its lower end to 
one end of a bell crank 138 pivotally mounted on a trasverse door beam 64. 
The opposite end of bell crank 138 is coupled to the upper end of a second 
lower control link 139 having its lowermost end coupled to a crank arm 140 
fixedly mounted on a transversely extending slide pack torque tube 141 
journaled for rotation in brackets 142 carried by a transverse door beam 
64 located somewhat above the bottom of the door and intermediate the 
points of pivotal connection of the upper and lower pairs of links 132, 
134 to the door. A pair of actuating arms 144 are mounted on slide pack 
torque tube 141 for rotation therewith and are positioned to engage and 
support respective ones of the pair of upper pivotal support links 132 
when the emergency evacuation system 59 is in the Disarmed condition. 
Under these conditions, as the door 50 is unlatched and moved upwardly a 
distance of approximately 2" in the manner previously described, the 
actuating arms 144 engage the undersides of pivotal links 132 as shown in 
FIG. 21 and prevent pivotal movement thereof; and, as a consequence, the 
slide pack board 130 and the slide pack 129 releasably secured thereto 
also move upwardly a distance of approximately 2" to a position where the 
emergency evacuation system 59 is free to move outwardly through the 
ingress/egress opening 51 with the door 50 as the latter is translated to 
its fully open position. 
In carrying out this aspect of the present invention, one end of the slide 
131 (best shown in FIG. 25) is secured to a girt bar 145 which, prior to 
separation of the slide pack 129 from the slide pack board 130, is carried 
in a pair of inwardly facing, C-shaped, girt bar support brackets 146 
mounted on and extending below the lower edge of the slide pack board 130 
with the girt bar 145 extending beyond the fore and aft ends of the slide 
pack 129 and being received within fore and aft floor-mounted girt bar 
fittings 148. Thus, the arrangement is such that when the emergency 
evacuation system is Disarmed--i.e., when the control links are in the 
position shown in FIG. 21--as the door 50 is unlatched and moved upwardly 
a distance of approximately 2", the slide pack board 130 also moves 
upwardly due to coaction of the actuating arms 144 and the upper pivotal 
links 132 which are restrained from pivotal movement. Consequently, the 
girt bar 145 carried in the support brackets 146 on the slide pack board 
130 is lifted upwardly a distance of approximately 2" which is sufficient 
to permit the girt bar 145 to move freely outward with the door 50 through 
the ingress/egress opening 51 with the girt bar 145 clearing and passing 
freely over the floor fittings 148. 
In normal operation, the on-board flight attendant will Arm the emergency 
evacuation system 59 prior to departure of the aircraft from the terminal 
departure gate; and, the system will remain Armed until such time as the 
aircraft is parked at the arrival gate. To accomplish this, the on-board 
flight attendant need only manually turn the arming lever 60 (in a 
clockwise direction as viewed in FIG. 20) through an angle of 
approximately 45.degree., thus rotating crank 135 from the solid line 
position shown in FIG. 20 to the dash-dot position shown. This serves to 
shift the upper control link 136 downwardly from the position shown in 
FIG. 21 to that shown in FIG. 22; and, as a consequence, bell crank 138 is 
pivoted in a counterclockwise direction, shifting lower control link 139 
downwardly from the position shown in FIG. 21 to that shown in FIG. 22 and 
thereby rotating the slide pack torque tube 141 in a counterclockwise 
direction as viewed in the drawings. As the torque tube 141 rotates, the 
actuting arms 144 splined or otherwise affixed thereto, are shifted from 
the position shown in FIG. 21 (where they engage the undersurface of 
pivotal links 132) to that shown in FIG. 22 (where the actuating arms no 
longer impede pivotal movement of the links 132). Therefore, as the 
aircraft door 50 is unlatched in the manner previously described and moved 
upwardly a distance of approximately 2" from the position shown in FIG. 22 
to that shown in FIG. 23, the weight of the slide pack 129 and slide pack 
board 130 (which are mounted in cantilever fashion on the inboard ends of 
pivotal links 132, 134) serves to maintain the slide pack 129 and slide 
pack board 130 in their lowermost positions, with the girt bar 145 still 
positioned within the floor fitting 148; and, this is accomplished by 
virtue of the ability of the pivotal links 132, 134 to freely pivot (in a 
clockwise direction as viewed in FIGS. 22 and 23) about their points of 
pivotal connection to the door frame structure. Moreover, as the door 50 
moves upwardly, the clockwise rotational motion of the links 132, 134 
serves to shift the links from the position shown in FIG. 22 to that shown 
in FIG. 23 when the door 50 is fully unlatched and raised; and, 
consequently, the girt bar 145 is moved slightly outboard where it is 
captively retained by the floor fittings 148 and prevented from moving 
upwardly. Thus, as the door 50 is progressively translated out of the 
ingress/egress opening 51 from a closed but raised position as shown in 
FIG. 23 to a partially open position (FIG. 24) and, ultimately, to a fully 
open position (FIG. 25), the girt bar support brackets 146 carried by the 
slide pack board 130 move outwardly away from the girt bar 145 which is 
now captively retained in the floor fittings 148, thus producing 
sufficient force to separate the slide pack 129 from the slide pack board 
130 and permitting deployment and inflation of the slide 131 in an 
otherwise conventional manner. 
Those skilled in the art will appreciate that there has herein been 
disclosed a simple, yet highly effective, mechanism for hingedly mounting 
relatively heavy aircraft passenger doors on the frame structure of the 
aircraft fuselage in such a manner that an outwardly opening plug-type 
door can be easily moved out of and into the ingress/egress cutout opening 
in an aircraft fuselage by either on-board flight attendants or ground 
personnel without having to turn the door inside out and without having to 
move the heavy door in an uphill direction during any portion of door 
opening and/or closing motion; yet, wherein the ingress/egress cutout 
opening is essentially devoid of inwardly projecting hinge and/or 
actuating mechanisms or components which tend to reduce the effective 
width and/or height of the unimpeded passenger access opening in the 
aircraft. Rather, the door, which is supported in cantilever fashion on a 
hinge assembly for movement about a vertical or near-vertical hinge axis, 
is moved into and out of the ingress/egress cutout opening with 
translatory motion with the various actuating and hinge mechanism free to 
move around the corner defined by a vertical frame member bounding the 
cutout opening to positions outboard of the fuselage structure and either 
forward or aft of the cutout opening when the door is fully open.