WO2003033345A2

WO2003033345A2 - Apparatus and method for aircraft cockpit security

Info

Publication number: WO2003033345A2
Application number: PCT/US2002/029225
Authority: WO
Inventors: Alvin S. Levenson
Original assignee: Levenson Alvin S
Priority date: 2001-10-11
Filing date: 2002-09-13
Publication date: 2003-04-24
Also published as: AU2002336530A1; WO2003033345A3

Abstract

A retrofit secure cockpit door is intended primarily for a passenger aircraft. The door is bullet-resistant and fire retardant and is provided with a patented Z-bar lock which will withstand a force of approximately 1,000 pounds and thus will allow the door to be opened safely, so that the pilot or copilot may receive a coffee or other item from the flight attendant. The upper portion of the door has an elongated, vertically-oriented bullet-resistant transparent window. This window is always substantially aligned with the center of the main aisle in the passenger compartment, regardless of the configuration of the bulkhead separating the cockpit from the passenger compartment, and regardless of the disposition of the cockpit door mounted loin the bulkhead. The lower portion of the secure cockpit door has a horizontally-oriented slot for receiving a meal tray from the flight attendant. This slot is a bullet-resistant plate mounted on the inside of the door and secured thereto by a manually-releasable lock. The bulkhead surrounding the door is retrofitted with the bullet-resistant, flame-retardant material.

Description

APPARATUS AND METHOD FOR AIRCRAFT COCKPIT SECURITY

FIELD OF THE INVENTION

The present invention relates to improved security of the cockpit of an aircraft, and more particularly, to the substantially improved cockpit security of regularly-scheduled commercial aircraft as well as chartered and cargo-carrying aircraft.

BACKGROUND OF THE INVENTION It has been approximately one (1) year since "9-11" and despite the urgency of the situation, and the distinct possibility (if not likelihood) that this enormous defeat may be repeated in the war initiated by the terrorists against us, no one to date has come up with a practical readily-available, relatively low-cost solution to this clear and present danger.

The "solutions" offered to date are as follows:

(1) Arming the pilots. This is a ridiculous solution. The passengers do not want a shootout at an "OK CORRAL" at 30,000 feet.

(2) Providing armed air marshals. Again, there is the frightening possibility of a shoot- out. Moreover, it has been estimated that around 10,000 trained, well-paid air marshals would be working in shifts just to cover all of the flights within (or from) the United States. Moreover, each armed air marshal occupies a passenger seat and takes it out of the potential revenue stream. All of this is not only very costly, but it will take a relatively long time to implement such a project; hence, this concept is basically impractical. (3) Improved security at the airport. While well intentioned, this solution has not been successful. Studies and other "test cases" have illustrated that the screening process has been quite porous and of a little real value. At the same time, it has substantially aggravated the passengers and caused them unnecessary delays.

(4) Shooting down the hijacked airplane. This drastic step is prevented by the cockpit integrity so that the military will not be called upon to shoot down an unarmed plane carrying innocent passengers.

As a result, security has not been improved to the extent necessary, passengers are reluctant to fly, and the airlines are going bankrupt.

These so-called "solutions" to the problem are merely "feel good"and "PR" solutions and, if anything, have had an adverse effect on the flying public and, hence, the airline industry.

Since the airline industry represents approximately 10% of the gross national product, there is a major impact on support industries such as hospitality and the overall economy of the nation. There is a need for a timely, cost-effective solution to maintain the integrity of the cockpit for the safety, security and peace of mind of the aircraft crews, the passengers and the general public.

BRIEF SUMMARY OF THE INVENTION The primary focus of the present invention is not so much preventing a bomb from getting on the airplane; it's preventing the airplane from being turned into a bomb.

The solution is to maintain cockpit security at all times and to be able to open the cockpit door, safely.

The terrorist/skyjacker must never be allowed access to the cockpit and must never be able to gain control of the aircraft.

Accordingly, it is the primary object of the present invention to provide a bullet-resistant, fire-retardant cockpit door, one which is provided with a patented Z-bar lock, which will withstand a force of around 1,000 pounds, yet will allow the cockpit door to be opened, safely and sufficiently to allow the pilot to receive a coffee or other item from the flight attendant . It is another object of the present invention to provide a bullet-resistant, fire-retardant transparent window within the secure cockpit door. The purpose, first, is for the pilot, copilot and/or flight engineer to see what is going on in the passenger compartment of the aircraft and, second, and even more important, to allow the passengers to see that the cockpit is secure and that the aircraft cannot be skyjacked and crashed by a terrorist into a building. It is still another object of the present invention to provide a secure cockpit for the flight crew. The cockpit is reconfigured to provide a toilet area and a storage area. The cockpit door has a window therein. The cockpit door and window are made from bullet-resistant materials. The door has a locking means, the Z-bar, which resists intrusion but can be opened, safely. The door also has a bullet resistant slot for providing meals to the pilot and copilot. The bulkhead surrounding the door is covered with the bullet-resistant material.

Preferably, the bullet-resistant, fire-retardant window is substantially aligned with the center aisle of the passenger compartment in the aircraft regardless of the configuration of the door and its position with respect to the bulkhead which separates the passenger compartment from the cockpit. Preferably, the cockpit door and the bulkhead surrounding the door, is made from a distinctive material, structurally and appearance-wise, and this is another important feature and advantage of the present invention, namely, in first serving as a deterrent effect to the terrorist/skyjacker and, second, in the perception of the passengers, even as they enter the aircraft, that their flight cannot be seized by a terrorist/skyjacker and his or her accomplices and flown like a guided bomb into a skyscraper or stadium resulting in the deaths of thousands of innocent people or shot down by our military aircraft.

In accordance with the teachings of the present invention, there is herein illustrated and described, a secure cockpit door for a scheduled passenger, chartered or cargo-carrying aircraft. This secure cockpit door includes a bullet-resistant, fire retardant door mounted within the bulkhead which separates the cockpit from the passenger compartment. The bullet-resistant, fire-retardant door has a manually-manipulatable locking means which will enable the pilot or copilot to open the door, safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential terrorist/skyjacker from crashing through the secure bullet-resistant, fire-retardant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened. The secure cockpit door further has a bullet-resistant, fire retardant transparent window securely mounted therein. This bullet-resistant, fire-retardant transparent window is substantially aligned with the center aisle of the passenger compartment of the aircraft; such that the pilot or copilot, usually while standing to open the door, can see who is on the other side of the door and determine whether there are any problems within the passenger compartment; and such that the passengers within the aircraft can see through the bullet-resistant, fire retardant transparent window, be assured that the cockpit is totally secured against a potential terrorist/ skyjacker, and know that the aircraft cannot be used as a manually-guided missile. Because of the urgency of the situation, the secure cockpit door preferably comprises a retrofit secure cockpit door intended to replace the conventional factory-installed non-secure door and to accommodate different aircraft configurations.

In the preferred embodiment of the present invention, the manually-manipulatable locking means comprises: a Z-bar door security system providing (1) entry, (2) inspection, and (3) dead bolt locking modes of operation, respectively, and including a latch plate for mounting on the frame of the door, said latch plate having a vertical slot for receiving a latch bar; a Z-bar latch assembly including (1) a base plate for securing to the edge of the door in juxtaposition to said latch plate, (2) an intermediate link pivoted to said base plate at the front edge of said base plate adjacent the door, and (3) a mode selection and latching assembly pivotally mounted to said intermediate link at the front edge of said intermediate link; said mode selection and latching assembly including a rotatably mounted control knob and a high strength latch member, and camming means for linearly advancing said latch member into engagement with said slot in said latch plate as said control knob is rotated, to implement the inspection and the dead bolt modes of operation; means secured to said control knob for securing the base plate, the intermediate link and the mode selection and latching assembly together while the latch member is extended into engagement with the latch plate, thereby providing the dead bolt mode of operation; and said camming means including camming surfaces permitting further rotation of said control knob without retracting the latch member to implement the dead bolt mode of operation.

In one embodiment, this Z-bar lock will withstand a force of approximately 1,000 pounds.

Preferably, the bullet-resistant, fire retardant secure cockpit door has an upper portion and a lower portion, and the bullet-resistant, fire-retardant transparent window comprises an elongated and vertically-oriented window in the upper portion of the cockpit door.

Moreover, the lower portion of the bullet-resistant, fire-retardant door has a horizontally- oriented slot formed therein, whereby the pilot or copilot may receive a meal tray. A bullet- resistant cover is provided for the horizontally-oriented slot, and this bullet-resistant cover is mounted on the inside of the cockpit door and is retained by a manually-releasable latch.

These and other objects of the present invention will become apparent from a reading of the following specification taken in conjunction with the enclosed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a pictorial view of a typical jet aircraft, in this case a 747, which is exemplary of the prior art within which the present invention may be applied.

Fig. 2 is a cross-section thereof, taken along the lines 2-2 of Fig. 1 and enlarged in scale, and illustrating a conventional non-secure cockpit door. Fig. 3 is a cross-section thereof, taken along the lines 3-3 of Fig. 2, and showing an exemplary plan view of the cockpit door in the bulkhead which separates the cockpit from the passenger compartment in the aircraft.

Fig. 4A-4F are pictorial sequence views, somewhat schematic, and showing the clear and present dangers existing in the prior art.

Fig. 4A illustrates the flight attendant knocking on the cockpit door. Unknown to the pilot, the flight attendant is under the control of the terrorist.

Fig. 4B illustrates the pilot lifting the bar (or other prior art lock) on the door.

Fig. 4C illustrates the pilot opening the door. Fig. 4D illustrates the terrorist crashing into the cockpit.

Fig. 4E illustrates terrorist/skyjacker killing the pilot (and copilot) and gaining control of the aircraft.

Fig. 4F illustrates the terrorist/skyjacker deliberately crashing the aircraft into a skyscraper. Fig. 5 corresponds to Fig. 2, but illustrates the secure cockpit door of the present invention.

Fig. 6 is a cross-section thereof, taken along the lines 6-6 of Fig. 5.

Fig. 7 is a detail cross-section, thereof taken along the lines 7-7 of Fig. 6 and enlarged in scale, and showing the mounting of the bullet-resistant, fire-retardant transparent window within the secure cockpit door of the present invention.

Fig. 8 is a further detail cross-section, taken along the lines 8-8 of Fig. 6 and enlarged in scale, and showing the mounting of the secure cockpit door within the bulkhead in the aircraft.

Fig. 9 is a still further cross-section, taken along the lines 9-9 of Fig. 6 and enlarged in scale, and showing the hinges on the secure cockpit door of the present invention. Fig. 10-25 illustrate the preferred locking means of the present invention.

Fig. 10 is a fragmentary perspective view of a door jamb and a door showing an embodiment of the Z-bar security system.

Fig. 11 is a plan view of the latch plate shown in Fig. 10.

Fig. 12 is an end view of the latch plate. Fig. 13 is a side elevational view of the Z-bar latch assembly shown in the fully extended position.

Fig. 14 is a length- wise sectional view of the Z-bar latch assembly.

Fig. 15 is a plan view of the mode selection and latching assembly. Fig. 16A is a sectional view of the control knob taken along the lines 16A-16A of Fig. 15 showing the latch pin in engagement with an indentation.

Fig. 16B is a sectional view of an inner surface of the control knob taken along line 16B- 16B of Fig. 15 and showing a camming groove and groove indentation.

Fig. 17 is a cross-sectional view of the Z-bar latch assembly showing the mode selection and latching assembly and the intermediate link locked to the base plate.

Fig. 18 is a bottom view of the base plate showing the mode selection and latching assembly and the intermediate link latched to the base plate.

Fig. 19 is a top view of an indicator plate showing the mode selection indications.

Fig. 20 is an exploded side view of the latch plate and cylindrical sleeve showing a second embodiment of the invention.

Fig. 21 is a bottom view of the top cap and handle of the second embodiment, as seen from the line 21-21 of Fig. 20.

Fig. 22 is a cross-section of the cylindrical sleeve taken along the line 22-22 of Fig. 20.

Fig. 23 is a sectional view of the latch plate taken along the lines 23-23 of Fig. 20. Fig. 24 is a top view of the bottom cap taken along the lines 24-24 on Fig. 20.

Fig. 25 is atop view of the second embodiment of the Z-bar door security system shown in partial cross-section showing the system in the latched position and the dead bolt cylinder in the latch plate assembly rotated to the locked position.

Fig. 26 is a pictorial (somewhat schematic) view of the inside of the cockpit, showing the pilot standing up to open the secure cockpit door of the present invention, and further showing that the pilot can see the flight attendant through the transparent bullet-resistant, fire-retardant window in the secure cockpit door.

Fig. 27 is a further pictorial view, corresponding substantially to Fig. 26, but showing the pilot opening the secure cockpit door to receive a cup of coffee from the flight attendant. Fig. 28 is a still further pictorial view, showing a terrorist/skyjacker jumping up from his first-class seat and attempting, without success, to crash through the secure cockpit door which is equipped with the patented Z-bar lock (the preferred locking means of the present invention).

Fig. 29 is a pictorial view of the slot in the secure cockpit door, as viewed from inside the cockpit, and showing the pilot releasing the latch on the bullet-resistant, fire-retardant hinged cover on the slot.

Fig. 30 is a further pictorial view, corresponding substantially to Fig. 27, but showing the pilot taking the meal tray slipped by the flight attendant through the slot in the secure cockpit door, and also receiving a beverage through the limited opening of the secure cockpit door. Figs. 31 A-31 C and Figs. 32A-32B illustrate that the bullet-resistant, fire-retardant window is substantially centered with respect to the main aisle in the passenger compartment of the aircraft.

Fig. 31 A shows the window centered in the secure cockpit door.

Fig. 3 IB shows the window repositioned within the secure cockpit door and to the right therein (as viewed from the passenger compartment) so that the window is still substantially centered with the aisle to compensate for the door being shifted to the left within the bulkhead.

Fig. 31C corresponds substantially to Fig. 3 IB, but shows the window shifted to the left so that, again, the window is substantially aligned with the passenger aisle.

Fig. 32A is a cross-section, taken along the lines 32A-32A of Fig. 31 A. Fig. 32B is a cross-section, taken along the lines 32B-32B of Fig. 3 IB.

Fig. 32C is a cross-section, taken along the lines 32C-32C of Fig. 31C.

Fig. 33 is a pictorial view, showing the test firing of a 9mm automatic pistol into the secure cockpit door of the present invention.

Fig. 34 is a plan view of a section of the secure cockpit door of the present invention after a "357" bullet had been fired into it and showing that while the secure cockpit door had cracks in it, nevertheless, the bullet was prevented from passing through the door and into the cockpit.

Fig. 35 is a section of the window in the secure cockpit door, showing how two "357" bullets were embedded in the window but did not pass through. Fig. 36 is an alternate embodiment of the present invention, wherein two first-class seats have been taken out of passenger compartment and replaced, respectively, with a toilet and a storage locker for the pilot and copilot (and a flight engineer, if necessary) so that the crew in the cockpit never has to leave the cockpit during the flight of the aircraft. Fig. 37 is a perspective view of the passenger compartment showing the secure door and the secure bulkhead of the present invention.

Fig. 38 is a cross-section thereof, taken along the lines 38-38 of Fig. 37. DESCRIPTION OF THE PREFERRED EMBODIMENTS GENERAL With reference to Figs. 1-3, a typical passenger jet aircraft A is shown (in this case a

Boeing 747) having a bulkliead B separating the cockpit C from the passenger compartment PC, the bulkhead B being provided with a conventional cockpit door D (which, of course, is totally non-secure).

As a side note, the inventor's colleague noted that on his recent trip from the East Coast to the West Coast, the pilot (and copilot) opened the conventional non-secure cockpit door twelve times on the way out and eight times on the way back. That's twenty opportunities for terrorist(s)/ skyjacker(s) on a suicide mission to crash into the cockpit, take control of the aircraft, and fly it into a skyscraper, stadium, government building (or what have you).

With reference to Figs. 4A-4F, it will be appreciated that it is relatively easy for even just a single terrorist/skyjacker X to overpower the flight attendant FA, crash through the door D, kill the pilot P and copilot CP, take control of the aircraft A, and crash it into a skyscraper S (Fig. 4F).

With reference to Fig. 5, and in accordance with the invention, a secure cockpit door 200 is installed within the bulkhead B of the aircraft A. Preferably, the secure cockpit door 200 of the present invention may be quickly and conveniently installed, as a retrofit.

There are approximately six thousand commercial aircraft (scheduled passenger flights plus chartered plus cargo) normally operating in the United States. Based upon present cost estimates, approximately two retrofit secure cockpit doors 200 can be provided, and at a one- time investment in security, for the annual cost of just one air marshal. Moreover, approximately ten thousand armed air marshals will be required working in shifts (just for flights within the United States) and it would take several (if not many) years to recruit, train and dispatch this "army" of air marshals to cover the current fleet of aircraft. In contrast, this fleet of aircraft in the United States could be retrofitted with the secure cockpit door 200 of the present invention (and more than likely) within just one year. We are in an urgent situation, and sensible actions must be taken immediately to prevent another catastrophe.

With this in mind, and with further reference to Figs. 6-9, the secure cockpit door 200 of the present invention is provided with a locking means 201, preferably comprising a patented Z- bar lock (as herein described in detail). The secure cockpit door 200 is bullet-resistant and fire- retardant and is further provided with a bullet-resistant, fire-retardant transparent window 202 in the upper portion 200A of the door 200. A slot 203 for a meal tray is included in the door 200. The bulkhead B surrounding the door 200 is retrofitted with the bullet-resistant, flame retardant material thus protecting the pilots and the control panel.

In a preferred embodiment, the secure cockpit door 200 of the present invention is made of MICARTA® , a registered trademark of (and commercially available from) Micarta Industrial

Laminates, 304 Hoover Street, Hampton, South Carolina 29924, U.S.A. Preferably, the material of the door 200 is a MICARTA^® BRASS™ bullet-resistant, fiberglass laminate. It is "level 3" and will withstand a forty-four caliber slug. It is primarily intended for use in bullet-resistant armored (cash) trucks (as in Dunbar trucks), architectural and building projects. Bullets fired point blank into the MICARTA^® are captured by the material and do not penetrate through the material.

It will be appreciated, of course, that other bullet-resistant or bullet-proof materials may be employed consonant with the teachings of the present invention. One example is "DYNEEMA" fibers, which is available from DSM High Performance Fibers B. V. , Eisterweg 3 6422 PN, Heerlen, Netherlands.

The bulkhead B surrounding the door frame also is covered with a layer of the same bullet-resistant material which is mechanically attached. This provides additional protection to the cockpit by preventing a potential terrorist/ skyjacker from firing a weapon around the door to harm the pilot, copilot or controls of the airplane. Moreover, and of further significance, the MICARTA^® BRASS™ has a distinctive "woven" copper-like finish or appearance which is readily noticed by the passengers and, of course, by the intended terrorist/skyjacker. Thus, the passengers "comfort level" is substantially enhanced while the very appearance of the material itself serves as a deterrent to a potential terrorist/skyjacker.

Preferably, the bullet-resistant transparent window 202 is elongated and vertically- oriented and is made of a LEXGARD^® MP-750 laminate. It is a "level 3" and will withstand a forty-four caliber plug. It is a three-ply LEXAN^® polycarbonate and acrylic laminate primarily developed for security protection (but not, significantly, ever suggested for use as a window in a secure cockpit door). LEXGARD^® and LEXAN^® are registered trademarks of GE and the preferred LEXGARD^® laminate MP-750 is commercially available from GE Plastics Structured Products, a division of General Electric Company located at One Plastics Avenue, Pittsfield, Massachusetts 01201.

A lower portion 200B of the secure cockpit door 200 of the present invention is further provided with a horizontally-oriented slot 203 so that a meal tray may be slipped therethrough

(as hereinafter described in detail).

The bullet-resistant fire retardant transparent window 202 is mounted within the secure cockpit door 200 by an "H-shaped" cross-sectioned bracket 204 (preferably of aluminum or other lightweight strong material) by means of screws 205 or other suitable means (Fig. 7). The peripheral edges 206 of the secure cockpit door 200 have a U-shaped seal or a frame 207, preferably of aluminum, secured thereto (Fig. 8). The secure cockpit door 200 is also provided with suitable hinges 208 for mounting the door 200 within the bulkhead B. The retrofitting of existing cockpit doors

One of the many features and advantages of the present invention is the ability to readily retrofit the cockpit doors of the existing aircraft. All a respective airline has to do is to provide the drawings, dimensions and tolerances of a respective bulkhead and the cockpit door therein for one of its type of aircraft, and a retrofit secure cockpit door 200 may be quickly produced, shipped to the airline's preferred destination, and easily and conveniently installed by the airline's maintenance personnel. Only a very minimum amount of time and labor is required, thereby effecting a substantial cost-savings. Retrofitted doors can be available for shipping within 30 days of receipt of an order. Alignment of the bullet-resistant window 202

As shown in Figs. 31 A-31C and 32A-32C, the bullet-resistant window 202 in the secure cockpit door 200 is always substantially aligned (centered) with respect to the main aisle 209 in the passenger compartment of the aircraft, regardless of the configuration of the bulkhead B and the location of the secure cockpit door D therein. Thus, the pilot P or copilot CP can always see who is on the other side of the secure cockpit door 200 and know what is going on in the passenger compartment PC and, equally as important, the passengers and flight attendants can readily see that the cockpit C is secure, and that the aircraft A cannot be taken over by a terrorist/skyjacker. This is another one of the many features and advantages of the present invention.

The preferred locking means 201

As disclosed and claimed in the inventor's own patent, no. 5,244,240 issued on September 14, 1993, the disclosure and claims of which are incorporated herein and as hereinafter set forth, there are three parts to this description of the preferred locking means 201 of the present invention. The first part is a detailed definition of the components that make up the preferred locking means 201. The second part describes how the preferred locking means 201 operates in each of its three modes: free-opening, inspection, and dead bolt. Finally, the third part describes a second embodiment of the preferred locking means 201 that adds additional security.

I. Components of the preferred locking means

A Z-bar door security system is composed of four major components: the base plate, the intermediate link, the mode selection and latching assembly, and the latch plate. a. The Base Plate

Figs. 10 - 19 illustrate an embodiment 20 of the Z-bar security system. Fig. 10 illustrates each of the four major components of the system, including the base plate.

Base plate 22 comprises base 42 which has suitable screwholes with screws 63 mounted therein for secure attachment of base 42 onto door 24. Base plate 22 has upturned flange edges 36. These flange edges have a pivot pin hole at the end of the base toward the door edge, and pivot pin 48 extends through this hole. A bias spring 46 is coiled around pivot pin 48 and bears at one end onto base 42. Base plate 22 further comprises an aperture 44, through which locking flange 66 (Fig. 14) can pass. b. The Intermediate Link Intermediate link 38 has at one end a pair of flanges 70 through which pivot pin 48 passes. Intermediate link 38 also has downturned, tapered flange edges 68. The narrow end of tapered flanges 68 begins near the flanges 70 and increases in width along the length of intermediate link 38. The wide end of each of the flanges includes an aperture 72 (Fig. 14) through which passes pivot pin 74. c. The Mode Selection and Latching Assembly

Mode selection and latching assembly 40 has a control knob 54, which includes a mode indicator including a view window 56 and symbols 58 (Fig. 19). A central post has three parts of different diameters, including outer portion 76 (Fig. 14) embedded in control knob 54, portion 78, which passes through washer 80, and portion 82, at the end of which is flange 66. Mode selection and latching assembly 40 also has a T-shaped latch bar 60, comprised of a long neck portion 62 and a relatively narrower crossbar 64 at the outer end thereof. Latch bar 60 is positioned in channel 116 (Fig. 17), along which the latch bar can slide. Opening or slot 84 (Fig. 15) in the long neck portion 62 of latch bar 60 allows control knob post 78 to pass through. A portion of control knob 54 acts as a camming means which drives latch bar 60 along channel 116. Control knob 54 has a groove 113 consisting of groove segments 86 and 88. Groove 112 overlies an assembly consisting of pin 104, spring 106 and sleeve 114, as shown in Figs. 15 and 6A. Sleeve 114 passes through latch bar 60. The bottom portion of spring 106 rests along the top of channel 116. Pin 104 is situated inside of sleeve 114 and is biased into groove 118 by spring 106. As control knob 54 rotates, pin 104 travels along groove 118. When pin 104 travels along groove segment 88, the contour of the groove pushes latch 60 either forward or backward, depending on the direction of rotation of the control knob. When pin 104 travels along groove segment 86, the contour of the groove does not affect the position of latch 60, and permits rotation of the knob and locking control flange 66 without shifting the position of the latch. Groove 118 has indentations 112 that serve as stopping points or detents for pin 104. The location of each indentation 112 corresponds to the proper control knob position for the free-opening, inspection, and dead bolt modes of operation. When pin 104 reaches a groove indentation 112, spring 106 forces pin 104 into the indentation. The user must apply additional rotational force to dislodge pin 104 from the indentation 112 in which it is located. d. The Latch Plate

Latch plate 30 comprises base 26 which has suitable screwholes in which screws 85 are mounted for secure attachment of base 26 onto door jamb 28. Latch plate 30 is rolled into a substantially cylindrical configuration 32 at one end. Base 26 has a "t"-shaped aperture 34 such that the lower portion of the "t" runs along the flat portion of the base, and the crossbar of the "t" crosses one edge of cylinder 32. The upper stem portion of the "t" follows a curved path along a portion of the surface of the cylinder. A tongue 86 extends from the edge of the cylinder to fill the lower portion oft-shaped aperture 34. Tongue 86 has at least one suitable screwhole 87 in which a screw is mounted for secure attachment of cylinder 32 and latch plate 30 to door jamb 28.

II. How the Z-bar Door Security System Operates

The Z-bar door security system operates in three modes. In the free-opening mode, the door is freely opened and shut without any interference from the system. In the inspection mode, the door can open only a limited distance. In the dead bolt mode, the system prevents the door from opening at all. The following is a detailed description of how the system operates in each mode. a. Operation in the Free-Opening Mode

In the free-opening mode, base plate 22, intermediate link 38, and mode selection and latching assembly 40 lay flat against each other and are latched together, as in Fig. 17. Post 82 and flange 66 have passed through rectangular base plate aperture 44. Control knob 54 has been rotated into the free-swing position, thereby rotating flange 66 into the locked position, as in Fig. 18, with portions of flange 66 overlying the sides of rectangular opening 44. Rotation of control knob 54 has also put latch plate 60 in the retracted position, disengaged from latch plate 30, so that the security system does not prevent the door from swinging open freely. b. Operation in the Inspection Mode To position the security system in the inspection mode from the free-swing mode, the user rotates control knob 54 to disengage flange 66 from base plate aperture 44. Simultaneously, latch bar 60 extends to engage with latch plate 30 through aperture 34, by operation of cam section 88. As door 24 swings open, base plate 22 and intermediate link 38 unfold from the latched position in Fig. 17 to the extended position of Figs. 4 and 5. Once base plate 22 and intermediate link 38 have fully extended, door 24 cannot swing open any further. Incidentally, the laterally extending portions of the crossbar 64 of the latch are held within the cylinder 32 of the latch plate, and the reduced width portion 62 of the latch swings up into the reduced width outer zone of the opening in the latch plate. c. Operation in the Dead Bolt Mode

To put the security system in the dead bolt mode from the inspection mode, the user shuts the door so that bias spring 46 causes intermediate link 38 and mode selection and latching assembly 40 to fold together over base plate 22. The user then rotates control knob 54 to the dead bolt position, such that flange 66 is positioned perpendicular to the length of base plate aperture 44. The shape of groove 118 is such that latch 60 does not retract as the user rotates control knob 54 from the inspection mode position to the dead bolt mode position. With the Z- bar latch assembly folded and locked together, and with latch 60 engaged with latch plate 30, the security system acts as a dead bolt, preventing the door from opening. III. Second Embodiment of the Latch Plate Figs. 20 through 25 illustrate a second embodiment 90 of the latch plate system of the Z- bar security system. In this embodiment of the invention, a latch-securing mechanism 92 is inserted into latch plate cylinder 32' for the purpose of securing the latch within the cylinder. Latch-securing mechanism 92 comprises tube 94, top cap 96, and bottom cap 98.

Tube 94 fits inside latch plate cylinder 32', as indicated by Fig. 20. Tube 94 has a T- shaped aperture 100 through which latch 60 passes after entering latch plate 30'. Top cap 96 fits over the top of tube 94. Fig. 21 shows handle 102, secured to top cap 96, that the user can turn to rotate tube 94. Bottom cap 98 is secured to the bottom of tube 94 and serves to mount and maintain tube 94 within latch plate cylinder 32'. Unlike top cap 96, bottom cap 98 does not have a handle, as illustrated in Fig. 24. Fig. 25 illustrates how the latch-securing mechanism operates. Latch 60 enters latch plate 30' at aperture 34' (Fig. 20), then passes through aperture 100 of tube 94. The user turns handle 102 of top cap 96, thereby rotating tube 94, and securing the ends of cross-piece 64 of the latch member behind the portions 120 of the rotated sleeve 92. The crossbar of latch 60 is held within latch plate cylinder 32', and cannot be pried out of latch plate 30' until the user turns handle 102 back to its original position.

Concerning dimensions, it is desirable that the bolt or latch member be of considerable strength, and it is preferably made of steel, at least 1/8 inch thick, and preferably 3/16 inch thick. It is 1 1/4 inch wide at the end, about 5/8 inch wide along its length, and about three inches long. These dimensions are given by way of example and not of limitation.

With the rotating cylinder actuated in the latch plate assembly to the locked position, the security is equal to and probably greater than that provided by conventional dead bolts, as the bolt or latch member of the present invention cannot be directly withdrawn from the latch plate.

It is to be understood that the foregoing detailed description and the accompanying drawings relate to preferred embodiments of the Z-bar lock (constituting the preferred embodiment of the locking means used in connection with the present invention). Various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, by way of example and not of limitation, the supplemental locking arrangements in the latch plate may be implemented by a sliding member instead of a rotating cylinder, and the locking end of the latch member may be bifurcated with inwardly directed end portions instead of outwardly projected end portions. In addition, instead of a locking member 66 on the control knob shaft, the three portions of the Z-bar assembly may be locked together by a separate mechanical locking mechanism.

It will be appreciated that other locking means may be employed consonant with the goals and objectives of the present invention and the concept and teachings inherent therein.

The testing of the secure cockpit door 200

With reference to Fig. 33, a guard 210 is firing his automatic pistol 211 into the secure cockpit door 200 of the present invention. The secure cockpit door 200 will withstand a "357" but, of course, not heavier weapons (but who gets on a plane with a "bazooka"!). With reference to Fig. 34, and following the test firings in Fig. 33, the bullet 212 could not penetrate the secure cockpit door 200 and was captured in the bullet resistant material. The door 200 is cracked, as at 213, but withstood the pistol 211 fired at close range.

With reference to Fig. 35, two bullets 214 and 215 (or fragments thereof) were "caught" in the bullet-resistant window 202 but, significantly, could not penetrate.

With reference to Fig. 36, two first-class seats have been removed, the bulkhead B repositioned and the cockpit C reconfigured, to provide a toilet area 216 and a storage area 217 for the pilot P and copilot CP (and any other cockpit personnel) such that no cockpit personnel will be required to leave the cockpit C in flight. The bullet resistant covering for the bulkhead B is shown in FIGS. 37 and 38.

Features and advantages of the invention

In summary, all of the goals and objectives of the present invention have been met: (1) the cockpit is totally secure and a potential terrorist/skyjacker cannot crash into the cockpit, kill or disable the cockpit crew, and gain control of the cockpit; (2) the cockpit door may be opened safely so that, while the pilot can receive a coffee or other item from the flight attendant, the terrorist/skyjacker cannot crash through or break the door down, since the door is equipped with the preferred locking means (the Z-bar lock), the flight crew has no need to fully open the secure cockpit door; (3) retrofitting the existing fleet of aircraft may be initiated very quickly and the retrofit program may be completed, comparatively speaking, at a minimum cost; and (4) the passengers' perception of aircraft control will be substantially enhanced while, at the same time, there is a visible deterrence to the potential terrorist/skyjacker.

This invention is the only practical solution to an urgent problem affecting the entire airline industry and, as a consequence thereof, the travel industry and the general economy as well. Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention, may be practiced other than has been specifically described herein.

Claims

WHAT IS CLAIMED IS;

1. A secure cockpit door for a scheduled passenger, chartered or cargo-carrying aircraft, comprising a bullet-resistant door mounted within a retrofit bullet-resistant bulkhead separating the cockpit from the passenger compartment, the bullet-resistant door having a manually- manipulatable locking means which will enable the pilot or copilot to open the door safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential skyjacker from crashing through the bullet-resistant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened, and the bullet-resistant door further having a bullet-resistant transparent window securely mounted therein, the bullet-resistant transparent window being substantially aligned with the center aisle of the passenger compartment of the aircraft; such that the pilot or copilot, usually while standing to open the door, can see who is on the other side of the door and determine whether there are any problems within the passenger compartment; and such that the passengers within the aircraft can see through the bullet-resistant transparent window, be assured that the cockpit is totally secured against a potential terrorist/skyjacker, and know that the aircraft cannot be used as a manually-guided missile.

2. The secure cockpit door of claim 1, comprising a retrofit secure cockpit door intended to replace the conventional factory-installed non-secure cockpit door.

3. The secure cockpit door of claim 1, wherein the manually-manipulatable locking means comprises: a Z-bar door security system providing (1) entry, (2) inspection, and (3) dead bolt modes of operation, comprising: a latch plate for mounting on the frame of the door, said latch plate having a vertical slot for receiving a latch bar; a Z-bar latch assembly including (1) a base plate for securing to the edge of the door in juxtaposition to said latch plate, (2) an intermediate link pivoted to said base plate at the front edge of said base plate adjacent the door, and (3) a mode selection and latching assembly pivotally mounted to said intermediate link at the front edge of said intermediate link; said mode selection and latching assembly including a rotatably mounted control knob and a high strength latch member, and camming means for linearly advancing said latch member into engagement with said slot in said latch plate as said control knob is rotated, to implement the inspection and the dead bolt modes of operation; means secured to said control knob for securing the base plate, the intermediate link and the mode selection and latching assembly together while the latch member is extended into engagement with the latch plate, thereby providing the dead bolt mode of operation; and said camming means including camming surfaces permitting further rotation of said control knob without retracting the latch member to implement the dead bolt mode of operation.

4. The secure cockpit door of claim 1, wherein the bullet-resistant cockpit door has an upper portion and a lower portion, and wherein the bullet-resistant transparent window comprises an elongated vertically-oriented bullet-resistant transparent window in the upper portion of the cockpit door.

5. The secure cockpit door of claim 4, wherein the lower portion of the bullet-resistant door has a horizontally-oriented slot formed therein, whereby the pilot or copilot may receive a meal tray.

6. The secure cockpit door of claim 5, further including a bullet-resistant cover for the horizontally-oriented slot, the bullet-resistant cover being mounted on the inside of the cockpit door and retained by a manually-releasable latch.

7. The secure cockpit door of claim 6, wherein the bullet-resistant door and the bullet- resistant transparent window are both fire retardant.

8. A retrofit secure cockpit door for a scheduled passenger, chartered or cargo-carrying aircraft wherein the retrofit secure cockpit door is intended to replace the factory-installed, non- secure cockpit door, comprising a bullet-resistant fire-retardant door mounted within the bulkhead separating the cockpit from the passenger compartment, the bullet-resistant fire- retardant door having a manually-manipulatable locking means including a Z-bar lock which will enable the pilot or copilot to open the door safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential terrorist/skyjacker from crashing through the bullet-resistant fire-retardant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened, the bullet-resistant fire-retardant door, including an upper portion and a lower portion, the upper portion of the bullet-resistant fire-retardant door further having an elongated vertically-oriented bullet-resistant transparent window securely mounted therein, the elongated vertically-oriented bullet-resistant transparent window being substantially aligned with the center aisle of the passenger compartment of the aircraft; such that the pilot or copilot, usually while standing to open the retrofit secure cockpit door, can see who is on the other side of the door and determine whether there are any problems within the passenger compartment; and such that the passengers within the aircraft can see through the elongated, vertically-oriented bullet-resistant transparent window, be assured that the cockpit is totally secured against a potential terrorist/skyjacker, and know that the aircraft cannot be used as a manually-guided missile; and the lower portion of the bullet-resistant fire-retardant door having a horizontally-oriented slot formed therein, whereby the pilot or copilot may receive a meal tray from a flight attendant, and a bullet-resistant cover for the horizontally-oriented slot, the bullet-resistant cover being mounted on the inside of said door and being retained by a manually-releasable latch.

9. A secure cockpit for a scheduled passenger, chartered or cargo-carrying aircraft, comprising a bullet-resistant door mounted within a bulkhead separating the cockpit from the passenger compartment, the bullet-resistant door having a manually-manipulatable locking means which will enable the pilot or copilot to open the door safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential terrorist/skyjacker from crashing through the bullet-resistant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened, and the bullet-resistant door further including an upper portion and a lower portion, the upper portion having a bullet-resistant transparent window securely mounted therein, such that the pilot or copilot, usually while standing to open the door, can see who is on the other side of the door and determine whether there are any problems within the passenger compartment; and such that the passengers within the aircraft can see through the bullet-resistant transparent window, be assured that the cockpit is totally secured against a potential terrorist/skyjacker, and know that the aircraft cannot be used as a manually-guided missile; and the lower portion of the bullet-resistant window having a horizontally-oriented slot formed therein for receiving a meal tray from a flight attendant, the slot being covered by a hinged plate on the inside of the door and retained by a manually-releasable latch and a bullet-resistant covering for the bulkhead surrounding the door wherein the cockpit is protected from weapons fired into the cockpit.

10. A secure cockpit door for a scheduled passenger, chartered or cargo-carrying aircraft, comprising a bullet-resistant door mounted within the bulkhead separating the cockpit from the passenger compartment, the bullet-resistant door having a manually-manipulatable locking means comprising a Z-bar lock which will enable the pilot or copilot to open the door safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential terrorist/skyjacker from crashing through the bullet-resistant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened, and the bullet-resistant door including an upper portion having an elongated vertically-oriented bullet-resistant transparent window securely mounted therein, the elongated vertically-oriented bullet-resistant transparent window being substantially aligned with the center aisle of the passenger compartment of the aircraft; such that the pilot or copilot, usually while standing to open the door, can see who is on the other side of the door and determine whether there are any problems within the passenger compartment; and such that the passengers within the aircraft can see through the bullet-resistant transparent window, be assured that the cockpit is totally secured against a potential terrorist/skyjacker, and know that the aircraft cannot be used as a manually-guided missile.

11. A secure cockpit door for a scheduled passenger, chartered or cargo-carrying aircraft, comprising a bullet-resistant door mounted within the bullet resistant bulkhead separating the cockpit from the passenger compartment, the bullet-resistant door having a manually-manipulatable locking means comprising a Z-bar lock which will enable the pilot or copilot to open the door safely and by a sufficient amount to receive a coffee or other item from a flight attendant, but will prevent a potential terrorist/skyjacker from crashing through the bullet-resistant door and gaining control of the steering mechanism and other aircraft controls within the cockpit whenever the door is partially opened, and the bullet-resistant door including an upper portion having a bullet-resistant transparent window securely mounted therein, and further including a lower portion having a secured slot therein for receiving a meal tray from the flight attendant.

12. The method of maintaining the security of the cockpit of an aircraft, thereby preventing a potential terrorist/skyjacker from entering the cockpit, killing or disabling the pilot, copilot and any other of the flight crew in the cockpit, and thereafter gaining control of the aircraft and flying it as a guided bomb into a skyscraper, stadium or other public place, comprising the steps of providing a retrofit bullet-resistant secure cockpit door, replacing the factory-installed conventional non-secure cockpit door in the aircraft with the retrofit bullet- resistant secure cockpit door, the retrofit bullet-resistant secure cockpit door being provided with a bullet-resistant transparent window; and, while the aircraft is in flight, viewing from the inside of the cockpit who is on the other side of the door, and opening the retrofit bullet-resistant secure cockpit door sufficiently and safely to receive a coffee or other item from the flight attendant, the retrofit bullet-resistant secure cockpit door preventing a terrorist/skyjacker from crashing through the door and into the cockpit.

13. The method of claim 12, wherein the retrofit bullet-resistant transparent window is disposed within the secure cockpit door so that the window is substantially aligned with the aisle in the passenger compartment in the aircraft regardless of the configuration of the bulkhead separating the cockpit from the passenger compartment, and regardless of the disposition of the door mounted in the bulkhead.

14. The method of claim 12, further including the step of providing a slot in the retrofit bullet-resistant secure cockpit door for receiving a meal tray therethrough.

15. The method of claim 14, further comprising the step of providing a bullet-resistant cover for the slot, the cover being hinged to the inside of the door, and providing a manually- releasable latch for the hinged cover.

16. The method of claim 15, wherein the window is elongated and vertically oriented and is disposed in an upper portion of the retrofit bullet-resistant secure cockpit door, and wherein the slot is horizontally oriented and is disposed in a lower portion of said door.

17. The method of claim 12, further comprising the step of removing two seats from the passenger compartment, reconfiguring the bulkhead to encompass the space of the seats, and reconfiguring the cockpit to provide toilet and storage facilities, respectively, for the pilot and copilot so that they never have to leave the cockpit while the aircraft is in flight.

18. The method of claim 12 further comprising the step of mounting the retrofit bullet- resistant secure cockpit door in an existing frame surrounded by a bulkhead, and covering the frame and bulkhead with a bullet-resistant material wherein the flight crew and control panel in the cockpit is protected from weapons aimed at the bulkhead around the cockpit door.