Patent Publication Number: US-2020290750-A1

Title: System and method for determining aircraft safe taxi, takeoff, and flight readiness

Description:
PRIORITY CLAIM 
     This application claims priority from U.S. Provisional Patent Application No. 62/816,868, filed 11 Mar. 2020, the entire disclosure of which is fully incorporated herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to systems and methods for determining takeoff and flight readiness of aircraft and specifically to a monitoring system and method providing visual confirmation to an aircraft cockpit that aircraft external components are in safe taxi, takeoff, and flight ready positions. 
     BACKGROUND OF THE INVENTION 
     Airport ground travel surfaces can be very congested places at today&#39;s airport terminals. Multiple aircraft are simultaneously arriving and departing, ground-based service and support vehicles and personnel are servicing parked aircraft, and ground crews are directing the arriving and departing aircraft into and out of gates. The avoidance of adverse ground incidents in these areas requires careful monitoring and control of the locations and movements of aircraft, ground vehicles, equipment, and personnel as pilots maneuver aircraft prior to takeoff. Aircraft pilots and cockpit crews must check flight plans and complete checklists under these conditions and, not only must they maneuver aircraft to prevent ground incidents, but they must also ensure that aircraft are ready for safe taxi to a takeoff location, for safe takeoff and then for safe flight. 
     Driving an aircraft on the ground during taxi with pilot-controlled landing gear wheel-mounted electric taxi or other drive systems without reliance on operation of the aircraft&#39;s main engines or the use of tow vehicles has been proposed by Applicant and others. As the pilot controls operation of electric taxi drive systems to maneuver an aircraft independently of engines and tugs during taxi to, from, and within an airport ramp area, pilot situational awareness may be increased compared to when aircraft are driven only with operating engines or even towed with tugs or moved with aircraft transfer apparatus. This increased pilot situational awareness is likely to improve aircraft ground travel safety. Monitoring of the ground level environment external to the portions of the aircraft not readily visible to the pilot or crew driving the aircraft would further improve pilot situational awareness, avoid potential collisions, and enhance safe operation of the aircraft as they are driven independently with electric taxi drive systems, and such monitoring and systems for conducting such monitoring have been proposed by Applicant. Portions of the aircraft exterior, primarily below the wings, not visible to the pilot and flight crew from the cockpit, may be equipped with cameras and sensors mounted on aircraft exterior locations to improve visibility of these exterior locations from the cockpit. While potentially helpful in avoiding collisions during ground maneuvers within an airport ramp area, there may be limitations to the information obtained, especially during low visibility weather conditions. Monitoring systems for aircraft driven with electric taxi drive systems that employ different types of sensing devices mounted on the exterior of the aircraft to provide an expanded view of the aircraft&#39;s ground travel path during pushback prior to taxi to a takeoff runway have also been proposed by Applicant. The available monitoring systems, whether on aircraft or on airport ramp structures or buildings, are directed to monitoring and providing information about the aircraft exterior ground travel environment so that collisions and ground incidents involving adjacent aircraft, ground vehicles or personnel, and ground structures may be prevented. Monitoring positions of external aircraft components to ensure readiness for safe taxi, takeoff, and flight has not been previously proposed. 
     The pilot and cockpit crew of an aircraft cleared for departure and takeoff must complete a number of tasks to ensure that the aircraft is ready for safe taxi to a takeoff location, safe takeoff, and safe flight. While pilot situational awareness during ground maneuvers within and out of a ramp area is greatly improved when an aircraft may be driven independently of tow vehicles and engines during pushback, there are still a number of checklist and other tasks that must be accomplished if the aircraft is to be ready for safe taxi, takeoff, and flight. Among the checklist tasks required prior to takeoff is setting the aircraft flaps at a setting that may be required for takeoff from a specific runway to which the aircraft has been assigned. Performance data required for the aircraft&#39;s takeoff may be acquired by an outside source and sent to the Flight Management Computer (FMC) in the aircraft cockpit. The FMC performance data may not look at the takeoff flap setting set by the pilot. During the process of preparing the aircraft for takeoff, the pilot must currently visually crosscheck the flap gauge with the FMC data to ensure that the flaps are at the correct setting. It is not presently possible for a pilot actually to see the aircraft&#39;s flaps to verify flap positions. While electromechanical flap sensors that measure flap position or angle have been proposed for gliders, available systems for aircraft powered for flight by engines provide only reactionary warnings when flap positions and flap settings are not aligned. These reactionary warnings, moreover, may not be activated until an aircraft&#39;s actual takeoff roll. Improper flaps settings and/or settings that cause misaligned flaps may not be detected by current warning systems and may not activate a warning. Takeoff of the aircraft under these circumstances could have serious adverse consequences. 
     In addition to the flaps, aircraft exterior components and systems that should be checked for takeoff and flight readiness include the aircraft&#39;s landing gears, tires mounted on landing gear wheels, and, after takeoff, landing gear position. When an aircraft is driven by electric taxi drive systems within a ramp area where there are ground personnel positioned to guide the aircraft during pushback, the ground personnel may visually inspect landing gear structures and tires. When the aircraft is driven out of the ramp area and onto taxiways to a takeoff location, the landing gears, landing gear components, and tires are no longer visible to ground personnel. The aircraft&#39;s pilot and flight crew typically do not have views of locations of the aircraft&#39;s landing gear on runways during taxi-out procedures, nor can they see landing gear components or tires during taxi to assess where the landings gears are on the runway or whether landing gear components and tires are functioning normally. 
     Once the aircraft has taken off, whether the landing gears have retracted normally may be indicated in some aircraft by an arrangement of primary and secondary landing gear position indicator lights. If the primary indicator lights indicate a non-normal condition, i.e., a landing gear is extended when it should be retracted, the secondary indicator lights should confirm the non-normal condition. In an illustrative situation, after an aircraft takeoff, the primary indicator lights indicated a non-normal landing gear condition (landing gear extension), but the secondary indicator lights indicated that the landing gear condition was normal (landing gear retraction). The pilot and crew were faced with conflicting information, and they could not visually verify which condition was accurate. To avoid a potentially dangerous situation, they flew the aircraft by the tower, which is not allowed, and requested verification of the abnormal landing gear position from tower personnel. A less drastic solution to this situation is clearly needed. 
     The foregoing discussion indicates the need for a system and method that improves pilot situational awareness of conditions and positions of aircraft exterior components important for safe taxi, takeoff, and flight readiness and that enables pilots and cockpit crews to obtain clear and accurate visual information which reflects the real time positions and conditions of aircraft exterior components, including aircraft flaps and landing gears, to ensure safe taxi, takeoff, and flight readiness. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention, therefore, to provide a monitoring system that enables pilots and cockpit crews to obtain clear and accurate visual information relating to an aircraft&#39;s safe taxi, takeoff, and flight readiness, particularly information that reflects the real time positions and conditions of aircraft flaps and landing gears. 
     It is another object of the present invention to provide a monitoring method that enables pilots and cockpit crews to obtain clear and accurate visual information relating to an aircraft&#39;s safe taxi, takeoff, and flight readiness, particularly information that reflects the real time positions and conditions of aircraft flaps and landing gears. 
     It is an additional object of the present invention to provide a monitoring system that provides a visual inspection of aircraft surfaces and structures, including at least flaps and landing gears, to a pilot and cockpit crew to confirm that actual positions align with settings so that the aircraft is in a safe flight ready state. 
     It is an additional object of the present invention to provide an aircraft monitoring system that visually monitors the aircraft&#39;s flaps settings and automatically communicates a real time view of the aircraft&#39;s flaps position and a visual, audio, or other indication of the alignment or misalignment of flaps position with flaps settings to the aircraft cockpit. 
     It is an additional object of the present invention to provide a monitoring method that enables pilots to safely set flap settings prior to or during forward taxi and verify flap positions during taxi to a takeoff location. 
     It is a further object of the present invention to provide an aircraft monitoring system that visually monitors the aircraft&#39;s landing gear positions and automatically communicates a real time view of the aircraft&#39;s landing gears and a visual, audio, or other indication of improperly extended or retracted landing gears or other unsafe condition to the aircraft cockpit. 
     It is yet a further object of the present invention to provide a monitoring system that provides real time visual points of view of external aircraft structures to the aircraft cockpit and is electronically integrated with the aircraft&#39;s flight management computer, an electronic flight bag, and other data systems. 
     It is yet a further object of the present invention to provide an aircraft monitoring system that visually monitors at least the aircraft&#39;s tail position and landing gear runway locations and automatically communicates a real time view of the locations of the aircraft tail and landing gears and provides warnings that will enable a pilot to avoid a tail strike or a runway excursion. 
     It is yet a further object of the present invention to provide a monitoring system for aircraft driven independently with electric taxi drive systems during ground surface travel at an airport employing monitoring units that may be a combination of a camera and/or a sensor and a scanning LiDAR device mounted in exterior aircraft locations to produce meshed real time and recorded data with views of the aircraft&#39;s flaps and with views of the aircraft&#39;s landing gears and tail for communication to the aircraft cockpit and integration with the aircraft&#39;s flight management computer and flaps, landing gear, and tail position indicators. 
     In accordance with the aforesaid objects, an integrated monitoring system and method are provided with capability for the real time monitoring of aircraft external structures and surfaces to determine the aircraft&#39;s readiness for taxi, takeoff, and flight and to maximize safety of aircraft takeoff. Monitoring units, which may be a scanning LiDAR device, either alone or in combination with a camera or another sensing device, are mounted in locations on the aircraft exterior to produce a composite stream of data that may be securely meshed and transmitted to an intelligent processing system to generate a visual display of the monitored area, particularly the aircraft flaps and landing gears and the aircraft&#39;s tail, for communication to aircraft pilots and airport control personnel with responsibility for determining an aircraft&#39;s readiness for taxi, takeoff and flight. The monitoring system and method may be advantageously employed on aircraft driven independently during taxi with electric taxi drive systems. Meshed real time and recorded data from the monitoring units may be transmitted to the intelligent processing system and may be communicated as an integrated visual display to the aircraft&#39;s cockpit to provide visually accurate information relating to flaps positions and settings and landing gear and tail positions. 
     An aircraft&#39;s flaps positions may be set and continuously monitored and automatically or manually altered with the present system and method to ensure that the flap positions align with optimal flap settings for the aircraft on the runway at the airport where the aircraft is taking off. Continuous monitoring of an aircraft&#39;s landing gears during takeoff and prior to landing, as well as during taxi, may ensure that landing gears are retracted or extended, as required and that conditions of tires or other landing gear components are normal. Landing gear positions may be automatically or manually adjusted as required, both to ensure that the landing gears are properly retracted or extended and to ensure that they are safely moving the aircraft on a runway surface. The position of the aircraft&#39;s tail during takeoff may additionally be monitored and automatically or manually changed to prevent a tail strike during takeoff. 
     The integrated monitoring method of the present invention may improve the safety of aircraft takeoff and of airport operations when the monitoring system is used to enable pilots and others with responsibility for aircraft readiness for takeoff and flight to ensure that aircraft flaps and landing gears are optimally takeoff and flight ready and that tail strikes are avoided. 
     Other objects and advantages will be apparent from the following description, claims, and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side perspective view of an aircraft driven on a ground surface with an engines-off electric taxi system equipped with the integrated monitoring system of the present invention; and 
         FIG. 2  is a view of the aircraft of  FIG. 1  showing selected exterior areas that may be monitored to provide a view of the aircraft&#39;s flaps and landing gears as the aircraft is driven with electric taxi drive systems prior to takeoff or prior to landing. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     The movement of aircraft into, out of, and within congested airport ramp surface areas safely while avoiding collisions and other adverse ground incidents is critical to maintaining the safety of the aircraft, as well as that of all persons and vehicles in this airport area. Monitoring systems may improve situational awareness as aircraft pilots and flight crew are driving an aircraft during ramp ground surface operations by providing a clear view of the spatial environment around the moving aircraft from the cockpit, as well as from ramp and ground control perspectives. Available monitoring systems, however, have focused primarily on the ground environment around an aircraft&#39;s exterior and the relative locations of adjacent aircraft, ground vehicles and personnel, and ground structures. The monitoring system of the present invention provides a targeted view of specific exterior structures on an aircraft, namely the flaps, the landing gears, and the tail, that must be positioned according to optimal settings or positions for an aircraft to taxi, takeoff, and fly safely, or to land safely and taxi safely after landing. The meshed data collected and analyzed from the monitoring system may enable manual or automatic control of the aircraft&#39;s flap setting and position and landing gear and tail positions for optimal taxi, takeoff, and flight readiness or optimal landing readiness. In addition, this data may be meshed with the electric taxi drive system to control and alter the aircraft&#39;s ground travel, if required, and thereby avoid a potential collision incident or runway excursion or incursion. 
     Currently, in aircraft driven during taxi by aircraft engines, flap takeoff settings are throttle activated. A warning is sent to the cockpit only if flaps are not within an identified takeoff range. This reactionary warning system is activated on the aircraft&#39;s actual takeoff roll. Flap position, which may raise the maximum lift coefficient, especially on takeoff, affects the speed at which an aircraft can safely maintain flight. The effect of flap position, which may cause the aircraft nose to rise or lower and the aircraft tail to correspondingly lower or rise, depends on the type of aircraft and the type of flap. There is more variation in takeoff flap position for airports and runways now than in the past, and more attention must be paid to optimal flap settings to ensure a safe takeoff. If the flap settings and, therefore the flap positions, are not within an optimal range for the specific airport or the specific runway, an accident or incident related to incorrect takeoff flap settings may occur. When aircraft are driven by electric taxi drive systems and equipped with the present integrated monitoring system, pilots are able to visually confirm optimal flap settings for the airport or runway, and flap settings may be adjusted manually or automatically, as required. 
     The more complex and variable changes in aircraft configurations, including flap settings, for takeoffs from different runways that are commonly encountered by today&#39;s pilots has led to increased incidences of tail strikes during takeoff. In the past, it was typical procedure to keep flap settings relatively constant while adjusting speed and power settings. Now, all three elements are routinely subject to change when there is a last minute change in runway assignment. In the name of efficiency, airline engineering departments are increasingly introducing more runway specific optimal flap settings coupled with variable speed and power settings for takeoff, representing a paradigm shift from the past practices to which most pilots are accustomed. Airlines may be implementing such changes without providing pilots sufficiently enhanced awareness of current flap settings. This insufficient pilot awareness may be a possible cause of improper flap settings for takeoff, as takeoff flap settings are always set manually by the pilot. The present monitoring system verification procedure is intended to alert pilots of incorrectly configured flaps prior to takeoff and to significantly reduce and potentially eliminate consequences that may result from improper flap settings, as well as misaligned flap requirements and flap positions. 
     Prior to takeoff, performance data for an aircraft, for example a Boeing 737NG, is usually acquired by an outside source and sent to the aircraft flight deck, where it is manually loaded to the Flight Management Computer (FMC). The performance data for the aircraft may also be externally uploaded in the FMC. The pilot typically sets the takeoff flap setting. The FMC performance data, however, does not look at the actual takeoff flap setting set by the pilot. In the event that the flaps are incorrectly set based on the required performance data, and there is no aircraft takeoff warning activated, continuing the takeoff process may be accompanied by adverse consequences. For example, a Flaps 5 takeoff setting may be used on a Boeing 737NG more than 90% of the time in normal routine operations. When the airport where the aircraft is taking off has a short runway that requires a Flaps 25 setting and the pilot selects the usual Flaps 5 setting, the flaps setting is not aligned with the performance data. As a result, the aircraft nose position and speed may be incorrect for takeoff, and the takeoff may potentially be disastrous. To avoid this situation, the only way to confirm the flaps setting at present is to visually crosscheck the flap gauge with the FMC data. 
     Pilots of aircraft are in a high workload environment during pushback and taxi out to takeoff. In the foregoing example, confirming the flaps setting by visually crosschecking the flaps setting with the FMC data, which is necessary and required 100% of the time, may or may not occur. In another exemplary situation, if a runway change is given to an aircraft by Air Traffic Control (ATC) while the aircraft is taxiing out, the pilot is required to derive new performance data reflecting the change and input it in the FMC. If a different flaps setting is required for the new runway, the pilot must select it. In neither of the situations described above is there an activated takeoff warning if the actual flaps settings are not aligned with the original or new performance data. As discussed below, the system and method of the present invention may provide a significant safety benefit by continuously monitoring flap setting against data inputted in the FMC to confirm and indicate alignment of flaps and data or to provide a warning indication of misalignment prior to takeoff when the flap setting requires a change during taxi or at other times. Advantageously, the present system provides a real time view of the actual flap positions to the cockpit. 
     In response to instances when pilots set flaps during forward taxi, and improperly set flaps produced adverse consequences, including hull loss crashes, many airlines now require that flaps be set prior to a forward taxi roll. The need to set flaps prior to forward taxi typically delays forward taxi motion by about one to two minutes. The flap setting verification method described herein permits pilots to set flaps at the gate prior to the aircraft being driven with the electric taxi drive system and during forward taxi while permitting a margin of safety that is greater than that possible with current procedures. 
     The integrated monitoring system of the present invention assists pilots to confirm that an aircraft is takeoff taxi ready and flight ready and that aircraft structures, including flaps and landing gears are in a takeoff taxi and flight-ready state. The present monitoring system may be advantageously employed prior to takeoff and prior to landing. Confirming that flaps settings are optimal may be required prior to and during both landing and takeoff, while landing gear retraction and extension positions may be confirmed just after takeoff and just prior to landing while the aircraft is in flight. Confirming tail position may be important at both takeoff and landing, as well as at other times. 
     “Electric taxi drive systems” and “electric taxi systems,” as used herein, refer to pilot-controllable systems used to drive aircraft independently of operation of aircraft engines and external tow vehicles or aircraft transfer apparatus. Such systems may include electric drive motor assemblies mounted completely within landing gear wheels that are activatable to drive the aircraft during ground travel in response to pilot control. An example of an electric taxi system developed by Applicant to drive an aircraft independently during ground travel without reliance on operation of the aircraft&#39;s engines or attachment to external tow vehicles or transfer apparatus is described in commonly owned U.S. Pat. No. 10,308,352, the disclosure of which is fully incorporated herein in its entirety. Other drive systems using drive motors that are not electric, including, for example, hydraulic or pneumatic drive motors may also drive aircraft in connection with the intelligent monitoring system and method of the present invention and are contemplated to be included within the terms “electric taxi drive systems.” 
     The terms “intelligent processor,” “artificial intelligence,” and “intelligent algorithms” are used herein to refer to and encompass systems of data processing and analysis that are conducted by computers capable of harvesting large amounts of possible input data, including images and other information from monitoring and sensing devices, that may be processed, analyzed, and categorized based on a set of rules and then may be communicated so that appropriate action may be taken, whether automatically by a system receiving the processed and analyzed data or manually by a human. 
     Referring to the drawings, which may not be drawn to scale,  FIG. 1  shows a side perspective view of an aircraft  10  equipped with an electric taxi drive system  12  mounted on the nose landing gear  14  to drive the aircraft during ground operations and travel. The aircraft  10  in  FIG. 1  is equipped with a pilot-controllable electric taxi drive system that powers aircraft ground movement without operating engines and tow vehicles. A preferred electric taxi drive system  12  may include a pair of electric drive motors mounted completely within the wheel volume in each nose landing gear wheel or, alternatively or additionally, within one or more of the main landing gear wheels  16  on aircraft  10 . The electric taxi drive system is controlled by a pilot and/or the crew of the aircraft from the cockpit  28  to drive an arriving aircraft during taxi-in, to maneuver the aircraft within an airport ramp area into a parking location, and then drive a departing aircraft in forward or reverse out of the parking location to a takeoff runway. 
     Each wing  18  on the aircraft has a set of flaps  20  inboard of a set of ailerons  22  on a trailing edge of each wing. Monitoring units  24  are positioned in exterior locations on the aircraft to provide a view of the flaps, and monitoring units  26  are positioned in exterior locations that will provide a view of the landing gears. Only one monitoring unit  24  is visible; it is anticipated that a second monitoring unit  24  will be located in a similar position on the opposite side of the aircraft fuselage. Similarly, only one monitoring unit  26  is shown. An additional monitoring unit  26  may be positioned closer to the main landing gears  16 . Alternatively, a single monitoring unit  26  may be adapted to provide views of both nose and main landing gears. An additional monitoring unit  27  may be positioned in an advantageous location to provide a view of the aircraft&#39;s tail  29 . The monitoring units are shown schematically and may be located in these or other locations that best provide the views of the aircraft exterior areas and components described herein. It is contemplated that the monitoring units may be mounted in aerodynamic housings on the aircraft exterior, as pop-up units that retract below the aircraft surface when not in use, or may have other configurations that both provide the required views of the flaps and/or landing gears and do not interfere with the aircraft&#39;s aerodynamic surface during flight. 
     An exemplary monitoring unit that provides and communicates this information may be a scanning LiDAR device, either alone or in a combination with a camera or another sensor. The monitoring unit may generate data from a single source or meshed data from multiple sources for processing and analysis, preferably by a processing system driven by intelligent software. Meshed data, and all other data generated by the system, may be communicated in a secure encrypted form in real time to pilots and all others with responsibilities for aircraft takeoff and landing. Generated data may also be recorded and then communicated in this form. As discussed, single or multiple ones of these monitoring units may be attached to exterior locations on the aircraft. Data from the monitoring units  24 ,  26 , and  27  may be meshed with data from other monitoring units on the aircraft (not shown) that are designed to monitor the aircraft&#39;s external ground environment. When needed, alerts or warnings of potential collisions or other incidents may be transmitted to aircraft pilots, ramp control personnel, air traffic control, and all others with a need to receive the data. 
     The monitoring units should have the capability to continuously and intermittently scan or “sweep” the portions of the aircraft&#39;s exterior required to determine flap positions or landing gear positions at all times when they are in use. Monitoring units may optimally operate continuously, intermittently, or in an optimum combination of continuous and intermittent operation to provide a constant stream of data. In one possible monitoring unit configuration of a scanning LiDAR device and a camera, the camera may be set to operate continuously, while the scanning LiDAR device may be set to operate intermittently. Other combinations of continuous and intermittent operation of these and other monitoring units may also be used. This capability may enable the pilot, and potentially others, to determine flap or landing gear position and manually or automatically adjust flap positions to align with optimal flap settings or cause landing gear to retract or extend, as required. 
     Additional sensors, sensor devices, monitoring devices, and the like, preferably digital or smart devices, that are designed to provide additional information relating to flaps and/or landing gear positions may also augment the capabilities of and provide back-up for the present monitoring system and method. For example without limitation, proximity sensors, ultrasound, radar, sonar, LADAR, and global positioning systems (GPS), similar to those currently used for enhanced environmental monitoring in automobiles, but specifically adapted for aircraft use may be used to enhance the capabilities of the monitoring units described herein. If the effectiveness of one type of sensor or monitoring device is limited, for whatever reason, these additional other sensors or monitoring devices may be available to monitor the aircraft&#39;s ramp travel and communicate information to the cockpit and other control locations. 
     Meshed data from a scanning LiDAR device and/or a camera or other sensor in each monitoring unit  24 ,  26 , and  27  may be sent to an artificial intelligence-based processing system, shown schematically at  34  on aircraft  10 , that is preferably an artificial intelligence-based system using intelligent algorithms and capable of intermediate and high level image understanding. The processing system  34  may be located on the aircraft, as shown, or in a control or other location off the aircraft, such as a ground or ramp control location or an airport control tower location where meshed data generated from multiple monitoring units may be securely transmitted for processing and communication. It is contemplated that all data transmissions through the present monitoring system will be encrypted for security and to prevent hacking. The artificial intelligence-based processing system described herein may have the capability to interpolate a three-dimensional view from a single two-dimensional image, in much the same way a human is capable of generating such an image. It is also contemplated that the artificial intelligence-based processing system may track alerts associated with incorrect flaps settings. This and other relevant data may be used to help airline performance departments continue to optimize power settings and flap settings for specific runways at specific airports. Data may also be shared between two or more aircraft that are equipped with the present monitoring systems. 
     Monitoring flaps positions in accordance with the present invention is shown and discussed with reference to  FIG. 2 . The monitoring units  24  shown in  FIG. 2  are configured and positioned to provide a view of the entire wing  18 . It is contemplated that a monitoring unit, shown schematically  25 , configured and positioned to provide a view of only the flaps  20  may also be provided to confirm flaps positions and settings before takeoff and before landing. The views of the areas  30  and  32  indicated by the dashed lines generated by the monitoring units  24  may be transmitted through the processor  34  to a visual display (not shown) in the cockpit  28 . This visual display enables the pilot and crew in the cockpit to see the actual flap position with a degree of accuracy not presently available. The FMC required flap setting may be compared with the actual flap setting as viewed through the monitoring unit. In one embodiment of the present monitoring system, visual indicators may be included with the display. For example, agreement or alignment between the actual observed flap position and the required flap setting may be confirmed with a green light, while disagreement or misalignment between flap position and flap setting may be indicated with a red light. Other visual or audible indicators may also be used for this purpose. 
     The present monitoring system may be adapted to provide communication between monitoring units ( 24 ,  26 , and  27 ) and the Electronic Flight Bag (EFB) and the FMC, which are not shown but are typically in the cockpit. Detected flap positions from the monitoring units may be displayed on the EFB through an application (app) designed for that purpose. As noted above, there is more variation in takeoff flap positions for airports and runways now than in the past. Consequently, a pilot cannot rely on the standard takeoff flap settings that have customarily been used during most takeoffs. For example, the standard takeoff flap setting for the aircraft is a Flaps 5, but a longer runway at a specific airport may generate a flight plan with a Flaps 10 setting so an aircraft uses a lower takeoff power profile and consumes less fuel. The app allows the pilot to input the flight plan takeoff Flaps 10 setting to the EFB when the flight plan is exported to the FMC. The app may also provide visual or audio indicators that communicate a match between detected flap positions and flight plan flap settings, for example with a steady green display, or a conflict between detected flap positions and flight plan flap settings, for example with a blinking light that turns red and/or by sounding an alarm. 
     The present monitoring system makes it possible to generate and compare, as well as transfer, data related to flap settings in different situations, for example at the beginning of a forward roll and prior to landing. Approximate flap angle may also be determined. The monitoring system software may transfer data relating to misaligned flap setting and position and improper landing gear position to alert airport personnel in locations other than the aircraft cockpit that action is needed to align flap setting and position or to retract or extend landing gears. It is anticipated that control systems may be provided with intelligent software that will automatically correct the improperly aligned flaps and the improperly positioned landing gears. 
     In addition to providing a view of the flaps  20  on aircraft wings  18 , the monitoring units  24  provide views of the leading edges  36  of the wings  18  and portions of engines  38  that are within the fields of view  30  and  32 . These views will allow visual inspection of the wings  18 , for example after de-icing, which will enable the pilot or crew to verify that those surfaces are clear of ice. During flight, the monitoring units may allow verification of wing and engine icing. Additionally, it will be possible to check in-flight damage due to mechanical failure, bird strikes, or other causes. In the event an evacuation is required, the monitoring units  24  can be used to determine that emergency exits are clear before the evacuation. It is anticipated that the monitoring units  24  will provide visual displays that may be useful in other situations as well. 
       FIG. 2  illustrates one possible field of view of the nose landing gear  14  provided by monitoring unit  26  within the dashed lines  40 . Other fields of view (not shown) that encompass only the main landing gears  16  or both the main landing gears and the nose landing gear may also be provided by one or more monitoring units, and the meshed data may be transmitted to the cockpit  28  as a visual display. As noted above, visually monitoring the positions of the aircraft nose and main landing gears serves particularly to confirm that the landing gears are properly retracted following takeoff and properly extended prior to landing. Verifying the positions of the nose and/or main landing gears, especially to identify situations that are not normal, may prevent an aircraft flying with extended landing gears and an aircraft landing with retracted landing gears and the potential adverse consequences of these non-normal situations. In the situation described above when the landing gear position primary and secondary indicator lights were not in agreement, visual confirmation from the monitoring unit  26  would have indicated that the secondary indicator lights were not functioning accurately, and the pilot&#39;s unauthorized flight by the tower would not have been necessary. In addition to providing a visual display of landing gear position, the present monitoring system may also verify whether a tire mounted on a landing gear wheel has blown. 
     During taxi, the monitoring unit  26  may be configured to provide a view of the nose landing gear wheels and the main landing gear wheels and their location relative to the edge of the taxiway, which will assist the pilot and crew in preventing runway excursions and incursions. More often at smaller airports but also at larger ones, there have been numerous reports of ground taxi incidents in which aircraft have left the hard taxi surface and traveled onto muddy or grassy areas, sometimes resulting in aircraft damage. These incidents may typically result from the taxiing aircraft&#39;s pilot not being able to see the actual location of the main landing gear and wheels and/or the nose landing gear and wheels while turning from a runway onto a taxiway or from one taxiway to another. Enabling aircraft pilots and cockpit crew to see the precise location of the nose landing gears and wheels and/or the main landing gears and wheels on the ground surface and to avoid runway excursions may result in significant safety and operations benefits to pilots, airlines, and airports, Preventing such runway excursions may reduce or potentially eliminate the runway, taxiway, and even entire airport closures that arise all too frequently today when these incidents occur. 
     Monitoring a tail skid (not shown) or tail  29  of the aircraft  10  with the monitoring unit  27  may provide a view of the area  42  for communication to a visual display in the cockpit  28  through the intelligent processor  34 . Providing the aircraft pilot and crew with a view of the aircraft tail  29 , particularly during takeoff and landing, shows the aircraft tail and tail skid real time positions relative to the ground and enables the pilot or crew to take the action required to raise the tail and avoid the aircraft tail or tail skid striking the ground surface. Currently, all tail strike incidents are considered to be potential structural failures and require the pilot to return the aircraft immediately to the airport for inspection. The present monitoring system provides additional real time information that enables the pilot to view the condition of the tail skid in flight following a tail strike occurrence, to evaluate the situation, and to decide what should be done based upon the real time information, Pilots are currently required to inspect the integrity of the tail-strike cartridges on tail skids during all pre-flight inspections for Boeing 737-800 aircraft, for example. With the present monitoring system, a pilot may perform this inspection while the aircraft is in flight following occurrence of a minor tail strike. Consequently, the automatic requirement to return the aircraft to the airport after tail skid contact with a ground surface may be eliminated when a pilot can verify that the tail strike cartridge has not been compromised. 
     The present invention further includes a method for monitoring aircraft flap positions and landing gear positions. Meshed data relating to aircraft flap positions and landing gear positions may be obtained from the monitoring units of the present monitoring system. This meshed data may be processed and analyzed, preferably by an artificial intelligence-based processing system using intelligent algorithms, to provide visual displays of flap positions and landing gear positions and conditions of other aircraft structures. Warnings of non-normal positions and conditions may be communicated to the cockpit, and, if warranted, flap or landing gear positions may be automatically or manually altered or required action may be taken to ensure that the aircraft is in a flight-ready state prior to takeoff. 
     The continuous secure data streaming provided by the present monitoring system may also provide an immensely valuable tool for the investigation of a number of aircraft incidents and accidents beyond those described above, including, for example, hull losses. The availability of real time video streams from the described monitoring units  24 ,  26 , and  27 , as well as from any additional monitoring units, may provide investigators with invaluable information that may orient investigations in a better direction at an early stage. For example, real time video information might determinatively indicate mechanical failure or might suggest intentional aircraft destruction, and an investigation may be focused accordingly. Further, the real time visual information generated by the present monitoring system might be useful in determining causation of incidents or accidents. 
     While the present invention has been described with respect to preferred embodiments, this is not intended to be limiting, and other arrangements and structures that perform the required functions are contemplated to be within the scope of the present invention. 
     INDUSTRIAL APPLICABILITY