NASA is collaborating with the Federal Aviation Administration (FAA) and aviation industry partners to develop and demonstrate new concepts and technologies for Integrated Arrival, Departure, and Surface (IADS) traffic management capabilities under the Airspace Technology Demonstration 2 (ATD-2) project. One of the goals of the IADS capabilities in the ATD-2 project is to increase predictability and throughput of airspace operations by improving Traffic Management Initiative (TMI) compliance. This paper focuses on the Approval Request (APREQ) procedures developed for the ATD-2 project between the Air Traffic Control (ATC) Tower at Charlotte Douglas International Airport and Washington Center. In March 2017, NASA conducted a Human-in-the-Loop (HITL) simulation to evaluate the operational procedures and information requirements for the APREQ procedures in the ATD-2 IADS system between ATC Tower and Center. The findings from the HITL are used to compare ATD-2 APREQ procedures with information about current day APREQ procedures.
In this exploratory archival study we mined the performance of 24 major US airports area navigation standard terminal arrival routes (RNAV STARs) over the preceding three years. Overlaying radar track data on top of RNAV STAR routes provided a comparison between aircraft flight paths and the waypoint positions and altitude restrictions. NASA Ames Supercomputing resources were utilized to perform the data mining and processing. We investigated STARs by lateral transition path (full-lateral), vertical restrictions (full-lateral/full-vertical), and skipped waypoints (skips). In addition, we graphed altitudes and their frequencies of occurrence for altitude restrictions. Full-lateral compliance was generally greater than Full-lateral/full-vertical, but the delta between the rates was not always consistent. Full-lateral/full-vertical usage medians of the 2016 procedures ranged from 0 in KDEN (Denver) to 21 in KMEM (Memphis). Waypoint skips ranged from 0 to nearly 100 for specific waypoints. Altitudes restrictions were sometimes missed by systemic amounts in 1000 ft. increments from the restriction, creating multi-modal distributions. Other times, altitude misses looked to be more normally distributed around the restriction. This work is a preliminary investigation into the objective performance of instrument procedures and provides a framework to track how procedural concepts and design intervention function. In addition, this tool may aid in providing acceptability metrics as well as risk assessment information.
A Human-In-The-Loop simulation was conducted in January of 2013 in the Airspace Operations Laboratory at NASA's Ames Research Center. The simulation airspace included two en route sectors feeding the northwest corner of Atlanta's Terminal Radar Approach Control. The focus of this paper is on how uncertainties in the study's trajectory predictions impacted the controllers' ability to perform their duties. Of particular interest is how the controllers interacted with the delay information displayed in the meter list and data block while managing the arrival flows. Due to wind forecasts with 30-knot over-predictions and 30-knot under-predictions, delay value computations included errors of similar magnitude, albeit in opposite directions. However, when performing their duties in the presence of these errors, did the controllers issue clearances of similar magnitude, albeit in opposite directions? This paper describes the use of a novel technique (Interrupted Time Series) to examine the controller response data.
The development of embedded systems often fails due to overdrawing the project duration or financial constraints. Regarding this problem, two reports - one for the British (2009) and one for the German (2014) Armed forces - have been examined in order to find possible fields of action that can be tackled in order to cope with this grievance. Four of those fields, i. e., integration/preparation of heterogeneous data, impartial comparability of standards, tailoring of complex processes and increased risk management, are targeted by this work. Therefore, we developed a methodology and an appropriate data model. The methodology is based on situational method engineering and product line engineering. Concepts taken from MIL-STD-881 and 498 provide the basis for our data model. For validation, our methodology was applied to the development of a "SET-FREQUENCY" function of a radio in a fictional rescue helicopter.
This article consists of a collection of slides from the author's conference presentation.
Prerequisites - to be provided by Customer. Provide overview of present workflow - not process. Provide requirements associated to the project (e.g. project objective and definition, functional requirements) that will be the basis of the 6 weeks MbSE engagement. Identify “core team” that will be assigned to the project for the next 6 weeks.
An emerging Next Generation Air Transportation System concept - Equivalent Visual Operations (EVO) - can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced flight vision system technologies are critical enabling technologies to EVO. Current research evaluated concepts for flight deck-based interval management (FIM) operations, integrated with Synthetic Vision and Enhanced Vision flight-deck displays and technologies. One concept involves delegated flight deck-based separation, in which the flight crews were paired with another aircraft and responsible for spacing and maintaining separation from the paired aircraft, termed, equivalent visual The operation required the flight crews to acquire and maintain an equivalent visual contact as well as to conduct manual landings in low-visibility conditions. The paper describes results that evaluated the concept of EVO delegated separation, including an off-nominal scenario in which the lead aircraft was not able to conform to the assigned spacing resulting in a loss of separation.
This paper addresses the airspace integration challenges related to the acquisition of a Medium Altitude Long Endurance Unmanned Aircraft System in the Netherlands Ministry of Defence. After being shelved for over four years, the program has recently been reopened with a somewhat altered ambition level. Integration of unmanned aircraft into the existing airspace system, with the ability to deal with both transponding and non-transponding other aircraft, is still one of the key challenges in unmanned aircraft operations. The current ambition however, is to achieve airspace integration in a gradual fashion, building on existing systems and technology. For the acquisition program, this ambition translates into the requirement to pursue systems that demonstrate scalability in terms of e. g., operational concept, available infrastructure, available data, interfaces and levels of autonomy. Since 2001, a collaborative research project between Delft University of Technology and the Netherlands Ministry of Defence has addressed several aspects of mission management of unmanned aircraft, including airspace integration. Within the project, a concept for sense and avoid has been developed that enables a seamless transition from human-in-the-loop self-separation to autonomous conflict avoidance in time-critical situations. The scalability of such a concept, allows for an evolutionary approach or a gradual implementation, where the level of integration with other systems, and corresponding capabilities, can be increased in a gradual fashion. The approach discussed in this paper aims to enable an airspace integration capability without having to do a "big bang" development where the entire envisioned air traffic management system is realized in one spiral, development cycle, or acquisition. It is an important part of gradually increasing the effectiveness of unmanned aircraft operations and making operations more flexible.
This paper describes the work that was done by Boeing Advanced Air Traffic Management (AATM) and IBM on the Joint Network Enabled Operations (NEO) Spiral One Project and carried forward using internal research and development funding. NEO is a project that provides interagency communication and collaboration through the use of modern network focused information systems tools and technologies. The work described here provided a set of aviation related data and services that could be combined by using IBM's Mashup technology. Mashup technology provides the capability to create lightweight, network- enabled applications by combining data and services according to user specifications. The Mashup environment allows users to create these applications in minutes. The applications are created by combining data and services that are realized as reusable components called widgets. Using the IBM Mashup environment, widgets providing access to aviation specific data and services such as an airports database, a runways database, Notices to Airman (NOTAM), Meteorological Reports (METAR), NOAA Rapid Update Cycle (RUC) Weather, the Corridor Integrated Weather System (CIWS), and other geospatial services were created. This paper shows how these widgets can be “wired” together to address a variety of aviation specific business cases.
Airport delays are a significant problem in the US air transportation system. Between 1999 and 2000 the number of flights delayed increased by 20 percent despite only a 0.4% increase in total operations. Newark International Airport (EWR), one of New York City's primary airports, is one of the airports in the US most impacted by delays. Newark had the highest percentage of operations delayed in 1999, and was second only to LaGuardia Airport in 2000. Nearly 85% of delays at Newark are caused by adverse weather impacting an airport that may be characterized as having limited capacity and a very full schedule. Although Newark is heavily impacted by weather, delays have not increased significantly since 1998. This indicates that the airlines, air traffic control (ATC), and the Port Authority of New York and New Jersey have successfully adapted.
While new versions of automated control systems such as flight guidance systems are introduced at a rapid pace, it is widely recognized that user interaction with these machines is increasingly problematic. One cause for this difficulty that is commonly cited in the literature, is the discrepancy between the machine's behavior and the operator's (e.g., pilot) expectations. This paper discusses a formal approach to the analysis of operator's interaction with complex automated control systems. We focus attention on the issue of interface correctness; that is, on the question whether the display provides adequate information about the machine's configurations (states, modes, and associated parameters) and transitions, so as to enable the operator to successfully perform the specified set of tasks. To perform the analysis several assumptions are made: (1) A complete formal model of the machine's behavior is available (e.g., as a state transition system, or as a hybrid-machine); (2) A specification of operator's tasks is available and can be formally described (e.g., the reliable and predictable transition between activities involved in executing a climb to a new altitude); (3) The pilot is well trained and has a correct 'mental' model of the machine's response-map. By 'comparing' the machine's model with the set of operator's tasks we formally (i.e., mathematically) evaluate two questions: 1) does the machine's output interface (display) enable the operator to determine, unambiguously, what the current configuration (e.g., mode) of the machine is, and 2) does the display enable the operator to determine, unambiguously, what the next configuration of the machine will be, in response to a specified interaction by the operator (e.g., engaging a mode or changing a parameter such as a speed or target altitude). This paper describes a methodology for conducting such an evaluation using examples from automated flight control systems of modem 'glass cockpit' jetliners. Taxonomy of the different types of discrepancies that lead to pilot inability to resolve the current and next configuration of the machine is suggested. Data from incident reports involving 'mode confusion' is used to corroborate these discrepancies. Finally, means for compensating, either by augmenting the display and/or the operator's 'mental model' are briefly mentioned.
A flight demonstration was conducted to address airport surface movement area capacity issues by providing pilots with enhanced situational awareness information. The demonstration showed an integration of several technologies to government and industry representatives. These technologies consisted of an electronic moving map display in the cockpit, a Differential Global Positioning System (DGPS) receiver, a high speed VHF data link, an ASDE-3 radar, and the Airport Movement Area Safety System (AMASS). Aircraft identification was presented to an air traffic controller on AMASS. The onboard electronic map included the display of taxi routes, hold instructions, and clearances, which were sent to the aircraft via data link by the controller. The map also displayed the positions of other traffic and warning information, which were sent to the aircraft automatically from the ASDE-3/AMASS system. This paper describes the flight demonstration in detail, along with preliminary results
The ability to accurately predict usable processing reserve is needed in many real-time software applications. Earlier research has shown that there are limits on the amount of available processor throughput that can be used to perform work with hard real-time deadlines. In this paper, we present an approach for determining and manipulating usable real-time processing reserve for multitasking systems that use preemptive, priority-based scheduling rules. Such systems must be prioritized using either rate monotonic, or deadline monotonic criteria. The approach computes real-time processing reserve for a schedulable task set, assuming that additional computation requirements will be levied on existing tasks. The approach includes a method for computing the maximum work that can be performed by an added task while preserving schedulability of the task set. Additionally, we introduce a method for balancing work within a task set to increase available real-time processing reserve. The method can be conditionally applied to harmonic tasks within a task set to improve the work efficiency of a processing resource.
In the next century, tactical air warfare will demand that fighter aircraft fly more sorties per day from austere or remote locations around the world with little or no logistics or maintenance support. To meet this demand, avionics must have greater functionality, adaptability, reliability and availability. The Air Force Pave PACE program, which began in 1990, is defining and developing the next generation avionics architecture for post-2000 aircraft. A key component of the software architecture is the "sensor manager", the software function which directs the operation of the Pave PACE integrated sensor suite. We look at the role of the integrated sensor manager in the Pave PACE avionics architecture, focusing on the operational issues which influence its design. Also a hierarchical sensor manager design is described which addresses these issues.< >
Considerable experience was acquired with Ada at the NASA Dryden Flight Research Facility during the on-going High Alpha Technology Program. In this program, an F-18 aircraft was highly modified by the addition of thrust-vectoring vanes to the airframe. In addition, substantial alteration was made in the original quadruplex flight control system. The result is the High Alpha Research Vehicle. An additional research flight control computer was incorporated in each of the four channels. Software for the research flight control computer was written in Ada. To date, six releases of this software have been flown. This paper provides a detailed description of the modifications to the research flight control system. Efficient ground-testing of the software was accomplished by using simulations that used the Ada for portions of their software. These simulations are also described. Modifying and transferring the Ada for flight software to the software simulation configuration has allowed evaluation of this language. This paper also discusses such significant issues in using Ada as portability, modifiability, and testability as well as documentation requirements.
An approach to automate the real-time analysis of flight critical health monitoring and system status is being developed and evaluated at the NASA Dryden Flight Research Facility. A software package was developed in-house and installed as part of the extended aircraft interrogation and display system. This design features a knowledge-base structure in the form of rules to formulate interpretation and decision logic of real-time data. This technique has been applied for ground verification and validation testing and flight testing monitoring where quick, real-time, safety-of-flight decisions can be very critical. In many cases post processing and manual analysis of flight system data are not required. The processing is described of real-time data for analysis along with the output format which features a message stack display. The development, construction, and testing of the rule-driven knowledge base, along with an application using the X-31A flight test program, are presented.
A technology applicable to the reflector antenna field is introduced. FLAPS (flat parabolic surface) allows the use of low-cost fabrication techniques to perform various collimating reflector functions, independently of any specific geometric shape, such as would be required with conventional reflectors. The various elements of control afforded by FLAPS technology allow versatile operation in a variety of simultaneous applications not normally compatible with conventional reflector designs
The existing and operationally proven X-band multifunction surface-based radar ARABEL is described. The salient points regarding the design are considered, including: phased array control; multiple waveform management; high performance in detection and location; real-time multifunction operation; and weight and size operational constraints. The final impact upon performance is measured in terms of target location accuracy, in a terrestrial referential: all mechanical and electronic contributions are accounted for in a comprehensive simulation of the total accuracy. Results of simulations are in good agreement with field measurements. The total angular root-mean-square (rms) accuracy is better than 3 mrad. This corresponds to a probability of 70% of not exceeding the guaranteed figure, for the checked Rayleigh distribution law
