Takeoff Performance Monitoring Research Articles

Experimental Testing of a Parametric-Model-Based Takeoff Performance Monitoring Strategy

The purpose of an aircraft takeoff performancemonitoring system is to provide to the pilot information pertaining to the level of safety with which a takeoff is proceeding. The concept of a takeoff performance monitoring system is not new. Instruments have been developed and flight-tested. However, the inclusion of a takeoff performance monitoring system as a standard instrument has yet to be embraced by manufacturers and operators. A simple theoretical dynamicmodel was developed to investigate the feasibility of using an observer systemduring the roll and takeoff phases of aircraft operation to provide to the pilot the information that is needed to maneuver safely. The viability of this simple model was validated using a prototype device installed in a 19-passenger commercial turboprop aircraft. Unlike previous work in this field, the Global Positioning Systemwas proposed as the sole source of kinematic information. This provided the possibility that a takeoff performance monitoring system could be devised that would require no additional ground-based installation. A Global Positioning System receiver and data acquisition systemwere installed in an aircraft operated by an airline servicing far-northernCanadian airports. The experimental investigation that was conducted to validate the theoretical model and signal processing technique showed that it was possible to predict the displacement of an aircraft to within 15 m, the length of the test aircraft, in sufficient time to aid the pilot in decision-making.

Bi-modal Aircraft Cockpit User Interface of the TABI/A

Transport regulators are examining the feasibility of requiring the adoption of takeoff performance monitoring systems in certain circumstances. Recent advances in the development of aircraft landing and takeoff performance monitoring systems have shown the feasibility of a cockpit instrument that could aid significantly in the decision making process during the most critical phases of flight, provided that the information can be effectively visualized. The design and construction of a cockpit interface to communicate the information in a timely and efficient manner has now been completed. The resulting Thrust and Braking Indicator/Advisor (TABI/A) integrates a visual display with audible advice.

Bi-modal Aircraft Cockpit User Interface of the TABI/A

Transport regulators are examining the feasibility of requiring the adoption of takeoff performance monitoring systems in certain circumstances. Recent advances in the development of aircraft landing and takeoff performance monitoring systems have shown the feasibility of a cockpit instrument that could aid significantly in the decision making process during the most critical phases of flight, provided that the information can be effectively visualized. The design and construction of a cockpit interface to communicate the information in a timely and efficient manner has now been completed. The resulting Thrust and Braking Indicator/Advisor (TABI/A) integrates a visual display with audible advice.

Design, Integration, and Preliminary Assessment of a Takeoff Monitor Display

The takeoff performance monitor is an instrument that monitors the progress of the takeoft and provides advisory information intended to support the crew in their decision to continue or abort the run. A critical component of the instrument is the display design. This paper reviews the requirements for, and constraints associated with, such a display and presents design criteria established at Cranfield University. The Cranfield design is then discussed, explaining the interpretation of the display in operation. Issues relating to the integration on board the flight deck and the reasoning behind critical design aspects are also described in detail.

Improved Algorithm for Takeoff Monitoring

The scope of takeoff monitoring is to provide a measure of aircraft performance during the takeoff run and to identify whether this lies within the predetermined limits of scheduled performance or otherwise. Used in conjunction with a good display, such a system, provided it is adequately reliable, will provide critical situational awareness to the crew and will thus contribute towards improving safety during takeoff. Cranfield University has developed a takeoff performance monitor based on an algorithm that determines estimates of relevant parameters from the history of the particular takeoff run, rather than relying on scheduled estimates. This, however, resulted in a delay between the start of the run and the generation of the first estimate of performance. This paper describes the improvements in performance achieved by the introduction of a modification that uses measured thrust-to-weight ratio to significantly shorten the delay and improve prediction accuracy, particularly at the start of the run.

Evaluation of Takeoff Performance Monitoring Algorithm in Large Jet Transport Operations

The issue of monitoring aircraft performance during takeoffhas been repeatedly considered in the last 50 years. This has been in response to concern over the low safety margins associated with this phase of flight and the lack of adequate objective performance-related information available to the crew during the takeoff maneuver. Two major difficulties, however, have to date inhibited the successful introduction of an instrument providing such information on the flight deck, namely, the provision of a reliable quantification of actual performance during the takeoff maneuver and the provision of an adequate display. This paper focuses on the former issue and evaluates the accuracy of a predictive performance monitoring algorithm developed at Cranfield University. The major hurdles that are associated with takeoff performance monitoring are briefly discussed, and the results of flight-based tests using data from large jet-transport operations presented. These results, which confirm a robustness that warrants the application of the algorithm in real-time performance monitoring, are also compared with those of an earlier flight test program using a twin turboprop aircraft.

Application of the Global Positioning System in Determination of Vehicular Acceleration

Aircraft landing and takeoff performance monitoring is an area of research aimed at improving the information available to the pilot for decision making during takeoff or landing. A system capable of instantaneously determining the stopping distance of an aircraft could form an integral component of a monitoring system. Particularly difficult to quantify is the frictional coefficient between the runway and the aircraft tires, should such a measurement be necessary. In secluded far-northern regions, where a monitoring system would be particularly useful given adverse weather, few airports are equipped to attempt frictional measurements. In such instances a monitoring system would need to be totally self-contained and able to determine aircraft ground speed, acceleration, and position relative to the end of the runway. Prediction of the aircraft's location at rest is then possible. It is proposed that the Global Positioning System (GPS) be used to determine aircraft acceleration, ground speed, and position relative to the end of the runway. A practical evaluation of the feasibility of this proposal showed clear superiority of a GPS-derived acceleration over a more traditional method employing accelerometers. Advantages of the GPS-derived measurement include a modest noise level, insusceptibility to gravity and temperature-influenced variations, and far simplified mounting criteria.

Takeoff performance monitoring system display options

This article summarizes the development of head-up and head-down cockpit displays for an airplane takeoff performance monitoring system (TOPMS). Basic TOPMS displays provide pilots with real-time graphic information concerning their airplane's current and projected runway performance. The displays also indicate the status of associated airplane systems (e.g., flaps, engines) and optionally, they provide advice and a continually updated prediction of where the airplane can be braked to a stop. The displays have been developed and evaluated on the NASA Transport System Research Vehicle (TSRV) B-737 simulator by more than 40 government, airline, and industry pilots who rated the displays favorably and judged them easy to monitor. The TOPMS has also been flight tested successfully on the TSRV B-737. Based on these evaluations and on discussions with the commercial aircraft community, the displays have evolved to a baseline final configuration containing basic performance and system-status data to which GO/NO-GO advisory and predicted stop point information can be added as options.

Evaluation of a takeoff performance monitoring system display

A takeoff performance monitoring system (TOPMS) has been developed to provide a pilot with graphic/numeric information pertinent to his decision to continue or abort a takeoff. The TOPMS instrument display consists primarily of a runway graphic overlaid with symbolic status and advisory information including 1) current position and airspeed, 2) predicted locations for reaching decision speed V and rotation speed VR, 3) ground-roll limit for reaching VR, 4) predicted stop point for an aborted takeoff from current conditions, 5) engine-failure flags, and 6) an overall situation advisory flag that recommends continuation or rejection of the takeoff. In this study, over 30 experienced multiengine pilots evaluated the TOPMS display on the Langley B-737 real-time research simulator. The display was well received and judged easy to monitor and comprehend.

Development of a takeoff performance monitoring system

The development and testing of a real-time takeoff performance monitoring system is discussed. The algorithm is madeup of two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate schedule performance data for that takeoff. The real-time segment uses the scheduled performance data generated in the pretakeoff segment, runway length data, and measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane and engine performance deficiencies are detected and annunciated. An important feature of this algorithm is the one-time estimation of the runway rolling friction coefficient. The algorithm was tested using a six degree of freedom airplane model in a computer simulation. Results from a series of sensitivity analysis are also included.