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Home » All Evidence from Incident Studies All Evidence from Incident Studies 77 matching pieces of evidence found.   Evidence Type: Excerpt from Incident Study Evidence: The autopilot behavior is perplexing; it responds differently to the same pilot action. Setting the altitude to a value behind the current aircraft altitude results in two different responses: In the first case the aircraft will continue at the current climb-rate and "kill the capture". In the second case the aircraft will capture the newly set altitude. So how can the pilot anticipate what the aircraft will do in each case? It turns out that there is a hidden condition here, that revolves around the altitude at which the aircraft transitions to the "Capture" mode (7,000 feet in our example): If the newly set altitude is below (e.g., 6,000 feet) the "start capture altitude", then the aircraft will kill the capture. But if the newly set altitude is above (e.g., 8,000 feet) the "start capture altitude", the aircraft will capture the specified altitude. Do pilots know about this behavior and the condition? No. It’s not in the manual nor is it mentioned in ground school or Initial Operating Experience (IOE) -- it is practically unknown! Now we are not talking about some minor deficiency, but a critical maneuver that sometimes takes place very close to the ground. The pilots’ user-model is inadequate for the task of capturing an altitude after resetting the altitude to a value behind the aircraft. If we go back to our earlier discussion, we have a condition in which the user-model is inadequate for the task. This deficiency corresponds to region 3 in Figure 1. (page 6/7) Issue: automation behavior may be unexpected and unexplained (Issue #108) See Issue details Strength: +1 Aircraft: unspecified Equipment: autoflight: autopilot Source: Degani, A., & Heymann, M. (2000). Pilot-Autopilot interaction: A formal perspective. Eighth International Conference on Human-Computer Interaction in Aeronautics, Toulouse, France. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: The autopilot behavior is perplexing; it responds differently to the same pilot action. Setting the altitude to a value behind the current aircraft altitude results in two different responses: In the first case the aircraft will continue at the current climb-rate and "kill the capture". In the second case the aircraft will capture the newly set altitude. So how can the pilot anticipate what the aircraft will do in each case? It turns out that there is a hidden condition here, that revolves around the altitude at which the aircraft transitions to the "Capture" mode (7,000 feet in our example): If the newly set altitude is below (e.g., 6,000 feet) the "start capture altitude", then the aircraft will kill the capture. But if the newly set altitude is above (e.g., 8,000 feet) the "start capture altitude", the aircraft will capture the specified altitude. Do pilots know about this behavior and the condition? No. It’s not in the manual nor is it mentioned in ground school or Initial Operating Experience (IOE) -- it is practically unknown! Now we are not talking about some minor deficiency, but a critical maneuver that sometimes takes place very close to the ground. The pilots’ user-model is inadequate for the task of capturing an altitude after resetting the altitude to a value behind the aircraft. If we go back to our earlier discussion, we have a condition in which the user-model is inadequate for the task. This deficiency corresponds to region 3 in Figure 1. (page 6/7) Issue: behavior of automation may not be apparent (Issue #83) See Issue details Strength: +1 Aircraft: unspecified Equipment: autoflight: autopilot Source: Degani, A., & Heymann, M. (2000). Pilot-Autopilot interaction: A formal perspective. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: Actually, not. The display is also inadequate for the task – and here is why: To resolve what the aircraft will do we need to know the altitude at which the autopilot transitions to capture (e.g., 7,000 feet). But in practice, it is almost impossible to obtain this value with the current display. First, the pilot has no preview of this value and the interface does not display it. Secondly, the transition to the "Capture" mode happens automatically. In order to obtain the altitude at which the autopilot transitions to "Capture", the pilot must "hunt" for the automatic transition, and at that very moment look down to the altitude tape on the interface and catch the aircraft altitude as it rolls by. Thirdly, this altitude value is not retained by the display; once the transition takes place, the value is gone and there is no way to retrieve it. For all practical purpose, it is impossible to reliably obtain this value. The current display is indeed inadequate for the task. (page 7) Issue: displays (visual and aural) may be poorly designed (Issue #92) See Issue details Strength: +1 Aircraft: unspecified Equipment: automation: displays Source: Degani, A., & Heymann, M. (2000). Pilot-Autopilot interaction: A formal perspective. Eighth International Conference on Human-Computer Interaction in Aeronautics, Toulouse, France. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: Actually, not. The display is also inadequate for the task – and here is why: To resolve what the aircraft will do we need to know the altitude at which the autopilot transitions to capture (e.g., 7,000 feet). But in practice, it is almost impossible to obtain this value with the current display. First, the pilot has no preview of this value and the interface does not display it. Secondly, the transition to the "Capture" mode happens automatically. In order to obtain the altitude at which the autopilot transitions to "Capture", the pilot must "hunt" for the automatic transition, and at that very moment look down to the altitude tape on the interface and catch the aircraft altitude as it rolls by. Thirdly, this altitude value is not retained by the display; once the transition takes place, the value is gone and there is no way to retrieve it. For all practical purpose, it is impossible to reliably obtain this value. The current display is indeed inadequate for the task. (page 7) Issue: information integration may be required (Issue #9) See Issue details Strength: +1 Aircraft: unspecified Equipment: automation: displays Source: Degani, A., & Heymann, M. (2000). Pilot-Autopilot interaction: A formal perspective. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: "The data presented in Table 4-1 suggest the same underlying problem: The crew fails to operate the FMS properly and, at the same time, fails to catch the error before an incident occurs." Table 4-1 shows the breakdown of the number of citations for various Flight Crew FMS Actions/Errors: Keyboard Errors - 15 citations (15%), Logic Errors - 3 citations (3%), Errors of Expectation/Interpretation (ATC related) - 12 citations (12%), Errors of Expectation/Interpretation (FMS logic related) - 27 citations (27%), and Mode control panel (MCP)/automation control selection errors - 18 citations (18%). [Total citations = 99, several categories are not listed in Table 4-1] (page 4.1) Issue: automation behavior may be unexpected and unexplained (Issue #108) See Issue details Strength: +2 Aircraft: unspecified Equipment: FMS Source: Eldredge, D., Mangold, S., & Dodd, R.S. (1992). A Review and Discussion of Flight Management System Incidents Reported to the Aviation Safety Reporting System. Final Report DOT/FAA/RD-92/2. Washington, DC: U.S. Department of Transportation, Federal Aviation Administration. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: "Several of the reports appear to indicate that the FMS can be programmed correctly, provide feedback to indicate this, yet still not perform as intended." (page 4.26) Issue: automation behavior may be unexpected and unexplained (Issue #108) See Issue details Strength: +1 Aircraft: unspecified Equipment: FMS Source: Eldredge, D., Mangold, S., & Dodd, R.S. (1992). A Review and Discussion of Flight Management System Incidents Reported to the Aviation Safety Reporting System. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: "5. CONCLUSIONS ... The major issues associated with the FMS-related incidents, addressed in this analysis include: - Raw Data and FMS/Aircraft Status Verification - FMS Algorithmic 'Behavior' - Improper Use of the FMC Automation Level - FMC Programming Demands - Multiple FMC Page Monitoring Requirements - Complex ATC Clearances - Complex FMC/CDU Tasks - Lack of Adequate Pilot Training - FMC/MCP Interaction Errors - Inaccurate Pre-Stored Databases All of these factors, singly or together, can combine to increase the pilots' workload to the point that they lose their situational awareness and 'get behind the airplane.' In this situation, the pilot who continues to focus on trying to understand what the FMC/CDU is doing is no longer truly involved in flying the airplane, but trying to troubleshoot a computer that happens to be installed in an airplane. The pilots that did best with FMS-related problems, in high workload situations, were those that elected to reduce the level of automation (by turning OFF the selected function) and appeared to recognize that they needed to become actively involved in flying the airplane. From these reports, it is clear that the current FMSs have not been designed for optimal use under all circumstances, by the flight crew, in the environment where ATC is heavily burdened and expects pilots to remain flexible and responsive to their changing needs of moving traffic. Based on this analysis, it would appear that pilots should not try to use the full features of the FMS under all conditions. Many of the pilots submitting these reports learned that fact, but only after they experienced the incident that initiated the ASRS report. This lends credence to those pilots who argued that the training they received was not adequate to prepare them for using these systems operationally." (page 5.1) Issue: automation may adversely affect pilot workload (Issue #79) See Issue details Strength: +1 Aircraft: unspecified Equipment: FMS Source: Eldredge, D., Mangold, S., & Dodd, R.S. (1992). A Review and Discussion of Flight Management System Incidents Reported to the Aviation Safety Reporting System. Final Report DOT/FAA/RD-92/2. Washington, DC: U.S. Department of Transportation, Federal Aviation Administration. See Resource details   Evidence Type: Excerpt from Incident Study Evidence: "From these reports, it is clear that the current FMSs have not been designed for optimal use under all circumstances, by the flight crew, in the environment where ATC is heavily burdened and expects pilots to remain flexible and responsive to their changing needs of moving traffic." (page 5.1) Issue: automation may not work well under unusual conditions (Issue #150) See Issue details Strength: <