Helge Lenz

Aircraft Wake Vortex Scenarios Simulation Package for Takeoff and Departure

The WakeScene-D software package (Wake Vortex Scenarios Simulation Package for Departure) has been developed for comprehensive airspace simulations of take-off and departure. WakeScene-D consists of modules that model traffic mix, aircraft trajectories, meteorological conditions, wake vortex evolution, and potential hazard area. The software package estimates the probability to encounter wake vortices in different traffic and crosswind scenarios using Monte Carlo simulation in a domain ranging from the runway to an altitude of 3000 ft above ground. The operating sequence of WakeScene-D, the employed sub-models and data bases, the simulation environment and evaluation tools together with the so far accomplished validation work are introduced.

Enabling advanced continuous descent approaches — Results of the European project optimal

This paper describes the development, implementation and validation of an extension module to a 4D capable Flight Management System to enable environmentally efficient CDA techniques in a future operational environment. It briefly explains an operational concept that will allow optimized CDA in high density traffic situations and demonstrates that with the developed FMS functions an optimized CDA can be flown in 4D so that a given RTA can be met with high accuracy. Flight trials with DLRs test aircraft ATTAS, a modified VFW 614 and with DLRs Advanced Flight Management System onboard, proved a highly accurate predictability of 4D optimized CDA trajectories. The work has been carried out within the OPTIMAL project [1], a European 6th Framework Program research project (2004–2008) which develops innovative procedures for the approach and landing phases of aircraft and rotorcraft. The objective is to minimize environmental impact and increase airport capacity while improving operational safety.

4D continuous descent operations supported by an electronic flight bag: A human-in-the-loop study

This paper describes a set of flight simulation experiments carried out with the DLRs Generic Cockpit Simulator (GECO). A new concept named time and energy managed operations (TEMO), which aims to enable advanced four dimensional (4D) continuous descent operations (CDO), was evaluated after three full days of experiments with qualified pilots. The experiment focused to investigate the possibility of using a 4D-controller on a modern aircraft with unmodified or only slightly modified avionic systems. This was achieved by executing the controller in an Electronic Flight Bag (EFB) and using the pilot to “close the loop” by entering speed and other advisories into the autopilot Flight Control Unit (FCU). The outcome of the experiments include subjective (questionnaires answered by pilots) and objective (trajectory logs) data. Data analysis showed a very good acceptance (both in terms of safety and operability of the procedure) from the participating crews, only with minor suggestions to be improved in future versions of the controller and the speed advisories update rates. Good time accuracy all along the descent trajectory was also observed.

Does Cognitive Lockup Depend on the Situation, on the Person, or on an Interaction of Both?

This paper focuses on investigating (a) whether cognitive lockup can be provoked in an experimental setup in a realistic, generic cockpit simulator and (b) whether the occurrence of cognitive lockup further depends on the pilot or on an interaction between the aviation situation and the pilot. To investigate these research questions, an experiment was conducted during which pilots aviated two scenarios. Both scenarios reflect an approach situation in which the second autopilot failed as a first event and the runway was changed as a second event. The main difference of the scenarios is the timing of the autopilot failure and the runway change: In the experimental condition, the events occurred later in time, which reduced the time frame available for the briefing. While aviating, the aircraft’s maximum deviation from the specified route was recorded. Statistical analyses showed that pilots were more drawn to cognitive lockup in the situation with more time-pressure resulting in a performance degradation in the aviation task. Aviation performance was further predicted by a significant interaction between the person and the situation, which shows a need to also consider person-related variables when explaining the occurrence of cognitive lockup.

Aircraft Wake Vortex Scenarios Simulation for Take-Off and Departure

The WakeScene-D software package (Wake Vortex Scenarios Simulation Package for Departure) has been developed for comprehensive airspace simulations of take-off and departure. WakeScene-D consists of modules that model traffic mix, aircraft trajectories, meteorological conditions, wake vortex evolution, and potential hazard area. The software package estimates the probability to encounter wake vortices in different traffic and crosswind scenarios using Monte Carlo simulation in a domain ranging from the runway to an altitude of 3000 ft above ground. The operating sequence of WakeScene-D, the employed sub-models and data bases, the simulation environment and evaluation tools together with the so far accomplished validation work are introduced. The current departure situation with a two-minute aircraft separation is compared to (i) a scenario with reduced separations of one minute, (ii) the mitigation effects of crosswind and (iii) the situation prevailing during approach and landing.

Operational landing credit with EVS head down display: crew procedure and human factors evaluation

Feasibility of an EVS head-down procedure is examined that may provide the same operational benefits under low visibility as the FAA rule on Enhanced Flight Visibility that requires the use of a head-up display (HUD). The main element of the described EVS head-down procedure is the crew procedure within cockpit for flying the approach. The task sharing between Pilot-Flying and Pilot-Not-Flying is arranged such that multiple head-up/head-down transitions can be avoided. The Pilot-Flying is using the head-down display for acquisition of the necessary visual cues in the EVS image. The pilot not flying is monitoring the instruments and looking for the outside visual cues. This paper reports about simulation activities that complete a series of simulation and validation activities carried out in the frame of the European project OPTIMAL. The results support the trend already observed after some preliminary investigations. They suggest that pilots can fly an EVS approach using the proposed EVS head-down display with the same kind of performance (accuracy) as they do with the HUD. There seems to be no loss of situation awareness. Further on, there is not significant trend that the use of the EVS head-down display leads to higher workload compared to the EVS HUD approach. In conclusion, EVS-Head-Down may be as well a feasible option for getting extra operational credit under low visibility conditions.

EVS: head up or head down

Feasibility of an EVS head-down procedure is examined that may provide the same operational benefits under low visibility as the FAA rule on enhanced flight visibility that requires the use of a head-up display (HUD). The main element of the described EVS head-down procedure is the crew procedure within cockpit for flying the approach. The task sharing between pilot-flying and pilot-not-flying is arranged such that multiple head-up/head-down transitions can be avoided. The pilot-flying is using the head-down display for acquisition of the necessary visual cues in the EVS image. The pilot flying is monitoring the instruments and looking for the outside visual cues. Results of simulation trials suggest that pilots can fly an EVS approach using the proposed EVS head-down display with the same kind of performance (accuracy) as they do with the HUD. There seems to be no loss of situation awareness. Further on, there is not significant trend that the use of the EVS head-down display leads to higher workload compared to the EVS HUD approach. In conclusion, EVS-head-down may be as well a feasible option for getting extra operational credit under low visibility conditions.

Just On Time - A Concept for iPad Enabled Timely Accurate Continuous Descent Operations

This paper describes the development of a concept to guide a transport type aircraft on a continuous descent while meeting a required time of arrival at a metering fix with an error of less than 10 seconds. This includes the development of the basic principle as well as a simulator study with three pilots. Following the improvement of the simulation model and the guidance algorithm a flight test campaign confirmed the performance of the implemented prototype and the acceptance of the concept by the pilots that was already seen after the simulator study. The development of the concept as well as the simulator campaign was done in the frame of the Clean Sky project sponsored by the European Commission. After promising results from the simulator campaign the work was continued as DLR internal project and the flight test results were made available to the Clean Sky consortium.