Search Results

Passenger boarding is always part of the critical path of the aircraft turnaround: both efficient boarding and online prediction of the boarding progress are essential for a reliable turnaround progress. However, the boarding progress is mainly controlled by the passenger behavior. A fundamental scientific approach for aircraft boarding enables the consideration of individual passenger behaviors and operational constraints in order to develop a sustainable concept for enabling a prediction of the boarding progress. A reliable microscopic simulation approach is used to model the passenger behavior, where the individual movement is defined as a one-dimensional, stochastic, and time/space discrete transition process. The simulation covers a broad range of behaviors and boarding strategies as well as the integration of new technologies and procedures.

In the last decades there have been many temporary engine failures, engine-related events and erroneous airspeed indication measurements that occurred by a phenomenon known as Ice Crystal Icing (ICI). This type of icing mainly occurs in high altitudes close to tropical convection in areas with a high concentration of ice crystals. Direct measurements or in-situ pilot observations of ICI that could be used as a warning to other air-traffic are rare to nearly non-existent. To detect those dangerous high Ice Water Content (IWC) areas with already existing airborne measurement instruments, Lufthansa analyzed observed Total Air Temperature (TAT) anomalies and used a self-developed search algorithm, depicting those TAT anomalies that are related to ice crystal icing events.

This paper focuses on the numerical simulation of the motion of regular shaped ice particles under the forces and torques generated by aerodynamic loading. Ice particles can occur during landing and take-off of aircraft at ground level up to the stratosphere at cruising altitude. It may be expected that the particle Reynolds number is high because the flow around the aircraft is in certain regions characterized by strong acceleration and deceleration of the flow. In combination with this flow pattern, the rotation of particles becomes important. Applicable translational and rotational equations of motion combined with a drag correlation taking into account rotation will be derived for a Lagrangian type particle tracking. Orientation is described with quaternions to prevent the singularities associated with the description by Euler angles. The influence of regular shaped particles on collection efficiencies is investigated.

The EU Horizon 2020 project SENS4ICE addresses reliable detection and discrimination of supercooled large droplets (SLD) icing conditions. These conditions are considered as particularly safety-relevant and have been included in airplane certification specifications. The SENS4ICE project comprises technology development, icing wind tunnel upgrading/testing and flight testing. A novel hybrid approach for icing detection combines direct sensing (atmospheric conditions / ice accretion) with an indirect technique based on changing aircraft characteristics. The first part of the project was devoted to the development and maturation of icing detection technologies, with a focus on Appendix O (of 14 CFR Part 25 and CS-25) icing conditions. Furthermore, several icing wind tunnel facilities have improved capabilities to represent Appendix O conditions.

The measurement and in-flight characterization of atmospheric icing conditions remains a challenging task. This is due to the large variability of microphysical properties of icing conditions. Icing may occur in pure supercooled liquid clouds of various droplet sizes, it may contain freezing drizzle or freezing rain drops and it also takes place in various types of mixed-phase conditions. A sensor or a combination of sensors to discriminate these icing environments would therefore be beneficial. Especially the phase classification of small cloud particles is still difficult to assess. Within the SENS4ICE project, the German Aerospace Center (DLR) suggests the use of the Nevzorov probe and the Backscatter Cloud Probe with Polarization Detection (BCPD) for the detection and differentiation of icing conditions during research missions that lack standard underwing probes.

The European Union’s Horizon 2020 programme has funded the SENS4ICE (Sensors for Certifiable Hybrid Architectures for Safer Aviation in Icing Environment) project [1], an innovative approach for the development and testing of new sensors for the detection of supercooled large droplets (SLD). SLD may impinge behind the protected surfaces of aircraft and therefore represents a threat to aviation safety. The newly developed sensors will be tested in combination with an indirect detection method on two aircraft, in two parallel flight programs: One on the Embraer Phenom 300 in the U.S. and one on the ATR-42 in Europe. In this framework the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center) is in charge of the airborne measurements and data evaluation of the microphysical properties of clouds encountered during the SENS4ICE field campaigns in February, March and April 2023.