Methodic aspects of aircraft glide slope correction for prevention of CFIT category accidents during pre-landing descent

Aviation accidents of the category of controlled flight into terrain in world commercial aviation are included into three "killers" in aviation together with loss of control in flight (LOC-I) and runway excursions (RE). As a result of long-term research of this problem the methods of CFIT risk level reduction, pilot training and retraining programs were developed and put into practice. Also several generations of onboard ground proximity or obstacle warning systems were created (GPWS, EGPWS, TAWS), the disadvantage of which is a passive – advisory type of warnings. The conclusions of the commissions concerning the results of aviation accidents investigations indicate the cases of crew disregard of an alarm of a ground proximity warning system and possibility of a go-around procedure to make a missed approach. Despite the aviation community actions, accidents of this category continue to occur. Therefore, search of new methods and solutions of the controlled flight into terrain problem is necessary. One of the possible ways to resolve this problem is making proximity warning systems active and two-mode operative. The first one is some type of warning to the crew about approaching the boundaries of a safe maneuvering area during approach to land as well as the recommendations to avoid a glide path deviation. The second way is that if the crew members don`t take any actions with a warning on or crew actions are not effective enough, it is necessary to regain a glide slope with temporary pilot disengagement from a control loop.

Investigating Untapped Capacity at Single-Runway Airports using Short Final Curved Approach, Dual Glide Slope, and Double Threshold

In Europe more than one third of the 100 busiest airports have only one runway and most of them have no possibility to build another one. Aircraft of all types and sizes must use that same runway which affects operational complexity. In such situations the problem of capacity appears since separation between aircraft is based on all of them following the same path and smaller aircraft following larger ones have to wait for the wake vortex to dissipate, in the case of both arrivals and departures. This paper offers a possible concept for increasing single-runway airport landing capacity. It is based on separating smaller aircraft to a final approach path that is not affected by the wake vortices produced by the larger aircraft. Published references dealing with this topic are included and discussed. The operation rules proposed are based on existing standards and some best practices. This paper does not discuss available technological solutions.

Approximation of pilot operational behavior affecting noise footprint in steep approaches

Landing aircraft create noise that disturbs residents living close to airports. One method to reduce such noise is to fly the final approach at a steeper glide slope than the normal 3.0 glide slope, thus increasing the distance between the source of the noise and the ground. If this is performed, there is a risk that the operational behavior of the pilot counteracts the noise reduction possible to achieve, due to the fact that the pilot must manage the aircraft's speed on a steeper glide slope. For practical reasons, there are few live trials and studies on pilot behavior during steeper approaches. In this project, a method to approximate pilot operational behavior during slightly steeper approaches, using flight data recorder data from standard approaches, was developed. The method exploits the fact that flying an approach in tailwind conditions creates the same operational challenges for a pilot as flying a steeper than normal approach does. The method was applied to 1159 flights. The results indicate that the pilots' operational behavior will change when glide slope angle increases. Extension of final flap and landing gear in steeper approaches will take place at a greater height but closer to the airport than for standard 3.0 ILS approaches. The result can be a reduction of the noise from arriving aircraft by up to 2 dB in some areas beneath the approach path if a 3.5 glide slope angle is used.

Assessment of the GIS-Aided Precise Approach Using the GNSS-GBAS Landing Systems

The radio navigational Instrument Landing Systems (ILSs) are currently intended to guide the aircrafts in lateral and vertical dimensions to the runway surface safely and precisely. Therefore, they are strongly related to the geographic location of an airport and its runway(s). The ILS systems use the aids of the radio frequency radiation to achieve this purpose, depending on the ground emitting stations, and providing the guidance to the runway centreline location along with the glide slope guidance during the Final Approach Segment (FAS). Furthermore, the new ILS systems are fully aided by the coordinates of the Global Positioning System (GPS) instead of the ground radiations, they use the waypoint fixes during the landing phase of flight by means of transmitting their corrections to the on-board receivers. Those new invented Ground Based Augmentation Systems (GBAS) are more precise and trustable, they also increase the capacity of the huge air traffic demands nowadays by multiple and non-straight approaches. As a result, the Geographic Information System (GIS) of any airport supported by the GBAS system is intended to be fully used and implemented in both instrumental and procedural aids. Many previous studies had indicated that the old procedural approaches should be changed to the new GIS aided ones, but without pointing out when and how to implement such important transfer. The purpose of this study is to assess the performance of the GIS aided precision procedures using the GBAS stations, and to identify to what extent they can enhance the navigational aviation in the air traffic management domain. A special focus will be put on the Hungarian Budapest international airport in terms of both capability motivating factors and the current GIS infrastructure aiding. Results showed a promising chance for more investment in installing the GBAS stations in the airport. That will enable more capacity and easier approaches in all weather conditions.

A L1 Adaptive Control Scheme for UAV Carrier Landing Using Nonlinear Dynamic Inversion

This paper presents a L1 adaptive controller augmenting a dynamic inversion controller for UAV (unmanned aerial vehicle) carrier landing. A three axis and a power compensator NDI (nonlinear dynamic inversion) controller serves as the baseline controller for this architecture. The inner-loop command inputs are roll-rate, pitch-rate, yaw-rate, and thrust commands. The outer-loop command inputs come from the guidance law to correct the glide slope. However, imperfect model inversion and nonaccurate aerodynamic data may cause degradation of performance and may lead to the failure of the carrier landing. The L1 adaptive controller is designed as augmentation controller to account for matched and unmatched system uncertainties. The performance of the controller is examined through a Monte Carlo simulation which shows the effectiveness of the developed L1 adaptive control scheme based on nonlinear dynamic inversion.

INTEGRATED 3D SURVEY AND DIAGNOSTIC ANALYSIS FOR THE BUILDING ENGINEERING: THE FORMER KINDERGARTEN SAN FILIPPO NERI IN DALMINE

<p><strong>Abstract.</strong> The paper aims to emphasise the positive contribution that the 3D laser scanning and digital photogrammetry survey, integrated with diagnostic analysis techniques, can make in the field of construction engineering. The case study of the former kindergarten San Filippo Neri in Dalmine intends to contribute to the development of methodologies and operational tools related to the knowledge and conservation of modern and contemporary heritage. After archival research aimed at retracing the building's technical-constructive evolution, the study was extended out through the metric and morphological survey of both its external walls and internal spaces, paying special attention to the analysis of the deformations of the large horizontal surfaces, such as floors and ceilings. Diagnostic investigations – thermographic and microclimatic – have completed the survey campaign, so allowed to read both the envelope and the substance of the building, and to identify the critical issues. This work adopts and shows the correct glide slope to succeed in an adaptive reuse project in which the design stage can result solely from the in-depth study of the building.</p>