Design and Testing of a Vertically Guided High Precision Approach into Salzburg Airport

The approach to landing on runway 33 of Salzburg Airport, Austria is severely impacted by mountainous terrain on the extended runway centerline. This renders all straight-in approaches but those based on Required Navigation Performance (RNP) Authorization Required (AR) impossible. Only the high navigation accuracy available under RNP AR minimizes the required obstacle protection areas sufficiently to be not penetrated by terrain. The combination of RNP AR and Localizer Performance with Vertical guidance (LPV) makes it furthermore possible to use a more precise angular guidance for the final approach. In Salzburg, this enables a reduction of the decision height from 368 ft to 218 ft above aerodrome level as critical terrain and obstacles now fall outside of the protection areas. A Level D full flight simulator test with an Airbus A350 showed that advanced RNP 0.1 coding is sufficient to achieve RNP 0.1 performance under all permitted environmental conditions

Special issue conclusion : The GLES Open Science Challenge 2021 in hindsight: experiences gained and lessons learned

Die GLES Open Science Challenge 2021 ist ein Pilotprojekt, das zeigt, dass Registered Reports ein geeignetes und gewinnbringendes Publikationsformat in der quantitativen Politikwissenschaft sind, die dazu beitragen können, die Transparenz und Replizierbarkeit im Forschungsprozess zu erhöhen und somit substanzielle und relevante Beiträge für unsere Disziplin zu liefern. Das Ergebnis ist die Veröffentlichung dieses Sonderheftes mit sieben Registered Reports, die auf Daten der German Longitudinal Election Study (GLES) basieren, die im Rahmen der Bundestagswahl 2021 erhoben wurden. Dieser abschließende Artikel des Sonderheftes bringt die Perspektiven von Autor*innen, Gutachter*innen, Organisator*innen und Herausgeber*innen zusammen, um eine Bilanz der verschiedenen Erfahrungen und Lehren zu ziehen, die im Laufe dieses Projektes gewonnen wurden

Development of an RNP AR APCH approach procedure within tight airspace constraints

Required navigation performance authorization required (RNP AR) approach (APCH) procedures are a special form of approaches with vertical guidance (APVs) where tougher navigation system requirements in terms of accuracy, integrity and functionalities allow smaller obstacle clearance areas and the use of curved legs in all approach segments. That leads to very flexible approach design possibilities compared to other instrument approach procedures and becomes especially valuable at airports surrounded by limiting terrain and/or airspace. This paper guides through the development of an RNP AR approach on runway 15L at Isa Air Base in Bahrain. The establishment of instrument approaches on this runway has been complicated so far as the final approach would have led straight through the controlled traffic region (CTR) of an adjacent air base. We show that entering the CTR, which ends less than 3.3 NM before the runway threshold, can be avoided with an RNP AR approach by employing a curved leg in the final approach segment and the highest possible navigation accuracy of RNP 0.1 – two unique features of RNP AR APCH. We then fly and test the procedure in an Airbus A320 level D full flight simulator under the wind and weather conditions considered by the procedure design rules. The results show that the actual navigation performance met the required one, so that we can prove that our approach is safe to fly

Design and Testing of RNP AR to SBAS LPV approaches into Salzburg Airport

We designed and tested a Required Navigation Performance (RNP) Authorization Required (AR) to Localizer Performance with Vertical guidance (LPV) supported by the space-based augmentation system of GPS approach for runway 33 of Salzburg Airport, Austria. Approach to landing on runway 33 is severely impacted by mountainous terrain to the south of the airport that lies within the runway extended centerline, endering all straight-in approaches but those based on RNP AR impossible. That is due to the high navigation accuracy available under RNP AR. It makes it possible to keep the obstacle protection areas, which are constructed around the approach path andmust be clear of obstacles to ensure the required obstacle clearance, very small so that they do not extend into the terrain. The combination of RNP AR and LPV, in turn, makes it possible to use the more precise angular guidance for the final approach available under LPV while still being able to exploit the significantly smaller RNP AR protection areas in all approach segments. In Salzburg, this enables us to reduce the minima from 368 ft to 218 ft above runway threshold level while at the same time establishing a longer final approach segment compared to existing RNP AR approaches because critical terrain and obstacles now fall outside of the protection areas. For the intermediate approach, we use curved legs based on a constant radius between two fixes (Radius to Fix legs) that lead onto the final approach course, followed by a horizontal segment to account for possible altitude differences when changing from barometric to geometric LPV altitude. The length of this segment is minimized based on current procedure design rules for standard LPV approaches, which are also used as a basis for the merging of the different protection areas. The approach is coded as advanced RNP with 0.1 nautical mile values for the 95-percent lateral accuracy (RNP 0.1) on each sequence as RNP AR can otherwise not be combined with LPV under the database coding standard ARINC 424. Level D full flight simulator tests with an Airbus A350 showed that this coding is sufficient to achieve RNP 0.1 performance under all permitted conditions with the approach being presented to the pilots as RNP AR. However, further research must go into the flyability of approach at very high temperatures, where the LPV glide path was missed due to configuration errors made by the pilots and the approach could not be repeated due to time constraints

Development and Evaluation of an RNP AR APCH approach procedure under tight airspace constraints

Required navigation performance authorization required (RNP AR) approach (APCH) procedures are a special form of approaches with vertical guidance (APVs) where stricter navigation system requirements in terms of accuracy, integrity and functionalities allow smaller obstacle clearance areas and the use of curved legs in all approach segments. That leads to very flexible approach design possibilities compared to other instrument approach procedures. This paper guides through the development and initial evaluation of an RNP AR approach on runway 15L at Isa Air Base in Bahrain. The establishment of instrument approaches on this runway has been complicated so far because the final approach would have led straight through the controlled traffic region (CTR) of an adjacent air base. We show that entering the CTR, which ends less than 3.3 NM before the runway threshold, can be avoided with an RNP AR approach by employing a curved leg in the final approach segment and the highest possible navigation accuracy of RNP 0.1—two unique features of RNP AR APCH. We then fly and test the developed procedure in an Airbus A320 full-flight simulator under the wind and weather conditions considered by the procedure design rules. The results show that the actual navigation and flight technical performance met the required one under all conditions without the bank angle and effective glide path limits being exceeded. An initial flight test with a Boeing B737-800 showed that the approach can also be flown with sufficient accuracy in practice

Flight Testing GLS Approaches using SBAS with the DLR A320 Advanced Technology Research Aircraft

We designed and built a system intended to combine the advantages of both the ground based and the satellite based augmentation systems (GBAS, SBAS) by using a converter between them. We installed a prototype system at Salzburg Airport and flight tested it on 12th of February 2020 using DLR’s A320 test aircraft equipped with flight test instrumentation. Using our system, 3D GLS type approaches are possible at any airport within the coverage of the SBAS. The system includes an SBAS-capable global navigation satellite systems receiver with a database and a GBAS-compatible data link. The correction and integrity data received from the SBAS satellite are automatically translated into GBAS compatible structures and sent to the airborne GBAS receiver using the final approach segment data block Without SBAS the system can revert to differential GPS. In both GBAS and SBAS, instant integrity information is provided by estimating protection levels, a high probability bound for the computed position. This is then compared to the alert limit of the respective system. Since both systems are quite similar, and the SBAS signal can nowadays be decoded even by low cost receivers, one can receive the augmentation data from the SBAS, slightly modify it to fit into the GBAS data structure and broadcast this data to a GBAS equipped aircraft. Said aircraft could execute a RNP approach with the Localizer Performance and Vertical guidance (LPV) final approach segment which would otherwise not be available. This may come especially handy in places where no non-precision minima are published, such as the RNP-E approach into Innsbruck and Salzburg. Since there are slight differences between the two systems, we made sure that integrity for the safety-of-life approach service is ensured. We named the system GLASS (GLS Approaches using SbaS), built a prototype and tested it with real GBAS avionics hardware. We performed 4 approaches to Salzburg Airport in Austria (LOWS). Salzburg is now equipped with a RNP approach using LPV only to runway 15 with significantly a lower minimum than the RNP approach with LNAV minimum called the RNP E 15. This is due to the location of the new missed approach point. Using the GLASS system, all GLS equipped aircraft would be able to take advantage of this new minimum line. We followed the approach track using FMS guidance and recorded the ARINC 429 output from the Collins GLU925 Multimode Receiver (MMR). The GLASS guidance was provided to the pilot on the electronic flight bag display for reference. We show a complete analysis of integrity data, MMR status information and MMR output guidance. We compare the GLS data from the MMR with standard SBAS data from an onboard Septentrio PolaRx3 receiver. The GLASS system provides the LPV final approach segment to GLS-only equipped aircraft such as the Boeing 737-800. This can enable increased access to airports that are currently not equipped with an xLS type approach such as Innsbruck (LOWI). Especially approaches in France could be of interest, since the government has officially declared to decommission all category I ILS installations in favor of RNP approaches with LPV. The system could also be carried on the airborne side rather than be a fixed installation on the ground. With a pilot selectable FAS block, it could enable LPV approaches without modifications to existing airborne hardware. Thus, any GLS capable aircraft could fly LPV approaches without requiring ground infrastructure modifications. In this case, the protection level scaling from GBAS is not an issue, since it can be compensated for by the GLASS system

Good things come easy: Subjective exposure frequency and the faster processing of positive information

Processing of evaluative information is a central theme in social cognition research. Most studies focus on processing advantages associated with negative information. Here, we demonstrate and explain the faster processing of positive information. Building on the "density" hypothesis (Unkelbach et al., 2008), we predicted that this advantage is explained by higher subjective exposure to positive information, and not valence per se. We argue that subjective exposure is a phenomenological proxy for informational density in memory. Three studies confirmed this prediction. Study 1 found that people were faster to identify positive than negative words. Using path analysis, Study 2 demonstrated that subjective exposure accounted for this valence effect. Study 3 replicated these findings when objective frequency was controlled across positive and negative valence. The implications for theories of how evaluative information is detected, processed, and retrieved are discussed