Research and Innovation Management HALS / DTOP High Approach Landing System / Dual Threshold Operation
HALS / DTOP 2 Table of contents HALS / DTOP High Approach Landing System / Dual Threshold Operation 3 Starting situation 3 Prinzip von HALS 3 DTOP concept 4 Next steps 4 Cooperation 5
HALS / DTOP 3 Research and Innovation Management HALS / DTOP High Approach Landing System / Dual Threshold Operation Starting situation The two parallel runways (25R and 25L) at Frankfurt Airport have a lateral separation of 518 meters from one another. The regulations of the International Civil Aviation Organization (ICAO), however, do not permit independent landing operations with such short distances between parallel runways. The reason for this directive is the whirlwind generated at the wing tips, so-called wake turbulence, which requires a certain separation from following aircraft. ICAO presently prescribes a separation of five nautical miles for aircraft of the wake turbulence category "Medium" following aircraft of the category "Heavy", even for diagonally stacked approaches with reduced lateral separation as at Frankfurt. The wake turbulence risk is thus one of the main criteria limiting the approach capacity at Frankfurt Airport. 25R 25L 26L Figures 1 and 2: Functional principle of the displaced landing threshold Prinzip von HALS The new landing procedure HALS/DTOP is an innovative option to solve the capacity problem at Frankfurt Airport, at least in the short term. The development and introduction of HALS is based on the knowledge that wake turbulence seldom spreads sideways between the time it is generated and the time it subsides. Extensive scientific research has shown that wake turbulence does not rise higher than 70 meters above the point at which it is generated. From the idea of creating a new, higher glidepath, a concept was developed for a second, strongly displaced landing threshold for the southern runway. Because of the horizontal shift of the landing threshold by 1500 meters, the glidepath is 90 meters higher than that of runway 25R. The remaining runway length of 2500 meters is more than enough for aircraft of the wake turbulence category medium up to the size of the Airbus
HALS / DTOP 4 A321. This second landing threshold was named 26L and is equipped with a new lighting and marking system designed specifically for this purpose, as well as an instrument landing system that permits landings up to weather category ILS CAT I. Figure 3: Lighting system for the displaced landing threshold 26L DTOP concept The HALS/DTOP concept was developed to use the two thresholds on one and the same runway simultaneously. HALS is a potential solution for the displaced threshold concept. HALS allows optimum utilization of the higher glidepath to reduce the required separation between heavy and medium aircraft pairs due to wake turbulence. Within the DTOP concept, the regular, existing, threshold and the new threshold on the southern runway will be used simultaneously. The potential for DTOP lies in the combination of the HALS procedure and conventional operations. Figure 4 illustrates the relationship. With the HALS procedure, the conventional threshold 25L cannot be used. The DTOP concept achieves a gain in operational flexibility in that the conventional threshold is available at the same time as the strongly displaced landing threshold (HALS). Next steps HALS The test phase that began in 1999 was completed in 2004. Since then, more than 4000 landings have been conducted successfully on runway 26L. Once the permit has been granted by the government, Fraport AG is planning to approve HALS for regular operations at Frankfurt Airport. DTOP Since 2004, Fraport has been working in cooperation with the Technical University Berlin on a project called Effects of Operating Two Landing Thresholds on One Runway as part of the LUFO III aviation research program of the German government.
HALS / DTOP 5 The goal of this project is to develop operating procedures across all partners within the interaction between air traffic control, pilots and airports to achieve: Optimum exploitation of the potential of dual threshold operations on one runway (DTOP) Reliable evidence of the capacity effects achievable Research into the working situation of pilots/controllers Flight operations safety evidence required for a permit for the procedure. The first DTOP study was successfully completed in the summer of 2004. This dealt with the demands on pilot workload under different weather conditions in view of the new lighting pattern with two active landing thresholds on one runway. The next step within the scope of the LUFO III project will be real-time DTOP simulation, which looks at the situation of the air traffic controllers in the approach and departure areas as well as, simplified, in the tower at Frankfurt Airport. Cooperation HALS/DTOP was developed by Fraport AG in cooperation with Deutsche Lufthansa AG and the German Air Traffic Control Service (DFS). Fraport developed the lighting and runway marking system and is entrusted with overall project coordination. Fraport also has the general leadership within the LUFO III DTOP procedure. DFS was responsible for implementation of the instrument landing system, development and introduction of air traffic control operating procedures, as well as for conducting the trial operations for HALS. On behalf of Fraport AH, DFS is carrying out the real-time simulation. Lufthansa is supporting the project by carrying out flight simulator tests and active participation in the HALS trial operations, as well as the flight simulator research on DTOP. Figure 4: Operating modes