Flight deck interval management and delegated separation for equivalent visual operations
An emerging Next Generation Air Transportation System concept — Equivalent Visual Operations (EVO) — can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced flight vision system technologies are critical enabling technologies to EVO. Current research evaluated concepts for flight deck-based interval management (FIM) operations, integrated with Synthetic Vision and Enhanced Vision flight-deck displays and technologies. One concept involves delegated flight deck-based separation, in which the flight crews were paired with another aircraft and responsible for spacing and maintaining separation from the paired aircraft, termed, “equivalent visual separation.” The operation required the flight crews to acquire and maintain an “equivalent visual contact” as well as to conduct manual landings in low-visibility conditions. The paper describes results that evaluated the concept of EVO delegated separation, including an off-nominal scenario in which the lead aircraft was not able to conform to the assigned spacing resulting in a loss of separation.
Time-based navigation and ASAS interval managed CDA procedures
Problem area With the continuing growth of air traffic as well as the ever increasing level of urbanization around most airports in Western Europe, the impact of aircraft noise and emissions on the quality of life for surrounding communities has become a serious issue to be dealt with. Throughout the world, much effort is being undertaken to increase the usage of Continuous Descent Approaches (CDA). This type of operation can provide significant reductions to community nuisance while improving the fuel economy in the approach. There are, however, still many issues to resolve prior to the realization of this type of operation during highdensity traffic at major airports. Present air traffic control procedures and technology do not easily allow flying such procedures except during night time when there is less traffic. To improve the throughput (for use during daytime) the initiation of a CDA procedure should be better planned and the execution should be more accurate.
Development of Noise Abatement Approach Procedures
*This article describes initial results of an Airbus research project, aimed at the development of efficient operational noise abatement approach procedures that can be operated with in-service aircraft, either manually or in FMS managed mode. The project is focused on the Continuous Descent Approach (CDA) procedure, defined as an approach procedure without recourse to level segments below a height of typically 7000ft. After a first qualitative review, a noise and performance analysis has been performed for a number of CDA variants for Airbus A320 and A340 aircraft. The FMS approach procedure, including a level-off deceleration segment prior to glide slope intercept, was selected as baseline procedure. This procedure provides optimized performance and noise relief relative to conventional approach procedures. The first CDA analysis revealed a maximum descent angle, allowing convenient deceleration in clean configuration, of 2° and modest associated noise reduction relative to the baseline procedure. An optimized version of this CDA procedure, featuring a modified configuration change schedule, led to 5dBA noise relief relative to the baseline procedure. On an experimental basis, also CDA procedures with steep final glide slope angles were evaluated. Following these assessments, a series of A340 flight simulator tests was undertaken to evaluate in-flight characteristics and pilot perception for the selected CDA procedures. Simulations executed in manual mode enabled identification of acceptable descent flight path angles. Simulations of the same procedures in FMS managed mode provided further insight in operational feasibility and pilot workload issues.