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.
Controlled Time-of-Arrival Flight Trials Results and Analysis
The CASSIS project has been tasked with developing a Concept of Operations for use of Time-of-Arrival Control in the terminal area. Reducing or replacing low level vec tors and holding with enroute delay through the use of time constraints is a key component in both NextGen and SESAR. A set o f revenue service flights using airborne time control to the Initial Approach Fix and the runway threshold was conducted in Septe mber 2008 as part of the CASSIS project. These flight trials facilitated an examination of the factors affecting time control behavior and the potential for use of airborne time control in the terminal area in nearand mid-term time frames. The impact of airborne control to a single time constraint on separation between a ircraft is also examined. This analysis shows that the use of curr ent generation avionics to meet a time constraint at a point in th e approach is possible with accuracies of less than 5 seconds, an d can achieve 2 minute landing spacing at the runway threshold with no loss of intermediate separations. Recommendations for futu re developments and considerations for larger scale im plementation are also discussed.
Airborne Required Time of Arrival (RTA) Control and Integration with ATM
This paper describes a method of controlling the speed of an aircraft to meet a required time of arrival (RTA) constraint over one or multiple waypoints. The motivation of an airborne RTA system is first discussed, then the control system is described in detail. First the method for meeting a single RTA waypoint is developed, then it is extended to multiple RTA waypoint constraints. Results from testing the system in a laboratory environment are discussed. Additionally, concepts for negotiating 4D trajectory constraints with an Air Traffic Management (ATM) provider are presented, and RTA is shown to be a useful tool for flying aircraft in a practical manner to meet 4D trajectory constraints.