Continuous descent operations (CDO) with required times of arrival (RTAs) have been identified as a potential solution to reduce the environmental impact without compromising capacity. However, in high traffic scenarios RTAs may not suffice to maintain safe separation, and air traffic controllers may still need to use “open-loop vectors”, disabling CDOs by depriving on-board flight management systems of required knowledge about the remaining distance to go. This paper proposes to face peaks of traffic without using open-loop vectors by combining the assignment of RTAs and pre-defined routes, taking advantage of the flexibility that procedures such as the tromboning provide in the lateral domain. The concept is illustrated by means of a practical example using the tromboning procedure of the Frankfurt airport. For each possible shortcut of this tromboning, the feasible RTA windows for engine-idle CDOs and powered descents have been computed using numerical optimisation. Results show that time windows up to 10 minutes could be achieved with engine-idle CDOs. These time windows could be widened up to 18 minutes by allowing the use of thrust and speed-brakes, at the expense of burning more fuel and producing more noise. Results also demonstrate that, for a given RTA, very distinct shortcuts could be assigned such that the RTA fits into the associated feasible RTA window.