Continuous descent operations (CDOs) with required times of arrival (RTAs) have been identified as a potential solution to reduce fuel consumption and noise nuisance in the ma- neuvering area and without compromising capacity. This paper assesses the feasibility of replacing current air traffic control sequencing and merging techniques (mainly based on radar vectoring) by a control based on RTAs over known and fixed arrival routes, aiming to enable CDOs by ensuring flight management systems have an unerring knowledge about the remaining distance to the runway threshold. The assessment has been performed for Barcelona El Prat airport (Spain), using arrival traffic for several representative days gath- ered from historical data. The earliest and latest trajectories at a metering fix for each inbound aircraft have been computed assuming engine-idle CDOs. Given the attainable RTA window for each aircraft, the feasibility of sequencing the arrival traffic with RTAs has been assessed by solving an aircraft sequencing problem. Results show that low traf- fic scenarios could be properly managed by only assigning RTAs. For certain scenarios, however, with high traffic loads and late RTA assignments, radar vectoring would still be necessary. The distance from the runway where inbound aircraft are expeced to receive the RTA has been also subject of study, demonstrating that the assignment of RTAs well before starting the descent would favor to remove radar vectoring and enable full CDOs.