This paper is assessing two methods that can be used in assessing the airport noise capacity when new operational practices are implemented at a certain airport. The example given is CDA-continuous descent approach implemented at Bucharest Henri Coanda International airport in Romania. A review of the main operational practices related to CDO (Continuous Descent Operations) with relevance for noise and emissions reduction, shows the importance of working in a team when implementing new operational practices, as well as the need to access data either through FDR (flight data recorder) or from measurements.- The example selected explains the difficulties one can have to extract FDR data. Although the authors of this paper benefitted from FDR from TAROM, the Romanian national airline, it was difficult to be extracted, so the assessment of the airport noise capacity focused on monitoring and measurements undertaken under the flight path. No commonly agreed methodology or toolset presently exists for assessing the benefits of CDA.- Noise modeling at airports may not be sophisticated enough to depict the benefit associated with CDA.Key to assessment is the supply of Flight Data Recorder output, the minor cost of provision of this could be offset against the potentially massive fuel benefits that would accrue to airlines if harmonized CDA can be promulgated.