Data quality, concepts and methodology

Data source and methodology

Aircraft Movement Statistics are accumulated from data originating with air traffic control tower units. Because staff in these units are highly trained in factual observation and actual reporting, the entries into the data base are of a very high quality. To maintain uniformity in the reporting of source data, the Aviation Statistics Centre (ASC) issues air traffic control units with an "Air Traffic Designators" handbook (TP-143) showing the official Transport Canada aircraft type designators and the designators of various domestic and international air carriers. Data errors caused during transcription and transmission on the NAV CANADA Aircraft Movement Statistics (NCAMS) network are identified as part of the built-in editing procedures. Furthermore, extensive editing cycles are part of the computer processing programs. All identified errors are manually corrected by ASC editing staff.

Collection

The records are completed daily, based on a twenty-four hour clock running from zero hour to 23:59. The times recorded are Greenwich Mean Time (GMT); however, published statistics are shown in local times. The records are transmitted electronically to the Aviation Statistics Centre (ASC). The Aviation Statistics Centre maintains a data bank of current information on all registered aircraft. The storage of this information allows for a reduction in the reporting burden of the survey respondents and limits the element of human error associated with the preparation of source documents. The data in the bank include registered aircraft identifications and their corresponding aircraft types, gross take-off weights, types of power plant (piston, jet or turboprop); whether the aircraft are fixed wing, helicopters or gliders. The data also provide a basis for identifying type of flights (commercial, private and government) and the geographical area in which the flights take place. The data bank also includes file against which the airport category is checked; the reported runway is validated and the time difference between GMT and local is allocated.