This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
BDRT
Both Dependent Runway Thresholds
Both Dependent Runway Thresholds (BDRT) is a runway configuration term used at airports with closely spaced parallel runways where simultaneous independent approaches are not permitted. In a BDRT configuration, the landing thresholds of both runways have operational dependencies - meaning aircraft on approaches to each runway must be sequenced and separated with respect to one another, rather than being treated as fully independent streams. The dependency arises from wake turbulence separation requirements, instrument approach procedure design constraints, or the lateral distance between runways being insufficient to meet independent parallel approach criteria.
BDRT operations require ATC to apply staggered approach sequences, diagonal separation, or other techniques to ensure the required separation between aircraft on adjacent finals is maintained. This typically results in lower combined arrival rates than would be achievable with fully independent parallel approaches. Airports such as Toronto Pearson (CYYZ) and Vancouver International (CYVR), which feature closely spaced runway pairs, make use of dependent runway configurations during periods of instrument meteorological conditions, directly affecting arrival sequencing and capacity planning.