出典:Wikipedia
出典:『Wikipedia』 (2011/07/14 10:25 UTC 版)
Continuous Descent Approach (CDA) or Optimized Profile Descent (OPD) is a method by which aircraft approach airports prior to landing. It is designed to reduce fuel consumption and noise compared to certain conventional approaches and involves maintaining a constant three degree descent angle during landing, until meeting the Instrument Landing System (ILS). Basically, instead of approaching an airport in a stair-step fashion, throttling down and requesting permission to descend to each new (lower) altitude, OPD allows for a smooth, constant-angle descent to landing.