DescendToReachLevelByTime
urn:aero:airm:1.0.0:ConceptualModel:Subjects:AirTrafficOperations:ATMServiceDeliveryManagement:DescendToReachLevelByTime
Instruction that a descent is to commence at a rate such that the specified level is reached at or before the specified time. When this message element is not concatenated with another vertical clearance, the level specified is the assigned level which is to be maintained.