DOWNWIND LEG
(See TRAFFIC PATTERN.)

DP
(See INSTRUMENT DEPARTURE PROCEDURE.)

DRAG CHUTE
A parachute device installed on certain aircraft which is deployed on landing roll to assist in deceleration of the aircraft.

DSP
(See DEPARTURE SEQUENCING PROGRAM.)

DT
(See DELAY TIME.)

DTAS
(See DIGITAL TERMINAL AUTOMATION SYSTEM.)

DUTY RUNWAY
(See RUNWAY IN USE/ACTIVE RUNWAY/DUTY RUNWAY.)

DVA
(See DIVERSE VECTOR AREA.)

DVFR
(See DEFENSE VISUAL FLIGHT RULES.)

DVFR FLIGHT PLAN
A flight plan filed for a VFR aircraft which intends to operate in airspace within which the ready identification, location, and control of aircraft are required in the interest of national security.

DVRSN
(See DIVERSION.)

DYNAMIC
Continuous review, evaluation, and change to meet demands.

DYNAMIC RESTRICTIONS
Those restrictions imposed by the local facility on an “as needed” basis to manage unpredictable fluctuations in traffic demands.