Pilot/Controller Glossary

Traffic Management Programs (STMPs), and airport-specific information. These notices are applicable to
operations within the United States and can be found on the Domestic Notices website.
DOWNBURST- A strong downdraft which induces an outburst of damaging winds on or near the ground.
Damaging winds, either straight or curved, are highly divergent. The sizes of downbursts vary from 1/2 mile
or less to more than 10 miles. An intense downburst often causes widespread damage. Damaging winds, lasting
5 to 30 minutes, could reach speeds as high as 120 knots.
DOWNWIND LEG-
(See TRAFFIC PATTERN.)

DP-
(See INSTRUMENT DEPARTURE PROCEDURE.)

DRA-
(See DEBRIS RESPONSE AREA.)

DRAG CHUTE- A parachute device installed on certain aircraft which is deployed on landing roll to assist in
deceleration of the aircraft.
DROP ZONE- Any pre-determined area upon which parachutists or objects land after making an intentional
parachute jump or drop.
(Refer to 14 CFR 105.3, Definitions)

DSP-
(See DEPARTURE SEQUENCING PROGRAM.)

DTAS-
(See DIGITAL TERMINAL AUTOMATION SYSTEM.)

DUE REGARD- A phase of flight wherein an aircraft commander of a State-operated aircraft assumes
responsibility to separate his/her aircraft from all other aircraft.
(See also FAA Order JO 7110.65, Para 1-2-1, WORD MEANINGS.)

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.