dist - dual
- doublet antenna
- dovetail halving
- dovetailing
- down elevator
- down flow carburettor
- down hole
- down link channel
- down lock cylinder
- down range
- down train
- downhole instruments
- downhole measurements
- downrange
- downrange direction
- downrange distance
- downrange ship
- downrange tracking system
- downrange trajectory
- downstream injection
- downstream sample
- downstream water
- downward ejection
- downward searching mode
- downward stage
- downward trajectory
- downwash flow
- downwash velocity
- downwind pattern altitude
- downwind position
- downwind takeoff
- dozer mounted scoop
- dpu limit
- draconian period
- draftsman
- drag
- drag balance
- drag brake system
- drag brake vehicle
- drag center
- drag chute box
