divergent oscillation. Oscillations whose amplitude increases with time. The oscillations of an airplane that has positive static stability but negative dynamic stability are divergent oscillations.

diverse vector area (air traffic control). That area, in a radar environment, in which a prescribed departure route is not the only suitable route to avoid obstacles. The area in which random radar vectors below the minimum vectoring altitude/minimum IFR altitude (MVA/MIA), established in accordance with the terminal instrument procedures (TERPS) criteria for diverse departures, obstacles and terrain avoidance, may be issued to departing aircraft.
dividend (mathematical term). The number in a division problem that is to be divided. The components of the problem 36 ÷ 3 = 12 are: 36 is the dividend, 3 is the divisor, and 12 is the quotient.
dividers (layout tool). A sheet metal layout tool that looks much like a drafting compass. Dividers are used to lay out circles or arcs of a circle and to divide a line into equal spaces.
divisor (mathematical term). The number in a division problem that is used to go into, or to divide, the dividend. The dividend is divided by the divisor. See dividend.
DME (distance measuring equipment). A pulse-type electronic navigation system that shows the pilot, by an instrument-panel indication, the number of nautical miles between the aircraft and a ground station.
The DME transmitter in the aircraft transmits a specific pulse of electrical energy. This pulse is received by the ground station and retransmitted on another frequency. When the pulse is received back in the aircraft, the time used for its travel to the ground station and back is converted into terms of nautical miles to the station. DME is a portion of the military TACAN (Tactical Air Navigation) system.
DME fix. A geographic location determined by reference to a navigational aid which provides distance and azimuth information. The direction of a DME fix is specified in degrees magnetic from the facility, and the distance from the facility is given in nautical miles.