Glossary Papakupu

Explanations of abbreviations and acronyms.
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    D

    D spar
    The main load-carrying structural component of a wing or rotor blade.
    Dacron
    A trade name for polyethylene terephthalate fibre.
    Daily Information Bulletin
    A controlled instruction, printed, typed or handwritten, issued by those authorised by the Rail Operating Rules
    Daily information bulletin (DIB)
    A memorandum provided to users of KiwiRail’s network that contains information about train running and track maintenance activities for that day.
    Damper
    A normally-open flap that can be released to close and seal an opening
    Damper bearing
    Damper bearing is installed on the tail rotor drive shaft to dampen normal lateral and vertical oscillations.
    DART
    Dynamic Automatic Radio Transmission
    Datum
    A datum is a reference point or plane from which measurements are taken. The datum for an aircraft’s centre of gravity is typically a vertical plane on, or ahead of, the nose of the aircraft.
    DC
    Direct current
    DCP
    A type of diesel-electric main line locomotive used on the New Zealand rail network.
    De-bonding
    An undesirable condition where the structural adhesive under the blade skin breaks down or fails as a result of surface erosion, corrosion or overstressing.
    De-icing
    Removal of ice and snow from aircraft surfaces
    Dead end (rope or cable)
    The end of a rope that does not take any load after being spliced or clamped with a ferrule
    Dead-ship
    Without the use of the ship’s propulsion systems.
    Deadweight Tonnage
    Maximum weight a ship can safely carry including cargo fuel and stores
    Deck cadet
    A trainee
    Deck officer
    A master or officer from a vessel’s deck department. It includes navigating officer roles.
    Deckhead
    Nautical term for ceiling
    Deep-water factory trawler
    A fishing vessel fitted with factory equipment for processing, packaging and freezing fish products
    Demurrage
    Charge for exceeding agreed laytime during loading or unloading
    Density altitude
    Density altitude is the ‘pressure altitude’ corrected for any temperature difference from the temperature at that altitude in the International Standard Atmosphere. The pressure altitude is the altitude in the International Standard Atmosphere with the same pressure as the part of the atmosphere in question.
    Departure controller
    The air traffic control position responsible for flights departing a terminal area.
    Departure signal
    A signal controlling entry to a block section, which is the entire section of line between two stations. Block sections can be divided into intermediate sections. Permission to pass a departure signal at red requires written authority from train control.
    Derail
    An event that occurs when a rail vehicle’s wheels disengage their connection with the top of the rail head.
    Derailment
    An event that occurs when a rail vehicle’s wheels disengage their connection with the top of the rail head
    Design life
    The period of time during which an item is expected by its designers to work within its specified parameters; in other words, the life expectancy of the item
    Detention
    Charge for delayed return or use of equipment beyond free time
    Dew poinbt
    The temperature at which air becomes saturated and can hold no more moisture.
    DFDR
    digital flight data recorder
    Dial test indicator
    A tool used to measure clearances and tolerances and variations in tolerance.
    Diesel electric locomotives
    Operates a diesel engine connected to an alternator that creates electricity, which is transferred into six electric traction motors that drive the wheels on the locomotive.
    Direct routing
    When an aircraft is flown along a route that has not been charted and has not been evaluated. Sometimes referred to as ‘random routing’
    Disaster
    A disaster for this purpose is defined as one or more of the following: 10 or more people reported killed; 100 or more people reported affected; a declaration of a state of emergency; and a call for international assistance.
    Disconnecting the autothrottle
    The autothrottle remains engaged until reverse thrust is selected after touchdown.
    Disembarkation
    Leaving or getting off a ship
    Disponent ship owner
    A disponent ship owner is a person who has a right to the use and possession of a ship, either as owner or as bareboat charterer from the beneficial owner of the ship for the time being.
    DME
    distance measuring equipment
    DOC
    Department of Conservation
    Doubler
    An additional piece of material used to strengthen the area of surrounding structure in a component.
    DOWN direction
    Trains running away from Otiria in the North Island and away from Picton in the South Island are travelling in the DOWN direction.
    Down main line
    A portion of rail track on a multiline rail network on which trains are run in the down direction
    Down-flooding
    The entry of seawater through any opening into the hull of an undamaged vessel.
    Downwind call
    Radio call made when established on the downwind leg and abeam the upwind threshold to positively establish the aircraft’s position in the circuit for other traffic
    Downwind leg
    A flight path parallel to the landing runway in the opposite direction to landing
    Draft loading
    Where couplers experience a tensile force as rail vehicles are pulled apart.
    Draft Survey
    Method to determine ship cargo weight by measuring draft changes
    Draft tensile force
    The outward force applied to the carriage-coupler connection
    Drag
    A mechanical force that results from the interaction of a solid body with a fluid. Drag acts in opposition to the direction of the propelling force
    Drainage culvert
    A piece of drainage infrastructure that connects stormwater pipes in order to direct water flow to an adjacent area. The culvert at the slip site was located on the hill side of the rail corridor, went under the rail lines and opened on the embankment where the road met the road shoulder area. This allowed debris to flow on to State Highway 1.
    Draught
    Vertical distance between a ship's waterline and keel
    Drawgear
    Assembly on rail vehicles for traction and cushioning of forces
    Drawgear system
    The component that connects the carriage to the coupler
    Driver
    The train driver
    Driver advisory system
    A computer touch-screen mounted in a locomotive cab that is connected to the locomotive power supply, global positioning system and cellular antennae and provides a visual output of topographical and network data along with suggested speeds and operating modes
    Driver Advisory System (DAS)
    A computer touch-screen mounted in the locomotive cab that is connected to the locomotive power supply, global positioning system and cellular antennae. It provides a visual output of topographical and network data along with suggested speeds and operating modes.
    Driver monitor
    A driver monitoring system that records and assesses a driver’s alertness and activates alarms when safety parameters are exceeded.
    Driver-training train
    An empty passenger train operated by a trainee driver under instruction from a qualified person. Trainees learn route-knowledge and train-handling skills before being allowed to drive with passengers onboard.
    Drivetrain
    The helicopter’s drivetrain is a group of components that transfers power
    Drogue
    A trailing ‘parachute-looking’ device used to create drag and regulate the fall rate of a tandem pair.
    Droguefall
    The portion of a tandem descent when a drogue has been deployed. It occurs between the initial freefall and the main parachute deployment
    Drone
    The generic term used when referring to a Remotely Piloted Aircraft System (RPAS), an Unmanned Aerial Vehicle (UAV) or an aircraft in operation without a pilot onboard.
    Drone operators
    The owner of a drone
    Drone pilot
    The person controlling the drone in flight.
    Drury
    Clevedon and Drury are designated visual reporting points for aircraft flying into Ardmore, to achieve geographical separation for inbound and outbound aircraft.
    Dry dock
    A basin that can be flooded to allow a vessel to be floated into it, then drained, to allow the vessel to rest on a dry platform exposing the entire hull. Dry docks are used for vessel construction, maintenance and repair
    Dynamic braking
    A braking method where kinetic energy is converted to electrical current by traction motors on powered axles. Energy is then re-delivered to traction supply (regenerative) or, as in the case of DFB locomotives, dissipated through resistors (rheostatic).
    Dynamic check
    This is where a pilot would attempt to lift off and hover close to the ground and check to see that the controls were in a position that allowed full deflection movement.
    Dynamic interaction
    A situation when the track geometry, wagon condition, wagon loading and train speed are individually within tolerance limits, or marginally in excess, but not to an extent that each variation on its own is sufficient to be a prime cause of a derailment. However, when in combination these conditions can result in a derailment.