Name	Data Type	Definition
designator	TextDesignatorType	The textual designator of the touch down and lift-off area.
length	ValDistanceType	The value of the physical length of the touchdown and lift-off area.
width	ValDistanceType	The value of the physical width of the touchdown and lift-off area.
slope	ValSlopeType	The slope (rate of upward inclination of the surface from the horizontal) of the surface of a feature.
helicopterClass	CodeHelicopterPerformanceType	The class of a helicopter based on its performance during a critical power unit failure after take-off.
abandoned	CodeYesNoType	Indicating that the surface is no longer in operational use, but it is still physically present and visible, although usually in a degraded state.

Association	Multiplicity	Role	To	Role description
hasAimingPoint	0..1	aimingPoint	ElevatedPoint	Aiming point for the TouchDownLiftOff zone.
hasExtent	0..1	extent	ElevatedSurface	Extent of the TouchDownLiftOff zone.
hasSurfaceDescribedBy	0..1	surfaceProperties	SurfaceCharacteristics	Surface characteristics of the touch down lift off zone.
isSituatedAt	0..1	associatedAirportHeliport	AirportHeliport	The airport the TouchDownLiftOff zone is associated with.
isSituatedOn	0..1	approachTakeOffArea	Runway	The approach and take off runway area containing the touchdown lift off zone.
isContaminated	0..*	contaminant	TouchDownLiftOffContamination	TouchDownLiftOff contaminant.
hasAnnotations	0..*	annotation	Note
isOperationalBy	0..*	availability	ManoeuvringAreaAvailability	The operational status of the TouchDownLiftOff area.

From	Association	Multiplicity	Role	To	Role description
GuidanceLine	connects	0..*	connectedTouchDownLiftOff	The TouchDownLiftOff zone connected by the Guidance line.
TouchDownLiftOffSafeArea	protects	0..1	protectedTouchDownLiftOff	The protected TouchDownLiftOff.
TouchDownLiftOffLightSystem	isProvidedFor	0..1	lightedTouchDownLiftOff	The touch down lift off zone lit by the TouchDownLiftOffLightSystem.
TouchDownLiftOffMarking	isMarkedOn	0..1	markedTouchDownLiftOff	The TouchDownLiftOff marked.
Navaid	isInstalledAt	0..*	touchDownLiftOff	The touch down or lift-off area for helicopters.
DesignatedPoint	isAtCentreOf	0..1	aimingPoint	The aiming point on the Touch Down Lift Off area.
SignificantPoint		0..1	aimingPoint	The point at the centre of the TLOF.
LandingTakeoffAreaCollection	isLocatedAt	0..*	TLOF	A load bearing area on which a helicopter may touch down or lift-off referenced by the procedure.

1 - Navaid , 1 - Runway , 1 - Significant Points , 1 - Surface Contamination , 1 - Surface Marking , 1 - TLOF , 2 - AirportHeliport Associations , 2 - Designated Point , 2 - Guidance Line , 2 - Surface Lighting Elements , 2 - TLOF Protection Area , 4 - Manoeuvring Area Availability , 5 - LandingTakeoffArea