Exterior helicopter light unit and method of operating an exterior helicopter light unit

An Exterior helicopter light unit, comprising:

• a movable light head comprising a light source,
• a first motor and a second motor for actuating the movable light head, and
• an inverse differential gear assembly coupling the first and second motors to the movable light head in such a way that the first and second motors can tilt and rotate the movable light head in operation,
• wherein the inverse differential gear assembly is a bevel differential gear assembly and comprises:
• a carrier structure, which comprises a cage,
• a first input gear and a second input gear, wherein the first input gear comprises a first bevel gear and the second input gear comprises a second bevel gear, each of the first and second input gears rotatably coupled to the carrier structure, with the first motor being drivingly coupled to the first input gear and the second motor being drivingly coupled to the second input gear,
• a connection structure, rotatably coupled to the carrier structure and coupling the first and second input gears to each other, wherein the connection structure comprises a third bevel gear and wherein the third bevel gear is in engagement with the first and second bevel gears, with the movable light head being in a rotation transmission relationship with the connection structure,
• wherein the carrier structure, the first and second input gears, and the connection structure are coupled in such a way that:
• a rotation of the first and second input gears in the same direction results in a rotation of the carrier structure, tilting the movable light head, and
• a rotation of the first and second input gears in opposite directions results in a rotation of the connection structure, rotating the movable light head.