Exterior aircraft light unit, comprising: a mounting structure, an LED arranged on the mounting structure, and an optical system, arranged on the mounting structure for creating an output light emission distribution of the exterior aircraft light unit, wherein the optical system comprises, in a first cross-sectional plane extending through the LED: a first concave reflector and a second concave reflector, each of the first and second concave reflectors (8, 10) having a proximate end positioned adjacent to the mounting structure and a distal end positioned removed from the mounting structure, with the first and second concave reflectors (8, 10) being arranged on opposite sides of the LED in the first cross-sectional plane, and a refractive optical element arranged between the first and second concave reflectors (8, 10) in the first cross-sectional plane, wherein the first concave reflector, the second concave reflector and the refractive optical element are separate optical elements in the first cross-sectional plane, and wherein the distal ends of both the first and second concave reflectors (8, 10) have back-tapered shapes, with the first and second concave reflectors (8, 10) curving towards each other at their distal ends, wherein a distance between the proximate ends of the first and second concave reflectors (8, 10) is smaller than a distance between the distal ends of the first and second concave reflectors (8, 10), which in turn is smaller than a distance between respective intermediate portions of the first and second concave reflectors (8, 10) in the first cross-sectional plane. a mounting structure, an LED arranged on the mounting structure, and an optical system, arranged on the mounting structure for creating an output light emission distribution of the exterior aircraft light unit, wherein the optical system comprises, in a first cross-sectional plane extending through the LED: a first concave reflector and a second concave reflector, each of the first and second concave reflectors (8, 10) having a proximate end positioned adjacent to the mounting structure and a distal end positioned removed from the mounting structure, with the first and second concave reflectors (8, 10) being arranged on opposite sides of the LED in the first cross-sectional plane, and a refractive optical element arranged between the first and second concave reflectors (8, 10) in the first cross-sectional plane, wherein the first concave reflector, the second concave reflector and the refractive optical element are separate optical elements in the first cross-sectional plane, and wherein the distal ends of both the first and second concave reflectors (8, 10) have back-tapered shapes, with the first and second concave reflectors (8, 10) curving towards each other at their distal ends, wherein a distance between the proximate ends of the first and second concave reflectors (8, 10) is smaller than a distance between the distal ends of the first and second concave reflectors (8, 10), which in turn is smaller than a distance between respective intermediate portions of the first and second concave reflectors (8, 10) in the first cross-sectional plane. a first concave reflector and a second concave reflector, each of the first and second concave reflectors (8, 10) having a proximate end positioned adjacent to the mounting structure and a distal end positioned removed from the mounting structure, with the first and second concave reflectors (8, 10) being arranged on opposite sides of the LED in the first cross-sectional plane, and a refractive optical element arranged between the first and second concave reflectors (8, 10) in the first cross-sectional plane, wherein the first concave reflector, the second concave reflector and the refractive optical element are separate optical elements in the first cross-sectional plane, and wherein the distal ends of both the first and second concave reflectors (8, 10) have back-tapered shapes, with the first and second concave reflectors (8, 10) curving towards each other at their distal ends, wherein a distance between the proximate ends of the first and second concave reflectors (8, 10) is smaller than a distance between the distal ends of the first and second concave reflectors (8, 10), which in turn is smaller than a distance between respective intermediate portions of the first and second concave reflectors (8, 10) in the first cross-sectional plane.