The sighting device consists of a circular mounting bracket and positioning studs, hand-tightening screws, a telescopic sight (marked with angles for field vision), a gauge to see the angle of adjustment and a spirit level bubble to confirm the correct angle is set.
- allows for horizontal and vertical alignment.
- marked internally with vision markers and angles for ease of use.
These are required to set the light to the correct vertical setting and azimuth for light fittings on the runway.
These angles are described in ICAO (Annex 14 Appendix 2) / EASA / FAA.
Example from ICAO Annex 14 Appendix 2 for Approach Lights:
