Directional Fixtures
Omnidirectional Elevated Fixtures
Angles are vertical. L-861 red and green cover 180° horizontally because they are used only in bidirectional fixtures.
Check a Measured Intensity
Pick the fixture type and colour from the same list as the Fixture tables tab. Values are new-fixture design values at full rated output.
How the FAA Values Are Defined
Main beam and 10 percent beam
The average intensity inside the main beam must meet the tabulated value, and no point inside it may fall below half of that value. A larger concentric beam, where one is given, must reach at least 10 percent of the value at every point on its edge. For in-pavement fixtures, any part of the 10 percent beam that lies below grade is disregarded.
Angles are taken from the photometric axes of a correctly installed fixture. The horizontal axis is parallel to the runway centreline, the vertical axis is perpendicular to the ground, and horizontal angles toward the runway centreline are positive. The test allows the beam to be shifted by up to 1° in each direction (in-pavement: 0.5° vertical and 1° horizontal) to fit the curve.
Upper limit
The measured average may not exceed three times the specified average. For L-850E, where a minimum rather than an average applies, the measured minimum may not exceed three times the specified minimum. Bidirectional split-colour fixtures with a single light source are exempt from this limit. When averaging along a test axis, the largest reading used may not exceed three times the smallest.
ICAO Annex 14 cross-reference
| Light | Annex 14, Vol I, Appendix 2 |
|---|---|
| Runway edge lights | A2-9 (45 m wide runway), A2-10 (60 m wide runway) |
| Runway centre line lights, white | A2-6 (30 m spacing), A2-7 (15 m spacing) |
ICAO gives intensities as isocandela diagrams for each light type, category and spacing. Those values are not reproduced on this page, so take them from your copy of Annex 14. The FAA and ICAO methods differ (ellipse averaging against minimum intensities at defined points), so the two sets of numbers are not interchangeable and a fixture must be checked against the standard its project specifies.
What this page does not cover
It does not include taxiway or heliport fixtures, approach lights, or PAPI. It shows new-fixture design values, not in-service maintenance limits, and it does not give chromaticity limits (SAE AS25050, and the ITE traffic-signal standard for L-850T, L-852G, L-852S, L-862S and L-804). Light output at lower CCR brightness steps is lower and depends on the lamp or LED driver; see FAA Engineering Brief 67 for LED fixtures.