14 C.F.R. § 27.1391
Minimum intensities in the horizontal plane of forward and rear position lights
Each position light intensity must equal or exceed the applicable values in the following table:
| Dihedral angle (light included) | Angle from right or left of longitudinal axis, measured from dead ahead | Intensity (candles) |
|---|---|---|
| 10° to 10° 10° to 20° 20° to 110° | 40 30 5 | |
| 110° to 180° | 20 |