where:
Ie = effective intensity (candles).
I(t) = instantaneous intensity as a function of time.
t2-t1 = flash time interval (seconds).
Normally, the maximum value of effective intensity is obtained when t2 and t1 are chosen so that the effective intensity is equal to the instantaneous intensity at t2 and t1.
Angle above or below the horizontal plane | Effective intensity (candles) |
0° to 5° | 150 |
5° to 10° | 90 |
10° to 20° | 30 |
20° to 30° | 15 |
14 C.F.R. §27.1401