1.   A warning light seems to have malfunctioned.

2.   But when the pilot switched on his flight systems, a red warning light glowed.

3.   If the temperature falls below a particular threshold, a warning light comes on.

4.   It is because at this time the warning light is more easily visible in the twilight than in the daylight.

5.   Looking right then left he saw the signals with their warning lights reassuring him of their presence.

6.   Passengers should keep their seat belts fastened until the warning light is extinguished.

7.   Red warning lights flashed on and off.

8.   The bulb had obviously been hit hard soas to break its filament, to ensure no warning light came on.

9.   The warning lights were clearly visible.