Most of us have been wondering why airlines follow certain protocols and I've gotten some explanations for some of the questions.

1) Switching off the cabin lights before take off and landing : most airline accidents take place during take off and landing . By dimming the cabin lights , your eyes get adjusted to the darkness outside and you would be better prepared in case of an emergency . Thus the idea is to make the cabin environment similar to the exterior environment.

Dimming the lights also makes the ' glow in the dark' floor pathways which points you to the nearest exit noticeable . people in the aisle seats would notice them when the lights are dimmed.

Most airplanes need to throttle to full power for take off and also to support the critical electrical equipment.

2) Usage of cell phones: an airline during the course of take off and before hitting the cruise altitude , needs to keep switching frequencies to communicate with the ATC and keeping your phone switched on increases the chances of a communication interference.

Technically , just switching off your phone wouldn't suffice. In order to kill any latent connection, the safest thing to do is to remove the battery .

3) Lifting up the shades:
The possibility of the wings catching fire is highest during take off and landing .
The passengers play an important role here . The pilots rely on the passengers to be their eyes and ears and report any instance of fire .