Hi,Why all the seats must be pull back up during landing and take-off? Also, why do we have to open all the window lids during take off and landing?Cheers,citybus2200

My guess.Seats- So the person behind you does not smash their face on your seat if there is a sudden stop and also to give more room if you have to make a fast exit.Trays- More room again in emergency. Nothing to drive your guts into when you make that same sudden stop or bump.

How about the window though, why do we have to open all the window lids?

Maybe if the frame gets bent out of shape, the windows will be open already, and have no way to get stuck... but I'm only guessing this because in small planes in emergency landing you pop the doors so they cant get jammed shut when you touch (or slam) down :)

So the fire crew can see in if they need to. Also, in the daytime so that the passengers' eyes are light adapted to they can see after evacuating the plane. Similarly, the lights are dimmed during a night landing.

Ah, that makes sense :D

Actually, egress is the main reason for both the tray tables and seatbacks having to be upright. And the reason for the window shades to be open and lights dimmed is so that the flight attendants can look outside to see whether or not it is safe to evacuate the plane.

The reasons presented for the seat back position are valid, however, the primary reason is due to seatbelt effectiveness. A sealtbelt is designed to be the most effective when a person is sitting in an upright position.When a seat is in the upright position so is the occupant, and the seatbelt, when cinched down properly, is effective. However if the seatback is reclined so is the person and in a rapid deceleration incident the person is ejected from under the seatbelt just like the forces u experience squeezing a watermelon seed between ur fingers!Joe T

The last post was right. Without a shoulder restraint you are likely to slip right under the seat belt at high speeds. The upright position should even be used while driving cars.Also don't forget wiplash. You're body is capable of fully bending forward. If the plane were to make a sudden and abrupt stop your body would fling forward. When the airplane stops completely you'd lash backwards again into position.Having the seat forward means the person behind you won't hit their head on it and that your body won't be thrown violently all the way back.And as for the windows...I guess visibility for those in and those out. Also...hate to say this but if there is ever a sever accident with fire inside involved it's likely that some glass might break letting smoke escap the cabin. With the slits closed it's possible the smoke won't go anywhere.