In Flight why crew member giving instruction for opening window shutter while take off and landing?

Question

What is the science involved with the study, design, and manufacture of flight-capable machines, and the techniques of operating aircraft?

Answer 1

Its a precautionary measure, when window shutters are open passengers can look outside and can see any unforeseen event which can be reported to the crew which improves the chances of saving life.
Some countries its a law while in some cases it has been enforced by airlines only...

Comments

Thank you Sir, I was thinking some scientific reason behind it.