Lifting those shades on flight windows during landing and take-off might be a boring task for many passengers. Some of the passengers believe that this is mainly for preparing them for jolty landing.
However, experts have revealed the exact reason for the same. Saran Udaya Kumar, the Aviation Safety Officer stated that in a case of emergencies, the crew has just 90 seconds for evacuating the plane. For making this possible, they prepare the passengers as well as the aircraft so that if anything goes wrong, quick evacuation is possible. This means that the cabin can be seen from outside by emergency personnel so that the situation can be assessed.
He explains that passengers have that curiosity and they keep looking out to see if something is wrong there. Usually, the stuff is reported by passengers right away.
Usually, in the case of emergencies, every second is important. Hence, if the shades are open, outside conditions can be seen easily so that evacuation can be planned accordingly. For instance, doors that have to be used for evacuation can be decided upon. Aeronautical Industry Professional, David Robinson provides an explanation that if customers are introduced to low light conditions before any occurrence of the unfortunate incident, the visual capacity might exceed 1000 times better in comparison with a situation wherein they have to suddenly plunge into darkness and have just 90 seconds for disembarking from the aircraft.
Kare Lohse, an Airline pilot states that there have been many cases when technical problems have been reported by passengers just by looking outside. However, this happens very rarely. They even ask passengers to fold up the tables and straighten up the seats during landing and take off, so that a quick exit is ensured.