What happens if you don't activate airplane mode on your phone?
Don't worry—it is unlikely that any planes have crashed due to mobile phone interference. However, you should always follow instructions and put your phone on airplane mode. Even though some may doubt the effect of phones on an airplane, it's best to be responsible.
Why do some flights in the Middle East take off late at night?
Planes are easier to maneuver in low temperatures. This is due to air density. Since cold air is denser than warm air, it is easier for planes to take off after midnight in the warm Middle Eastern climate.