To improve the safety of flights, several measures were taken over the next few decades.
One safety rule that was implemented in the 1960s was the 90-seconds rule.
The 90-seconds rule mandates all airlines using planes with a capacity of 44 people or more to demonstrate the ability to conduct an emergency evacuation in 90 seconds or less.
Research suggests that most accidents happen during landing (48% of the total) and take-off (13%).
This means there are higher chances of an emergency situation during take-off and landing.
And tilted seats can make evacuation time-consuming and tricky.
This is one reason flight attendants insist on the upright position of the seat.
The other reason is to prevent or limit injuries.
The seat is locked in the upright position and unlocked in the reclined position.
In the case of an emergency, an unlocked seat will have more force during impact.
So, a jerk causing a rapid back-and-forth movement of the neck can lead to severe injuries to you and the passenger behind you (their head would be 3-inches closer to your backrest).
