I am convinced that it is a very appropriate measure.

Think of the shock the family/near relatives of the pilot have if they understand the situation: That their father/husband has brought down the plane intentional.

It's like being bombed out of your house and life by a relative with additional thousands of victims. All those who lost one in the plane.

It's a double tragedy within some days. They really need time to understand that and also to evacuate to some friends/safe harbour.

You can imagine the media hunt on the family.

Or imagine them living in a compound near the airport where the majority of residents work at one airline. Or a small, tiny village.....

Or a situation like the murdered air controller after the Überlingen incident.

So the first measures would be to bring out the relatives out of the line of media fire.

How would you respond if your loved one/father has done such a criminal act???