How to understand "takeoff mandatory " amd another sentence?
1. A number of other countries have made transmission of passenger data before takeoff mandatory including the United States, Canada, South Africa and Australia.
2. the International Air Transport Association spokesman Anthony Concil says India needs to be in harmony with the global standard the airlines are already meeting.

Question:
Here how to understand " takeoff mandatory" ?
how to understnad " to be in harmony with the global standard the airlines are already meeting. " ? the airlines are already meeting? what dose it menat?

Question

How to understand "takeoff mandatory " amd another sentence?
1. A number of other countries have made transmission of passenger data before takeoff mandatory including the United States, Canada, South Africa and Australia.
2. the International Air Transport Association spokesman Anthony Concil says India needs to be in harmony with the global standard the airlines are already meeting. 

Question: 
Here how to understand " takeoff mandatory" ?
how to understnad " to be in harmony with the global standard the airlines are already meeting. " ?  the airlines are already meeting? what dose it menat?

Answer

oohh, this is pretty complicated. its hard to understand.

1: what it means by "takeoff" is the airplane flying away. takeoff kinda means to leave
mandatory means you have to do it, like a rule or law

so i think what it means is that the airport needs to have your information before you can get on the airplane. the information it wants is probably stuff like your name and other things like that.

2: the airlines are not actually meeting, it gets kind of confusing unless you are familiar with english.
what it means is that the airports in india have to agree to global standards. global standards are like rules the whole world goes by.

i hope i made this easier to understand, i tried.
if you still dont understand maybe i can try to help you later.