On the ???

[Teia]

on the fly, i guess. but which about the answer?

Hi

Here is the answer given by the link Tdol provided for us:

On the fly
If you do things on the fly, you do things without preparation, responding to events as they happen.

[midomania]

I've answered wrong but it's ok i've learned new information thanks.

[ZaG]

on the fly: impulsive
on the not: id assume at the request or order
on the trot: consecutive, almost rhythmatic, consistant

[rj1948]

On the trot -without break