since in "since most aviation English" (l. 61) has the same meaning as the underlined word in:
A
I haven't seen him since our meeting at the airport;
B
Since I left the plane, I haven't been feeling well;
C
He has been a pilot since he graduated in 1980;
D
Let's go to the airport since we're so close to it;
E
The time to go to the airport has long since passed.