The student scrawls a note on paper, holding it up to the window - "Where are we?"
A man inside the building holds up a note - "In a helicopter."
The pilot nods knowingly, pulls the chopper up above the cloud cover and takes a direct heading, drops beneath the cloud cover, exactly at the heliport, and lands.
The student is amazed. "How did you know where we were?"
"Easy", said the pilot. "We got a technically correct answer that was of no use.
Spoiler:

