Johnny's brain registered automatically the fact that he was being shot at.

They probably meant that as a hint that he was to clear out or come down, one or the other.

Well, if they'd take that darned searchlight out of his eyes so he could see, he would come down fast enough.
In desperation he slanted down steeply toward an open space, and the open space immediately showed a full border of lights, revealing itself a landing field such as he had read of and dreamed of but had never before seen.

It shot up at him swiftly; too swiftly.

He came down hard.