I turned to look for my friend in the black aeroplane, but the sky was empty. Explain it

Dear Student,

This line was told by the author after he came out of the storm and could see the runway for safe landing. This means that as the author turned to thank the other pilot, he realised that the plane that had helped him, had disappeared as soon as he was out of the storm. There was no one there. 

Hope this information will clear your doubts about topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards