16 books • 6 series
Book #6: Grumman FF
Book #11: Curtiss F11C/BFC & BF2C
Book #15: The Grumman SF
Book #17: Hawker Fury (Part 2)
Book #18: The Supermarine Spitfire F.24
Book #6: Colonel Gaddafi's Hat
Book #1: The Adventures of Shea, Gray and Daye