I’m aware that The Six Queer Things (1937) was the seventh and final novel to be published by Christopher St. John Sprigg following his death in the Spanish Civil War, but — having read two of his previous books — its contents belie its status as his final work, marking it out more as an apprentice effort from an earlier stage in his career. Both Death of an Airman (1934) and The Perfect Alibi (1934) sit more comfortably in the Golden Age milieu, where Queer Things is replete with details and developments that would have thrilled the late Victorians but impressed a crowd drunk on Agatha Christie, John Dickson Carr, and Ellery Queen to a decidedly less marked degree.
An experienced pilot crashes his plane and dies, and at the inquest the jury returns a verdict of ‘death by misadventure’. They’re correct, and there’s nothing else to investigate. Nah, I’m kidding, of course — we’re deep in the Golden Age here, so it has to be more complicated than that, and before you know it there are amateur sleuths, mistaken identities, re-examination of bodies, codes, intrigue, and the threat of more murder zipping around like so many flies at a picnic. As an exemplar of what the Golden Age did so well, Death of an Airman joins 
The Invisible Event 