I second eckhard's recommendation of Song of the Sky, especially if you liked the piston heavies and raw navigation thing.
Another brilliant one for that is Sir Gordon Taylor's autobiography The Sky Beyond. Don't let the fact that it's an autobiography put you off - it's still an excellent and fast-paced read. Quick taster: GT learning astro nav as a young man and practicing it in a biplane on floats, perforce at night, and the method he used to alert himself to reaching flare height when returning to alight on a lake in the dark... Or acting as Kingsford-Smith's nav on an early trans-Tasman flight in a Fokker tri-motor with one engine shut down due to vibration and one of the others losing oil at a distressing rate... Or crossing the Pacific in a Catalina and trying to find a tiny atoll in the middle of thousands of miles of nowhere after flying for what would still be an ultra-long-haul amount of time even today.... One of my all-time faves. Enjoy!