August is traditionally vacation month for many U.S. families, so in case you find yourself with some extra time or maybe a rainy day at the beach, you can be prepared by downloading a broad selection of aviation-themed e-books for free, courtesy of NASA.
The books include historical accounts of the development of unique aircraft like the U-2 spy plane and the F-16XL fighter jet; a comprehensive history of NASA research planes; the X-31 experimental aircraft; or the F/A-18, which was flown to test “aeroelastic” wings. Other selections feature sonic-boom experiments, the X-15, the development of aviation pressure suits, and lots more.
All of the books can be downloaded free at the NASA website (http://tinyurl.com/y85uxfvm) for use on Kindle or other e-book readers. If you don’t use an e-book device, the books also can be downloaded as PDF files.
Source - https://www.avweb.com/avwebflash/?