As an engineer and aviation enthusiast, the most fascinating book I ever read was Skunkworks by Ben Rich.
Amazon product ASIN 0316743003Rich worked at the Skunkworks in the 50s, 60s and 70s so he was deeply involved in the U2, A12, SR71 and F1117 projects.
His accounts of how the design process worked were incredible, how they used a number of off the shelf components to create the U2 (if I recall correctly the fuselage was was basically an F104 or maybe it was an F102?).
The technical breakthroughs in the A12 were even more incredible.
All on a relatively shoestring budget.
That was certainly the golden age in aircraft development.
Contrast that to the cluster the recent F35 project was with massive cost over-runs and long delays.
I was able to see a SR71 fly at Oshkosh in ‘89. Saw it come in on a Friday, made a return trip on Monday to see it leave.
A NASA SR71 did a flyby there in the late 90s. It was supposed to do a supersonic flyby later but broke and had to do an emergency landing in Milwaukee. I am glad I got to see them fly several times. The Mach cone from the afterburners is really something!