My Google wanderings have turned up the existence of this book, published in 1972, which contains an essay on The Last Flight by Tom Shales which was apparently one of the first modern appreciations of it:

https://www.amazon.com/review/R2CT5QKROL2I8V (link goes to a review which kindly transcribes the TOC -- it looks like there may be other good things in it too)

Am attempting to acquire; will report back if interesting.