Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not up to previous Putnam Standards

This is one of the later Putnam efforts in the larger format.Whether its because of the different format, a reduction in 3-view drawings, or simply the writing, I didn't like this book as much as the 20+ other Putnam aviation books in my library. It lacks the detail and (dare I say) "charm" of the early books written by true marque experts, who could make the history of esoteric UK firms (a specialty of the early Putnam books) interesting.I'm a huge fan of Bell helicopters, and I found the information hurridly and confusingly presented. In the Bell 47 section, it presents all the the various productions models without any background or context. It comes across more like one of the souless "aviation encylopedias" filled with lots of numbers, than a well-researched history of a noteworthy firm.Let's hope they return to the old format.