A hardback copy of a WWII era "Hydromatic Quick-Feathering Propellers" by Hamilton Standard in good condition overall with scattered use and wear marks consistent with the items age. The book "Hydromatic Quick-Feathering Propellers" is an authoritative service manual and operational guide published by Hamilton Standard during World War II. It details the engineering, maintenance, and mechanics of their innovative hydraulic aircraft propellers. The book is historically notable and highly sought after for several distinct reasons: Technical Instruction: It serves as a comprehensive handbook, breaking down the inner workings of hydromatic control, distributor valve assemblies, pistons, and cams. Model Coverage: The books generally outline specific models (such as 23E50-31 and above) equipped with constant-speed control. Application: It explains how pilots and mechanics can utilize engine oil pressure to adjust blade pitch and quickly "feather" a propeller mid-flight to reduce drag if an engine fails. Original copies of this publication from the early 1940s are renowned for their unique design. These sell on eBay for an average of $40-100 with some listed for as high as $150. idders are welcome to preview items in person during our normal operating hours Tuesday through Saturday 11am-6pm. Estimated shipping parcel size (LxWxH) 20 inches x 16 inches x 4 inches. Please note, shipping estimates are provided for LiveShipping calculations only and may vary based on weight and location. The auction house will combine multiple lots to reduce shipping cost. Please inform the auction house prior to paying your invoice for special shipping requests. Our primary method of shipping is via UPS Ground.