Check the listing for details. ARMY AIR CORPS TYPE D-3 TIME & DISTANCE COMPUTER. Condition: Used. Listed at 28.50 USD. Normal 0 false false false EN-US JA AR-SA The Army Air Corps Type D-3 Time & Distance Computer is an original pre-WWII flight instrument used by pilots for essential in-flight calculations. This rare, two-sided device measures 3 1/2 inches in diameter and bears the marking "US ARMY AIR CORPS" on the front, signifying its authentic early military issue. Designed for quick, reliable computations, it allows for altitude correction, temperature altitude adjustments, and time-distance calculations, essential for navigation accuracy in the cockpit. This particular Type D-3 model remains in very good condition, with wheels that turn freely, allowing smooth functionality for accurate data adjustments. Early models like this one were manufactured in limited quantities and are highly sought after by collectors due to their scarcity and historical significance. For aviation history enthusiasts and military memorabilia collectors, this pre-war piece is a rare find, capturing a pivotal era in aerial navigation. All items sold are 100% guaranteed. WE SHIP WORLDWIDE