Hamilton Khaki Aviation watches

Khaki Aviation is Hamilton's family of pilot's watches. The flying connection goes back to 1918, when Hamilton was official timekeeper for US airmail flights between Washington, Philadelphia and New York, and Hamilton watches went on Admiral Byrd's 1926 flight over the North Pole.

The Khaki Pilot Day Date is the core of the line and the watch Cooper wears in Interstellar: a day and date, at 42 mm on the H-40 or 46 mm on the H-30. The Pilot Pioneer Mechanical of 2019 reaches further back, to the W10 Hamilton made for the British Army in the 1970s. It keeps the tonneau case and a hand-wound movement, the H-50 with 80 hours of reserve, but its grained black dial drops the W10's broad arrow. The Pioneer name has since spread to round automatics, some cased in aluminium, a 43 mm Pioneer Mechanical in steel or bronze, and a mechanical chronograph.

The Converter, presented in 2020, puts a bidirectional slide-rule bezel modelled on the E6B flight computer on the wrist, for working out speed, distance, fuel burn and unit conversions. The 42 mm automatic runs on the H-10, an upgraded ETA 2824-2 with 80 hours of reserve and a Nivachron hairspring; the 44 mm GMT uses the H-14 and the 44 mm chronograph the H-21-Si, a Valjoux 7750 derivative with 60 hours. All three are rated to 100 m, rare for a slide-rule pilot's watch.

The X-Wind is built around a drift-angle calculator, which lets a pilot work out the crosswind to expect on a flight. It is a big watch, 44 to 46 mm, made as an automatic chronograph on the H-21, a Day Date on the H-30 with 80 hours of reserve, and a GMT Chrono Quartz with a split-seconds hand. Split-seconds timing also turns up in the ETO, which adds flyback, and in the Pilot Pioneer Chrono Quartz, while the Worldtimer Chrono Quartz adds world time and a day and night indicator.