Theory and practice in an unusual shape
Ninety years after Charles Lindbergh’s spectacular crossing of the Atlantic from west to east, Longines commemorates the valiant airman’s in-flight achievement and his subsequent conceptual brilliance. Tribute is also paid to Longines’ erstwhile employees, who spent several years translating the pioneering pilot’s theoretical concepts into ticking horological reality. This homage to a grand past is justifiably named The Lindbergh Hour Angle Watch – 90th Anniversary. With a diameter of 47.5 mm, this jumbo timekeeper is anything but petite – its titanium case and steel bezel coated with black PVD attract admiring attention to its wearer’s wrist; the bezel is calibrated to take into account the equation of time when determining the Greenwich Hour Angle. The bold appearance is underscored by an eye-catching dial with the cleverly designed indexing that greatly assisted pilots in navigation’s pre-GPS era. The inner circle can be rotated to synchronize the display of seconds with a time signal. Thanks to this system, pilots are able to verify the accuracy of their watches at a glance. The design of the rest of the dial orients itself on the earth’s rotations. The indexing, in tandem with the hands for the hours, minutes and seconds, helps a pilot speedily and accurately calculate three angular values to the nearest minute of arc. Adding these values yields the Greenwich Hour Angle relative to the sun. A sapphire crystal with multiple coatings of antireflective treatment improves the legibility of the various data. To accurately power the three hands, Longines opted for 16-line automatic Caliber L699.2, approximately 37 mm in diameter, with a 46-hour power reserve. Connoisseurs know that this is an ETA A07.L01 movement with 24 functional jewels and a balance paced at four Hertz. While this pilot’s watch isn’t suitable for deep dives under water because its case resists pressure only to three bar. The aviation-style leather strap can be easily lengthened for wearing it over the sleeve of a flight suit.