We're reconsidering the role of pilot's watches in the modern era. This issue, "Praise for Pilot's Watches," from Vol. 98 of Chronos Japan, has been republished on webChronos. This time, we'll explore the GMT mechanism, developed as a civilian pilot's watch, and its evolution and current state, focusing on the functions of GMT models from Rolex, Breitling, Bell & Ross, and others.
This is the successor to the GMT-Master, developed at the request of Pan American World Airways. Utilizing an independently adjustable hour hand and a bidirectional rotating bezel with 24-hour display, it is possible to display the time in up to three countries at once. The photo shows the previous model equipped with the Cal. 3186. The current model is equipped with the Cal. 3285 movement, which has a significantly improved power reserve. Automatic winding (Cal. 3186). 31 jewels. 28,800 vph. Power reserve approximately 70 hours. 18KWG case (40mm diameter). Water resistant to 100m. Private collection.
Photographs by Masanori Yoshie
Interview and writing by Hosoda Yuto (this magazine)
Text by Yuto Hosoda (Chronos-Japan)
[Article published in the July 2022 issue of Kronos Japan]
Civilian pilot's watches evolved to keep track of multiple time zones
With the rise of jet airliners, the popularity of watches that display multiple time zones has skyrocketed. While nowadays it is primarily a travel watch, the GMT was originally developed as a mechanism for commercial pilots to wear, and some pilots continue to use this function even today.
PILOT'S WATCH Category 2
CIVILIAN
After World War II, in the 1950s, airlines began introducing jetliners. The arrival of jetliners, capable of cruising speeds nearly twice as fast as those of propeller-driven passenger aircraft, the mainstay of modern airliners, suddenly made intercontinental flight more accessible to mankind. At the same time, commercial pilots, who began traveling between different time zones, began to demand watches capable of displaying a second time zone.
Originally, there was the Louis Cottier World Timer, a wristwatch that displayed multiple time zones, but this mechanism, which packed the current time in 24 cities into a circle just under 4cm in size, was not necessarily user-friendly for pilots in flight. So in 1953, Pan American World Airways commissioned Rolex to develop the Oyster Perpetual GMT-Master. While previous pilot watches had been designed for fighter pilots, or military watches, the GMT-Master could be said to be the first watch designed with civilian pilots in mind.
Although the term "civilian pilot" is broadly used, the types of aircraft they fly vary widely, from small propeller planes to jumbo jet passenger jets. However, one thing they all value is the GMT function. This is because time information exchanged with air traffic control during flight is based on Coordinated Universal Time (UTC), regardless of whether the flight crosses time zones. In other words, the ideal civilian pilot watch would have a GMT function that is also easy to read while in flight.
The Rolex Oyster Perpetual GMT-Master II was a pioneer in this field, boasting exceptional ease of use and legibility for its GMT function. While the crystal is anti-reflective, only on the back, to prevent peeling over time, the thick hour, minute, and GMT hands, along with Chromalight, which maintains its brightness over time, make the time legible in a wide range of situations. With attention to detail, including an independently adjustable hour hand and a tactile bidirectional rotating bezel, this timepiece remains the benchmark for civilian pilot watches.
The Bell & Ross BR 03-93 GMT is a model that combines a GMT mechanism with a square case modeled after a cockpit clock. The rotating bezel, painted black and red for day and night, has an aluminum insert, evoking the nostalgia of classic GMT watches. While the Arabic numerals are not coated with luminous paint, they are thick and highly legible in broad daylight. Luminous paint is applied to the bar indexes, hour and minute hands, and GMT hand, ensuring good visibility in the dark as well.
This is a new generation pilot's watch from Fortis, a brand with deep ties to the aerospace industry. It features a Kenissi movement with a power reserve of approximately 70 hours. It incorporates features to enhance instant legibility, such as the Brickstrack indexes coated with Super-LumiNova X1. Automatic winding (Cal. WERK13). 27 jewels. 28,800 vph. Approximately 70-hour power reserve. Titanium case (43mm diameter). Water resistant to 20 bar.
(Center) Omega Speedmaster Moonwatch Master Chronometer
The Speedmaster Moonwatch has achieved Master Chronometer status. While the basic design follows the fourth-generation model, the level of refinement in the details has been further improved. The bracelet's comfort has also been improved by changing the bow tube shape and making the clasp more compact. Manual winding (Cal. 3861). 26 jewels. 21,600 vph. Power reserve of approximately 50 hours. Stainless steel case (42mm diameter, 13.58mm thick). Water resistant to 5 bar.
(Bottom) Bell & Ross "BR 03-93 GMT"
This model features an iconic square case inspired by cockpit clocks and a bidirectional rotating bezel with a 24-hour display. The large Arabic numerals, Super-LumiNova-coated hands, and the GMT hand with a red tip provide excellent visibility and readability. Automatic movement (BR Cal. 303). 25 jewels. 28,800 vph. Power reserve of approximately 50 hours. Stainless steel case (42mm x 42mm). Water resistant to 100m.
Like Bell & Ross, the Ball Watch Roadmaster Pilot GMT is a classic civilian pilot's watch equipped with a GMT. This model's rotating bezel is made of ceramic, and the indices are self-luminous rather than luminous, giving it a contrasting character. The pushers at 8 and 10 o'clock allow the hour hand to be advanced and retracted independently, making for excellent operability. The Fortis Flieger F-43 Triple GMT is also a watch that allows the hour hand to be adjusted independently. Additionally, the Super-LumiNova is coated with X1 grade, which has a 60% higher afterglow brightness than normal after two hours.
GMT is an ideal mechanism because it allows pilots to intuitively read two or three time zones. However, there are other pilot watches that display multiple time zones besides GMT. The IWC Pilot's Watch Timezoner Chronograph is a "worldtimer for pilots" that overcomes the complicated operation and visibility of worldtimers. When you turn the bezel, which is engraved with the names of 24 cities, the hour hand and the sub-hour hand move in sync. Therefore, simply by positioning the name of the city you want to know the time in at the 12 o'clock position, you can easily find the time in that country. While it is not possible to simultaneously read multiple time zones, the instantaneous time zone adjustment is extremely convenient.
This world timer allows you to change the time zone and date simply by pushing and turning the bezel. The central dial displays the 24-hour display, while the subdial at 12 o'clock features a chronograph counter coaxially positioned for the hours and minutes, ensuring excellent legibility despite the inclusion of multiple complex mechanisms. Automatic movement (Cal. 89760). 39 jewels. 28,800 vph. Power reserve of approximately 68 hours. Stainless steel case (46mm diameter, 16.8mm thick). Water resistant to 6 bar.
The Super Chronomat lives up to its name with its massive appearance. The bezel features a scratch-resistant ceramic insert. A quartz UTC module built into the bracelet allows for a second time zone display. Automatic winding (Cal. 01). 47 jewels. 28,800 vph. Power reserve of approximately 70 hours. Stainless steel case (44mm diameter, 14.4mm thick). Water resistant to 200m.
Similarly, the Oris Big Crown ProPilot Worldtimer also sets the time zone by turning the bezel. The basic operation is the same as a GMT watch, but since the crown is not used to adjust the hour hand independently, the advantage is that the time can be adjusted without unscrewing it. There are also examples such as the Breitling Super Chronomat B01 44, which has a quartz UTC clock on the bracelet, separate from the head.
The 1960s, when the DC-8 entered service in Japan and jetliners began to become commonplace, was the period when the space race reached its peak. The Omega Speedmaster, also known as the Moonwatch, used in the Apollo program during this period could also be considered a pilot's watch. The current Speedmaster Moonwatch Master Chronometer has undergone significant evolution, particularly in terms of its movement, but it still retains its Hesalite crystal in the lineup. Hesalite is also included in NASA's official equipment requirements, as it prevents damage to astronauts and their equipment if the crystal breaks under reduced pressure.
This dual-time watch allows you to adjust the hour hand forward or backward in one-hour increments by rotating the bezel. The second time zone, displayed on a subdial at 3 o'clock, can only be adjusted using the crown. An indicator allows you to tell at a glance whether the second time zone is day or night. Automatic movement (Cal. Oris 690). 30 jewels. 28,800 vph. Power reserve: approximately 38 hours. Stainless steel case (diameter 44.7mm). Water resistant to 10 bar.
This GMT watch advances the hour hand with a pusher at 10 o'clock and resets it with a pusher at 8 o'clock. This revolutionary adjustment mechanism is equipped with a locking mechanism to prevent accidental operation. The titanium case enhances comfort. Automatic winding (Cal. RR1204-C). 26 jewels. 28,800 vph. Power reserve of approximately 38 hours. Ti case (40mm diameter, 14mm thick). Water resistant to 300m. Limited to 1000 pieces worldwide.
