We reconsider the role of pilot's watches in the modern era. This issue of Chronos Japan, Vol. 98, "Praise for Pilot's Watches," has been republished on webChronos. This time, we'll be introducing multi-function pilot's watches. The Breitling Navitimer and other masterpieces with unique additional functions will captivate not only watch enthusiasts but also mechanical enthusiasts.
Photographs by Masanori Yoshie
Masamasa Hirota (this magazine): Interview and writing
Text by Masayuki Hirota (Chronos-Japan)
[Article published in the July 2022 issue of Kronos Japan]
A unique multi-function pilot's watch that goes beyond being just a sub-instrument
This reissue of the legendary flyback chronograph, produced in extremely limited numbers in the 1950s, has now become a regular model. This model features a blue dial, giving it a modern look. The titanium model uses Grade 23 movement, a rare find in the watch industry. Automatic (Cal. F388B). 35 jewels. 36,000 vph. Power reserve of approximately 50 hours. Diameter 42.5mm, thickness 13.77mm. Water resistant to 3 bar. (Right) Ti case. (Left) 18KRG case.
One of the trends in pilot watches was that they were used as a secondary tool for instruments. Since the 1920s, various manufacturers have worked to add more functions to pilot watches, and in 1952 Breitling perfected the idea with the Navitimer. Even today, various manufacturers continue to produce multi-function pilot watches. Their uniqueness, which goes beyond functionality, is what fascinates even mechanical enthusiasts.
PILOT'S WATCH Category 3
HIGH FUNCTION
This model features a rotary slide rule with a wind correction angle calculation function, allowing pilots to calculate the effects of crosswinds while maneuvering. It also features a chronograph and day-date function, as well as a silicon balance spring. Automatic winding (Cal. H-21-Si). 21,600 vibrations per hour. Power reserve: approximately 60 hours. Stainless steel case (diameter 45mm, thickness 14.85mm). Water resistant to 10 bar.
(Bottom left) Breitling Navitimer B01 Chronograph 43
This model could be said to be the perfected version of the Navitimer. The clear printing is achieved by masking the letters, then applying black plating and then peeling off the masking. The Navitimer has steadily evolved since its inception, but this manufacturing method has remained unchanged. Automatic winding (Cal. 01). 47 jewels. 28,800 vph. Power reserve of approximately 70 hours. Stainless steel case (diameter 43mm, thickness 14.2mm). Water resistant to 3 bar.
(Bottom right) Oris Big Crown ProPilot Altimeter
This model features a mechanical altimeter housed inside the case. The crown for setting the altitude is located at 4 o'clock, and a pointer-style meter is located around the outer edge of the dial. The altitude display is available in both feet and meters, making it truly a "professional" model. Automatic winding (Cal. Oris 733). 26 jewels. 28,800 vibrations per hour. Power reserve of approximately 38 hours. Stainless steel case (diameter 47mm, thickness 17.7mm). Water resistant to 10 bar.
It was in the 1920s that pilot's watches began to evolve in their own way. After Longines added a rotating disc to their pilot's watches, they came to be expected to serve as a tool to complement aircraft instruments. From then on, various manufacturers added various functions to watches in this genre, the most popular of which was the rotating slide rule.
The world's first wristwatch with a rotating slide rule was the Breitling Chronomat in 1942. However, the slide rule's functions were limited to multiplication, division, and triplet calculations. While useful for simple calculations, it was not suitable for use in an aircraft cockpit. Marcel Robert, who worked for the company, completely improved this slide rule. By changing the display, he made it easier to perform multiplication and division, and also made it possible to see multiple answers at once.
More importantly, it incorporated the functionality of the E-6B aviation slide rule. Developed in the 1930s and completed in 1940, this was the first flight computer capable of being used for dead reckoning and was used by the US military during World War II. By removing several elements, Robert was able to shrink the pilot's slide rule to the size of a wristwatch. The first pilot's watch to incorporate this was the Navitimer in 1952. This marked the completion of the concept of pilot's watches as a complement to aircraft instruments.
Improvements to the watches themselves also continued. One such improvement was the flyback mechanism, which allows the chronograph to be restarted without stopping it. Developed by Longines in 1936, this mechanism was adopted by Tutima in 1941 for its pilot's chronograph movement, the UROFA59. After the war, it spread throughout the watch industry through the French military's "Type 20" standard. While the flyback mechanism no longer has much meaning, it is still useful for timing a flight between two waypoints and then immediately moving on to a third waypoint, or for calculating consecutive average speeds. It is easy to see why the French military added the flyback mechanism to their pilot's watch standards.
However, at the time, the only ébauche capable of incorporating a flyback function was the Valjoux, and it wasn't until Breguet introduced the Lemania chronograph and Blancpain introduced the Frédéric Piguet chronograph that the function really took off. The Breguet Type XXII and Blancpain Air Command continue this lineage.
As the "10Hz" on the dial indicates, this is a chronograph with a flyback function equipped with an ultra-high frequency movement. It features a central coaxial counter, a 24-hour display, and a date function. The beating of the balance can be seen from the case back. Automatic winding (Cal. 589F). 28 jewels. 72,000 vibrations per hour. Power reserve of approximately 40 hours. 18KRG case (diameter 44mm, thickness 18.05mm). Water resistant to 10 bar.
As aviation instruments have evolved, pilot's watches no longer require numerous additional functions. However, some models still offer unique features. For example, Hamilton's Khaki Aviation X-Wind Auto Chrono features a rotary slide rule with a wind correction function, which calculates the direction the aircraft should be pointed based on the effects of crosswinds.
Regardless of whether anyone will actually use it, this watch, which highlights the intriguing mechanism, can be seen as an attempt to present a new form of multi-function pilot's watch. The same can be said for the Oris Big Crown ProPilot Altimeter, which is equipped with an altimeter. Developed by Thommen, a specialist manufacturer of aircraft instruments in Waldenburg, Switzerland, this altimeter has enough functionality to be used as a secondary altimeter, but it also has a tool-like feel that makes even non-pilots want to use it.
If we're looking for functionality as an instrument, the best choice for a high-performance pilot's watch would be one equipped with a quartz movement. Citizen's Promaster Eco-Drive GPS Satellite Radio Wave Watch is a pilot's watch packed with features such as a rotating slide rule, home time/local time switching, an alarm, and a chronograph. The bezel is also engraved with the International Civil Aviation Organization's International Distress Signal, which is used to display the signal and wait for rescue in the event of distress.
This multi-function quartz watch is packed with complex mechanisms, including a perpetual calendar and chronograph, as well as the ability to obtain location and time information from GPS satellites. The "Double Direct Flight" function, which allows for easy time zone adjustment, is a practical feature for businesspeople who frequently work overseas. It features quartz movement (Cal. F990), a titanium case (47.2mm diameter, 16.7mm thick), and is water resistant to 20 bar.
The Gravitymaster is a G-SHOCK with its exterior modified for pilot watches. Originally conceived with tough environments in mind, the G-SHOCK has become a favorite among many pilots. The Gravitymaster's refinement as a pilot watch is further enhanced by the addition of Triple G Resist, which offers shock resistance, centrifugal force resistance, and vibration resistance. Another unique feature of a pilot watch is that it is exceptionally equipped with JIS Class 1 magnetic resistance (4800A/m) for a G-SHOCK.
This robust pilot's watch features a vibration-resistant structure to prevent the band from falling off due to vibration, high shock resistance, and a strong band with carbon fiber inserts. It can be linked to a smartphone application to adjust the time and keep a flight log. It can also adjust the time using standard radio waves or GPS satellite signals. It is Tough Solar. Resin case (diameter 57.1mm, thickness 18.2mm). Water resistant to 20 bar.
Smartwatches, which are computers worn on the wrist, are likely to become the most promising multi-function pilot watches of the future. Garmin's MARQ Aviator is equipped with a horizontal attitude indicator, direct navigation, display of NEXRAD (Next Generation Weather Radar) operated by the US National Weather Service, flight log recording, and direct navigation to the nearest airport in case of an emergency. While its operating time is not long at 24 hours in GPS mode, its high functionality pushes the multi-function pilot watch, which serves as a secondary instrument for aircraft, to the ultimate level.
This professional pilot smartwatch features a sunlight-readable reflective Chroma display. It can be linked to a global aviation database and weather radar for in-flight navigation. It can also be used for activities like golf, swimming, and running, thanks to various applications. It has a Ti case (46mm diameter, 14.7mm thick). It is water resistant to 10 bar.
