Pilot’s watches are some of the most coveted timepieces around, as flying is certainly still creating emotions and provokes a unique feeling of freedom. However, “pilot’s watch” is a wide definition, which covers multiple styles of watches. Even at Hamilton, the Khaki Aviation collection comprises military-inspired models, modern technical pieces and vintage-oriented watches. The brand’s latest addition is a proper flying instrument, which can perform technical calculations, as a tool working in conjunction with cockpit instruments. Its name is the Hamilton Khaki Aviation Converter collection and as the watches are now available, we take a closer look at the Automatic Chronograph Black & Gold model.
Hamilton is no stranger to the pilot’s watch. In fact, the brand has great legitimacy in this field – as well as other military fields. The brand, for instance, provided the first U.S. Airmail service with watches, as of 1918. Today, Hamilton is still involved in pilot’s watches with the Khaki Aviation collection, which comprises, for instance, the X-Wind watches, supplied to air racers. What Hamilton is adding with the Khaki Aviation Converter is a collection of instrumental watches, with the ability to perform flying calculations.
A look back at the Converter collection
Earlier this year, we introduce to you the Converter collection in an in-depth article, covering most models to be released – it was, back then, an announcement, as the watches are available as of October 2020. The difference between the Converter and a simpler 3-hand pilot’s watch is about purpose and functions. Classical pilot’s watches are often to be considered as observation tools, precise, often oversized and ultra-legible pieces to keep accurate track of the time. The Hamilton Khaki Aviation Converter Collection is a classic pilot’s watch that enables flying calculations to be performed on the wrist, with a so-called “slide rule”. As such, Hamilton has created a wrist computer.
The most noticeable element of the Converter is its slide rule bezel – a function also known as “flight computer” or “logarithmic bezel” – a device that enables mathematical calculations while in flight. These bezels were first integrated into wristwatches in the early 1940s – to be precise, in 1940, with MIMO watch manufacture and Breitling almost simultaneously filling a patent. A slide rule was a crucial tool for pilots – which is still in use and taught in flight schools. It is a mechanical analogue computer, used to primarily perform multiplication and division but also functions such as exponents, roots or logarithms. While modern avionics make the slide rule slightly outdated, back in the 1940s and 1950s, pilots needed it to perform calculations, in order to track speed, fuel consumption, distance, rate of climb or descent and flight time.
With the integration of the slide rule on watches, pilots had the ability to perform both timings and calculations on a single device. And the Hamilton Khaki Aviation Converter has a bezel that has been modelled after the famous E6B. The bezel is bi-directional and its logarithmic gradations interact with the fixed scale around the dial. It allows calculating distances, speeds and fuel consumptions, but also to carry out various unit conversions, such as kilometres/nautical miles or feet/metres, or currency conversions for those flying internationally. On the Hamilton Khaki Aviation Converter, the insert is made of K1 mineral glass (hardened glass with scratch-resistant coating) with graduations printed underneath, allowing for great contrast and good protection against scratches.
As for the watches themselves, Hamilton doesn’t much play on the vintage trend here, as the Converter isn’t a re-edition of a past model. Instead, it brings a classic, slightly retro-inspired but also instrumental watch focused on functionality. The cases, available in steel – with black PVD coating and gold-plated elements on some models – are modernly sized at 42mm or 44mm, depending on the movement. The construction is extremely solid, with great attention to details, such as nice polished accents contrasting over the brushed surfaces, or well-designed notches on the bezel and crown, so the watch can be used with flying gloves. All the watches are rated to 100m water-resistance.
The Hamilton Khaki Aviation Converter is available in 3 different configurations. The first is a 42mm time-and-date model, with a dial focused on legibility and function. Inside is a solid movement, Caliber H-10, an upgraded version of the ETA 2824-2 equipped with balance spring made of Nivachron alloy, with anti-magnetic properties and a longer power reserve of 80 hours.
The second model features on the most classic complications for a pilot’s watch, the GMT function, displayed via a central 24-hour hand and an additional track on the inner flange. This model, with its 44mm diameter, is easily recognizable, being the only one available with a blue dial. Inside its case is the Calibre Hamilton H-14, which also comes with upgraded specifications, such as an 80-hour power reserve and anti-magnetic properties.
Finally, Hamilton also integrates a fully adequate chronograph function to this collection – indeed, the stopwatch function works great in conjunction with the slide rule bezel (Navitimer owners will understand why here…) This is the most robust version of the collection, with its 44mm case. The dial is nicely complex, with multiple indications displayed, but still the same instrumental spirit. Inside the case is an upgraded Valjoux movement, but more details to come in the hands-on session below.
The entire Khaki Aviation Converter collection (9 references overall) can be discovered here, at www.hamiltonwatch.com.
The Converter Automatic Chronograph Black & Gold
In March, we had the opportunity to discover almost the entire collection, to the exception of the Black PVD coated and gold-plated edition. Problem solved, as we have this chronograph on the wrist today, and this two-tone edition certainly is the model that shows the strongest character. Maybe more disruptive, bolder and less conventional than the classic steel on black dial version, but one that won’t fly under the radar for sure.
Overall, even with its more fancy colour scheme, this black & gold edition of the Converter Chronograph retains its highly engineered look and feel. The case, which measures 44mm in diameter and about 14.5mm in height, has certainly a great presence on the wrist and a cool instrumental style that perfectly fits the concept behind this collection. The black PVD coating, which is applied on all part of the watch save for the bezel, crown and pushers, also benefits to the watch as creating a more compact visual feeling. Despite its robust proportions, the case is well shaped and offers great comfort, with curved lugs.
Hamilton being an accessible-luxury brand, the gilt elements are not made from solid gold but plated in rose gold. The contrast with the black case makes for a striking look that won’t remain unnoticed, but (guilty pleasure), it certainly is the coolest of the Converter editions. The watch is worn on a thick and flat leather strap, in matte black leather with alligator embossing. Altogether, the feeling on the wrist is that of a high-quality watch that is ultra-durable and made for action.
With all its functions, the dial of the Khaki Aviation Converter Automatic Chronograph seems quite complex at first, especially when combined with the equally information-packed bezel. There’s no denying that the watch needs to be explored to be fully understood – which is always the case with watches featuring a slide rule bezel. Still, the multiple tracks and indications are well highlighted, making their use practical – thanks to contrasting colours, polished frames and generous luminous material. The central part of the dial is dedicated to the time, the calendar indications and the chronograph. To make them easier to read, the day-date complication, as well as the chronograph sub-counters, are both framed by metallic rings, here gold-coloured. Also, a nice touch specific to the chronograph models, the sub-counters have a gradient effect that not only adds depth to the whole dial but also enhance the visibility on the indications.
In addition to the classic indications, the Converter – hence its name – has multiple tracks and tools for calculations. From the centre to the periphery, the first one (next to the seconds track) is a classic tachymeter scale, which calculates speeds. Then, printed on the angled inner flange, and working in conjunction with the rotating bezel is the slide rule, is a logarithmic scale based on the E6B “Whiz Wheel”. It can carry out various unit conversions; kilometres/nautical miles, pounds/kilograms, litres/gallons, feet/metres for instance.
To power its latest collection, Hamilton is relying on modern movements. This Converter Chronograph is using the Calibre Hamilton H-21 Si. While its architecture is known, being the Valjoux 7750 with cam-lever system, Hamilton carries multiple updates to make this movement more efficient and more reliable. First, it is equipped with a high-tech silicon balance-spring, which negates the effects of magnetism on the escapement – useful in a cockpit but also in daily life. Second, the entire kinematic chain has been refined, from the barrel to the escapement, the mainspring has been improved to increase the power reserve from 42 hours to now 60 hours, but the frequency has been kept at 4Hz for more precision.
Availability and Price
The entire Hamilton Khaki Aviation Converter collection is now available in stores and on the brand’s website. Prices start at EUR 1,045 for the time-and-date model in steel, up to EUR 2,045 for the present black & gold Converter Automatic Chronograph – a fair price for a watch of that quality and with a modern automatic chronograph movement.
More details about the collection and orders at www.hamiltonwatch.com.