Oris Big Crown Pro Pilot Automatic Chronograph Black Dial Green Nylon Men's Watch 774-7699-4134TS

The most complicated Richard Mille watch to date, the RM 039 is a horological monument as is apparent at first glance. With this giant-sized model, functionality has been taken to the highest heights of micromechanical engineering. The 50mm-diameter, 19.4mm thick movement houses the most sophisticated Richard Mille movement. A few figures give an idea of the magnitude of this phenomenon. It has eight hands and three apertures - without being a perpetual calendar. It is operated via five pushers and a crown - all of which are active pushpieces and not merely correctors, and yet it is not a striking model. Despite its 1,000 components, the manual-winding RM039 calibre is not endowed with 14 or 22 horological complications as one might expect, but actually has 'only' eight. So what is the source of such complexity?

It certainly does not stem from the UTC function (the official name of what is still often referred to as GMT), nor from its large date. The crux of the matter lies in the chronograph, and not even so much because it is of the flyback variety. The determining factor is the presence of a countdown mechanism that is an extremely rare feature on mechanical timepieces. The pusher at 9 o'clock serves to switch from chronograph to countdown mode by activating the 8 o'clock dial aperture. The 4 o'clock pusher shifts the red-tipped chronograph minutes hand and the countdown can then be started, stopped and zero-reset like the chronograph with its built-in flyback function. The RM 039 is the only watch to boast such a mode of operation that is largely responsible for the high number of components (as well as for the line of zeroes on the price tag).

In addition to this standout chronograph, the RM 039 is endowed with properties that have become signatures of the Richard Mille identity: a tourbillon, a function selector, along with exceptionally high-quality hand finishing despite the technical appearance of the calibre. Above all, it features a stunning degree of graphic skeleton work. Despite their large numbers, all components have been hollowed out in the centre at least once in order to create a lighter effect both visually and weight-wise. The baseplate is made of titanium in pursuit of these same objectives, while also ensuring the degree of rigidity that is indispensable in a construction this big, this high and comprises this many openings.

So exactly what kind of functions is such a machine dedicated to driving? The evocative full name of the RM 039 Tourbillon Aviation E6-B Flyback Chronograph clearly hints at the fact that two of its characteristics are dedicated to pilots. The flyback chronograph was invented for aviators using timing operations to perform in-flight calculations. Resetting to zero without having first to stop the mechanism saves milliseconds that can make all the difference between arriving safely or getting lost when navigating using instruments. Speaking of which, the RM 039 does in fact have an instrument specially designed for pilots, the E6-B slide rule. Also known as a flight calculator, it is an elaborate version of the slide rule found on a number of pilot's watches. The seven scales on the watch - including a tachymetric one and two on the vertical part of the bezel - provide a whole host of calculation options. Unit conversions, multiplications and divisions, as well as determining ground speed, fuel consumption, ascent speed and other vital data can be calculated in case the onboard electronics break down. All of which still raises the problem inherent in every slide rule: even having once grasped how they work, you have to use them regularly in order to memorise how they work.

The case matches this impressive complexity. Being made from titanium prevents this juggernaut from tipping the scales at more than 400 grams - a weight it would doubtless have reached if it had been in steel, not to mention gold. Its volumes, curves, satin-finishing and bevelling are so complex that the case alone calls for a full day of quality control, in addition to hundreds of hours of machining. The result is a model priced at more than one million Swiss francs. Fortunately, Richard Mille did not add into the mix its other favourite complication, the split-second mechanism, since that would have made the movement 3mm thicker and further bulked up the cost. But split-second chronographs are not useful to pilots and thus have no place here.