Frank Sans C Video

High-flying pilot watches

A must have among the world of stunning mechanical pieces, pilot watches are real tools as well as a reminder that watchmaking and aviation are inextricably linked. These instruments are resistant, vintage, technical pieces that hold a lot of history. Watch Frank Sans C’s latest video to find out more.

By Nicolas Yvon, Frank Declerck

A calculation instrument for Hamilton

Hamilton – founded in Pennsylvania in 1892 – set out to conquer the sky as soon as 1918 by equipping the pilots of the U.S. Airmail service before becoming the official supplier for Uncle Sam’s army. The most American Swiss manufacturer keeps on perfecting its expertise and developing technical instruments to this day with the Khaki watch and its military background.
Take this Khaki Aviation Converter Auto Chrono for instance, it features a bi-directional rotating bezel with a rotating slide rule to calculate various unit conversions (feet/metres, nautical miles/kilometres, currency conversions, etc.) and measurements (speed, fuel consumption, distance, etc.). Moreover, the bezel and crown are deeply notched to allow an easy manipulation and make it more sophisticated. The automatic movement also includes a silicon balance spring – a non-magnetic high-tech material. This is a coveted model with a strong character, to say the least!

Chez Hamilton, le chronographe Khaki Aviation Converter Auto Chrono est une véritable montre-outil
Hamilton’s Khaki Aviation Converter Auto Chrono comes with a bi-directional rotating bezel and a circular slide rule.

Hamilton Khaki Aviation Converter Auto Chrono

Steel case
44 mm diameter
Water resistance 100 m
H-21-Si automatic chronograph movement 
60-hour power reserve
Grey chrono counters (30 minutes and 12 hours) and small seconds at 9 o’clock
Luminescent hands and indexes
Double day/date window at 3 o’clock
Brown cow leather strap with a tang buckle

Our Khaki Aviation Converter Auto Chrono technical data sheet


Longines, a code name and a shifted dial

A winged hourglass as an emblem does suggest that the house shares some historic ties with the world of aviation. Longines reinterprets its most emblematic period pieces, such as the Avigation Watch Type A-7 1935, with its cryptic name. Why 1935? Well, simply because that’s the year the first model was created. Why Type A-7? That’s what the American army used to call watches that met its high selection criteria. 
This chronograph looks like it needs to be set straight because of its dial shifted 40° to the right. The choice was more practical than aesthetic because this way, the pilot could easily read the indexes without having to let go of the plane’s control yoke.
Another thing to know, the Avigation Type A-7 1935 chronograph features a single push-piece – integrated to the crown – and the various functions (power, stop and reset) are controlled through successive pressures by a column wheel, which, traditionally, is a sign of great workmanship.
Inherently original, this chronograph is an eye-catching piece.

Le modèle Longines Avigation Watch Type A-7 1935 possède un cadran décalé pour faciliter au pilote la lecture du cadran en vol
The Longines Avigation Watch Type A-7 1935 includes a single push-piece integrated to its crown.

Longines Avigation Watch Type A-7 1935

Steel case
41 mm diameter
Water resistance 30 m
L788 automatic movement
60-hour power reserve
White lacquered dial
30-minute counter and 60 seconds hand with a railway-track-style chapter ring
Date window
Blued steel cathedral hands
Honey lacquered hands and stylised numerals
Brown alligator leather strap and calfskin lining

Our Longines Aviation Watch Type A-7 1935 technical data sheet


Navitimer, Breitling’s emblematic must have piece

The Nativimer chronograph – Navi for navigation – is the undisputed icon of the Breitling house, which up until very recently still sported a winged-B as an emblem. While the wings disappeared, the manufacturer carries on the legacy of its most famous watch, created in 1952, by offering various versions that combine vintage and modern mechanics. The piece featured here looks very similar to the original with its bi-directional rotating bezel integrating a circular slide rule. It is also COSC-certified (by the Official Swiss Chronometer Testing Institute), which means that its precision is between -4/+6 seconds per day. When it comes to the design of the watch, we absolutely dig its reverse panda dial.

Comme le modèle originel de Breitling en 1952, cette version Navitimer B01 Chronograph 46 possède une règle à calcul circulaire
The Navitimer model features a circular slide rule and has been an icon of the Breitling house since 1952.

Breitling Navitimer B01 Chronograph 46

Steel case
46 mm diameter
Water resistance 30 m
Automatic Breitling B01 movement with bi-directional self-winding and ball-bearing system
70-hour power reserve
Sapphire case back
Black reverse panda dial featuring white counters (small seconds, 30-minute and 12-hour chrono)
Luminescent hands and indexes
Black alligator leather strap with a tang buckle

Our Navitimer B01 Chronograph 46 technical data sheet


Breguet Type XX, an extraordinary flyback

It goes without saying that Breguet is historically renowned for its tourbillons, since the notorious complication was created in 1801 by the founder of the house. But Breguet’s name is also closely linked to the history of aviation. Indeed, a century later in 1907, Louis Charles, Breguet’s great-great-grandson, invented the gyroplane – the ancestor of the helicopter – before making reconnaissance planes and bombers during World War I! It makes sense that the inventor was also a watchmaker and that he designed his first wrist chronographs for pilots in 1935. In 1955, the French army commissioned him to make the Type XX – the famous chronograph which equipped the French Airforce and Navy until the beginning of the 1980s.
The Type XXI is the offspring of the famous instrument. The automatic movement features the flyback function – a system that was specifically developed for pilots – that is visible through the case back. The pilot can reset the chronograph and start timing again (to time course changes) in one single motion.
This piece is as legendary as its name suggests.

Le modèle Type XXI 3817 de Breguet indique les secondes et les minutes de chronographe au centre
Breguet’s Type XXI 3817 chronograph includes the flyback function, developed specifically for pilots.

Breguet Type XXI 3817

Steel case
42 mm diameter
Water resistance 100 m
Automatic movement Cal. 584Q/2 with a silicon balance spring
48-hour power reserve
Screw-in crown
Sapphire case back
Bi-directional rotating bezel
Slate grey dial featuring beige luminescent hands and indexes
Central minute counter with a small seconds
Day/night indicator at 3 o’clock, 12-hour counter, date window at 6 o’clock, small seconds at 9 o’clock.
Brown calfskin leather strap

Our Breguet Type XXI 3817 technical data sheet


Pilot’s Watches: IWC’s emblematic collection

When talking about pilot watches, IWC simply cannot be left out. The design of Schaffhausen’s emblematic collection of the same name is inspired by the first military observer’s watches that the manufacturer started to develop in 1940.
The Blue Angel edition is a stunning flyback chronograph that honours the U.S. Navy Flight Demonstration Squadron created in 1946. It should be noted that the Blue Angels pilots helped develop the model. It features a sun-brushed blue dial and the hours are displayed on the inner ring while the minutes are on the outer one – a classic design inspired by military observer’s watches from the 1930s and 1940s.
Similarly to a lot of pieces from the collection, a soft iron inner case protects the calibre against magnetic fields and the sapphire glass is secured, even in case of drop in air pressure. The inner ring for the hours makes the originality of this watch.

La Montre d'Aviateur Chronographe Edition "Blue Angels" de IWC arbore l'échelle des minutes sur le pourtour comme les anciennes montres d'observation des années 30 et 40.
The Pilot’s Watch Chronograph Edition “Blue Angels” showcases the colours of the Navy Flight Demonstration Squadron.

IWC Pilot’s Watch Chronograph Edition “Blue Angels”

Ceramic case
44.5 mm diameter
Water resistance 60 m
IWC-manufactured calibre 89361
68-hour power reserve
Screw-in crown
Blue Angels crest engraved on the case back
Chronograph movement showing timed hours and minutes together on a subdial at 12 o’clock
Sun-brushed blue dial with a yellow inner ring for the hours and a white outer ring for the minutes
Luminescent hands and indexes
Blue calfskin leather strap

Our Pilot’s Watch Chronograph Edition “Blue Angels” technical data sheet


Cartier Santos-Dumont, a dandy and aviation pioneer’s watch

Major figure among the Parisian dandies of the beginning of the 20th century, the Brazilian Alberto Santos-Dumont is first and foremost a genius creator who will forever remain an aviation pioneer.
The story behind the eponymous wristwatch is well known. In 1904, when pocket watches were still in fashion, Louis Cartier developed this piece for his friend Santos-Dumont, who had asked him to design an instrument that would allow him to look at the time without letting go of the control yoke of his flying machine.
Made of yellow gold, this 300-piece limited edition is nicknamed “La Baladeuse” in honour of Dumont-Santos’ private dirigible in which he flew above the capital and the Parisian region. The case back incidentally adorns an engraved image of La Baladeuse.
With this model – which is extraordinarily thin (7.3 mm thickness) – the maison Cartier offers a very elegant chromatic piece with the yellow gold, the champagne dial and the green alligator strap. Most certainly the classiest pilot watch.

La montre Cartier Santos-Dumont XL - La Baladeuse est une édition limitée à 300 exemplaires
The Cartier Santos-Dumont XL Watch and the aviation pioneer’s private dirigible, La Baladeuse, engraved on the case back.

Cartier Santos-Dumont – La Baladeuse 

Yellow gold case
Dimensions: 46.5 x 31.4 mm
Cartier Manufacture calibre 430 MC mechanical movement with manual winding
38-hour power reserve
Beaded crown set with a sapphire cabochon
Sun-brushed champagne dial
Blued sword-shaped hands
Railway-track-style chapter ring and Roman numerals
Cartier’s secret signature in one of the arms of the V of the VII
Case back engraved with La Baladeuse
Green alligator leather strap


Longines Lindbergh Hour Angle, it tells the time and so much more

The story of Longines and Charles Lindbergh started in 1927, when the winged-hourglass house timed the aviator’s feat of flying over the Atlantic in 33 hours and 30 minutes – from New York to Paris – on his own for the first time.

Sketch by Charles Lindbergh about the calculation of hour angle thanks to various scales featured on the watch.

Technical discussions between the aviation pioneer and Longines’ watchmakers resulted from this adventure and lead to the creation of the hour angle watch. Thanks to various rotating scales, the pilot can calculate the longitude.

La montre Longines Lindbergh à Angle Horaire affiche un diamètre imposant de 47,5 mm
A true tool-watch, the Longines Lindbergh Hour Angle allows the pilot to determinate the longitude.

The watch needs to be set on the Greenwich time zone first, which is equal to 0° longitude. Then the rotating bezel enables to take into account the equation of time – which is the difference between civil time and true solar time, which can vary between -16 and +14 minutes per day. Finally, the hour angle of the Greenwich meridian is calculated by adding the number shown by the hour hand on the blue chapter ring and the one shown by the minute hand on the bezel.
As for the rest, it is sometimes said that images speak louder than words (Editor’s Note: even more so when you don’t understand all the words!), so take a look at this well-made video that explains how the instrument works.

Short video made by Longines to explain how the watch works.

Longines Lindberg Hour Angle Watch

Steel case
47.5 mm diameter
Water resistance 30 m
Small button under to the onion-shaped crown to open the transparent case back
Automatic L699 calibre
46-hour power reserve
Bi-directional rotating bezel
White lacquered dial
Blued steel Breguet “pomme”
Brown alligator leather strap and calfskin lining

Our Longines Lindberg Hour Angle Watch technical data sheet