Reconsidering the role of pilot watches in the modern era, we have republished the feature "Pilot Watch Praise" from Vol. 98 of Chronos Japan on webChronos. This time, we will explain why the automatic chronograph ETA7750, developed by Valjoux in 1973, has been adopted in so many pilot watches.
Text by Masayuki Hirota (Chronos-Japan)
[Article published in the July 2022 issue of Kronos Japan]
Why the ETA7750, the epitome of a versatile chronograph movement, was chosen for pilot watches
Although it has faded into obscurity, the ETA 7750 was long synonymous with mechanical chronographs. Completed in 1973 and revived in 1983, this movement was the driving force behind the revival of pilot's watches.
General-purpose chronograph movement "ETA7750"
The chronograph boom of the early 1980s can be attributed to the revival of the ETA 7750. This automatic chronograph, completed by Valjoux in 1973, was inexpensive yet practical, highly accurate, and durable. However, after absorbing Valjoux, ETA discontinued production of the 7750 in 1975 and ordered Valjoux to destroy the movement and machine tools. In response, designer Edmond Caput is said to have concealed the machine tools and other information.
With the boom in mechanical watches, ETA decided to re-produce the 7750. Various manufacturers began using this automatic chronograph movement to produce a new generation of pilot's watches. Representative examples of this era include Breitling's Chronomat and Sinn's 103. Incidentally, even during this period, ETA's automatic movements featured mechanical chronograph movements equipped with Dubois-Dépraz's DD2000 series modules. However, there was a reason why the 7750 was adopted.
Among the more expensive automatic chronographs, the 7750, which made extensive use of pressed parts, was inexpensive. Despite this, it featured the same brake lever as a column-type chronograph and a 12-hour counter at 6 o'clock, just like a high-end model. The 7750 also boasted excellent accuracy thanks to its high-torque mainspring and large-inertia balance wheel. The complex automatic winding mechanism was deliberately simplified to a single-winding mechanism, enhancing durability.
It was only natural that Breitling and IWC subsequently adopted the ETA7750 for their pilot watches. However, movements used in pilot chronographs, which are used in harsh environments, would malfunction if installed as is. Instead, each company assembled the movements in-house and added their own unique know-how to refine this excellent base movement into a chronograph that could withstand professional use.
Nowadays, pilot chronographs are being produced by many companies, but without the revival of the ETA7750, the state of the watch might have been a little different.
