The Breitling Navitimer serves not only as a precise timekeeping device but also as a practical tool for pilots.

The Breitling Navitimer is renowned for its blend of luxury and functionality. It serves not only as a precise timekeeping device but also as a practical tool for pilots. Its iconic feature is the circular slide rule bezel, which allows for various mathematical calculations, useful in aviation for tasks such as converting units, calculating speed, distance, and fuel consumption.

Additionally, the Navitimer often includes a chronograph function, enabling it to work as a stopwatch with sub-dials measuring elapsed time. Many models also feature an automatic movement, which means the watch is powered by the motion of the wearer's wrist rather than a battery. Known for their high precision, Navitimers often have COSC certification, ensuring their accuracy.

Flying with a Breitling Navitimer

The Breitling Navitimer, first introduced in 1952, quickly became an iconic timepiece, particularly favored by pilots and aviation enthusiasts. Its creation was closely tied to the Aircraft Owners and Pilots Association (AOPA), one of the world's largest aviation organizations founded in 1939 to promote general aviation and ensure safe and efficient air travel.

In the early 1950s, Breitling collaborated with AOPA to design a watch specifically for pilots. This collaboration resulted in the Navitimer, which stands for "navigation timer." The watch's innovative circular slide rule bezel allowed pilots to perform crucial calculations, such as converting units, calculating speed, distance, and fuel consumption, directly on their wrist.

To highlight this partnership, early Navitimer models prominently featured the AOPA logo on the dial.

How does a slide Rule Work?"

A circular slide rule, like the one on the Breitling Navitimer, operates on the principles of logarithms to perform mathematical calculations. Here's how it works:

The slide rule consists of two logarithmic scales: one on the rotating bezel and one on the fixed inner part of the watch dial. By aligning these scales, you can multiply, divide, and perform other calculations through the relative positioning of the numbers.

For multiplication, you align the "1" on the outer bezel with a number on the inner scale. Then, you find the second number on the outer bezel and read the corresponding value on the inner scale. For example, to multiply 2 by 3, you align the "1" on the outer bezel with the "2" on the inner scale. Then, you find "3" on the outer bezel and see that it aligns with "6" on the inner scale.

In other words, the inner is a multiple of the outer. One kilogram is 2.2 Pounds, so you would align the '10' with '22', all subsequent units on the scale would be multiples of 2.2

You can read '10' as 1, 10, 100, 1000 etc, just add a zero to the end!

Deriving fuel consumption using a Breitling Navitimer

Likewise, fuel consumption is simply a multiple. For every hour you spend in the air, you use 'X' Gallons. For example, if a pilot were to use 5 gallons in 20 minutes, he would rotate inner dial to match up with the '5' on the outer scale. From there, he would quickly and easily be able to determine his fuel burn in units per hour, by reading off the '60' and subsequently be able to ensure he had enough fuel for the remainder of the leg.

For division, the process is reversed. You align the number you want to divide by on the outer bezel with the number on the inner scale. For instance, to divide 6 by 3, you align "3" on the outer bezel with "6" on the inner scale. Then, "1" on the outer bezel will align with "2" on the inner scale, giving the result.

This mechanism allows pilots and users to perform quick calculations without the need for electronic devices, making it a valuable tool for aviation and other fields requiring rapid arithmetic operations.