The Navitimer is an aviator chronograph that has been manufactured by the Swiss manufacturer Breitling SA since the 1940s. Its features include a slide-rule and a 12-hour timekeeping bezel. After you operate the Navitimer a few times, it is fairly easy to do. Does this Spark an idea?
Set the Watch Date
Twist the crown on the right-hand side of the Navitimer watch casing counter-clockwise until it pops free. Pull the crown out to the first notch. Twist the knob clockwise to adjust the date. Push the crown back in and twist it clockwise to lock it.
Set the Watch Time
Twist the crown on the right-hand side of the Navitimer watch casing counter-clockwise until it pops free. Pull the crown out to the second notch. Twist the knob clockwise and counter-clockwise to move the hour and minute hands and adjust the time. Push the crown back in and twist it clockwise to lock it.
Calculate the Rate of Descent/Ascent
To work out your rate of ascent or descent, you need to know the elevation change and the time period. For example, changing 6900 feet in 15 minutes. Set the change in elevation (in this case 6900) on the white disc opposite the time period (in this case 15). Opposite 10 (the unit index) on the black disc you can read the rate of ascent/descent on the white disc, in this case 460 feet per minute.
Divide with the Navitimer
To divide on the Navitimer, set the quantity to be divided on the white disc, opposite the number you are dividing by on the black disc. Opposite the unit index (the number 10 on the black disc) read the answer on the white disc.
Multiply with the Navitimer
Set the number by which the other will be multiplied (multiplier) on the white disc opposite the unit index. Read the answer from the white disc opposite the number being multiplied on the black disc.
Tags: white disc, black disc, white disc opposite, this case, unit index, ascent descent