Zenith created the iconic Rainbow Flyback model in 1997 based on technical specifications established for the French Air Force. The result was a rugged, high-performance timepiece capable of standing up to the most extreme conditions.
The brand with the guiding star now draws inspiration from this high-precision instrument in presenting an eminently sporty version named El Primero Stratos Flyback Rainbow.
In 1969, Zenith introduced El Primero, the first ever integrated automatic watch, also beating at the exceptional speed of 36,000 vibrations per hour and thus displaying 1/10th second precision – an achievement that makes it the world’s most accurate series-produced chronograph to this very day.
Zenith therefore naturally responded to the bid for tender launched by the French Ministry of Defence which was seeking to develop a watch for fighter pilots, especially since the brand had earned an impressive reputation in the field of aviation right from the start of the 20th century.
The technical specifications to be met by the Manufacture were unequivocal: the goal was to develop a watch capable of maintaining excellent precision even in extreme conditions of use – including violent accelerations from 9 to 11 g’s, variations in pressure and temperature, as well as vibrations and magnetic fields. In rising to this demanding challenge, the Manufacture once again pushed back the boundaries of reliability and resistance to present the Rainbow Flyback model in 1997.
Today, the brand with the guiding star draws inspiration from this landmark model in offering a reinterpretation: the El Primero Stratos Flyback Rainbow, driven by the El Primero Calibre 405 B automatic movement.
While this chronograph naturally beats at the frequency of 36,000 vibrations per hour enabling 1/10th second precision, it is also equipped with a date display, a telemetric scale, and above all with the famous flyback function. Closely bound up with the world of aviation, the latter enables pilots to stop, start and restart the chronograph at a single press on the push-piece, compared with three presses required for a standard chronograph.
The 45.5 mm steel case is topped by a rotating bezel bearing an aluminium ring. The rounded sapphire crystal is shaped like an astrodome – the dome located on the fuselage’s dorsal ridge to enable astronavigation. The equally transparent engraved sapphire case-back reveals the fascinating mechanism of the world’s most accurate series-produced calibre.
On the dial side, the minutes counter at 3 o’clock appears in colours enabling night-time readings in infrared-lit cockpits, exactly like the first model developed in cooperation with a fighter pilot, while the hours are displayed at 6 o’clock and the small seconds at 9 o’clock.
The white superluminova hour-markers make a striking contrast with the black of the dial and case, while the chronograph sweep seconds hand stands out in red. The inner bezel ring bearing a telemetric scale creates an overall depth effect. The eminently virile and stylish El Primero Stratos Flyback Rainbow is fitted with a steel bracelet.
El Primero 405B, automatic
Calibre: 13 14’’’ (diameter: 30 mm)
Thickness: 6.60 mm
Frequency: 36,00 VpH – 5 Hz
Power reserve: min. 50 hours
Finishing: oscillating weight with “Côtes de Genève” pattern
Hours and minutes in the centre
Small seconds at 9 o’clock
– Central sweep seconds hand
– 30-minute counter at 3 o’clock
– 12-hour counter at 6 o’clock
– Telemetric scale
Date window at 6 o’clock
Case, Dial and Hands
Unidirectional rotating bezel with black aluminium disc
Diameter: 45.5 mm
Opening diameter: 35 mm
Thickness: 14.10 mm
Glass: domed sapphire crystal glare-proofed on both sides
Case-back: transparent sapphire crystal
Water-resistance: 10 ATM
Dial: black with 30-minute counter in original colours
Hour-markers: Arabic numerals in SLN C1 superluminova
Hands: rhodiumed, faceted and coated with SLN C1 superluminova