Jaeger-LeCoultre Mark XI (RAF-issued), 6B/346, Steel


Brand: Jaeger-LeCoultre
Model: Mark XI - 6B/346
Movement: mechanical manual-winding
Case material: stainless steel
Case size: 35 mm
Crystal: plexiglass
Bracelet/strap: black Nato strap with tang buckle
Functions: Time-only: Hours, Minutes, Center seconds
To note: unrestored dial
Water resistance: N/A
This rare, vintage military Jaeger LeCoultre Mark 11 in stainless steel is in fantastic condition and has perfect mechanical functionality. It is estimated that only 2,950 were issued to the military, with none ever sold to the public. This incredible watch has been fully serviced and is guaranteed for authenticity.

The Jaeger-LeCoultre Mark 11, alongside its relatively more common sibling, the IWC Mark 11, is perhaps the finest military mechanical timepiece ever produced. It can certainly lay claim to being the original Pilot’s watch, and one of the most expensive commissions by a military, anywhere. Issued by the British Ministry of Defence (MoD), these watches were made to the very strict 6B/346 specifications, and as such, are of incredibly high quality. They were issued to navigators in the Royal Air Force (RAF).

The 35mm stainless steel case features long lugs, fixed bars, screw-down caseback and a domed plexiglass, all following the specifications of the MoD. There were variances in the hands Jaeger-LeCoultre used, with this example coming with syringe hands. The caseback features all of the correct engravings as designated when issued.

Specific to this example, it is from 1948 as shown by the caseback designation ‘/48’. The dial is in exceptional unrestored condition, with its luminous material aged to a nice orange patina. The text remains crisp and white. There are some minor scratches to the caseback and plexiglass that is expected, given the age of the watch.

One of the important characteristics of the Mark 11 was its need to be highly antimagnetic, achieved through the iron dial and iron dust cap, which creates a Faraday cage, protecting the movement from magnetic fields.

Inside the watch, is perhaps its most impressive aspect, the JLC Calibre 488/SBr - a chronometer grade movement with a hack device and centre seconds. It is rhodium brass finished with Geneva stripes. It was the precursor to the famously accurate Geophysic movement, released in 1958. The movement itself is marked with the British Broadarrow, and is distinctive in its look with its stop lever.

The Jaeger LeCoultre Mark 11s were renowned for their timekeeping accuracy, as this was a fundamental specification required by the British Armed Forces. As a result, these watches were regulated in five positions and tested in temperatures ranging from -5 degrees to 46 degrees over a 44-day testing period. This was conducted in the chronometer workshop of the Royal Greenwich Observatory in Herstmonceux.

With pilot watches very much in demand today, due to their casual and utilitarian feel, this particular piece certainly fits the bill, especially with its wearable 35mm case and with both dial and case in exceptional unrestored condition.

Viewings can be arranged in Central London by appointment.
Year: 1948
Condition: vintage
Warranty: 12 months limited
Box: N/A
Paperwork: N/A
Availability: now
UK Delivery: free next day
Overseas delivery: 3-5 working days
Returns: 14 days