Here we have a good example of an all original 1940s LeCoultre 6B/159 WW2 RAF Pilot watch. It has the chrome on brass alloy case, measuring 32mm with the snap on case back. The dial is bright and nicely aged, with the black Arabic numerals and minutes/seconds track. It has a pleasing even speckled patination. The thermally blued hands are all original, with the distinct lozenge style. To the right is the original, well sized crown with coin edged finish. To the rear, the case back has the signing ‘AM 6B/159’ with the serial number A26543. The watch is powered by the LeCoultre calibre 470 movement. It has been recently serviced and is keeping reliable time.

The 6B/159 watches were issued to pilots and navigators in the RAF who required extremely accurate timekeeping. Other crews with less sensitive timekeeping needs were issued 6B/234 watches. The 6B’s were manufactured by Omega, Jaeger-LeCoultre, Longines, Cyma, Movado, Ebel and Waltham.

It is thought that around 4000 LeCoultre 6B/159 examples were produced.

The first variation (which this is) has the sector layout with the circle to the centre of the dial. The case was formed of chromed brass alloy and very rarely, in full stainless steel.

The LeCoultre example is differentiated by its single piece front case and snap on rear. The dial also has the circle to the centre, with this being the only 6B/159 to have Lozenge style hands.

The 6B code is the RAF stock code for navigational equipment to be used onboard an aircraft. The watches have the clear central second hand, vital for accurate timing and use in an aircraft. To further aid this, the central second hand also has hacking function, allowing for exact second hand setting.

The watches were vital in navigation and could be used to make dead reckoning calculations. Dead reckoning is the process of calculating the current position of a moving object (a plane), by using a previously determined position (fix) and incorporating estimates of speed, heading and elapsed time.

The watch is modelled on a 17.75cm wrist circumference.
Please see the images as these compliment and aid the description provided below.
A further condition report is below.

Dial:
The dial is original and is in good condition for the age. It is an aged white tone with an even speckled patination associated with age. The signing is good and clear in the black tone, without wear. The minutes/seconds track and hour markers are good and clear.

Hands:
The hands are all original. They have the thermally blued finish with has some light corrosion with age. They are in good condition for the age.

Glass:
The acrylic crystal is a replacement which is in very good condition.

Crown:
The crown is formed of Stainless Steel and is in good original condition.

Case:
The case has the chrome plating on brass alloy. It has wear to the chrome plating on the tips of the lugs and areas on the sides. The fixed bar lugs are original, good and strong.

Caseback:
The snap-on case back is stainless steel and has the polished finish. The issue markings are good and clear.

Strap:
The watch comes on a new NATO style strap.

Movement:
The movement is a LeCoultre calibre 470. It is a manual wind movement, with sweep central second. It has a jewel count of 17 and a frequency of 18,000 BPH.

The movement has been recently serviced. It’s keeping time to within + 20 seconds a day, with an amplitude of 240 degrees and a beat error of 4.1m/s.

Case dimensions
Case width: 32mm
Case width with crown: 33.75mm
Case length: 32mm
Case length lug to lug: 42.5mm
Case depth: 9.8mm
Lug width: 16mm