The cockpit watches issued to the Royal Flying Corps (RFC), Royal Naval Air Service (RNAS), Admiralty and later Air Board during the First World War represent the earliest standardised British military aviation timekeepers. Designed for installation in aircraft instrument panels, these robust pocket-watch-based instruments were supplied by a wide range of British contractors using Swiss-made eight-day movements before the adoption of the later 30-hour Mark V standard.
Military Ownership & Service Marks
Several official markings are encountered on surviving examples:
- A↑D – Painted to the dials of Admiralty Mark I and Mark II watches; generally interpreted as Air Department of the Admiralty.
- A↑S – A rare marking recorded on only one known Mark IVA supplied by S. Alexander & Son. Its meaning remains uncertain and may simply represent the supplier's initials.
- W↑D – War Department marking used principally on Mark IVA watches until 1917. Found in several engraved and stamped variants.
- A̲↑ – Introduced from 1917 and associated with the Air Board. Found on all Mark V watches and some late Mark IVA examples.
- Crowned A.M. – Air Ministry ownership mark applied during the inter-war period, often indicating continued RAF service or storage.
- Sterile Case Backs – Common on Admiralty Mark I and Mark II watches, where dial markings alone identified the instrument.
Eight-Day Movements
Prior to the introduction of the Mark V 30-hour movement, British aviation watches utilised a variety of Swiss eight-day calibres:
Octava Watch Co.
The most widely encountered movement, used in Admiralty Mark I and II, the rare Mark III, most Mark IVA variants and a small number of Mark V watches. Serial numbers are stamped on the base plate adjacent to the balance wheel.
Charles Hahn & Cie (later Landeron)
A gilt-finished eight-day movement used by G. Davenport & Co., Etienne & Cie, S. Smith & Sons (M.A.) Ltd and W. Ehrhardt. Similar examples supplied by Nicole, Nielsen & Co. suggest a common source of manufacture.
Eterna Calibre 83
A distinctive gilt-finished movement supplied exclusively by H. Williamson Ltd for Mark IVA production. Easily distinguished from Williamson's military Astral movements used in General Service watches.
Douard Patent Movement
Used by S. Smith & Sons (M.A.) Ltd for Admiralty Mark II watches. Identified by patent reference "+7032", corresponding to a Swiss patent granted to Amédée Douard of Bienne in 1893.
Admiralty Mark I
Introduced circa 1914 and supplied exclusively by Elliott Brothers of London, the Admiralty Mark I is regarded as the earliest standardised British military aviation cockpit watch. Available with either black luminous or white non-luminous dials, it employed the Swiss Octava eight-day movement and typically featured an unmarked case back.
Admiralty Mark II
Produced by Thos. Armstrong & Bros, Manchester, and S. Smith & Sons (M.A.) Ltd, the Mark II continued the eight-day format but employed either Octava or Douard Patent movements depending on contractor. Both luminous and non-luminous variants were produced, with certain Armstrong examples distinguished by a unique stamped "long-arrow" case-back motif.
Mark III
An extremely rare and poorly documented type known from only two recorded examples. Characterised by the dial inscription "Elliott Bros, London, Rolex 8 Days, Mark III, W↑D", the model remains controversial, although surviving movement serial numbers suggest an early wartime origin.
Mark IVA
Issued under Royal Aircraft Factory Specification No. 68, the Mark IVA became the principal British aviation cockpit watch of the First World War. Production was distributed among numerous contractors including G. Davenport & Co., S. Smith & Sons, George Favre Jacot & Cie (Zenith), H. Williamson Ltd, W. Ehrhardt, Etienne & Cie, S. Alexander & Son and others.
Each contractor was assigned an identifying suffix or digraph incorporated into the serial numbering system. Mark IVA watches display considerable variation in dial style, movement type and military markings. Early examples generally featured white dials, while black dials became standard after 1917.
Mark V Military Aircraft Watch, c.1917–1920
The Mark V aircraft watch represents an important development in British military timekeeping during the First World War. Although the original specification has not yet been located, surviving examples indicate a standardised design featuring black dials, the majority being non-luminous and clearly marked as such. Most were fitted with 30-hour movements, although an 8-day movement variant was also produced.
Archive records confirm that the first orders for Mark V watches were placed with Omega in May 1917, suggesting that the specification had already been approved by the Royal Aircraft Factory. During 1917, responsibility for issuing specifications for aircraft equipment transferred to the Air Board, and Mark V watches bear the distinctive Air Board ownership mark—an underlined letter "A" surmounted by a broad arrow—found on equipment supplied under Air Board contracts.
The Mark V programme also marked a significant change in procurement policy, with contracts placed directly with Swiss manufacturers for complete watches rather than separately sourced components. The established military serial numbering system was retained, although supplier identification now employed two-letter codes preceding the serial number.
Manufacturers assigned to the Mark V programme included Omega (B.B.), Invicta (B.D.), Doxa (B.E.), Octava (B.G., 8-day movement), Record (B.H.), Electa (B.K.), Paul Garnier (B.L.), Zenith (C.B.), and Moser (C.C.).
Surviving examples suggest three principal dial variations. Type I dials feature gilt script on a glossy black background and are associated with Omega, Invicta, Doxa, and Electa. Type II dials display white reversed script on a matt black dial and are known from Electa, Record, and possibly Invicta examples. Type III dials retain the matt black finish and white script of Type II but introduce block-style numerals in place of italic figures; these are associated with Omega, Doxa, Paul Garnier, Zenith, and Moser.
Today, the Mark V watch is recognised as one of the most historically significant British military aviation timepieces of the First World War, reflecting both the rapid evolution of military aviation and the growing reliance on precision Swiss watchmaking during the conflict.
This information has been compiled from readily available material on the World Wide Web. Further good reference can be obtained from Books:
- Z. M. Wesolowski – A Concise Guide to Military Timepieces 1880-1990, and Volume1 British Military Time Pieces, & Volume 2 German Military Time Pieces by Konrad Knirim
- A Taylerson – Military Timepieces: Watches Issued to British Armed Forces 1870-1970