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- L -

Landing Compass (Swinging)

Additional compass used for swinging aircraft compasses. Its use is explained in The Aircraft Engineer's Handbook (follow this link) by Sloley and Coulthard (No. 4 Instruments, 6th ed. 1946). Example: Air Ministry Type O6A (later models: Sestrel).


The French company Société des établissements HENRY-LEPAUTE (11, rue Desnouettes, Paris XVe) was a famous manufacturer of clocks and watches. It also produced numerous electrical and optical materiel. This compass type was patented in 1910 (no. 407.416). Its characteristic feature is the double pivot. The upper one's length can be adjusted vertically (see image from Patent below).

Compensation airship compass with two pivots

Click on images for enlarged views

Pictures by courtesy of the Conservatoire Régional des Sciences et Techniques (CRST)  in Mâcon, France
Detail view of the course markings:
NM / NV : Nord magn. / nord vrai (True North)

Side view

Technical Data
Diameter: 123mm
Height, bowl: 58mm
Height, overall: 96mm

Side view (principle according to patent)

Le Prieur

French inventor of a drift computer called navigraphe (see NAVIGATION)

Letecke Pristroje Praha

Letecke Pristroje Praha (Aircraft Equipment Prague) was a Czechoslovakian company located in Prague.


On his transatlantic flight from NY to Paris in 1927, Charles Lindbergh's aircraft the Spirit of St. Louis* was equipped with an earth induction compass. He had then made by Longines the hour angle watch called after him. (* note the T-shaped anemometer protruding out of the fuselage behind the cockpit)
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W. LUDOLPH GmbH & Co. KG (Bremerhaven) is a German company manufacturing nautical and aeronautical compasses.(more information HERE).
Some examples of compasses (FK = Führerkompass = pilot compass).

Compass types F.K.5P and F.K.6

Compass types F.K.10P and.F.K.15

Pictures of the compass in the official Luftwaffe-Teaching book Luftfahrt-Navigation (Sönnichsen, 1940, see menue Miscell. / History and Bibliography) in which a full description of the instruments and their technical data are given.
- F.K.5P: further development of F.K.5
- F.K.10P: further development of F.K.10/32

Technical Data (F.K.15)
- Ø base: 240mm
- Height compass bowl: 152mm
- Height vanes upright: 270mm
- Weight: 4.4kg
Model F.K. 10/32

(Pictures courtesy
Technical Data
- Compass of the Junkers 52

Model F.K.10/33

(Pictures courtesy northwest-spb)
Technical Data
- Dim.: Ø x Height:  160  x 135 mm
- Markings: FK 10/33, Fl 23225, F.E.22, W.K. 13916


A. J. Hughes writes in his History of Air Navigation (1946, p. 34) that the first experiments (dealing with the behaviour of the compass) 'were made by Keith LUKAS at the Royal Aircraft Factory (Farnborough) in 1917 and this led to very important results, as the compass had to be carefully observed  and special methods of damping introduced which minimized the effect of northerly turning error. The work of Keith Lukas was the most important scientific contribution made during the 1914-18 war to air navigation' (See chapter AIR MINISTRY / Compass type Mark II).
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- M -


Repeater compass invented by Pioneer Instr. Co. (patent no. ?, in 19xx ?). The system consists of a transmitter and from one to three indicators as desired. It has no moving parts other than a compass float and the indicator pointers. The transmitter unit comprises a liquid magnetic compass, below which is mounted an electrical pick-off of the stationary induction (source: A. J. Hughes, History of Air Navigation, p. 109).


Alexander G. MARQUIS, a Briton living in Rochester, N.Y. USA, invented in 1911 a new compass type which was tested by the aviator William Hilliard in his aeroplane at Mineola, L. I. The needle pointed south and was observed in a mirror apparently pointing north (see pic. at right). Full description available, published in The Scientific American, March 1911.


On some WWI compasses the maker's name indicated is "MAUVE Paris" together with the words Aéronautique Militaire which also appear on the early AERA and VION compasses. The only available data are to be found in the U.S. document dated 1923 about all compass types used at that moment.

Technical Data
Dia.: 92 mm, Height 60 mm
See the enlarged views of the compasses displayed at left (excerpt of the document Report No. 128)


A flyer tells us that the manufacturer L. MAXANT (loc. 38, rue Belgrand in Paris) built a compass for airplanes and airships (click on link for pic.) probably shortly after WWI. It was available in three sizes (dia.: 55mm, 80mm and 105mm - weight: 700, 900 and 1400 grs).




The French captain Antoine Marius Camille MOREL (address: Villa Joséphine, 17, rue Joseph. Mourillon-Toulon) filed as early as 1909 several patents together with A. KRAUSS (see examples below). The company MOREL merged with Ets. Barbier, Bénard et Turenne - B.B.T. (successor of KRAUSS) and was renamed MOREL-B.B.T. It was located 82, rue Curial, Paris 19. MOREL built these instruments in the 1930's and 40's. Go to B.B.T. for the compass types built later.
The compensation procedures for the MOREL & B.B.T. compass types are explained in Capitaine Gaujour's books (published in 1936 and 1946, photocopies available).
Pic at r. : Description and user instruction for MOREL & BBT compasses ( 12 p. + 1 oversize fig., photocopies available)

Fig. of a patent for a compass for aircraft and vessels dated 1922: CLICK HERE.

Type A4 (with sighting vanes)

Pic. of compass above courtesy H. Desaunay and B. Chapelle

Picture of cockpit at r. courtesy Collection Ville de Biscarrosse, Musée de l'Hydraviation (unknown photographer).
Title: The A4 compass on top of the steering pylon in the Latécoère 631 Lionel de Marmier, 1945, South-America round trip. Presentation made by Lieutenant flight engineer Le Morvan.
Technical data
Type A (observer) with horizontal card:
- Dim. (dia. x ht.): 202 x 200mm, card dia.: 120mm
- Weight: approx. 10 lbs / 4,850 grs
This instrument can be fitted with additional sighting devices. Read the Techn. descr. published in L'Aérophile (4/1936).

Click on the image at l. for the descr. published in Traité pratique de navigation aérienne de Duval et Hébrard, 1934).

Link to pic. :  cockit of the Oiseau Blanc flown by Nungesser and Coli.

 Pictures at r.: Ads (1927)


Cockpit picture: see descr. window at left


Type B3 and B4
Technical Data
Type B (pilot) * with vertical card:
- Dim.: 140 x 200mm (approx.)
- Card dia.: 82mm
- Weight: 6 lbs/3000gr

For the 1927 patents for compasses type A and B (Morel & Krauss) CLICK HERE

For the 1936 patent for a small aircraft compass (picture: see BBT) CLICK HERE

* Link to picture - courtesy
MOREL (B.B.T.) developed also a telecompass based on photo cells type CR12 also called MENGDEN (see BAMBERG).

Click on the image at r. to view the complete article published in the French review L'Aérophile (4/1936)

Mod. Morel-BBT B 3
on a maintenance tripod 
(see enlarged view)
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- N -


Just like out at sea, the compass is only one of several instruments used for air navigation. In the early days of air travelling, the navigators could determine their position and course using highly precise clocks and observing the stars. The large long-range aircraft had until not so long ago an instrument for this purpose (see pic. SPERTI astro-compass and Periscop-Sextant) that indicated true north when pointed at a known star (incl. the sun!). Due to the higher speed of modern aircraft, computing had to be performed in always shorter time. Before computers took over this task, several instruments were used (we won't deal here with GPS !).
Pic. at r. courtesy Brooke Clark. N6GCE      

For flights above ground, artificial means like radio beacons are used (see VOR - in Wikipedia) whose signals are computed by radio compasses - examples: Bendix, UGR-4. Because of the aircraft's speed, the rapidly changing position of the aircraft in relation to the earth's magnetic field and the influence of the aircraft's own metallic masses, an additional device is used called flux valve or flux gate). Its information is transmitted to the compass gyro (examples: Siemens-HalskeKearfott). In the event that these electronic means fail, aircraft are equiped with a conventional stand-by compass.
After the International Air Traffic Commission (the forerunner of the IATA) was created in 1919, navigators had to possess a certificate (click on link for syllabus).

Lateral winds put an aircraft off-course. We display instruments used to compute the drift (link to descr. of early instruments) caused by the wind:
1 - Navigraphe Le Prieur (for earlier drift assessing devices go to DALOZ).
2 - Estimateur Arcaute (April 1932)

Manufacturer: La Précision Moderne

Ad. published in L'Aéronautique (1926-1928)

Description in Engl., French and Spanish

Drift computer by Arcaute (1932) as published in  L'Aéronautique (full user instr. available)
Winteris Drift Sight

3 - Course and Distance Calculators (in German Dreiecksrechner).
(If not otherwise stipulated, all pics by K. Pätzold - click for enlarged views)

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Course and Distance Calculator (CDC)
GB / WW1

(Pic. Hist. of Air Nav. by A. J. Hughes, 1946)
Type DR-3, German Luftwaffe / Wehrmacht (1943)

Manufacturer: Dennert & Pape. Ein anderes Modell war das von K. E. Tröger (Foto M. Dick)
Drift Computing Ruler (NVA / GDR) and user instr.

Type NPL (USSR) integrated in the leg tablet (Knieplanchet)

Drift computer
(Red Army / USSR)
with user instr.

Northerly Turning Error

Definition here: northerly turning error. For more information see also French "erreur de nord" German "Kurvenfehler".
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- O -


Ottica Meccanica Italiana (OMI) was an Italian company producing photogrammetric instruments. It was founded in Rome in 1926 by Umberto Nistri (1895 ?-1962). From 1962 on, his son Raffaello Nistri (1920-1981) was president of the company. Since the 1980s the company has been part of Agusta. The air photography branch split into S.A.R.A. Nistri and Aerofotogrammetrica Nistri.  Three aircraft compasses are known, the two instruments described below and the PEZZANI model (scroll further down). Nistri filed in 1956 a patent for a marching compass. See also in Marching compasses / Barker - 4.2.

Pictures courtesy

Top view without the divided circle

Picture courtesy Kye Meeks
Technical Data

Dimensions ( Ø x height):  x mm


Type 03
Technical Data

Dimensions ( Ø x height): 82 x 106mm
Link to view of main parts

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- P -


Albert PATIN was an engineer and industrialist who lived in Germany in the 1930's and during WWII. He filed among others a Patent (no. 853.724) for a remote indicating (or distant reading, DR) compass (compare to BISSON's patent for a ship compass). This system was installed in the German transport aircraft type Junkers 52. He created in 1938 his own company Albert Patin Werkstätten für Fernsteuerungstechnik GmbH* located in a village called Mittelsteine (renamed Ścinawka Średnia in 1947) at the Slovakian-Polish border where he developed and manufactured various devices for the German Airforce Luftwaffe (French and German patents) . The company's condidential three-letter code was gzy. A. J. Hughes writes in his History of Air Navigation (1946) : The Patin compass [see pic. at r.] is a repeater compass that has proved to be one of the most important compasses in this war. After WWII, U.S. special services brought A. Patin to the USA so that he worked for the U.S. Airforce together with many other German technicians and scientists (link to excerpt of W. Samuel's book American Raiders) although he participated in the Nazi Germany's war industry (link to excerpt of Linda Hunt's book Secret Agenda).
* Translation: A. P. Remote Control Engineering Co. Ltd, in red on the paper:Flight Safety
Source: German Archives, Col. Gaujour (s. below), Wikipedia, Secret Agenda
(L. Hunt, 1991), American Raiders (Wolfgang Samuel, 2004).


(Pictures by courtesy of

Descr. in col. Gaujour's compensation instructions (1946). A picture of the system called Patin Repeater Compass (invented in 1933?) was also published in the book History of Air Navigation by A. J. Hughes (1946).
Technical Data
Original Luftwaffe doct.

Label on 1st series instrument

Three versions of the pilot slave compass
 KT / f8
Patent no. 853.724
Fig. 2
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Pattern 200, 223, 259 etc.

Note: This entry is about aeronautical compasses. For ships compass patterns please got to Nautical Compasses / DENT & Co.

The British Ministry of Defence (MoD) defines its requirements for supply of instruments, weapons, equipment, by the issue of patterns.  Any supplier may manufacture and offer such items for sale, but those items will be examined and certified as type-approved, i.e. they comply with the official pattern.  A pattern number is purely a mark of compliance to a standard set out by the MoD.
In the following examples, the compass Pattern 200 is a mix of the typical aircraft compass featuring a horizontal card (installed in the lower part of the instrument panel and to be read from above) and a prism for observation at eyes' height. The Pattern 200 was the first compass to be officially designated an aeroplane compass. It was designed and patented by Captain Creagh-Osborne (patent no. 1148/15, see also marching and wrist compasses). This design was continuously used but without the prism until at least the end of WWII on the Air Ministry compasses.
The instrument Pattern 223 is the only British a/c compass that we know of featuring quadrantal side spheres for correction of deviation (compare with the French VION compasses). Go to the HUGHES chapter for more patterns (especially the Centesimal design).
The compasses Pattern 255, 259 and 261 are displayed in the chapter Creagh-Osborne above.
(See also Verner's pattern and Nautical Compasses / DENT).

Pattern 250, 251, 252

For more information about this series go to Creagh Osborne

Pattern 253 D.B. (Dead Beat) & A.C. (Centesimal Aperiodic Compass),

Pattern 254 (compare to the Air Ministry O.6 Landing Compass,
see also HUGHES)

Pattern 255, 256, 257, 258, 259.

Pics above and at left: Air Pub 802

Pattern 261 micrometric (identical to the marching model)

Pattern 5/17: s. Creagh Osborne
Pattern 5/27: small Pattern 253
Pattern 6/18 and R.A.F. MARK II:
see chapter Air Ministry (A.M.)
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PDK / ПДК in Russian

PDK is the abbreviation of the Russian words Потенциометрический дистанционный компас (ПДК) i.e. Distant Potentiometer Compass). These instruments were made by a Russian manufacturer. No other data momentarily available. Your help is needed. Two models are known: PDK-3 and PDK-45. These are master compasses. They feature only a small compass inside a round window and deliver a signal for indicators in the cockpit (see PDK-49 below) and elsewhere in the aircraft called repeaters.

(Pictures courtesy R. Scarpa)


The integrated compass of PDK-3
Technical Data
- Dim. (Dia. x H.): ? mm.
- Inscriptions in Russian:
НАПРАВ ПОЛЕТА = Direction of flight (on either side of the white arrow)
- Manufacturer's label and logo:

Functional diagram

(Pictures courtesy eBay seller Bokluci)
Technical Data

- Dim.: 100 x 80 mm.
- Inscription on label:
УКАЗАТЕЛЬ РДК-49 = Indicator PDK-49


Nautical instrument used onboard of ships. Go to BEARING COMPASS.


Dr. James PENTZ published in 1919 in several reviews and newspapers a description of a compass that would also tell a pilot of an aircraft in the clouds where up and down is. This system was also studied by a U.S. government agency (Rep. no. 128 / 1923).

Pentz' compass system as described in the Report No. 128

Click the images for viewing each complete description

Popular Science - May 1919

Delmarvia Star - July 13, 1919

Milwaukee Journal - Sep. 7, 1919


Maurice Percheron was a French aircraft engineer. He wrote a manual about the use of the map and the compass in aircraft (1917).
The drawing of the compass doesn't seem to represent a specific compass model. Read his biography on the website of the French editor Denoël.

Fig. 4 - Setting the course for a flight from Evreux to Beauvais (50° N-E) taking the declination into account (NM = magn. North)

Fig. 9 - Taking side wind drift into account

(Click on images for enlarged views)

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PEZZANI Tipo 0-2 

The Italian manufacturer Ottica Meccanica Italiana (OMI), founded in Rome in 1926 by Umberto Nistri (1895 - 1962) and taken over by AGUSTA in 1980), produced from the early 1930the end of WWII a compass called PEZZANI Tipo 0-2 (for more details go to historicacollectibles - featuring a button for automated translation).

Picture courtesy
(see more pics on this website)

Photo at left and drawing above:  handbook (1931/1936)

(Click on images for enlarged views)
Technical Data
Dim.: see fig. at l.
Weight : 2 1/2 lbs/1.250 kg

Pfadfinder für Aviatik GmbH

see PLATH below.


In 1925 the Italian marchese di Pinedo flew from Rome to Australia, then to Tokyo and back to Rome. He had designed his own version of an aperiodic observer's compass type S.O.2 that equipped his Savoia-Marchetti seaplane (source: H. Hughes, History of Air Navigation 1946, p. 49 - pictures at right: History of Air Navigation and Instruments for Aerial Navigation, 1930s - enlarged view).


The U.S. manufacturer PIONEER Instrument Company was created in 1919 by Morris Maxey Titterington and was acquired by and became a Division of BENDIX Aviation Corporation, New Jersey (N.Y.) in 1928. For more information go to our BENDIX entry and check also "Rockwell Collins" in Wikipedia. The inventors Adolf URFER and Ch. H. COLVIN (among others) filed patents for compasses when working with Pioneer & Bendix. Pioneer invented the MAGSYN Compass and also produced the Earth Inductor Compass utilized by Lindbergh on his transatlantic flight in 1927 (falsely called there Earth INDICATOR compass!). More details HERE. See also SALMOIRAGHI below.

Picture courtesy R. Pavan
(Click on the image for enlarged view)

View of the compass in instruments panels
Technical Data
The design's patent was filed by J. P. WARBURG in 1919.

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C. PLATH was a German manufacturer (more information in Nautical Compasses) who took over Pfadfinder für Aviatik after WWI and built many aeronautical compasses. The first models featured a counter-clockwise 360 degrees scale on the bowl's rim and some were apparently only half-gimballed probably to be mounted in Zeppelin balloons were lateral bank angles are negligeable.
Descr. and user instr. in the book Der Flugzeugkompass by captn. Fritz Gansberg, 1917 (copy available).
Pic. at r. courtesy McMillan      
Pfadfinder für Aviatik (link to ads 1915 & 1917) was a German maker located in Berlin-Johannisthal who built a compass of the same name during WWI. It was probably bought (after the war?) by C. PLATH who built several compass types of the same name (see pics below).  The museum Musée du Léman in Nyon, Switzerland, possesses a Pfadfinder für Aviatik compass which is said to have been installed on the steamship Dauphin (1882-1916). Its card is printed on a float and features cardinal points in German, counter-clockwise.

Pictures courtesy Jürgen Plesse
(Click on the images for enlarged views)

Inscriptions on both sides of the NORTH mark:
Pfadfinder* Armee-Kompass III
(* pathfinder)
On the opposite side of the disk:

Technical Data
- Dim. (dia. x height) : 120 x 90mm.
- S/N: 17160
- Divisions: 360° clockwise every 10° both on the disk and the chapter ring of the bearing setting hand
- Lighting device: side lamp

The Pfadfinder compass in Der Flugzeugkompass

Compass types Z9 and Z10

Rose Ø: 95 mm   /  40 mm

(Zum Vergrößern, Bilder anklicken)
Suspended compass Z4h and compass with projected rose image PH 10
Z4h weight: 470 g

Functional descr. of the PH 10 compass

See pictures of an instrument on the site

(The enlarged image shows the original German text. Read the translation below)
The images at left were published in the Luftwaffe handbook
Die Luftfahrt-Navigation 
(cptn Sönnichsen, 1940)

Rose and glass in cylinder

Projektionskompass PH 10

See PLATH, type PH 10 above. Translation of the beginning of the description in German: "The  compass with projected rose image is used both as a steering compass and as an additional device for various functions of aircraft radio direction finders. The magnetic system of this compass consists of a rose that has a diameter of 17 mm (see pic. above) and a total weight of just under 0.4 g. Using optics, the rose image is projected onto a screen at a magnification of eight times. Since with the reduction in size of the magnets the magnetic moment only decreases in direct proportion, while the weight simultaneously decreases to the third power, the projection compass is left with a disproportionately large magnetic moment, while the decrease in weight causes the friction on the pivot to become almost zero."
See the full original German text HERE.

P.Z.O. - Polskie Zaklady Optyczne

Compass made by the Polish optics maker P.Z.O. created in 1921 in Warsaw and sold in 1996. Successor of Fabryka Aparatów Optycznych i Precyzyjnych H. (Henryk) Kolberg  (Optics and Precision Instruments H. Kolberg). This compass is called Z-6 and described as having been built by H. KOLBERG i. Ska (i.e. & Co.) on the Polish web sites like the forum on Polish Aviation Lotniczapolska. The instrument's label indicates ZÜRN SYSTEM, so that the inventor should be an engineer called ZÜRN about whom no information is available. The only other information available about this compass are to be found in the French book L'aéronautique en Pologne (1935, p. 117/119). Source: the Museum of Polands Aeronautics' (Muzeum Lotnictwa Polskiego) online library (see note and watermark on pictures below).

Pic. court. W. WOZNIAK

Pictures courtesy Muzeum Lotnictwa Polskiego
Click on the images for enlarged views)
Technical Data
Dim.: unknown; weight: 3 lb 12 oz / 1.7 kg
Installled on Bomber aircraft Pzl 37

NOTE: The Museum of Polands' Aeronautics offers an online library but the access is only possible on the Polish version, the English version is not implemented: first click on Zbiory in the pull-down menue, then on Biblioteka i Digitalizacja and then on the red words Digitalizacja zasobów ikonograficznych i archiwalnych MLP. The list comprises numerous works in several European Languages.
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- R -

Radiation hazard, radioactivity

The self luminescent paint used for markings between the years 1915 and 1950 contained Radium. Click HERE for more details.

Radio compass

See: BENDIX (USA), UGR-4 (Soviet-Union)

R.A.E. / R.A.F.  - Royal Aircraft Establishment / Factory

The designation of the first compasses specially designed for aircraft is somehow confusing (Air Compass, Aerocompass, R.A.E. / R.A.F etc.). Most of them are described here in the AIR MINISTRY chapter but some will be found in the chapter dedicated to one of their inventor Cptn CREAGH-OSBORNE. The compass designated R.A.F.  was developed by the ROYAL AIRCRAFT FACTORY in Farnborough, not to be confused with the Royal Air Force (R.A.F.)  which resulted from the merging of the Royal Flying Corps (air arm of the British Army) and the Royal Naval Air Service (RNAS) in 1918. The abbreviation RAE / RAF refers hier to the  Royal Aircraft Establishment / Factory founded in 1910 in Farnborough which participated in the specification of navigation compasses and bombing sights (s. a. ANDREWS inverted compass).
Picture at right: The R.A.F. pilot's compass Mk II and the Air Compass Mark II (excerpt of Report no. 128)

Repeater Compasses

As its name implies, the remote indicator of this type of instrument comprises a full 360° repeater dial read against a lubber-line, or a fixed 360° dial with a revolvable pointer. The repeater is usually fitted with an adjustable grid to prominently denote the course set to be steered' (source: A. J. Hughes, History of Air Navigation, p. 102-103). Example: PATIN. Check also the table showing the separate development of Tele- and Repeater compasses (source: ibid. p. 106).


This compass was designed by Henri Rosenfeld, 38, rue de Notre-Dame-de-Nazareth. In the (luxurious) flyer, he pretends that fluid-filled compasses were not as good as dry-capsule compasses...

Technical Data
- Dimensions : ?
- Weight : ?
- Production period: probably WWI

Original flyers available
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- S -


Angelo Salmoiraghi was an Italian engineer (1848-1939, see his photograph in Wikipedia in Italian language) who joined in 1870 the manufacturer FILOTECNICA located in Milano and became its head and owner later. A compass called type ns 1200 was described in the French review L'Aérophile in Aug.1936. Two models were offered: Atlantico (rose window breadth: 94 mm) and Mediterraneo for light aircraft.
(For original version click on image at r.)
Salmoiraghi is also famous for his driftmeter (see DALOZ) and for an adapted version of a PIONEER compass (see below) signed FILOTECNICA.

Pictures courtesy R. Pavan

Instrument with lamp - At right: click for full text of advert.
Technical Data
- see pic below


Michael Sendtner A.G., Fabrik für Präzisions-Instrumente, München, Schillerstraße 22 (Munich, Germany). The company founded in 1879 (closed in 1930?) built precision instruments (telescopes etc.).  This compass principle is similar to the models issued to the German Imperial Navy (Kaiserliche Marine), namely C. Plath's Pfadfinder and Ludolph's.

Pictures courtesy bonic_de2014
Technical Data
- Ø bowl: 115 mm, height: 60 mm
- Ø Compass card: 85 mm
- Weight: 4.8 lbs
- Production period: WWI
Description (in the NASA Technical Report No. 128, 1923)


Maxime Louis Jean Clément SERPEILLLE was granted a patent (no. 423,468 on 19 Apr. 1910) for a drift correction device called Map Compass for Aircraft (Boussole-carte destinée à être employée plus spécialement en aéroplane, dirigeable et autres machines volantes). It was described in L'Aérophile, issue 15/1/1912 (copy available). This system resembles Daloz' design. It was built by HUE (HUET ?), constructeur d'instruments de précision, 63, rue des Archives, Paris. (at r. : Fig. 2)
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Sestrel is the trademark brand of Henry Browne & Son who were important British compass makers. This company was sold to John Lilley & Gillie Ltd  and SIRS Navigation (both in UK) in 1993 (read more in the section Nautical Compasses). The version Mk II of this instrument was described in the aeronautics review FLIGHT in Feb. 1933 (compare to the A.M. / Air Ministry compasses) where it is designated an a-trochilic compass, another name for aperiodic.
Click on the image at right for fulll description.


Technical Data

- Dim. (H x Ø): 160 x 115mm
- Weight: 2.35 kgs
- Manufacture date: WWI

Pictures courtesy G. Rooney

Technical Data
- Dim. (H x Ø): 100 x 200mm
- Weight: c. 5 kgs
- Production year: early 1920s

Pictures courtesy videmaison2000


The Eugene M. Sherman Company of Seattle designed and manufactured nautical navigational aides, notably the line of Dirigo gimballed compasses. A.S.S.C.  (see label below) was the Aviation Section Signal Corps, which was the aerial warfare service of the US Army from 1914-1918. R.A.F. was likely the Royal Aircraft Factory (aka the Royal Aircraft Establishment) and not the Royal Air Force since the latter didn't come into existence until 1918. R.A.F. was a British aeroplane maker which manufactured 3 aircraft used during WWI by the American Expeditionary Force (A.E.F.):  B.E.2 Reconnaissance aircraft, F.E.2 Fighter/Bomber, and the better known S.E.5 Fighter.  

Pilots Compass
Pictures by courtesy of
  Technical Data
- Dim. (H x Ø): 3 x 6 " / 77 x 152 mm
The markings on the compass card have long since faded

R.A.F. Pilots Compass


The Sherrill Research Corporation was founded in 1938 in Peru, Indiana, and later headquartered in Mexico, Indiana. It made Sherrill (and later Air Way) brand compasses for decades for automotive, marine, aviation and military use. We display here the AEG models and a special version called M6 designed for the M6 battle tank and other WWII land vehicles. Read a comprehensive description HERE.

The models AEG and AEG-1 look the same
 Picture at right courtesy friebe-aero

Model M-6
Fig. excerpt of the
Instruction Manual
(link to a view of the tank)
Technical Data
- Dim.: 200 x 160 x 150 mm
- Ordnance drawings no. C121174 and 7067878

Ads for models AEG and M-6 published in Flying Magazine, Aug. and Dec. 1944
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Siemens & Halske was the name of a German company established in 1847 by Werner von Siemens and Johann Georg Halske called Telegraphen-Bauanstalt von Siemens & Halske and located in Berlin.

1 - Siemens developed shortly after WWI an electrical tele-compass.
2 - Auto pilot with a tele-compass for rudder command
3 - Gyro-magnetic compass (Kurskreisel) Lku4, Siemens-Halske, built 1943-1945. This equipment was installed in the instrument panel of the German Junkers aircraft Ju 52 and Ju 88.
The center picture shows a JU 88 cockpit. The Lku4 appears (in red) at the top in the middle of the instrument panel.
Excerpt from the original notice "D.(Luft)T.5404", issued January 1943: "The upper scale is the course setting rose. The desired course is set by means of a motor activated by a flux valve. The lower scale shows the actual course indicated by the inertial navigation system (gyro)."

(Click on image for enlarged view)
1 - (At left) Tele-compass with electrical data transfer.

Compass for auto pilot (s. drwg. at right)
2 - Tele-compass as a signal source for the rudder command (1935)

Image at right: click for full view of functional drawing

(Click on picture for detailled view of front and rear side)

Flight deck and instrument panel of the Junkers Ju 88. The Lku (in red) was located at the top, center.

(Click on picture for an enlarged view)
Technical Data
(original in German
dated March 1940)

- Dimensions: 160 x 130 x 120mm
- Weight: 2.6 kg.


Model name of a compass sold by Air Transport Equipment Inc. (ATECO) New York. USA. Probably identical to the type F made by Consolidated Instruments.

Technical Data
Dim.: 7" high x 4.5" wide.
Overall depth: 3"

(Pic. courtesy cturtles1958 - Click on the images for enlarged views)

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Company founded in 1851 by instrument maker Samuel SMITH, watchmaker to the Admiralty (read more in Wikipedia). Aircraft business started with the outbreak of WWI. Henry Hughes became a subsidiary of SMITH & SON in 1935 but the HUSUN compasses already appear in ads published in FLIGHT in 1929 under SMITH's logo together with one P4 model called HUSON (the abbrev. MA between the wings stands for Maker to the Admiralty). The only other occurrence of this compass designation is found in Aircraft and Flying by Monk and Winter, Gresham Publishing Company, London, 1934. The short technical description is that of the "dead beat" or "aperiodic" principle.
NOTE: We cannot rule out that the designation HUSON is a typo or a momentarily used abbreviation for HUghes & SON.


See also SPERRY GYROSCOPE in Wikipedia. An early large compass (76mm Ø card) called Navy standard compass no. I  (pic at right) was carried in large flying boats and bombers. It is described in the Report no. 128. For unknown reasons, it is also described in FLIGHT (date ???) as a Mk XVI! A smaller Type II (50mm Ø card) was used on the smaller airplanes. Another one was an adapted Creagh-Osborne design called Air compass Mark II. As early as in 1915, Sperry had developed an instrument called drift indicator. The compass used was the first KELVIN aero-compass.

Standby Compass

(Click on the image for an enlarged view)
Technical Data
- Dimensions: 70 x 60 x 60 mm
- Weight: 8 ozs./240 gr
- Manufacturer: AIRPATH
- Type: C2300
- Date stamp: APR 82.
The deviation can be rectified by turning the screws concealed behind the plate at the lower front part:
- the left hand screw is for the north-south axis
- the right one for the east-west axis.

Star Compass Company

Former manufacturer of compasses located in Boston, Massachusetts, created by Gustave A. Salzgeber who patented in 1931 a compass design (no. 1,799,648, copy avlbl.) also produced by Consolidated Instruments (source Milton Historical Soc.).  
Click on the image at r. for a full-page view of the patent figs.      


Telltale (overhead) compasse produced by this Swiss manufacturer (read more details about the company in the dept. SURVEY COMPASSES). Read below its description in Report no. 128.

Technical Data

(Click on the images for enlarged views)

Picture courtesy histoirémilitaria
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- T - 

Tanks and Armoured Vehicles

Apparently some tests were conducted during WWI with compasses fitted in battle tanks (see SHERRILL and VION). Captain F. Creagh-Osborne R.N. wrote a booklet (The Magnetic Compass on Land, 15 p., 1915) for the armoured car section of the Naval Air Service (link to short description, p. 14) but he mainly describes therein two other instruments (p. 7 & 8), a wrist compass (see Chetwynd/Kelvin) and a marching compass featuring a lense-shaped lid - designed by himself.

 Picture courtesy S. Wiggins    

NOTES: We received a message sent by a former Lt Col of the Royal Tank Regiment about a document kept in The National Archives (TNA,  WO 194 54 - Tanks and Ancillary Vehicles 1915 - 1918 - Notes- Mechanical Warfare Department, Inspection Department Royal Arsenal dated Jan 1925 Mark V Sheet 1) telling us "that the Mark V was the last British heavy tank to be used in WW1 and had an extensive number of modifications / improvements compared to the early Mark I to IV. The reference does mention when a specification was planned but not implemented and the compass has no such caveat by it. "
Another contributor wrote: "All I know about tank compasses, is that they never worked reliably. Every time you changed the direction of the gun barrel or its elevation, the compass card flew all over the place. The Americans tried them. Bendix made various models (see type 1829), but they just didn't work. In desert conditions they used sun compasses. Later, in the 1960s and 1970s they started using gyro compasses. Nowadays they use GPS."

T.A. 103

The French system called T.A. 103 builds the transition from the pure compass-based navigation to a compound system in which a compass delivers a signal to several devices to form a magnetic gyroscopic navigation instrument, i.e. a compass gyro. The letters T and A are the initials of its inventor J. C. Thédenat (see below) and of the company that built it, ALKAN. It was at the base of the development of the system called D.R.C. (Distant Reading Compass). Description (only in French available) in col. Gaujour's book, 1946. Link to pic.: Le club des collectionneurs / Collection Willys69.


This type of instrument was invented after WWI. Several technical solutions were developed first by C. Bamberg (optical device), Askania (pneumatic d.) and Siemens (electrical d.). In 1932 Holmes and Hughes added another design made by Smith's Aircraft Instruments (read descr. in Flight). It was a primitive remote indicating compass not to be confused with the improved system called repeater compass (example: PATIN). The indicator of a tele-compass is not a conventional compass dial but merely a centre zero dial with a swinger pointer (galvanometer) which plainly shows when the plane is headed right on its set course or is deviating therefrom to the right or left. Check also the table showing the separate development of Tele- and Repeater compasses (source: A. J. Hughes, History of Air Navigation, p. 106). Compare with BAMBERG's photo-electrical system and with MOREL typ CR12 Mengden.


Jean Camille Thédenat (1901-1935) was a French Navy officer and a pilot. He invented an early compass gyro called Appareil Directeur T.A. 103. He filed a patent no. 793.300 * (published on Jan. 21, 1936): Perfectionnements aux installations permettant à bord des engins de navigation, notamment à bord des aéronefs, de déterminer, de faire prendre à ces engins et de contrôler le cap convenable pour la navigation et pour le jet sur un point déterminé de projectiles ou charges quelconques, ainsi que pour d'autres fins.
* Note: on fig. 1, the compass is referenced by the letter C.


Profile: see Marching Compasses. This compass is displayed in an instruments panel shown in an advertisement for the company Korect Depth Gauge.

Model T.LK18
Production date unknown, probably before WWII

Name T.LK18
and S-zero-Y line

Pictures by courtesy of M. Doveton
Click on images for enlarged views
Technical Data
Dimensions: 100 x 80 x 80 mm
The cardinals (N, W, S, E) and half-cardinals (triangles) which were printed with radium-compound paint have turned black with the time.
NOTE: We cannot guarantee for sure that this instrument was produced by TELEOPTIK. This assumption results from the study of the inscriptions left and right of the north marking. The various letters can be interpretated as the maker's name and designation of the instrument: T.LK would thus stand for Teleoptik and Letač Kompas, i.e. Pilot Compass if we are right in assuming that it is written in a Slav language in latin letters like Polnish, Czech or Kroatian. Since we only know of a single maker whose name begins with the letter T in these countries namely Teleoptik in former Yugoslavia, we consider that the language must be Kroatian. On the opposite side of N we see a line with three letters which we read as follows:
 ___S__0 (zero)__Y___
In all Slav languages, the cardinal point North is called Sever (abbreviated S) and South "Yug" (like in Yugoslavia, (see menue Miscell. / Cardinal points-  table - Serbocroatian). This could represent a symbolic view of a correction of the deviation. Since this instrument features a connector (link to picture) and there are no screws to perform such a correction we consider that this compass was slaved and didn't need any correction of deviation. Thanks for helping if you have 1st hand information.

Pictures Compassipedia
Click on images for enlarged views

Model (Tip = Type) 407:
Production date unknown, probably after WWII
Logo of Teleoptik (T in a triangle) 

Technical Data
Dim.: ... mm
Designation in Kroatian language: Pilot Compass
There is another model designated TIP 443 but have no picture of it.


SILVA's head Gunnar Tillander invented in 1944 an aircraft compass. Pic. at right: Figs of U.S. patent no. 2,359,691.


Morris Maxey Titterington was a US inventor. He founded PIONEER and invented the earth induction compass (see also Lindbergh).
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- U -

UGR-4 (УГР-4 in cyrillic letters)

Russian-made (USSR) radio compass. Unknown manufacturer

Pictures courtesy K. Pätzold

Marking on dial:

The label reads:

(Click for enlarged view)

Technical Data
- Diameter: ? mm
- Weight : ? kg


Adolf URFER was an inventor who filed at least two patents implemented in compasses built by Pioneer / Bendix, the #1.873.684 (in 1932) and 1.939.374 (in 1933).


Former French company (for more information click HERE. Visit also the sections nautical and survey compasses).
Fig. at r.: advertisement published in L'Aéronautique (Paris, 1923) - Source:
The compensation procedures for some VION compass types are explained in Capitaine Gaujour's book (copies available).

See also our entry about the FUNCTIONAL TESTING DEVICE (click on link for immediate access)

Auguste Henri Eugène VION filed several patents between the two World Wars. They describe precisely the development of the main instruments shown below. Some were translated into English (UK and US issues) and one into German. The successor company Société d'Exploitation des Etablissements VION also filed 2 patents in 1966.

French Patents and US or GB issues if available (copies available)
- 558.994 - Perfectionnements aux compas à liquide - gobe-bulles et éclairage en-dessus (sept. 1923)
- 564.946 - Dispositif pour la compensation des déviations des roses de compas (janv. 1924); GB: Compass for Navigation Purposes, 214.209; USA: 1.596.639
- 639.734 - Compas de pilote avec dispositifs pour sa transformation en compas de relèvement (janv. 1928); USA: Compass, 1.694.194
-  - Compas pour avions (ou aéronefs - titre supposé, 18 juin 1927 - voir détails dans le tableau); GB: Improvements in or relating to Mariners' Compasses, 292.489 (15 nov. 1928); USA: Magnetic Compass for Aviation, Navigation and other Purposes, 1.962.312;
Germany: Kompass, insbes. für Flugzeuge, 566.628 (1928 / 1932)
- 640.901 - Dispositif pour la compensation de la déviation supplémentaire des roses de compas (juil. 1928)
- 670.915 - Dispositif pour l'observation et la rectification des orientations de marche, en navigation aérienne ou maritime (déc. 1929);
GB: Improvements in Electro-magnetic Apparatus for the Observation and Correction of Travel of Aerial and Marine Craft, 314.786
- 749.267 - Perfectionnements aux compas pour pilotes (1932) - see table below
- 794.813 - Compas de planches de bord, pour navigation aérienne ou autres applications (1934) - see table below
- 798.902 - Compas à rose cylindrique dite "verticale" (1935) - see table below

Wing compass V.P.S. 28
(patent no. DE* 566.628, U.S. pat. no. 1,962,312, 1928). It was attached to the wing above and in front of the pilot's head. The angle values could be read via a prism.

* DE stands for DEUTSCH = German,
We didn't find the French original patent no.

(Click on images for enlarged views)

Click on image for view on aircraft

German issue, page 1:
This invention was patented on June 19, 1928 but published as late as on December 8, 1932 only!
French pat. no. 749,267 (1932)
No. 794,813 (1934)

No. 798,802 (1935)

No. 1,501,923 (1966)
Spherical case

No. 1,505,506 (1966)
Topic: friction of the pivot
VION catalogues/manuals for compasses with vertical (pic. at left) and with horizontal (right) rose:

Enlarged view: Text and Figs.
(Photocopies available)
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In a manual for compasses with vertical rose of winds (1930's) we find a list of the VION compasses then available:
- Type V.31 (dia. 60mm) for fighters and T.31 for tourism aircraft,
- Type Q.S.C.V.29 (dia. 85mm) for reconnaissance aircraft, bombers and also for medium-size airmail and commercial aircraft
- Type G.N.R.V.30 (dia. 120mm) for large-size commercial and freight aircraft and heavy bombers.
Picture at right: Cockpit of a Latécoère 631 with the compass types V.A.82 and 150 (behind the steering horns)
Courtesy Collection ville de Biscarrosse-Musée de l'Hydraviation-Origine Moine)

Compasses with Horizontal rose of winds:
- Orientation : Q.S.C. 25 Pilote (Navigation)
- Navigation : Q.S.C. 27 Pilote et Relèvement (pilot and bearing compass)
- Grande Navigation et Grand Raid : Q.S.C. 27 Pilote et Relèvement.
Two other special compasses are also described in the book Traité pratique de navigation aérienne (Duval & Hébrard, 1935) :
- type P.B. 50 (PB = planche de bord = instrument panel, see below) and 
- type H. 32 for aerial photography
Picture at right: Cockpit of a Potez 54 with the compass type GNRV 30 in North Africa in 1942 on a reconnaissance base
Courtesy U.S. Army archives

Type NAVIGATION A.M.1 - Flotteur V7

Rose of wind is identical to model Q.S.C. 27

Side view of compass bowl with the prism fitting (half gimbal suspension)
Technical Data
- Dia.: ? mm
- Height: ? mm
- Manufacture date : c. mid 1920s

Type ORIENTATION A.M. 2 - Type 3
Compass for aircraft or airship?

Pictures courtesy Schröder
Technical Data
- Dia.: ? mm
- Height: ? mm
- Manufactured in 19..?
- Markings: Label in Polish language Remove air bubbles by turning the compass around its axis of suspension

Aircraft compass - model name and date unknown
Click on pictures for enlarged views.

Technical Data
- Diameter: 105mm
- Height: 60mm
- Gimbal structure:155mm wide (screw heads), 100mm high.
- Weight: 2 pounds, 12 ounces
Type T.31

Images: VION Manual

(Click for enlarged view)
Type V.31

Picture courtesy misterfrizz69

Technical Data V.31
The compass parts

Type  F 37 B

(Click on the picture for an enlarged view)
Side view

Technical Data
Marking: Aéronautique militaire

(Pictures courtesy MOGLIA - priv. coll.)
Type Q.S.C.* 25 and Q.S.C. 27
* Abbrev. unknown
Picture courtesy eglantine 38 - Priv. coll.

Ad published in 1929

Link to a pic. of modell Q.S.C. 27 with prism and suspension equipment (excerpt of User Instr.)

View in the book  'Cours de compensation' by capitaine Gaujour (1936)

Note: the designation "2.S.C. 27" is a typo

Below : instructions for compensation

Technical Data

The compensation magnets


Pictures © J. Houcke
Type Q.S.C.V. 29
Pic. at right: ad published in 1933

(Click on images for enlarged views)
Type G.N.R.V*. 30
(* Grande Navigation Rose Verticale)

Technical Data (see cell above)

Type P.B.A. 60

Click on the picture at left for a view of the front face without the cover plate
Pictures courtesy bieber231 - priv. coll.
Type V 47
Technical Data

Pic. at l. © J. Houcke
Click on the image at r. for a full-page view of the relevant VION catalogue.
Type V.A. 82
Technical Data

Click HERE for a full-page view of the relevant VION catalogue

Pic. at left: Ad published in 1936 (click on the image for a view of the entire ad)
Pic. at r.: The compass equipped with bearing sights patent no. 639,734.
Type H.A. 82

(Pictures Jaypee - private coll.)
Technical Data
Black divisions and cardinals on white card
Magnifying prism

(Description in the official manual, 4 p. available)
Type H.A. 83

(Pictures Jaypee - private coll.)
Technical Data
Luminous markings on black card

Description in the official manual, 4 p., available
Typ 100
technical Data
White card, black figures
Magnifying prism

(Pictures courtesy M. Petri)
Type P.B.50
(PB = planche de bord = instr. panel)

Read full description in the enlarged view of the image (Traité pratique de nav. aérienne, 1935)
Type 112 - Light or emergency compass
Dim.: 60 x 60 mm
Production period: 1950s-60s

Picture F. Girot
Type 150 and 161
Dim.: ... x ... mm
Production period: 1940's-60's
Picture: Compensation instructions by Col. Gaujour, 1946)

Pic at r. excerpt from doct. NFD-113 (1960)

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Land vehicles

These two instruments (Type 14 and 143) were installed in UV's driven by French geologists of the French Nuclear Energy Authority (CEA) in the 70's in Africa (Niger). Information and pictures communicated by P. C. Guiollard, Ph.D. in History of Science and Techniques and collector of mine compasses. 
Type 143 featured an integrated red-light illumination.

Type 14

Scale seen from below

Pics courtesy P.C. Guiollard
Type 14

The compensation mechanism (on top)
Type 142 - 143

Technical data - Type 142 - 143
Dia. (incl. screws): approx. 2 in. / 50 mm
Height (incl. lighting tube): 2 2/3 in. / 65 mm
Built: 1970's
Integrated lighting device in tube below
(link to pic. dismantled)
Access to compensating screws via slide top.
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- W -


J. P. WARBURG was a U.S. engineer residing in Washington D.C. who patented a magnetic compass in 1919 (no. 1,474,394).
This design was re-used by HUGHES & Son and PIONEER.

W.D. 32

The abbreviation W.D. stands for WAR DEPARTMENT. We don't know on which vehicles and during which period this instr. was used. Thank you for helping us.

Pictures courtesy Bernie

Technical Data
Dia.: 80 mm
Period: Probably WWII


This company published an ad in the booklet The Magnetic Compass in Aircraft by Captain Creagh-Osborne (1915).
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- X -

Unknown Aircraft Compasses

The following pictures show compasses with no manufacturer's name.

Pictures courtesy A. Picker

Pictures courtesy G. Rooney

View of the compass card, the 1-2-3-0 cross and the scale for adjustment of declination 
Technical Data
Dim. (height x dia.): 700 x 500 mm
No external marking

Above the compass card is a cross made of four thin rods bearing each a mirrored figure with luminous paint: 1, 2, 3 and 0.
They are attached to a central post on top of which is a broad white arrow (for flight direction?).
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- Z -


ZÜRN was a Polish engineer who designed aircraft compasses shortly after WWI. The most famous model is the type Z-6 built by PZO (see description and pics in this entry) but a report on the Polish aircraft industry names more models all beginning with the letter Z, also listed in the German C. PLATH catalogue.

List of ZÜRN's pilot and observer models. Fig. 24 at left depicts a Z-9.

Pictures courtesy Polish Aviation Museum's archives

Picture courtesy nreg172
Type Z 4 for pilote (Führer)

Technical Data
See Pic at r. catalogue of C. PLATH, description of the various models
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