AERONAUTICAL COMPASSES

A
AERA
AIRPATH (go to "Standby compass")
AIR MINISTRY (A.M.)
ASKANIA
AVIARICHTER

 B
B, B-3A (Type B)
Ballooning
BAMBERG
BENDIX

 C
COLLINS
CREAGH-OSBORNE

 D
DALOZ - DOIGNON
DEPERDUSSIN

E
ELGIN WATCH CO.
F G H
HAMILTON INSTRUMENTS
HUGHES & Son
HUSUN

I

J
Japanese manufacturers (WWII)
K
KEARFOTT
KI-13A (КИ-13A in cyrill. letters)

 L
LEPAUTE Henry
LUDOLPH

 M
MAXANT
MONODEP
MOREL (B.B.T.)

N
Navigation

O
P
Pattern 200, 223, 259 etc.
PDK / ПДК in cyrill. letters
PERCHERON
PIONEER (see BENDIX)
PLATH

 Q R
Radiation
Radio Compass
ROSENFELD 		S
SIEMENS & HALSKE
SMITH's Aircraft Instruments
SPERRY
Stand-by Compass


T - U
UGR-4 (YГP-4 in cyrillic letters)

 V
VION (inluding compasses for land vehicles)
 W
W.D. 32 		X - Y - Z
Unknown aircraft compasses

- A -

AERA

PROFILE - Aera was a French company located in Paris which supplied many flight instrumenst in the 1920s. On some equipment (watches, altimeters etc.) appears its bird-shaped logo. It is not sure whether Aera built the compasses itself or had its logo printed on them by the real manufacturer, maybe VION.



Picture posted by 'Guynemer' on the web site "Lagrandeguerre.cultureforum.net"

Logo on a bord watch

Click on images for enlarged views.		 Technical Data
- Dim.:?
- Weight:?
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AIR MINISTRY (A.M.)

PROFILE - The Air Ministry was formerly a department of the British government with the responsibility of managing the affairs of the Royal Air Force. It existed from 1.4.1914 to 1964. Different types of aircraft compasses were built for the A.M.: the P Series compasses were pilot’s compasses, the O Series being observer's compasses.
During WWII, they were built by several makers, not just Hughes. After the serial number on the bezel, there is a suffix letter, which denotes the manufacturer. Henry Hughes and Sons (later Kelvin Hughes) also made compasses under the trade name Huson, the most common example being the Huson Mk3.

We display here just a few examples: The model 06A, a landing compass was a hand bearing compass for use on the ground (for modern instruments see SESTREL, SAURA). Other compasses installed on-board of aircraft were based on a same design like the P series. Some were equiped with a mirror and the O2 had an azimuth circle.
The compasses used by the RAF were aperiodic compasses, i.e. they settled onto a true course after a turn without overcompensation, this being achieved by means of sophisticated features like strong magnetic moment, small inertia and heavy damping. For further information concerning navigation on RAF aircraft with these compass types and more technical details concerning the aperiodic compasses, please go to cairdpublications.

The following information concerning the various P models' chronology was sent by a friendly visitor. Any complementary data will be welcome:

Picture at right courtesy M. Goosey: A P12 compass (click on the image for an enlarged view).

- The P.3 was a vertical card compass dated about 1930. I suspect (but have no hard evidence) that P.1 and P.2 were assigned to WW1 RFC (Royal Flying Corps, predecessor of the RAF) compasses that remained in service after the Air Ministry was formed.
- The P4 was a mid-1930s compass and was used in “large” aeroplanes, including the Hawker Hart, Sunderland and early four-engined bombers. It was replaced by the P10, which was identical in size but had four cross hairs rather than two. Some P4's were modified with four cross hairs as P4A. It was the P10 that would have been fitted to the Lancaster rather than the earlier P4, but I have no doubt that P4's were also used when the need arose.
- I have no information about the P5.
- The P6 was fitted to “small” aeroplanes. It was replaced by the P8, which had a slightly larger bezel.
- The P7 was an inverted version of the P6 and was replaced by the P9, which was an inverted P8.
- The P8 was in common use from about 1937 and was used in the Spitfire, Hurricane, Tiger Moth, etc. and was replaced by the P11. There was also a version marked as the P8M (M for MARINE ?). Some P8's and P8M's were modified with four cross hairs.
- The P9 was an inverted version of the P8 and looked similar to the P7.
- The P10 was an improved version of the P4 with four cross hairs.
- The P11 was an improved version of the P8 with four cross hairs.
- The P12 was an inverted version of the P11 viewed via a mirror which hung below the bezel (see picture). It probably was the last magnetic compass in the P Series.

CAUTION - RADIATION HAZARD

The cardinals (N-E-S-W) and the 10-deg. markings on the compasses were made of a radioactive compound (radium and zinc sulfide) which is still very "hot" although the paint is no longer visible in the dark. In 50 cm (1 1/2 ft) distance, the gamma radiation measured is 0.35 µSv/h (microsieverts/hour). The natural background radiation is about 0.10 µSv/h. The threshold for dangerous radiation is 0.30.
Click on picture for an enlarged view
DON'T OPEN THESE INSTRUMENTS AND NEVER MINGLE WITH RADIOACTIVE PARTS.
DON'T STAY DURING LONG PERIODS NEAR THEM.

Read the news about contaminated beaches because of the dumping of decommissioned equipement after WWII.


TYPE 06A
Stores* Ref. 6A/I.248
* see Miscellaneous/Terminology



(Click on the pictures for enlarged views)		 AIR PUBLICATION 1275
General description and section view
(Photocopies of AM compass manuals can be ordered)
  

Technical Data
- Diameter: 3.8 in. (95 mm)
- Overall length: 9 in. (190 mm)
- Weight: 2 lb. 4 oz (approx. 1 kg)
- Serial no.: 38899H
The Air Ministry logo (see pic. below) was not engraved on all items. Some featured only the Army's broad arrow ("crow foot").



The compass card's winged North symbol (mirrored view):
TYPE P. 2

  

(Click on the images for enlarged views)

Pic. at right: The casing without the divisions ring.
The aircraft's axis (direction of flight) was represented by means of a long pin located on the casing's side wall opposite to the word AFT. The card's south-north axis was enhanced by means of an arrow featuring a letter S at one end and a letter N in a red triangle at the northern end. The arrowhead features two bird wings with feathers like on the TYPE 06A's card above (click on link for pic). 		Certain characteristics like the divisions ring and N-S arrow are maybe evolutions  compared with the Type P.1.

The system was apparently gimballed like ships compasses.



Pictures courtesy G. Rooney
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 Technical Data  
Dimensions
- Height: 3 1/8 in. /  80mm
- Dia. (top rim): 6 1/2 in. / 165mm
- Dia. (base): 5 1/2 in. / 140mm
- Dia. of compass disk: 2 3/8 in / 60mm
Markings: Type . P. 2 . (with three dots!), AFT, No. 195 D.

The card already featured the spider leg-shaped damping wires (see also the exploded view of Type P.6).

The card supplier's name in the north symbol (stylized fleur de lys) is HUSUN (click on link for pic). The center letters are masked by the S-N arrow. This is the abbreviated trade name of H. Hughes & Son Ltd. 
TYPE P. 3
Front view (compass)

(Click on the images for enlarged views)
 LH and RH views:

   

Pictures courtesy aspentree123
 Technical Data
Compass type: vertical type, free rotating sphere
Dimensions
- Height: 10 in. / 250mm
- Dia. of compass window: 2.25 in. / 55mm
Weight: 3 lb 11 0z. (1.66 kgs.)
Markings
Type P3, S/No. 734 H* and a large letter M in white paint; Stores Ref. 6A/O.224
Materials
- Compass casing: brass; mouting frame: aluminum, grip: wood
Type P4, P6, P8 compasses
Stores Ref. 6A/O.227, .367 and .726
These compasses had apparently the same shape. Only internal technical details vary.

P4 top view and exploded view of P6
(Click on the images for enlarged views)
 Side view:




A P4 in situ in a Lancaster bomber's cockpit
(Cockpit picture by courtesy of www.spitfirespares.com)

 Technical Data

P4 - Built in (Lancaster?) bombers
- Diameter: 7 1/4 in. (184 mm)
- Weight: 5 lb. 14 oz (approx. 2.5 kg)
- 4 magnets

P6 - Built in ...?
- Diameter: 5 3/8 in. (136 mm)
- Weight: 2 lb. 4 oz (approx. 1.2 kg)
- 2 magnets

P8 - Built in Spitfire
- Diameter: 5 3/8 in. (136 mm)
- Height: 3 in (77 mm)
- Weight: ... oz (approx. 0,821  kg)
 
AIR PUBLICATION 1275
General description and section view




(Click on the images for enlarged views)

(Photocopies of AM compass manuals can be ordered)
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 A compass in its transit container
Type P7
Stores Ref. 6A/O.430





(Click on the images for enlarged views)		 AIR PUBLICATION 1275
General description and section view
(Photocopies of AM compass manuals can be ordered)

 Technical Data

Like P6 but with additional mirror

- Diameter: 5 1/2 in.
- Height: 8 in.
- Weight: 4 lb. 8 oz. (approx. 2.3 kg)
Type O2 with azimuth circle
Stores Ref. 6A/O.380


(Click on the images for enlarged views)		 AIR PUBLICATION 1275
General description and section view
(Photocopies of AM compass manuals can be ordered)

 Technical Data
- Diameter: 6 1/4 in.
- Weight: 6 lb. 2 oz (approx. 3 kg)

Azimuth circle
(stores Ref. 6A/O.411)
Bomb Sight Type D
Stores Ref. 6E/O.276



This instrument is primarily designed for use in the course-setting bomb sights Mk VII A, B and C.

(Click on the images for enlarged views)		 AIR PUBLICATION 1275
General description and section view
(Photocopies of AM compass manuals can be ordered)

 Technical Data
- Diameter: 4 in.
- Weight: 1lb. 11 oz (approx. 750 gr)
SEITENANFANG

ASKANIA

PROFILE - German manufacturer (more information HERE). The confidential three-letter-code during WWII was bxx (click on link for pic.).
See also Wrist, Marching and Nautical compasses.

Orterkompass (Observer / Navigator compass)
Lkf 5b "Franz"
Supply no. Fl.23203-1,
predecessor model of OK 38
This instrument was also produced by C. Plath and W. Ludolph.

Enlarged view of the compass card:
click on picture at r.

Technical data
- Dia.: 120 mm
- Height: 80 mm (case) + 50 mm (glass dome)
- Weight: ca. 750 g (w/o attachment parts)
- Techn. Data in the ASKANIA catalogue
Material supply document "Flieg" of model OK 38: Fl. 23204.
Compare with other versions in this List of German a/c compasses during WWII.
Link to picture Instruments panel.
Slaved compass assy.
Ad. published in 1941
 Technical Data
The assembly comprises the following parts
(table: picture of the catalogue)
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AVIARICHTER

PROFILE - Joachim Richter was a German watchmaker located Am Wald 2, Ende Erzbergerstr. 75 Karlsruhe 31. Miscellaneous aeronautical equipment.
Automatic watch Model 08/15 Military (pic. Maistero/Watch Lounge). He also built at least until 1945 pilots' goggles (pic. profifilm.de, mod. 1935).

Model FK.16
(Führerkompass = pilot compass)


Pictures Henri Note
(Click for enlarged views)
Technical Data
- Weight: 206 gr
- Depth: 60 mm
- Diam 57 mm
 
The FK16 is a LUDOLPH development and product. It is also integrated in their navigation equipment for divers.
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- B -

Ballooning

PROFILE - In its 1910 catalogue, the French compass maker and retailer VION displayed two pocket compasses with transparent glass bottom, stating that this design was specially conceived for ballooning. The other compass (on the enlarged image of the catalogue) was probably made by S-L.


Special compass for ballooning as shown in the VION catalogue (c. 1910)

Click on picture above for full descr.		 Technical Data
- Diameter: 45 mm
- Depth: 12 mm
- Weight: 40 gr
- Manufacturer: probably Houlliot
- Serial no.: 56 (punched on the side)

It was carried in a leather pouch with snap lock and a large round window. Early 20th c.
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BAMBERG, Carl

PROFILE - Carl Bamberg was a German compass manufacturer located in Friedenau near Berlin.
For more information click HERE.
See also Pocket Compasses



Pictures courtesy Horst Kahnt
(click for enlarged views).

Technical Data
- Diameter: 115 mm
- Height: 84 mm
- Weight: ... g ?
This compass was installed in following vehicles: (?)
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BENDIX

PROFILE - BENDIX Aviation Corporation is a U.S. company created in 1928. For more information go to WIkipedia.



The upper plate masks a lamp.

Pictures courtesy Tony KING
(Click for enlarged view)


Rear face (connectors)		 AIRCRAFT COMPASS MARK VIII - TYPE 1822

Technical Data
- Broadth: 87 mm
- Height: 80 mm
- Weight: 883 g
Markings: BU. AERO. U.S. NAVY

F.S.S.C. No. : 33-C-800
MFR'S Part No.: 1822-1-B

Cut-away view (Installation instr.) 		PIONEER VEHICLE COMPASS - TYPE 1829
This compass was used in all sorts of land vehicles incl. tanks. It is said to have also been used in aircraft (Installation Instr. avlbl.) but we lack evidence.

Pictures courtesy priv. coll.
(Click on images for enlarged views)

Patent for a new system allowing to uniformly illuminate a compass rose (1938)



 (Click on image at left for view of full page - Photocopy available)		 Excerpt:

"The novel means of the present invention comprise a transparent ring of light-conducting material (40) [...] composed of glass, quartz, "Lucite" or any other suitable material. The light from a lamp (42) may be introduced in the ends (40c) of the ring and conducted thereby around the periphery of the compass. The ring-light is provided with a plurality of light-reflecting surfaces (fig. 2, 40a and 40b) extending around the circumference of the ring, the reflecting area of these surfaces gradually increasing in amount of the distance as the distance from the light source increases."

The flight instrument below is a radio compass indicator. It is not a compass per se but an indicator that has a needle coupled to a synchro motor that is coupled (via a 5-wire cable, connector PL 118) to another device or mechanism that actually performs the compass function (e.g. flux valve). The knob labeled VAR allows the calibrated direction ring to be set (E-W) for variances in magnetic declination that is different at all localities over the world and varies over time (especially as the airplane proceeds in an East-West direction). Magnetic variation is noted on maps and aeronautical charts which allows the pilot or navigator to correct for this variation as the airplane proceeds from one location to another.
(This definition was kindly given by LLoyd Crawford.)



(Click on the pictures for enlarged views)		 Radio compass / Signal indicator I-82-A
Signal Corps U. S. Army
S/N: 4771
Period: WW2

Technical Data
- Diameter: 13 cm
- Depth: 9 cm
- Weight: 600 gr
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- C -

COLLINS

PROFILE - ...
The Online Compass Museum doesn't possess any information about this company. Your help is welcome. This company is kindly invited to contact the curator.

CREAGH-OSBORNE

PROFILE - Captain Frank Osborne Creagh-Osborne (1867/1943) was Superintendent of Compasses at the Admiralty and a British inventor. He developed several compass systems which were manufactured by H. Hughes & Son Ltd, Dent & Co & Johnson Ltd and also by Sperry Gyroscopes (see also the sections Marching Compasses and Wrist Compasses). In 1915, Henry A. Hughes took part in a meeting at the Admiralty and explained the advantages of this compass (source: minutes of meeting in 'Improvements in prismatic compasses with special reference to the Creagh-Osborne patent compass' - Ask for a copy).

Creagh-Osborne published in 1916 a booklet (photocopies of the French version available, 52 pages) about the use of compasses in aircraft. He described therein not only the systems integrated in the instrument panel but also the compasses utilised by the observer, i.e. attached to his wrist by a leather strap. According to Ellis Island's immigration records, he landed in New York on June 8, 1918 on board a ship called Olympic arriving from Southampton.

See also Marching and Wrist compasses

Description and user instructions for Air Compasses (French edition)



(Click on the pictures for
enlarged views)
Instrument panel compasses
Pattern 255 and 259



Observer's wrist compass Pattern 261

 The patent numbers indicated on the compasses (1148/15 and  17736/15) refer to the application documents and the year 1915 (copies available).

The compass type described in Pat. no. 17,736 is for the patterns family 255/259. The numbering started in 1913 with pattern 200 and the compasses were issued from 1915 on.



Patent no. 1148 describes several prismatic and liquid dampened compass types displayed in the Marching and the Wrist compasses sections.



Side/top view with the manufacturer's label of DENT & Co. & JOHNSON Ltd.
Air Compass Pattern 259




 Technical Data
- Dimensions (height x breadth): 152 x 135 mm
- Depth (w. lugs): 108 mm
- Depth (w/o lugs): 89 mm
- Weight: c.1.7 lb.
- Divisions: 360 deg. every 10.
- Fluid damping



Click here for a view of the manufacturer's label of H. HUGHES & Son Ltd. (see below).
Air Compass Type 5/17



Pictures courtesy mfc80
 Technical Data
- Dimensions: ... x ... x ...  mm
- Weight:  lb.
- Divisions: 360 deg. every 10.
- Dry capsule

This extremely simplified compass was used in the famous WW1 Sopwith RFC/RAF aircraft. The figure 5/17 means design-appproved May 1917. More than 50,000 pcs were built. (Source: Steady as she goes, Fanning, 1986).
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- D -

DALOZ (DOIGNON)

PROFILE - Gaston-Jules DALOZ (living in Ramerupt, Aube, France) filed in Aug. 1910 a patent (no. 419.682) for a system that permitted to follow the displacement of the landscape on ground through the transparent card of a compass (see detailed description and comment as published in FLIGHT no. 107, iss. Jan. 14, 1911). The parallel lines were introduced via an additional patent in Nov. 1910.
The device was then further developed by Abel-Louis DOIGNON* (patent no. 431.275, May 1911) who added a liquid damping and mechanical solutions permitting a rapid (re-)setting.
In spite of this, the compass was not to be used as such (no cardinals) and the pilot needed an additional standby-compass.
* See Doignon's marching compass.




The original Daloz-Patent
(Cover 9 2/4" x 1 ft)


Original drawing of DALOZ's system


The further development
(DOIGNON's patent)

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DEPERDUSSIN - Model MONODEP

PROFILE - Deperdussin was a French aircraft manufacturer (see Wikipedia) located 19, rue des Entrepreneurs, Paris.
This instrument with a very unusual design was invented in 1912 by Gaston Emile Colombel who lived 50, rue de Moscou, Paris (pat. no. 26,282, British issue). It was installed in the following aircraft during the first crossings of the Channel, three of them in thick fog: Biélovucie flying a Hanriot machine, Moineau flying a Bréguet, Prévost a Deperdussin, Guillaux a Clément).
The brochure & catalogue (13 p., photocopy available on request) also contains exerpts of letters sent by pilots after winning races:
- Crossing of the Alpes by Biélovucie in 1913.
- Coupe Pommery (1,129 km) won by Guillaux in April 1913.
- Races Paris-Amiens-Paris and Circuit Forézien (400 km) won by Molla. The latter flew the best time on the 1st leg of the waterplane race from St. Malo to Jersey and return in thick fog (letter dated Feb.1913).
A. Védrines thanked the inventor Colombel in the name of Serbian Air Force pilots.

Model MONODEP 1912
Dampening of vibrations by means of springs.



 		Model MONODEP 1914
Gimballed item, scale with MILS divisions (1/4 of full circle = 1600)



(Click on images for enlargement) 		Technical Data - (Functional description / patent's fig.)*
The compass magnets are concealed in the bowl. The visible card rotates in a vertical plane and is linked to the magnets via a right-angle gear. Only the cardinals are painted on the card (red star for North). The route to be flown is set on the external scale (graduated 90° or 1600 MILS for a full circle) by means of an arm linked through the cover glass via a 1:4 gear to a second arm terminated by a red star which indicates the position of the card's north red star. A full circle of the scale corresponds thus with only a 1/4 of the card's rotation. The heading measured on a map is set via a special protractor and the external arm on the scale. The pilot only has to make sure that the two red stars remain superimposed.
Model 1914 featured an integrated lighting with a battery which could be replaced in flight (6 hrs life time). The card was divided into four quarters of different colours and called Capitaine ROISIN after its designer.
The magnetic declination could be set during production.! This seems surprising now but in those days, the aircraft range was not big enough to make an in-flight adjustment necessary.
* The patent describes a flat instrument.
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- E -

ELGIN Watch Company

PROFILE - Major U.S. watch maker. Incorporated August 1864, sold in 1968. During World War II, all civilian manufacturing was halted and the company moved into the defense industry, manufacturing military watches, chronometers, fuses for artillery shells, altimeters and other aircraft instruments and sapphire bearings used for aiming cannons. (Source Wikipedia)

The B-3A compass was a later version of the “Type B” compass introduced in World War I. Most of the production of this particular model occurred around 1929. Very few of these would still have been in use by the WWII timeframe. They were one of the most common forms of military aircraft instrumentation as they could be used in just about any aircraft type ranging from trainers to pursuit (i.e. fighters) and bombers.
(Source Smithsonian Institution)


Front side
Rear side
 		B-3A

Compare with Creagh-Osborne's Pattern 259 and 5/17 design.

Markings: Air Compass A.C. U.S. Army, Type B-3A made by the Elgin National Watch Company. 


Pictures courtesy P. Grace
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- H -

HAMILTON INSTRUMENTS

PROFILE - This manufacturer is not associated with Hamilton Standard, a U.S. Company created in the 1920's by Thomas Foster Hamilton (July 28, 1894 – August 12, 1969) who was a pioneering aviator and the founder of this company.

We received the following information:
'The Hamilton HI-400 Vertical Card Compass was invented by a man known as "Ham" Hamilton at Hobby Airport in Houston Texas in the early 1970s. He owned a small aircraft instrument repair shop known as Hamilton Instruments at Hobby Airport. I knew "Ham" at the time because I was an avionics technician working for Associated Radio Service Company, also at Hobby Airport. "Ham" brought his prototype into our shop and showed it to us. It was a great invention. The model number "HI-400" stands for Hamilton Instruments-400.
Hamilton later sold his invention to Precision Airmotive, also at Hobby Airport. These compasses are still being made, but it is momentarily not known by whom. It is supposed that "Ham" is either very old now, or has passed on.'



Click on the picture for enlarged view		 Technical Data
- Dimensions: 70 x 60 x 50 mm
- Weight: 270 gr/0.6 lbs.

The deviation can be compensated in order to show a correct display by turning the screws at the lower front part:
the left-hand screw (green paint mark, upper one on pic. below) is for the North-South axis and the one on the right (painted yellow) is for the East-West axis.
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HUGHES (Henry H~ & Son Ltd.)

PROFILE - Henry Hughes was born in 1816. In 1838 Henry Hughes & Son was founded at 120 (later at 59), Fenchurch Street, London as a maker of chronographs and scientific instruments. Henry died in 1879 and his son Alexander succeeded him as chairman. The firm was incorporated as Henry Hughes & Son Ltd in 1903. Hughes & Son worked together with Captn. Creagh-Osborne among other inventors (see Type 5/17).
 In 1935, S. Smith & Son Ltd. acquired a controlling interest in the company. This resulted in the development of new marine and aircraft instruments (see HUSUN below). Following the destruction of the Fenchurch street offices in the Blitz of 1941, discussions with Kelvin, Bottomley & Baird Ltd resulted in the establishing of the joint venture company Marine Instruments Ltd at 107, Fenchurch Street, London in 1942. Henry Hughes & Son Ltd was a founding company of KELVIN HUGHES (see Wikipedia, Nautical Compasses and this company's own website).

HUSUN

PROFILE - HUSUN was the abbreviated trade name of H(enry) HUGHES & Son Ltd. This name appears on some aircraft compasses like the TYPE P.2 (see Air Ministry above). It was also re-used by other manufacturers (see another example SMITH's Aircraft Instruments
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- I - J -

Japanese Compasses (WWII)

We concentrate here various information to be found on the followings websites:
- Compass pictures: liveauctioneers, wehrmacht-awards, warrelics, warbirdsite, collectair,
- Background Information (on Gunsight.jp):
Japanese Army aircraft compasses
Japanese military aircraft instruments (list of data plates)
Reading Japanese data plates

Manufacturers names:
Tokyo Aviation Indicator Company
Yokogawa Kenki Seisakusho


Picture courtesy G. Rooney

Main component of an  instrument with a mirror on top in which the mirrored figures 0-1-2-3 located at the end of wires could be read (see pic. at right).

Top view: the wire cross with the figures 0-1-2-3 at the ends and the deviation correction scale. View of a similar compass with a scale (0-10°) inside the bowl. The adjustment for deviation caused by metallic masses on-board was done by means of plugs stuck in the base stemm. (Pictures courtesy Liveauctioneers)

 Technical data
Dimensions (ht. x dia.) : 70 x 50 mm
Compass with mirror 8'' ht. x 6 1/2'' dia. (230 x 162mm).
Mounted on spring-loaded gimbal.
No external markings here but a similar compass is known in its original container. It is marked completely in kanji with a plate indicating Noritake.

We don't know how the wire cross with the four figures 0-1-2-3 was to te used. Your help is needed.
The tiny arrow on top indicates probably the flight direction.

The manufacturer's label



Pictures courtesy ebay member axialcompressor
 Manufacturer: Tokyo Aviation Indicator Company
(see website Reading Japanese Data plates)

The characters on the nameplate read
“Type 1 Magnetic Compass Model 1”


Pictures courtesy ebay member 4corners54		 Dimensions (dia.x ht.): 4 x 5in. (100 x 125mm)
Manufacturer: Tokyo Aviation Indicator Company
(see website Reading Japanese Data plates).


Picture courtesy ebay member messerschmitt*109		 Type 92 Magnetic Compass
Manufacturer: Yokogawa Kenki Seisakusho
(see website Reading Japanese Data plates).

Comment: "It was mainly used in single engine navy aircraft like the Zero, Nakajima B5N2 Kate, and Aichi B7A2 Grace. It was also used in the Okha 11, the infamous "Baka Bomb".

(Pictures and author Gunbunny /  Wehrmacht-awards).
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- K -

KEARFOTT - USAF N-1 Master Indicator

PROFILE - KEARFOTT is a North American manufacturer of flight instruments (more information HERE).
The instrument presented hereafter is an evolution of Kearfott's N-1 navigation system which was developed approximately in 1948.
The N-1 Compass System is a remote indicating magnetic slaved, directional gyro-stabilized compass system, specifically designed for airborne use in all latitudes. The Earth magnetism sensor is called here C-2 Remote Compass Transmitter. In addition to its use as a compass system, the N-1 also provides an azimuth reference signal for directional control of the automatic pilot and directional reference for other equipment. In magnetic slaved operation, the N-1 indicates the magnetic heading of aircraft during normal flight conditions. It is a highly accurate system that enables precise navigation on long range flights by taking into account both the Earth's rotation and curvature. This feature made it thus possible to perform grid navigation, i.e. to fly directly on 'great circle' routes and achieve the shortest possible distance between two points on the Earth.

Kearfott ultimately produced around ten thousand systems for USAF and commercial applications. There are still approximately 500 systems installed and active (e.g. in C-130 Hercules aircraft) within the USAF inventory and the AF has an ongoing repair depot activity (complete description in the original KEARFOTT document available).
Source: ASTRONAUTICS Corp. of America

The dial represents a motionless compass card. The long pointer indicates the actual aircraft's heading and the short one its present position between the Equator and one of the poles (LATITUDE scale: northern hemisphere is located left, southern hemisphere is right).
Example below: Actual position readings: Heading: 32° NE, Latitude: 38° N.


• Knob in upper right corner reads:
LATITUDE CORRECTION N-S
• Knob in lower right corner reads:
SYNCHRONIZER L-R

Click HERE for descriptive drawing of front face.


Rear face: with cover - click on image for enlarged view without cover

Click HERE for descriptive drawing of rear face.



The N-1 system components

Click HERE for functional drawing.

Operation instructions avlble (prov. iss. July 1952, 42 p.)

 Master Indicator Technical Data
- Dim.: 120 x 120 x 220mm
- Weight: approx. 4.5 kg / 9 lbs.



(Click on images for enlarged views)

Description: Normally the small pointer on the latitude scale is set to "off" for magnetic slaved operation. When running in "free gyro", then the small pointer is adjusted to the approximate latitude that the aircraft is operating in and corrects the gyro for "earth rate" precession ('Free Gyro' operation is the normal operating mode in the arctic and antarctic regions near the Earth's magnetic poles).
The latitude pointer is set by the navigator and it does not give any position. Many times navigators operating in the antarctic (particularly in the Southern Latitudes) have set their latitude as N instead of S and suffered large induced corrections because of the wrong latitude.
The very small pointer on the L / R indicator, indicates input by the magnetic flux gate detector (C-2 Remote Compass Transmitter) which is remoted on the wing or other portion of the fuselage. It will continuously fluctuate back and forth as it receives the magnetic information.
(Explanations transmitted by Breckinridge S. Smith - Major, USAF ret.)
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KI-13A (КИ-13A in cyrillic letters)

PROFILE - Unknown manufacturer.
Russian stand-by compass, 1960s.

Label



Pictures ...
(Click for enlarged views) 		The  models KI-12 and KI-13 as described on the Russian website:
www.aerokubinka.ru/graph/s/1/668_nav03.doc




 Technical Data
- Dia.: mm
- Length: mm
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CONT'D