- A -
PROFILE - The
Air Ministry was formerly a
department of the British government with the responsibility of
managing the affairs of the Royal Air Force.
Different types of aircraft compasses were built for the A.M. We
display here to begin with the model 06A, a landing compass. It was a
hand bearing
compass for use on the ground. Today, the British company SIRS still
produces such compasses (see their own website: www.sirs.co.uk).
Other compasses installed on-board of aircraft were based on a same
design like the P4 and the smaller P6.
The P7 was equiped with a mirror and the O2 had an azimuth circle.
06A compass
(stores Ref. 6A/I.248)
(Click on the pictures for
enlarged views) |
AIR
PUBLICATION 1275
General description and section view
(Copies
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 (pic. below) was not engraved on all items. Some
featured only the Army's arrow.
The compass card's winged North symbol (mirrored view):
|
P4
and P6 compasses
(stores Ref. 6A/O.227 and 6A/O.367)
A.M. P6 compass - paint removed
(Picture sent by
a visitor
-
Click for
enlarged views) |
AIR
PUBLICATION 1275
General description and section view
(Copies of AM
Compass manuals can be ordered)
 |
Technical
Data
P4
- Diameter: 7 1/4 in.
- Weight: 5 lb. 14 oz (approx. 2.5 kg)
- 4 magnets
P6
- Diameter: 5 3/8 in.
- Weight: 2 lb. 4 oz (approx. 1.2 kg)
- 2 magnets
|
P4 Compass
The Compass alone (above) and in situ in a Lancaster bomber cockpit
(below):
Cockpit picture courtesy www.spitfirespares.com
(Click on the pictures for
enlarged views) |
Side view
The Air Ministry logo:
|
The compass in
its transit container
 |
P7 Compass
(stores Ref. 6A/O.430)
(Click on the pictures for
enlarged views) |
AIR
PUBLICATION 1275
General description and section view
(Copies 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. ? kg)
|
02 Compass with azimuth circle
(stores Ref. 6A/O.380)
(Click on the pictures for
enlarged views) |
AIR
PUBLICATION 1275
General description and section view
(Copies of AM
Compass manuals can be ordered)
 |
Technical
Data
- Diameter: 6 1/4 in.
- Weight: 6 lb. 2 oz (approx. ? kg)
Azimuth circle
(stores Ref. 6A/O.411)
|
- B -
PROFILE - Carl Bamberg was a German compass manufacturer in Friedenau
near Berlin.
For more information click
HERE.
Pictures by Horst
Kahnt - click for enlarged views. |
|
Technical Data
- Diameter: 115 mm
- Height: 84 mm
- Weight: ... g ?
This compass has been installed in following vehicles: (?) |
PROFILE - Bendix Aviation Corporation, Baltimore, MD USA
The Online Compass Museum doesn't possess any information about this
Company. Your help is welcome.
This company is kindly invited to contact the museum's curator.
This flight instrument 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 by a 5-wire cable (connector PL 118)
to another synchro motor that is coupled to some other 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 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 pictures for
enlarged views) |
 |
Radio compass
Signal indicator I-82-A
Signal Corps U. S. Army
SN: 4771
Technical Data
- Diameter: 13 cm
- Depth: 9 cm
- Weight: 600 gr |
- C -
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 museum's curator.
(click on pictures for enlarged
view)
PROFILE - Captain Frank Osborne Creagh-Osborne (1857/1922) was
Superintendent of Compasses with the Admiralty and a british inventor.
He developed several compass systems which were manufactured by H.
Hughes & Son Ltd (59, Fenchurch Street London) and Sperry (see
also categories Marching Compasses and Wrist Compasses). In 1915, Henry
A. Hughes
published a book called 'Improvements in prismatic compasses with
special reference to the Creagh-Osborne patent compass'.
Creagh-Osborne published in 1916 a booklet (copies of the French
version are available, 52 pages) about the use of compasses in
aircraft. He described therin not only the systems integrated in the
instrument panel but also the compasses utilised by the observer, i.e.
attached to his leg or his wrist by a leather strap.
According to the Ellis Islands immigration records, he landed in New
York on June 8, 1918 on board a ship called
Olympic
arriving from Southampton.
(Click on the pictures for
enlarged views) |
Instrument panel
compass
 |
Observer's
compass
... |
- H -
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.
 |
- K -
PROFILE - KEARFOTT is a North American manufacturer of flight
instruments (more information
HERE).
The instrument presented here is an evolution
of Kearfott's N-1
navigation system described in the diagramm below and which was
developed approximately in 1948. This large and
heavy
instrument comprises the gyroscope.
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).
Two pointers show the actual aircraft's heading and its position
between the Equator and one of the poles (LATITUDE: North hemisphere is
left, South is right).
(Source: ASTRONAUTICS Corp. of America)
Readings:
- Heading: 30°
- Position: 76° North
Knob top reads:
LATITUDE CORRECTION N-S
Knob bottom reads:
SYNCHRONIZER
(Click
to enlarge)
|
Rear face:
connector and pin diagramm |
(Click to enlarge)
Functional
drawing of the basic N-1
system
The heavy instrument displayed here comprises both the indicator and
the gyroscope.
|
Technical
Data
- Dimensions:
120 x 120 x 220 mm
- Weight: approx. 4.5 kg / 9 lbs.
(Click
to enlarge)
|
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 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.)
- L -
PROFILE - W. LUDOLPH GmbH & Co. KG (Bremerhaven) is a German
company manufacturing nautical and aeronautical compasses.
(more information
HERE.
Examples of older compasses: FK 6, FK 10, FK 13
(FK = Führerkompass = pilot compass)
 |
(Pictures
courtesy www.spitfirespares.com) |
Model FK 10/32
Technical Data
- Compass of the Junkers 52
|
- S -
(Click on picture for
enlarged view) |
Stand-by compass (manufacturer
unknown)
The declination can be taken into account to show a correct display by
turning the screws concealed behind the plate at the lower front part:
- the left hand screw is for the north-south axis
and
- the right one for the east-west axis.
Technical Data
- Dimensions: 70 x 60 x 60 mm.
- Weight: 240 gr
- Date stamp: APR 82. |
PROFILE - 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 an located in
Berlin. (...)
...
The Online Compass Museum doesn't possess any further information about
this Company. Your help is welcome. This company (or its successor) is
kindly invited to contact the museum's curator.
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)."
Technical Data
- Dimensions: 160 x 130 x 120 mm
- Weight: 2.6 kg.
(Click on picture for
detailled view of front and rear side) |
Instrument panel of the
Junkers Ju 88
(click on picture for
enlarged view) |
Technical Data
(original in German)
dated March 1940
|
- V -
PROFILE - Former French company (for more information click
HERE)
Aircraft compass - model name and date unknown
Click
for enlarged views. |
|
Technical Data
- Diameter: 105mm
- Height: 60mm
- Gimbal structure:155mm wide (screw heads ), 100mm high.
- Weight: 2 pounds, 12 ounces
- Markings: VION PARIS et AÉRONAUTIQUE MILITAIRE
|
Aircraft compass patent (1928)
Click on the drawing above to enlarge the simple view or in the center
column for detailed original
patent illustrations. |
Patent - Figures (pdf files)
Figure 1
Figure 2
Figure 4
Figures 3 & 6
|
VION MANUAL
 |
Compass
type T.31
Pictures: VION Manual (www.aeroarchives.org)
(Click for
enlarged view) |
Compass type V.31
|
Technical
Data
The compass parts
 |
Compass type
Q.S.C.V. 29
(Click for
enarged views) |
Compass type
G.N.R.V*. 30
(* Grande Navigation Rose Verticale)
|
Technical
Data
(Pictures: see above) |
Compass
type F 37 B
(Click on the
picture for an enlarged view) |
Side view
 |
Technical
Data
Marking: Aéronautique militaire
(Pictures
courtesy MOGLIA - priv. coll.) |
Compass type QSC
27
|
|
Technical
Data
Compensation magnets
(Photo Houcke -
priv. coll.) |
Compass type PBA
60
Click on the picture for a view of the front face without the cover
plate |
Side view
(Pictures courtesy bieber231 - priv. coll.) |
Technical
Data
Divisions: ... |
Compass
type H.A. 83
 |
...
|
Technical
Data
This model existed also in a 82 mm diam. version
(Pictures Jaypee -
priv- coll.) |
