The de Havilland Gipsy Major or Gipsy IIIA is a four-cylinder, air-cooled, inline engine, first run in 1932, and used in a variety of light aircraft produced in the 1930s, including the Tiger Moth biplane.

The engine was a slightly modified Gipsy III, which was effectively a de Havilland Gipsy engine modified to run inverted so that the cylinders pointed downwards below the crankcase. This allowed the propeller shaft to be kept in a high position without having the cylinders blocking the pilot’s forward view over the nose of the aircraft. One initial disadvantage of the inverted configuration was the high oil consumption (up to four pints per hour) requiring regular refills of the external oil tank, this problem improved over time with the use of modified piston rings. The Major was a slightly bored-out (118 mm from 114 mm) Gipsy III. First built in 1932, total production of all Gipsy Major versions was 14,615 units.

The CNIAR 4GI was a licence-built 130 hp De Havilland Gipsy Major.

In Canada the Gipsy Major was the engine of choice for the DHC1 Chipmunk trainer, which later replaced the Tiger Moth in the RAF. By that time however, the Gipsy Major was eclipsed by the Blackburn Cirrus Major and the American Lycoming and Continental horizontally opposed engines. In its final supercharged form, the Gipsy Major used in helicopter applications delivered 220 hp (164 kW).

Variants:
Gipsy Major I
Gipsy Major IC – Higher compression ratio (6:1) and maximum RPM for racing use.
Gipsy Major ID – Fuel pump added, plus screened ignition harness and priming system.
Gipsy Major IF – Aluminium cylinder heads, 5.25:1 compression ratio.
Gipsy Major 7 – Military version of Gipsy Major 1D, increased climb RPM.
Gipsy Major 8 – Sodium cooled exhaust valves, cartridge starter for DHC Chipmunk.
Gipsy Major 10 – Electric starter option.
Gipsy Major 30 – Major redesign, bore and stroke increased. 6.5:1 compression ratio.
Gipsy Major 50 – Supercharged. 197 hp.
Gipsy Major 200 – Designed as a light helicopter engine. 200 hp.
Gipsy Major 215 – Turbo-supercharged helicopter engine. 220 hp.

Applications:
Airspeed Ferry
AISA I-115
Arrow Active
Auster Aiglet
Auster Autocar
Auster Autocrat
Beagle Terrier
Boulton Paul P.92
British Aircraft Cupid
British Aircraft Eagle
British Aircraft Double Eagle
Blackburn B-2
Chrislea Super Ace
Comper Mouse
Comper Streak
Comper Swift
De Bruyne Snark
de Havilland Dragon
de Havilland Dragonfly
de Havilland Australia DHA-3 Drover
DHC-1 Chipmunk
de Havilland Fox Moth
de Havilland Hornet Moth
de Havilland Leopard Moth
de Havilland Moth Major
de Havilland Puss Moth
de Havilland Tiger Moth
de Havilland T.K.2
de Havilland T.K.4
Elliotts Newbury Eon
Fairey Primer
Foster Wikner Wicko
General Aircraft Cygnet Major
General Aircraft Monospar
Handley Page Manx
Hirtenberg HS.9
Ikarus Aero 2
Koolhoven F.K.43
Koolhoven FK.47
Koolhoven F.K.54
Miles Aerovan
Miles Falcon Major
Miles Gemini
Miles Hobby
Miles Hawk Trainer
Miles M.35 Libellula
Miles M.39B Libellula
Miles Magister
Miles Mercury
Miles Messenger
Miles Minor
Miles Monarch
Miles Sparrowhawk
Miles Whitney Straight
Percival Gull Major
Reid and Sigrist Desford
Rogozarski SIM-Х
RWD-5bis
RWD-19
Saab 91 Safir
Saunders-Roe Skeeter
Spartan Cruiser
Stampe SV.4
Thruxton Jackaroo
VL Viima

Specifications:

Gipsy Major I
Type: 4-cylinder air-cooled inverted inline piston aircraft engine
Bore: 4.646 in (118 mm)
Stroke: 5.512 in (140 mm)
Displacement: 373.7 in³ (6.124 L)
Length: 48.3 in (1227 mm)
Width: 20.0 in (508 mm)
Height: 29.6 in (752 mm)
Dry weight: 300 lb (136 kg) Mk 1F to 322 lb (146 kg) Mk 1D
Valvetrain: OHV
Fuel system: Downdraught Hobson A.I.48 H3M (Mk 1C and Mk 7) or H1M (others)
Oil system: Dry sump, gear-type pump
Cooling system: Air-cooled
Power output: 122 hp at 2,100 rpm, 145 hp (108 kW) at 2,550 rpm
Specific power: 0.39 hp/in³ (17.6 kW/L)
Compression ratio: 5.25:1 (Mk 1 and 1F) or 6.0:1 (others)
Fuel consumption: 6.5 to 6.75 gph (28.4 to 30.7 L/h) at 2,100 rpm
Oil consumption: 1.75 pints (0.99 L) per hour.
Power-to-weight ratio: 0.48 hp/lb (0.78 kW/kg)

The de Havilland Gipsy Twelve was a British V-12, piston aero engine developed by the de Havilland Engine Company and first run in 1937. Approximately 95 were manufactured. It was known as the Gipsy King in Royal Air Force service.

Applications:
de Havilland DH.91 Albatross
de Havilland DH.93 Don

Specifications:

Gipsy King I
Type: Inverted 60 degree V-12 inline piston engine
Bore: 4.646 in (118 mm)
Stroke: 5.512 in (140 mm)
Displacement: 1121.3 cu in (18.3 L)
Length: 82.6 in (2,098 mm)
Width: 31.5 in (800 mm)
Height: 37.4 in (950 mm)
Dry weight: 1,058 lb (480 kg)
Valvetrain: Overhead valve
Supercharger: Single speed
Fuel type: 87 Octane petrol
Cooling system: Air cooled
Reduction gear: Spur geared, reduction ratio 0.667:1
Power output: 425 hp at 2,450 rpm at 0 psi boost (five minutes maximum)
Compression ratio: 6:1
Power-to-weight ratio: 0.4 hp/lb

Designed by Geoffrey de Havilland the air-cooled V-8 ‘Ghost’ was developed from the ADC Cirrus aero engine by using two banks of four cylinders and first run in 1928. This appeared at first to be a retrograde step as the Cirrus was itself developed from the Renault 80 hp V8 engine however with the improved Cirrus cylinders the Ghost developed over twice the power of the French engine for a lower weight. Another difference from the Renault was the use of a propeller reduction gear, the Ghost’s sole known aircraft application was the prototype de Havilland Hawk Moth high-wing cabin monoplane.

Specifications:
Type: Inline air-cooled, upright, 90-degree, V-8 piston engine
Bore: 4.5 in (114 mm)
Stroke: 5.0 in (128 mm)
Displacement: 498.56 cu in (8.17 L)
Designer: Geoffrey de Havilland
Valvetrain: One inlet and one exhaust valve per cylinder
Fuel system: Carburettor
Fuel type: 74 octane petrol
Cooling system: Air-cooled
Reduction gear: Spur geared, right hand tractor
Power output: 198 hp (148 kW)
Compression ratio: 5:1

By 1927 the Moth threatened to become a victim of its own success as continuing demand was depleting the stockpiles of surplus Renaults needed to build its Cirrus engine. The Moth having provided a solid financial cushion, de Havilland Aircraft decided to start its own engine factory. Geoffrey de Havilland went to Frank Halford and this time asked him to design a completely new aircraft engine of weight and performance comparable to the latest version of the Cirrus, the 105 hp (78 kW) Cirrus Hermes.

Halford and de Havilland agreed on a 135 hp (101 kW) test engine later to be de-rated to 100 hp (75 kW) for production models. While Halford went to build the engine, de Havilland designed its test-bed: the D.H.71 racer. Two D.H.71s were built and although in a bout of over-confidence named Tiger Moth, their racing career was rather uneventful. Their only notable claim to fame came in capturing a world speed record of 186 mph (299 km/h) for their weight class. What the D.H.71 did not accomplish in racing successes, it did accomplish in developing the new engine and by the time the career of the D.H.71 was over, the 100 hp (75 kW) production version of its engine, now named the Gipsy, was ready to start its career.

The upright four-cylinder Gipsy I was an air-cooled in-line engine weighing 300lb and developed 98hp at 2100rpm. With a cylinder bore of 4.5in and stroke of 5in, displacement was 319cu.in (5.231t).

It was soon developed further into the 120 hp (89 kW) Gipsy II with its stroke increased to 5.5in. Both types were to be used in the D.H.60G Gipsy Moth. The new engine proved itself to be docile, easy to maintain and, as demonstrated in many long distance flights by the new Gipsy Moth, reliable.

The new engine still had its cylinders built on top of the crankshaft and therefore were sticking out of the top of the fuselage, right in the pilot’s field of vision. Lowering the engine was impossible as the crankshaft was directly connected to the propeller and the propeller could not be placed too low. The solution came as several pilots boasted that they would be able to fly their Moth upside down for as long as they wanted if it were not for the carburettor and fuel tank now being inverted. Halford decided to test this by mounting a Gipsy engine upside down and then inverting its carburettor so it was now right side up again. The design proved to run just as flawlessly as the regular Gipsy engine and soon the Gipsy I and II were replaced on the production lines by the Gipsy III inverted four-cylinder engine. The Moth with this new engine became the D.H.60 G-III; as the Gipsy III was quickly developed further into the Gipsy Major, the D.H.60 G-III was baptised the Moth Major.

Building on the success of the D.H.60, de Havilland now started building other sports aircraft and trainers, all of which were powered by its own Gipsy engines. The company now produced Gipsy engines for other manufacturers as well and the Gipsy Major in particular became the engine of choice for scores of light aircraft designs, British as well as foreign. Most notably it was the engine of the D.H.82A Tiger Moth trainer.

Variants:

Gipsy I
Original production version. 1,445 built.

Gipsy II
Stroke increased to 5.5 in (140 mm). Power 120 hp (90 kW) at 2,300 rpm. 309 built

Gipsy III
As Gipsy II, inverted. 611 built.

Gipsy IV
A smaller inverted four-cylinder in-line engine, derived from the Gipsy III, intended for light sporting aircraft. Forerunner of Gipsy Minor. Power 82 hp (61 kW).

Gipsy R
Racing engine for de Havilland DH.71 Tiger Moth. 135 hp (100 kW) at 2,850 rpm.

Wright-Gipsy L-320
Licence production in the USA of the Gipsy I

Applications:

Gipsy I
Avro Avian
Bartel BM-4
Blackburn Bluebird IV
Breda Ba.15
de Havilland DH.60G Gipsy Moth
de Havilland DH.60T Gipsy Moth Trainer
de Havilland D.H.71 Tiger Moth racer
PZL.5
Simmonds Spartan
Southern Martlet
Spartan Arrow
Westland Widgeon

Gipsy II
Airspeed Ferry
Avro Avian
Blackburn Bluebird IV
de Havilland DH.60G Gipsy Moth
de Havilland DH.60T Gipsy Moth Trainer
PZL.5
RWD-4
Saro Cutty Sark
Saro Windhover
Short Mussel
Simmonds Spartan
Southern Martlet
Spartan Arrow
Spartan Three Seater

Gipsy III
Airspeed Ferry
Arrow Active
Avro Avian
Bartel BM-4
Blackburn Bluebird IV
Blackburn B-2
Blackburn-Saro Meteor
Breda 33
Cierva C.24
Comper Swift
Darmstadt D-22
de Havilland Fox Moth
de Havilland DH.60G Gipsy Moth
de Havilland Hornet Moth
de Havilland DH.60GIII Moth Major
de Havilland Leopard Moth
de Havilland Puss Moth
de Havilland DH.82A Tiger Moth I
de Havilland T.K.1
Desoutter Mk.II
Heinkel He 64C
Klemm Kl 26
Klemm Kl 27
Klemm Kl 32
Miles Hawk
Miles Hawk Major
Pander P-3
PZL.19
Saro Cutty Sark
Saro-Percival Mailplane
Spartan Cruiser
Westland-Hill Pterodactyl

Gipsy IV
de Havilland Swallow Moth

Gipsy R
de Havilland DH.71 Tiger Moth racer

Specifications:

Gipsy I
Type: 4-cylinder air-cooled inline piston aircraft engine
Bore: 4.5 in (114.3 mm)
Stroke: 5 in (127 mm)
Displacement: 318.1 cu in (5.21 L)
Length: 40.5 in (1028.5 mm)
Width: 20 in (508 mm)
Height: 29.9 in (759.5 mm)
Dry weight: 285 lb (129.3 kg)
Valvetrain: Overhead valve
Fuel system: Zenith carburettor with altitude control
Fuel type: Petrol (Aviation grade fuel not required)
Cooling system: Air-cooled
Power output: 85 hp at 1,900 rpm (sea level): 98hp / 73kW at 2100rpm
Compression ratio: 5:1
Power-to-weight ratio: 0.3 hp/lb

Gipsy II
Power output: 120 hp (89 kW)
Stroke: 5.5in

In 1925 Geoffrey de Havilland was looking for a reliable cheap engine for use in a light sports aircraft. Halford gave it to him by building a four-cylinder crankcase and adding to it half of the air-cooled V8 240 hp (180 kW) Renault 8G’s cylinders, several other of the Renault’s components, and standard parts used in car engines.

The result was a 60 hp (45 kW) in-line aircraft engine that, although it fell short of the promised horse-power, was still superior to all contemporary engines for light aircraft. It was a true aircraft engine at a time where its competitors were more often than not motorcycle engines adapted to running at high altitude. The engine secured, de Havilland Aircraft commenced manufacture of the D.H.60 Moth and the combination of reliable powerplant – the ADC Cirrus – and reliable training craft – the Moth – marked the start of serious sports flying in Britain.

American Cirrus
Type: 4 cylinder in line, vertical air cooled
Rating 5.1 compression: 90 hp at 1900 rpm
Rating 5.1 compression: 95 hp at 2100 rpm
Rating 5.4 compression: 93 hp at 1900 rpm
Rating 5.4 compression: 98 hp at 2100 rpm
Displacement: 310 cu.in
Compression ratio: 5.1-1 to 5.4-1
Bore: 4 3/8 in
Stroke: 5 1/8 in
Length: 38 1/2 in
Height: 36 3/8 in
Width: 18 3/4 in
Weight: 275 lb
Fuel consumption: not more than .54 lb/hp/hr
Oil consumption: not more than .0213 lb/hp/hr
Lubrication: Force feed, wet sump
Ignition: 2 Scintilla magnetos
Carburation: Stromberg
Spark plugs: 2 pr cylinder B.G. and AC
Price: $1600