The need of a replacement for the D.H.10s used on the RAF’s air-mail service between Cairo and Baghdad, coupled with an agreement reached in 1925 for Imperial Airways to take over the service, led to a requirement being issued which was met by the de Havilland D.H.66 Hercules. A three-engined biplane with a 4.39cu.m baggage compartment, space for seven passengers and 13.17cu.m of mail and a three-man crew.
The prototype flew on 30 September 1926 following an order for five aircraft from Imperial Airways. The prototype carried out acceptance flights, took part in some crew training and was delivered to Cairo by mid-December. An inaugural flight between Croydon and India left the UK on 27 December and arrived in Delhi on 8 January 1927.
West Australian Airways DH.66 in UK
The fifth aircraft was delivered to Cairo in March 1927. The performance of these aircraft impressed West Australia Airways, then using D.H.50s. Four examples of the Hercules were ordered, the first flying in March 1929, and the type entered service with WAA on the Perth-Adelaide route on 2 June. By then Imperial had ordered a sixth aircraft and its seventh and final aircraft followed in February 1930.
Passengers board West Australian Airways DH.66 Hercules G-AUJQ at Forrest, Australia
Imperial’s sixth Hercules had an enclosed pilot’s cabin, a modification which later became standard on the remaining aircraft. The airline’s need for these last two Hercules followed the loss of three in crashes between September 1929 and April 1931, but only the first caused fatalities. Aircraft shortage led to the purchase by Imperial of two WAA Hercules in 1930-1. One of these crashed in Southern Rhodesia in November 1935 and Imperial eventually withdrew its last aircraft from service in December 1935, having sold three to the South African Air Force. Their eventual history is not known, but the longest surviving Hercules was probably one of the two former WAA aircraft, being used in New Guinea between Lae and Wau, and destroyed by enemy action in 1942.
Engine: 3 x Bristol Jupiter VI radial piston engines, 313kW, 420 hp Take-off weight: 7076 kg / 15600 lb Empty weight: 4110 kg / 9061 lb Wingspan: 24.23 m / 79 ft 6 in Length: 16.92 m / 55 ft 6 in Height: 5.56 m / 18 ft 3 in Wing area: 143.72 sq.m / 1546.99 sq ft Max. speed: 206 km/h / 128 mph Cruise speed: 177 km/h / 110 mph Ceiling:3960 m / 13000 ft Range: 845 km / 525 miles Pax cap: 7
Designed in the late 1920s and first flying in 1927. A two bay single engined biplane with the pilot seated in an open cockpit behind a fully enclosed eight seat cabin. Powered by a Bristol Jupiter XI, a geared radial engine of 500 hp.
The hoped for boom in private flying after the 1914 18 War did not materialise and the Government realised after a few years that the only way to get people into the air would be by subsidising the flying clubs. Both the Air Ministry and the Daily Mail offered prizes for the best single and two seat lightplanes, but the resulting Light Aeroplane Competitions at Lympne produced machines that were really far too small and light for club and training work. Realising this, de Havilland got down to the task of designing and building a really practical little two seater. They determined that it would have to sell for not more than £600, be simple and safe enough for anyone to fly, and have folding wings so that it could be towed behind a car and kept in a reasonable sized garage. As no suitable engine was available, de Havilland got an engine designer friend of his, Frank Halford, to cut a Renault V 8 engine in half, making an in line four out of it. Halford had such a four cylinder engine running in just nine weeks the Cirrus. The only entirely new major component was the crankcase. The cylinders and head were identical to those on the old V 8s, as was the five bearing crank, which now had to carry but half the former loads. The result of these combined endeavours was the prototype DH 60 Moth, G EBKT, with 44.7kW / 60 hp Cirrus engine, which de Havilland flew for the first time on February 22, 1925, from the company’s Stag Lane aerodrome.
The Moth’s construction was robust but definitely simple. The Moth was all carpentry: wood spars and ribs and interplane struts; wooden longerons for the fuselage, ply covered to make it as strong as a box. To fold the wings, you pulled forward the pins that locked them to the center section, inserted a wooden jury strut to prevent the top wing from sagging, then folded them back on hinges at the rear spar and clipped them to the body it took just two minutes. The Cirrus sat high up on a forward extension of the top wooden longerons, with its four cylinders and valve gear exposed to the slipstream. The engine was fed by gravity through a copper pipe from an airfoil shaped 24 gallon tank fitted in the center section of the top wing. A long exhaust pipe ran back past the two open cockpits, and this plus the engine’s slow rotation speed made the Moth extraordinarily quiet. You spoke to the other occupant through a gosport tube. There were no brakes, but the swiveling tail skid was connected to the rudder, so you could steer easily across the meadow. The lit¬tle Moth spanned 30 feet, weighed just 770 pounds empty (1,350 loaded), could better 90 mph and cruise at 80, climbed at 430 fpm, touched down at 40 and enjoyed a very light wing loading. The Moths were powered by engines ranging from the 60 hp A.D.C. Cirrus I to the 105 hp Cirrus Hermes.
DH60 Genet engine
de Havilland invited the London press for demonstration rides a few days after the first flight; he entered (and himself flew) Moths in all the air races, including the King’s Cup; with his wife as passenger, he set an altitude record in a later Gipsy Moth at almost 20,000 feet.
His first sales breakthrough came from the British Government which ordered Moths for five flying clubs (the first flying clubs in the world) then being set up with state subsidies. The Moths cost £2 15s. an hour to operate; with the subsidy, the clubs needed only to charge 30s. an hour dual and £ 1 solo. Twenty pounds would get you a private pilot’s license. By contrast, a new Moth cost £885 to buy in 1925.
de Havilland steadily developed the airplane, adding automatic leading edge slats to the top wing and restructuring the fuselage in steel tube. He improved its Cirrus engine, and then, when the stock of war surplus motors from which the Cirrus was concocted ran short, got Halford to design a new but similar engine, the 100 hp Gipsy. It was fitted in the D.H.60G Gipsy Moth, which was used by many of the record breaking pilots of the thirties, including Amy Johnson, as well as for club and private flying.
de Havilland DH60 Cirrus Moth G-EBLV & de Havilland DH60X Moth G-EBWD
The first Moth was flown by Alan Cobham from London to Zurich and back in a single day on 29 May 1925; and in 1927 Moths accomplished the London-Cape Town return flight and won the first prize for aerobatics at the Copenhagen International aeroplane meeting.
Amy Johnsons DH.60 G-AAAH c/n804 was built in 1928 at Stag Lane as the fourth production Gipsy Moth. It was registered on 30 August 1928 to Air Taxis Ltd. Within two weeks it was flown to Kenya. Following two years of use by Air Taxis it was sold to Amy Johnson on 30 April 1930 for her attempt on the England to Australia solo record. Leaving Croydon on 5 May 1930 she arrived at Darwin 19½ days later. Subsequently damaged at Brisbane G-AAAH, named Jason, was shipped back to the UK, purchased by the Daily Mail and finally presented to the Science Museum in October 1930.
DH.60 G-AAAH
As production of the early models tapered off, the improved DH-60M Gipsy Moth was introduced in 1928. The Gipsy featured a welded steel-tube fuselage, folding wings, and engine options up to 120 hp. Three years later the engine underwent a major modification. In order to lower overall height and improve forward visibility but to raise the propeller shaft height, the engine was inverted as the Gipsy III.
This new DH60 became the DH60G-III Moth Major but still with wooden fuselage.
As a result of interest being shown in de Havilland’s D,H.60M “Metal Moth” as a cheap introduction to combative military operations, de Havilland built in November 1930 what they described as a “D.H.T. (Training) Moth”. Essentially a D.H.60M with a de Havilland Gipsy II engine with an inverted fuel system, aircraft No 1672 was complete by December 5.
Following review, the company decided that it could be further improved; anchorage of the front and rear lift wires was repositioned, allowing unhindered access onto the walkway and the root-ends of the upper mainplanes were cut away to improve the upward view.
Designated as a D.H.60T Moth Trainer and registered G-ABKU on April 1, 1931, it was despatched to the Aeroplane & Armament Experimental Establishment (A&AEE) at Martlesham Heath under de Havilland’s test marks E.3, but was dismantled in July and “reduced to redundant stock”.
Moths were also built at Lowell, Massachusetts, fitted with Wright built Gipsy engines and sold by the Curtiss Flying Service Organization. The Moth Aircraft Corporation became a division of Curtiss Wright, and production was moved to Robertson, Missouri. Nearly 200 Moths were built in the U.S. be¬fore the deepening Depression killed the venture in 1931. To assist hangerage, the wings folded to reduce the width to 9 ft 8 in. The DH60G was also built under licence by Marane Saulnier of France. The DH60G III Moth Major, similar to the Gipsy Moth but with the engine inverted. A “one off” specimen DH60M was built in the United Kingdom in 1929 for the 1930 Round Europe Touring Competition as G-AAXG (later ZK-AEJ), the metal fuselage Moth was fitted with a 120 hp Gipsy II engine. The fuselage was basically a “rounded off 60”. The elevator and rudder were same as the later Tiger, however the wings provided a slightly different profile. The differences with the rest of the DH.60 clan come with the engine installation, a standard Gipsy II of 120 hp, two inches lower than the standard, and a slimmer than usual wing tank. A 15 gallon tank was made to fit into a faired over front cockpit.
de Havilland DH60M ZK-AEJ 23 of July 1946
The DH60T was a strengthened DH60M with a welded steel fuselage for export and military use and powered by 120hp. Capable of carrying 4 20 lb practice bombs under the fuselage. Compared to the civil DH60, to assist escape from the front cockpit, the rear flying wires were angled forward to the front wing root fitting The cockpit doors were also deepened. But the centre section struts still enveloped the front cockpit so to meet specification 15/31 for a new trainer these were moved forward: this markedly improving egress with a parachute. To reduce the effects of centre of gravity and centre of pressure changes caused by the now forward staggered upper mainplanes, the wings were swept back 19 inches, measured at the tips. A 120-bhp Gipsy III inline motor was installed with the sloping line of the upper engine cowl enhancing the visibility for the instructor in the front cockpit. Eight DH60Ts were built but now called the “Tiger Moth”. Then it was decided that the dihedral of the lower wings needed to be increased to reduce damage during training. This aircraft was redesignated and became the DH82.
DH60X
Altogether some 2058 versions of the DH-60 Moth series were built, from Cirrus Moth to Moth Trainer, in England during the seven years of production, with an additional 150 built by Moth Aircraft Co. of Lowell, Massachusetts, from Cirrus Moth Trainer. And some 685 were of the “G” variant, 595 of these being built at Stag Lane, and the rest overseas. Amy Johnson flew from England to Australia in one, the then Prince of Wales bought one, at the peak of it popularity about three new aircraft were produced each working day at Stag Lane.
The Moth was selected by all the British Flying Clubs formed under the Air Ministry scheme. In addition to the home markets, many civil examples were exported and military models delivered to air forces as tandem two-seat trainers, including those of the UK, Australia, Irish Free State, Sweden, Finland, Japan and Canada. Moths had been licence-built in Australia, Finland and elsewhere. Other engines fitted included the 63.3kW Cirrus II, 67kW Cirrus III (as installed in the D.H.60X) and 56kW Armstrong Siddeley Genet (as the Genet Moth).
The RAF ordered 134 Moths. By 1939 most of these original aircraft had been retired but with the outbreak of war the RAF impressed at least 146 civilian owned Moths. They were used for a wide range of miscellaneous communication activities.
During 1929-36 and 1939-43, fourteen DH60Gs were used by the New Zealand Air Force for training and utility work. One, ZK-ADT Huia, was owned by National Airways Corp during April-September 1947.
Australian National Airways DH 60G Gipsy Moth pre-WW2
The three Australian National Airways DH 60G Gipsy Moth were impressed into RAAF service in 1940. A further 48 civilian Moths were impressed between December 1939 and September 1940 for training. The RAAF operated 122 Moths of various models, 74 by 1936, until the Tiger Moth became available.
DH60 Cirrus Moth Engine: ADC Cirrus 1 four cylinder, 60 hp Prop: 6 ft 4 in (1.93 m) dia 2 blade Wingspan: 30 ft / 9.14 m Length: 23 ft 8 11 in / 7.23 m Height: 8 ft. 9.5 in Wing area: 243 sq.ft / 22.58 sq.m Weight empty: 770 lb Gross weight: 1,240 lb / 562 kg Max speed: 91 mph. Cruising speed: 80 mph / 129 km/h Typical range: 320 miles / 515 km at 80 mph Seats: 2
DH 60 Moth Engine : DH Gipsy I, 99 hp Length : 23.819 ft / 7.26 m Wingspan : 29.035 ft / 8.85 m Wing area : 225.291 sq.ft / 20.93 sq.m Max take off weight : 1351.7 lb / 613.0 kg Max. speed : 79 kts / 146 km/h Wing load : 5.95 lb/sq.ft / 29.0 kg/sq.m Range : 278 nm / 515 km Crew : 2
DH 60 Moth Engine 120 hp de Havilland Gipsy II Length 23ft 11 in Wingspan 30ft Wing area 243sq.ft Gross wt. 1,750 lb Empty wt. 920 lb Maximum level speed 105mph (91kt) Normal cruise speed 85mph (74kt) Initial climb rate 720 fpm Range 320 miles Ceiling 18,000 ft Seats 2
D.H.60G Gipsy Moth Engine:1 x de Havilland Gipsy I inline, 75kW/ 100 hp Take-off weight: 748 kg / 1649 lb Weight: 417 kg / 919 lb Wingspan: 9.14 m / 30 ft Length: 7.29 m / 23 ft 11 in Height: 2.68 m / 8 ft 10 in Wing area: 22.57 sq.m / 242.94 sq ft Max. speed: 164 km/h / 102 mph Cruise speed: 137 km/h / 85 mph Ceiling: 4420 m / 14500 ft Range: 515 km / 320 miles Seats: 2
de Havilland DH60G Gipsy Moth Engine: de Havilland Gipsy I, 85 hp Price 1929: 650 pounds Speed: Maximum level 102 mph Altitude: Maximum ceiling 14,500 ft Range: 320 miles Seating: 2
DH60G-III Gipsy Moth Engine: Gipsy III, 120 hp
DH60M Engine: Gipsy I, 100 hp Max speed: 102 mph Range: 320 miles
Engine: 1 x 385hp Armstrong Siddeley Jaguar III Take-off weight: 1907 kg ./ 4204 lb Empty weight: 1089 kg / 2401 lb Wingspan: 13.11 m / 43 ft 0 in Length: 9.07 m / 29 ft 9 in Height: 3.28 m / 10 ft 9 in Wing area: 39.51 sq.m / 425.28 sq ft Max. speed: 203 km/h / 126 mph Ceiling: 5861 m / 19250 ft Armament: 2 x 7.7mm machine-guns Crew: 2
de Havilland found he could buy 80 horsepower V 8 Renault aero engines for the equivalent of about $6 each. First flying in 1923 at Stag Lane, he built and sold three big Renault powered biplanes, DH 51s, but the design was too large for popularity. DH had got an engine design¬er friend of his, Frank Halford, to improve a couple of these till they were producing 120 hp for the DH 51s.
The design was developed around the 67kW R.A.F.1A engine, of which war surplus supplies were available at knockdown prices. First flown in July 1924 by Geoffrey de Havilland, the D.H.51 (G-EBIM) proved to be satisfactory, but since the engine did not have dual ignition a Certificate of Airworthiness was refused. Ten hours of airborne testing would have been required with the single-ignition RAF1A, but de Havilland decided that the cost of this was not justified.
It was decided to re-engine the D.H.51 with an Airdisco engine by October 1924 and this move, although conferring considerably enhanced performance, took the aircraft well outside the economic operating bracket for which it was designed. Within a short time it had been fitted with new shorter span wings with automatic flaps to become the sole DH51A.
As a result, only three were built; the first being written-off in 1931 and scrapped in 1933 respectively, G-EBIM.
The second was G-EBIQ.
The third, G-EBIR c/n 102, built in 1925 and shipped to Kenya in early 1926, became the first aircraft on that country’s civil register. It was registered G-KAA in September 1928 and VP-KAA in January 1929. Dismantled during the war, and airfreighted to the UK in 1965, it survived to fly again and now, after several rebuilds, is again back in the UK, maintained by the Shuttleworth Trust at Old Warden as the oldest airworthy design of the de Havilland Aircraft Company.
D.H.51 Engine: 1 x Airdisco inline piston, 89kW Take-off weight: 1016 kg / 2240 lb Empty weight: 609 kg / 1343 lb Wingspan: 11.28 m / 37 ft 0 in Length: 8.08 m / 26 ft 6 in Height: 2.97 m / 9 ft 9 in Wing area: 30.19 sq.m / 324.96 sq ft Max. speed: 174 km/h / 108 mph Ceiling: 4570 m / 15000 ft
In 1922 de Havilland used the experience gained in its operation to design a replacement for war-surplus D.H9s, the de Havilland D.H.50. The D.H.9C’s Siddeley Puma engine was retained and they carried four passengers in an enclosed cabin between the wings, with the pilot to the rear in an open cockpit, first flown on 30 July 1923. It was flown by Alan Cobham to compete and win first prize in reliability trials which were being flown daily between Copenhagen and Gothenburg from 7-12 August. In 1924 Alan Cobham entered the King’s Cup with the prototype D.H.50, G-EBFN, with which he won at an average of 106.6 mph.
Between 10 November 1924 and 17 March 1925, a survey flight to India and Rangoon, Burma, was made in a DH50. In the aircraft were Sir W. Sefton Brancker (then director of civil aviation), Alan Cobham, and representatives of Imperial Airways. As a result, landing grounds and routes were established to Ramadi, Iraq. Cobham made several long-distance flights with the prototype before using the second aircraft, powered by a 287kW Armstrong Siddeley Jaguar radial engine and re-designated D.H.50J, for a 25,749km flight from Croydon to Cape Town, carried out between 16 November 1925 and 17 February 1926. This was followed later in 1926 by a survey flight to Australia and back, for which twin floats were fitted. The second DH.50, G-EBFO, was fitted as a floatplane.
D.H. 50J
Initially 14 DH50As were built; 9 for an Australian order. One, sold to QANTAS in 1924, later became the first aeroplane to be used for the Australian Flying Doctor Service. QANTAS began building DH50s at Longreach in the late 1920s, and the first was completed in August 1927. Four DH50As and three DH50Js were completed. In 1925 26 one of these aircraft, refitted with a 385 hp Jaguar radial engine, was used by Sir Alan Cobham for his famous survey flights to Cape Town and Australia behalf of Imperial Airways.
West Australian Airways Ltd was formed at Perth in 1921 to operate Geraldton-Derby airline and licensed to build the de Havilland D.H.50 in Australia. They produced their first aircraft in 1926. Larkin Aircraft Supply Company built a single D.H.50A. Seven were built by Aero in Prague, Czechoslovakia, and three D.H.50As at Brussels by SABCA in Belgium. The SABCA aircraft were used in the Belgian Congo. Of the total de Havilland production (17 aircraft), only four were based in the UK, two of them with Imperial Airways. One went to the Czech.government, 10 to Australia and one to New Zealand. The one in RNZAF service was from 1927 to 1931.
The longest survivor was the 15th British production aircraft, delivered in 1928 to the Australian Controller of Civil Aviation and destroyed by enemy action in New Guinea during 1942. A wide variety of engines was used in the D.H.50 family; including the 224kW A.D.C. Nimbus, 313kW Bristol Jupiter IV, 336kW Jupiter VI, 384kW Jupiter XI, 336kW Pratt & Whitney Wasp C and, in the Czech-built versions, the 179kW Walter W-4.
DH.50 Engine: 1 x Siddeley Puma inline piston, 172kW / Prop: 2-blade Take-off weight: 1769 kg / 3900 lb Empty weight: 1022 kg / 2253 lb Wingspan: 13.03 m / 42 ft 9 in Length: 9.07 m / 29 ft 9 in Height: 3.35 m / 10 ft 12 in Wing area: 40.32 sq.m / 434.00 sq ft Max. speed: 180 km/h / 112 mph Cruise speed: 153 km/h / 95 mph Ceiling: 4450 m / 14600 ft Range: 612 km / 380 miles Crew: 1 Pax cap: 4
DH50A Engine: Siddeley Puma, 230 hp Max speed: 109 mph ROC: 605 fpm Range 375 miles
D.H.42 Engine: 1 x 420hp Armstrong Siddeley Jaguar IV Take-off weight: 1769 kg / 3900 lb Empty weight: 1141 kg / 2515 lb Wingspan: 12.50 m / 41 ft 0 in Length: 12.04 m / 39 ft 6 in Height: 8.61 m / 28 ft 3 in Wing area: 36.14 sq.m / 389.01 sq ft Max. speed: 201 km/h / 125 mph Ceiling: 4877 m / 16000 ft
De Havilland’s first venture into the field of private-owner aircraft was the de Havilland D.H.37, a two-seat biplane built to the specification of Alan Butler, a DH director. The first of two aircraft flew in June 1922 and the second in 1924, the second being sold to Australia. Butler’s aircraft was used extensively over the next five years, and in 1927 its Rolls-Royce Falcon III engine was exchanged for a 224kW A.D.C. Nimbus, the aircraft being converted to single-seat configuration for racing as the D.H.37A. However, in June that year it crashed while flying as a two-seater, killing the passenger and injuring the pilot. The Australian D.H.37 had a longer life, being used initially by the Controller of Civil Aviation and later by the Guinea Gold Company in New Guinea, being the first aeroplane in that country. It crashed in New South Wales in March 1932.
de Havilland D.H.37 G-AUAA (c/n 105)
D.H.37 Engine: 1 x Rolls-Royce Falcon III inline piston engine, 205kW Take-off weight: 1505 kg / 3318 lb Empty weight: 961 kg / 2119 lb Wingspan: 11.28 m / 37 ft 0 in Length: 8.53 m / 27 ft 12 in Wing area: 36.97 sq.m / 397.94 sq ft Max. speed: 196 km/h / 122 mph Ceiling: 6400 m / 21000 ft
All Aero 