20 September 1943: Geoffrey Raoul de Havilland, Jr., chief test pilot of the de Havilland Aircraft Co., Ltd., made the first flight in the prototype DH.100, LZ548/G, at Hatfield, Hertfordshire. (The “/G” in the identification indicated that the aircraft was to be guarded at all times.) Assigned the code name Spider Crab, the production DH.100 would be better known as the de Havilland Vampire.
The flight lasted approximately 30 minutes and the airplane exceeded 400 miles per hour (644 kilometers per hour). De Havilland reported that the prototype was trimmed with the left wing down, had overly sensitive ailerons and demonstrated instability in yaw with rudder applications.
This oscillation in the yaw axis—called “snaking”—was determined to be a result of the overly effective vertical fins. After wind tunnel and flight testing, it was decided to reduce the fins’ area, resulting in the flat top configuration seen in bottom photograph.
The DH.100 was a single-seat, single-engine fighter powered by a turbojet engine. The twin tail boom configuration of the airplane was intended to allow a short exhaust tract for the engine, reducing power loss in the early jet engines available at the time.
LZ548/G was originally powered by a Halford H.1 turbojet which produced 2,300 pounds of thrust (10.231 kilonewtons) at 9,300 r.p.m. This engine was produced by de Havilland and named Goblin.
The Goblin is a linear descendant of the early Whittle units. It comprises a single-sided centrifugal compressor delivering air to sixteen combustion chambers grouped symmetrically around the axis of the unit and leading to the nozzle of the single-stage axial turbine which drives the compressor. Compressor impeller and turbine rotor are coupled by a tubular shaft to form a single rotating assembly which is mounted on only two ball bearings. The maximum diameters of the engine, around the compressor casing, is 50in., [1.27 meters] and with a jet pipe of minimum length fitted the overall length is about 8ft. [2.438 meters] Equipped with a jet pipe and all the necessary engine auxiliaries the dry weight of the complete unit is 1,500 lb. [680 kilograms] Fuel consumption is at the rate of 1.23 lb. / hr. per lb. thrust.
—FLIGHT and AIRCRAFT ENGINEER, No. 1923. Vol. XLVIII. Thursday, 1 November 1945 at Page 472, Column 2
The Vampire entered service with the Royal Air Force in 1945 and remained a front-line fighter until 1953. 3,268 DH.100s were built.
The first of the three prototype Vampires, LZ548, crashed after takeoff from Hatfield, 23 July 1945, due to a fuel pump failure. Geoffrey Pike, the pilot, was not injured.
6 September 1952: At the Farnborough Air Show, an annual event held at the Royal Aircraft Establishment Farnborough, Hampshire, England, de Havilland test pilot John Douglas Derry, DFC, with flight test observer Anthony Max (“Tony”) Richards, put the prototype DH.110, WG236, into a supersonic dive from 40,000 feet (12,182 meters), pulling out just short of the airfield and the estimated 120,000 spectators.
Derry then made a high-speed, low-level circuit of the airfield, and as he straightened out, the airplane broke apart and crashed onto Observation Hill.
Both Derry and Richards were killed, as were 29 spectators. Another 63 were injured.
This melancholy affair has, inevitably, received wide publicity, and several inaccurate reports have been printed. A member of the staff of Flight who witnessed the accident describes it as follows: “Two small white puffs of cloud appeared in a clear patch of sky north of the airfield, presumably showing where the D.H.110 had exceeded Mach 1 in its dive. After about a minute there were two loud reports in split-second succession. The lower part of the dive must have been near-sonic, for the aircraft appeared overhead—at about 1,000–1,500ft—at almost the same instant; the supersonic ‘bangs’ had scarcely overtaken the 110, although they had evidently been produced at least 12 miles away. The aircraft flew out of sight to turn and line-up for a low flight above the main runway, which it made from the south-west at a speed estimated as 600–650 m.p.h. It then turned left into the circuit and flew back over the northern boundary at about 400ft. The break-up appeared to begin just before a steep 90-degree turn towards the enclosures. Small fragments came away from the 110, which gained height as the two Avons and the nose became detached from the airframe. One engine fell on a crowded slope behind the caravan parks, causing most of the casualties; the other landed harmlessly farther south. The nose, following the same path as the power-units, hit the grass just in front of the packed enclosure parallel with the runway and broke up. A number of small pieces landed on the runway itself while the airframe, minus tail-unit, nose and engines, dropped comparatively gently into the north-west corner of the airfield.”
—FLIGHT and AIRCRAFT ENGINEER, No. 2277, Vol. LXII. Friday, 12 September 1952, at Page 344, Column 1
Film taken from the ground showed that as the airplane came level, the starboard outboard wing separated, followed by the port outboard wing. The aircraft pitched violently upward with an acceleration of more than 12 Gs, and the cockpit, engines and tail then disintegrated.
The DH-110’s swept wings placed the ailerons well aft of the airplane’s center of gravity. When the pilot began his bank to the right, away from the crowd, he also began to climb. This caused the wing outer panels to twist, placing unexpected stresses. The right wing failed in torsion. The resulting roll then caused the left wing to fail.
The flight crew was not faulted.
Changes were made in the location of the spectators and maneuvering aircraft at the airshow from that time forward.
The de havilland DH.110 was a prototype all-weather interceptor intended for operation by the Fleet Air Arm from the Royal Navy’s aircraft carriers. It was a two-place, twin-engine swept-wing fighter capable of supersonic speed. WG236 was the first prototype, which made its first flight the previous year, 26 September 1951. At the time of the accident WG236 had flown approximately 125 hours. The second prototype, WG240, had been scheduled to fly the demonstration for the air show, but had to be replaced for maintenance reasons.
The DH.110 used the twin-tailboom configuration of de Havilland’s DH.100 Vampire and DH.112 Venom fighters, but the wings were swept to 45°.
WG236 was 51 feet, 8 inches (15.748 meters) long with a wingspan of 51 feet, 0 inches (15.545 meters) and height of approximately 11 feet (3.35 meters). Its maximum takeoff weight was 35,000 pounds (15,876 kilograms).
WG236 was powered by two Rolls-Royce Avon RA.3 engines The RA.3 was a single-spool axial-flow turbojet with a 12-stage compressor section and single-stage turbine. It was rated at 6,500-pounds-thrust (28.91 kilonewtons). The second prototype used the more powerful RA.7.
The DH.110 had a maximum speed of 610 knots (0.924 Mach) at Sea Level, and 536 knots (0.936 Mach) at 40,000 feet (12,182 meters).
Planned armament for the production fighter was four 30 millimeter ADEN cannon.
Both airmen were posthumously awarded the Queen’s Commendation for Valuable Service in the Air.
CENTRAL CHANCERY OF THE ORDERS OF KNIGHTHOOD
St. James’s Palace. S.W. 1
12th September, 1952
The QUEEN has been graciously pleased to give orders for the publication of the names of the persons shown below as having received an expression of Commendation for valuable service in the air:—
QUEEN’S COMMENDATIONS FOR VALUABLE SERVICE IN THE AIR.
John Douglas Derry, D.F.C. (deceased), Test Pilot, de Havilland Aircraft Company, Ltd.
Anthony Max Richards (deceased), Flight Test Observer, de Havilland Aircraft Company, Ltd.
For services when testing an experimental aircraft.
John Douglas Derry was born 5 December 1921 at Cairo, Egypt. He was one of four children of Douglas Erith Derry, M.C., M.B., Ch.B., Professor of Anatomy at the Government Medical School there, and — Ramsay Derry.
Derry was educated at the Dragon School, a preparatory school for boys in Oxford, England, and at Charterhouse, in Surrey. In 1939, he enlisted in the Royal Air Force as an aerial gunner and radio operator. He was assigned as a crewman on Lockheed Hudson bombers with Coastal Command, before being sent to Canada for pilot training in 1943. On his return to England he was “seconded” to the Air Transport Auxiliary.
Derry returned to combat operations in October 1944, flying Hawker Typhoons on close air support missions with No. 182 Squadron. Shortly after, he was transferred to No. 181 Squadron as a flight commander. In March 1945, Derry returned to No. 182 as the squadron’s commanding officer.
On 29 June 1945, Acting Squadron Leader Derry was awarded the Distinguished Flying Cross. His citation, published in The London Gazette, reads:
This officer has participated in a large number of sorties as air gunner and later pilot. He has at all times displayed great determination and skill and his courage has been of the highest order. In April 1945, he led his squadron in an attack against enemy gun positions. Despite intense opposition the attack was pressed home with great accuracy. The success of this operation was due in no small measure to Squadron Leader Derry’s gallant and skillful leadership. This officer has set a fine example to all.
—Fourth Supplement to The London Gazette of Tuesday, the 26th of JUNE, 1945, Numb. 37154, at Page 3405, Column 1.
Her Majesty, Wilhelmina, The Queen of The Netherlands, awarded Acting Squadron Leader Derry the Bronzen Leeuw (Bronze Lion).
After No. 182 Squadron was disbanded 30 September 1945, Squadron Leader Derry was appointed commanding officer of the Day Fighter Leader School at the Central Flying School, flying the Hawker Tempest.
After being released from service, Derry became an experimental and production test pilot for Vickers Supermarine. In October 1947, he moved to de Havilland.
On 12 April 1948, he flew a de Havilland DH.108 set a Fédération Aéronautique Internationale (FAI) World Record for Speed over a Closed Circuit of 100 Kilometers without Payload, averaging 974.026 kilometers per hour (605.232 miles per hour).¹ The Royal Automobile Society awarded Derry The Seagrave Trophy, “for the most outstanding demonstration of transportation by land, air or water: The Spirit of Adventure.”
On 6 September 1948, Derry exceeded the speed of sound in the de Havilland DH.108. He was awarded the Gold Medal of the Royal Aeronautical Club.
More than one member of Flight‘s staff was proud to know John Derry—a fine-looking young man and an inspiring personality—and on occasions to talk of flying and testing with him. We recall his cheerful unassuming manner, his completely straightforward and natural approach to any topic, and his firm opinion upon matters which he himself had studied and investigated. He was undoubtedly one of what we now call the new generation of test pilots, men who must be able to back their flying experience and skill as pilots with a full technical understanding.
—FLIGHT and AIRCRAFT ENGINEER, No. 2277, Vol. LXII. Friday, 12 September 1952, at Page 344, Column 2
5 July 1927: Less than one year after learning to fly an airplane, Lady Bailey, with Mrs. Geoffrey de Havilland (the former Miss Louise Thomas) as a passenger, took off from the de Havilland airfield at Stag Lane, Edgeware, London, England, and climbed to an altitude of 5,268 meters (17,283 feet) setting a Fédération Aéronautique Internationale (FAI) World Record for multi-place light aircraft.¹ (Mrs. de Havilland is listed as “crew” in the FAI record.)
Lady Bailey was flying Captain Geoffrey de Havilland’s personal airplane, a DH.60X Moth, construction number 276, registration G-EBQH.
Lady Bailey was born Mary Westenra, daughter of the 5th Baron Rossmore. She married Sir Abe Bailey at the age of 20. Soon after becoming a licensed pilot in early 1927 (Royal Aero Club Aviator’s Certificate 8067), she flew across the Irish Sea, the first woman to do so. After her World Record altitude flight, she set several long distance solo flight records, including an 8,000-mile (12,875 kilometers)flight from Croydon, South London to Cape Town, South Africa with a DH.60 Cirrus II Moth, G-EBSF, and an 10,000-mile (16,093 kilometers) return flight made with another DH.60 (after G-EBSF was damaged). These were the longest solo flight and the longest flight by a woman to that time.
Lady Bailey was twice awarded the Harmon Trophy (1927, 1928). In 1930, she was invested Dame Commander of the Order of the British Empire. During World War II, The Hon. Dame Mary Bailey, DBE, served with the Women’s Auxiliary Air Force with the rank Section Officer, equivalent to a Royal Air Force sergeant.
Lady Mary died 29 July 1960 at the age of 70.
G-EBQH was a prototype for the de Havilland DH.60 Cirrus II Moth, and was powered by an air-cooled, normally-aspirated 304.66-cubic-inch-displacement (4.993 liter) A.D.C. Cirrus Mark II four-cylinder vertical inline engine. This was a right-hand tractor, direct-drive, overhead-valve engine with two valves per cylinder and a compression ratio of 4.9:1. It had a normal power rating of 75 horsepower at 1,800 r.p.m. and a maximum power rating of 80 horsepower at 2,000 r.p.m. It drove a two-bladed, fixed-pitch propeller. The Cirrus Mk.II was 3 feet, 9.3 inches (1.151 meters) long, 1 foot, 7 inches wide (0.483 meters) and 2 feet, 11.6 inches (0.904 meters) high. It weighed 280 pounds (127 kilograms).
G-EBQH was used as a factory demonstrator and test aircraft. The DH.60X crashed in February 1928 but was rebuilt and later sold. It was flown in the King’s Cup Air Races of 1927, 1928 and 1929 by Alan S. Butler, the chairman of de Havilland. The prototype was modified to a single-place configuration with a Cirrus Mark III engine, and was known as the Moth Special. In the 1929 race, it set the fastest time for a light aircraft.
Records indicate that G-EBQH changed ownership a number of times. Its Certificate of Airworthiness expired in 1937 and its status is not known.
24 May 1930: After a 19-day, 11,000 mile (17,700 kilometer), solo flight from Croyden Aerodrome, London, England, 26-year-old Amy Johnson arrived at Darwin, Australia, in her de Havilland DH.60G Gipsy Moth, G-AAAH, named Jason. She received a £10,000 prize from the Daily Mail newspaper.
For her accomplishment, she was appointed Commander of the Most Excellent Order of the British Empire (CBE). She was also awarded the Harmon Trophy, “for the most outstanding international achievements in the arts and/or science of aeronautics for the preceding year, with the art of flying receiving first consideration.”
Her Gypsy Moth is in the collection of the Science Museum, London, England.
Amy Johnson was a rated Engineer (aircraft mechanic) and Navigator, as well as a licensed pilot. She had set many flight records, both individually and with her husband, James Mollison, whom she had married in 1932. He proposed to her during an airplane flight, only eight hours after having met her.
During World War II, Amy Johnson flew for the Royal Air Force as a First Officer of the Air Transport Auxiliary (equivalent to the RAF rank of Flight Lieutenant). On 5 January 1941, at approximately 3:30 p.m., Johnson bailed out of the Oxford and parachuted into the Thames Estuary. The airplane crashed into the river a short distance away and sank.
Amy Johnson’s parachute was seen by the crew of HMS Haslemere, a barrage balloon tender assigned to the Channel Mobile Balloon Barrage in the Estuary. They attempted to rescue her and in the process, the ship’s captain, Lieutenant Commander Walter Edmund Fletcher, Royal Navy, dove into the water. In the cold temperatures and rough conditions, Fletcher died. For his effort to rescue Johnson, he was awarded the Albert Medal, posthumously.
In recent years, stories have emerged that the AS.10 was shot down after Johnson twice gave the incorrect response to a radio challenge. Tom Mitchell, an anti-aircraft gunner of the 58th (Kent) Heavy Anti-Aircraft Artillery Regiment, at Iwade, a small village along the shore of the Thames Estuary, said in 1999 that he shot her down under orders, firing 16 shells at the Oxford. The men of the battery were ordered to never mention the incident. There were contemporary reports that a destroyer had also fired on Johnson, though the Admiralty denied this.
The de Havilland DH.60 was a light-weight, two-place, single-engine, single-bay biplane. The fuselage was covered with plywood and the wings and tail surfaces were covered with fabric. It was 23 feet, 5½ inches (7.150 meters) long with a wingspan of 29 feet, 0 inches (8.839 meters) and overall height of 8 feet, 9½ inches (2.680 meters). The airplane was designed so that the wings could be folded parallel to the fuselage, giving it an approximate width of 9 feet (2.7 meters). The wings had a chord of 4 feet, 3 inches (1.295 meters). The vertical gap between the wings was 4 feet, 10 inches (1.473 meters) and lower wing was staggered 3 inches (7.62 centimeters) behind the upper. Both wings had 3.5° angle of incidence and 3.5° dihedral. There was no sweep. Empty, the DH.60 had a weight of 764 pounds (346.6 kilograms) and loaded weight of 1,650 pounds (748 kilograms).
The original DH.60 Moth, which first flew in 1925, was powered by an air-cooled, normally-aspirated 4.503 liter (274.771-cubic-inch-displacement) A.D.C. Aircraft Ltd., Cirrus inline 4-cylinder overhead valve (OHV) engine with two valves per cylinder and a compression ratio of 5.4:1. The direct-drive engine produced 60 horsepower at 1,800 r.p.m., and 65 horsepower at 2,000 r.p.m. The Cirrus was 0.983 meters (3.225 feet) long, 0.908 meters (2.979 feet) high and 0.450 meters (1.476 feet) wide. It weighed 260 pounds (118 kilograms). The A.D.C. Cirrus was designed by Major Frank Bernard Halford, who later designed the de Havilland Gipsy engine, as well as the Goblin and Ghost turbojet engines.
The DH.60G Gipsy Moth was first produced in 1928. It was powered by a 318.09-cubic-inch-displacement (5.212 liter) air-cooled de Havilland Gipsy I inline 4-cylinder direct-drive engine with a compression ratio of 5:1. It was capable of producing 130 horsepower, but de-rated to 100 horsepower at 2,100 r.p.m. The Gipsy I was 40.5 inches (1.029 meters) long, 29.9 inches (0.759 meters) high and 20 inches (0.508 meters) wide. It weighed 285 pounds (129 kilograms).
The Gipsy Moth has a cruise speed of 85 miles per hour (137 kilometers per hour) and maximum speed of 102 miles per hour (164 kilometers per hour). Range for the standard aircraft is 320 miles (515 kilometers). The service ceiling is 14,500 feet (4,420 meters).
De Havilland built 8 pre-production and 31 production DH.60 Moths. 595 DH.60s of all variants were produced at Stag Lane.
8 April 1954: South African Airways Flight 201, a chartered British Overseas Airways Corporation de Havilland DH.106 Comet 1, aircraft registration G-ALYY, departed Rome at 1832 UTC, bound for Cairo. The Comet was under the command of Captain Wilhelm K. Mostert, with First Officer Barent J. Grove, Navigator Albert E. Sissing, Radio Officer Bertram E. Webstock, and Flight Engineer August R. Lagesen. Air Hostess Pamela L. Reitz and Flight Steward Jacobus B. Hok were in the passenger compartment with the 14 passengers.
As the airliner climbed toward 35,000 feet (10,668 meters), they made several position reports. Last heard from at 1907 UTC, radioing an expected arrival time at Cairo, the Comet disintegrated in flight and fell into the Mediterranean Sea. Searchers found a debris field and floating bodies the next day near the volcanic island of Stromboli. All 21 persons aboard were killed.
This was the second catastrophic failure of a DH.106 in just three months. BOAC immediately grounded its entire Comet fleet, and the British Air Ministry revoked the airliner’s certificate of airworthiness. Production of the airliner at de Havilland was halted.
The first crash had been presumed to be a result of an in-flight fire, and the second, an uncontained turbine engine failure. But an extensive investigation eventually determined that the cause of both crashes was the in-flight break up of the fuselage pressure hull. Metal fatigue of the fuselage was caused by the repeated expansion and contraction of pressurization cycles. Cracks in the aluminum skin formed at corners of the passenger compartment windows and then spread outward. This resulted in catastrophic explosive decompression.
The DH.106 Comet 1 was the first production version and was very similar to the two prototypes. It can be visually identified by its square passenger windows. It was flown by a pilot, co-pilot, flight engineer and navigator. The airliner could carry up to 44 passengers.
The airplane was 93 feet (28.346 meters) long with a wingspan of 115 feet (35.052 meters) and overall height of 29 feet, 6 inches (8.992 meters). The Comet 1 had a maximum takeoff weight of 110,000 pounds (49,895 kilograms). It was powered by four de Havilland Engine Company Ghost 50 centrifugal flow turbojet engines, producing 5,000 pounds of thrust, each. This gave it a cruising speed of 460 miles per hour (740 kilometers per hour) and cruise altitude of 42,000 feet (12,802 meters). The airliner’s range was 1,500 miles (2,414 kilometers).
Twelve DH.106 Comet 1 airliners were built.
The de Havilland Comet was the first commercial jet airliner and its introduction had revolutionized the industry. The two disasters were a blow from which the company never really recovered.