Tag Archives: Major Frank Bernard Halford CBE FRAeS

22 February 1925

Aviation, , , , , , , , , , , , , ,
Captain Sir Geoffrey de Havilland, OM, CBE, AFC, RDI, FRAeS (27 July 1882–21 May 1965)
Captain Geoffrey de Havilland, O.B.E., in the cockpit of an airplane, circa 1925. (Topical Press Agency/Hulton Archive/Getty Images)

22 February 1925: At the de Havilland Aircraft Company airfield at Stag Lane, Edgware, London, Geoffrey de Havilland, O.B.E., took his new DH.60 Moth, c/n 168 (later registered G-EBKT), for its first flight.

The DH.60 was a light-weight, two-place, single-engine, single-bay biplane. The fuselage was constructed of plywood and the wings and tail surfaces were covered with fabric. The Moth 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 and the lower wing was staggered slightly behind the upper. Their total area was 229.0 square feet (21.3 square 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.

The DH.60 had an empty weight of 764 pounds (346.6 kilograms) and its gross weight was 1,650 pounds (748 kilograms).

An A.D.C. Cirrus aircraft engine at the Science Museum, London. (Nimbus227)

The Moth 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 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.

De Havilland built 8 pre-production and 31 production DH.60 Moths. 595 DH.60s of all variants were produced at Stag Lane.

The prototype de Havilland Aircraft Company DH.60 Moth, G-EBKT.
The prototype de Havilland Aircraft Company DH.60 Moth, G-EBKT. (Unattributed)

On 29 May 1925, Alan Cobham flew the prototype from Croydon to Zurich and back in 14 hours, 49 minutes. Cobham also flew the Moth in The Kings Cup Air Race, though weather forced him to land short of the finish. It placed second in a follow-up race.

The G-EBKT was used as a demonstrator for de Havilland for a brief time before being sold to Sophie C. Elliot Lynn, 26 March 1926. She flew the Moth in the Paris Concours d’Avions Economiques in August 1926. (Mrs. Elliott Lynn later became Mary, Lady Heath.)

Sophie Elliott Lynn with her pale blue de Havilland DH.60 Moth, G-EBKT. (Unattributed)
Sophie Catherine Elliot Lynn with her pale blue de Havilland DH.60 Moth, G-EBKT. (A Fleeting Peace)

In 1927, G-EBKT was sold to the London Aeroplane Club. It crashed at Dennis Lane, Stanmore, Middlesex, 21 August 1927, injuring the pilot and a passenger:

On Sunday afternoon, Pilot Officer Stanley Pritchard-Barrett, flying on D.H. “Moth” G-EBKT with his wife as passenger, crashed in the grounds of the residence of Major Sir Maurice FitzGerald,Bt. He was severely injured about his head, and his wife, who was a passenger, had a leg broken. The machine fell from a height of about 90 ft.

The London Aeroplane Club “Moth” is apparently a complete write-off.

—Flight

G-EBKT’s registration was cancelled 20 January 1928.

© 2019, Bryan R. Swopes

20 September 1943

Aviation, , , , , , , , , , , , ,
Geoffrey de Havilland, Jr., exits the cockpit of one of the company's jet aircraft. (Photograph Courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Geoffrey de Havilland, Jr., exits the cockpit of one of the company’s jet aircraft. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

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.

Right front view of the first prototype de Havilland DH.100, LZ548/G.
Right front view of the first prototype de Havilland DH.100, LZ548/G, prior to its first flight. The letter “P” in a circle next to the RAF insignia identifies the airplane as a prototype. The “/G” in the identification number indicates that a guard is required at all times. (De Havilland Aircraft Co., Ltd.)

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.

Right side view of the de Havilland DH.100 Spider Crab LZ548/G.
Right side view of the de Havilland DH.100 Spider Crab LZ548/G.

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.

av_gb_4603_jet-history_goblin_p080_wThe 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.

Right rear quarter view of the prototype de Havilland DH.100, LZ548/G.
Right rear quarter view of the prototype de Havilland DH.100, LZ548/G. In this photograph, the airplane’s vertical fins have been squared off. This would be a feature of the production Vampire F.1.

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.

© 2016, Bryan R. Swopes