Tag Archives: Halford H.1

20 September 1943

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

5 March 1943

Fifth of eight F9/40 prototypes, Gloster Meteor DG206/G was the first to fly, 5 March 1943. (BAE Systems)

5 March 1943: Gloster test pilot Neill Michael Daunt took Gloster Meteor DG206/G for its first flight at RAF Cranwell in Lincolnshire, England. DG206/G was the fifth of eight F9/40 prototypes, but first to fly. (The “/G” in the identification indicated that the aircraft was to be guarded at all times.)

Designed by Wilfred George Carter, Gloster’s Chief Designer, the Meteor was a single-place, twin-engine, low-wing monoplane with tricycle landing gear. It was powered by two turbojet engines.

Gloster F9/40 DG205/G, the first prototype Meteor to fly. Left to Right: Test pilot John A. Crosby-Warren; test pilot Neill Michael Daunt; Frank McKenna, Managing Director, Gloster Aircraft Co.; Air Commodore Frank Whittle, RAF; and Wilfred George Carter, Chief Designer, Gloster. (Mary Evans Picture Library)
Test pilot Neill Michael Daunt, center, with a Gloster Meteor. (Test & Research Pilots, Flight Test Engineers)

Before the Meteor’s first flight, more than 100 Meteors had been ordered. The Mk.I was the first operational model with 20 built, but these were quickly upgraded to the Mk.III.

The Meteor Mk.III was 41 feet, 0 inches (12.497 meters) long with a wingspan of 43, feet 0 inches (13.106 meters) and overall height of 13 feet, 0 inches (3.962 meters). The wings had an angle of incidence of 1°. The center wing section had 0° 52½’ dihedral, while outboard of the engine nacelles, the wings had 6°. The total wing area was 374.0 square feet (34.8 square meters).

DG206 was initially intended to be powered by two Power Jets W.2 turbojet engines, however, when these were not ready, the Halford H.1 was substituted. The 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.

Cutaway illustration of the Halford H.1B Goblin turbojet engine. (Flight)

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 first fifteen Mk.IIIs were powered by Rolls-Royce Welland W.2B/23 engines, while subsequent airplanes were equipped with Rolls-Royce Derwent B.37 which produced 1,800 pounds of thrust (80 kilonewtons).

The Meteor Mk.III had a maximum speed at Sea Level of 435 miles per hour (700 kilometers per hour) and 465 miles per hour (748 kilometers per hour) at 30,000 feet (9,144 meters). Its critical mach number (Mcr) was 0.74. The maximum permissible speed (VNE) of 500 miles per hour (805 kilometers per hour) up to an altitude of 6,500 feet (1,981 meters). The airplane could maintain a rate of climb of at least 1,000 feet per minute (5 meters per second) until 31,000 feet (9,449 meters). At 20,000 feet (6,096 meters) with two 180 gallon (681 liters) drop tanks its range was 581 miles (935 kilometers).

The Meteor was armed with four Hispano Mk.II 20 mm autocannon grouped together in the nose, with 180 rounds of ammunition per gun. Total duration of fire was 15 seconds.

First operational sortie by a Meteor was flown from RAF Manston, by Flying Officer William H. McKenzie, RCAF, 1430, 27 July 1944, patrolling for inbound V-1s.

Gloster Meteor F Mk.I EE227, YQ Y, No. 616 Squadron, RAF Manston. (Flight Lieutenant Miller, RAF Official Photographer/Imperial War Museums CL 2926)

© 2023, Bryan R. Swopes