UK Jet Progress 1944
Aircraft
Gloster G.40 E.28/37 Pioneer
Developed as a flying testbed for the Whittle W.1 gas turbine.
The first prototype W4041 refitted with a 1,160lb W.1A engine is still flying with the RAE. The second prototype W4046 crashed and was destroyed due to aileron jamming on 30 July 1943. The third prototype, W4047 was first flown on 20 September 1943 and was refitted with a 1,700lb Rolls-Royce Welland engine during December 1943.
Gloster G.41 Meteor
Eight prototypes were ordered (DG202-210). DG206 made the first flight on 5 March 1943 with two de Havilland H-1 Goblin engines. DG202 and DG205 flew with RB.23 Welland (as the Power Jets W.2 had become) test engines on 12 June and 24 July 1943 respectively. DG203 fitted with two 2,100lb Armstrong Siddeley ASX axial-flow turbojets flew on 13 September 1943 followed by DG204 in November with 2,000lb RB.26 Derwent turbojets. DG207 flew on 20 January 1944 with a modified fin, rudder and dive brakes and the final prototype DG208 flew with two production 1,700lb thrust Wellands on 18 April 1944. DG203 during early 1944 was refitted with 2,800lb ASX turbojets.
Meteor F.Mk.I
The prototypes were followed by twenty G.41A production aircraft from 12 January 1944. These had improved canopies and 1,700lb Wellands. The eighteenth aircraft, EE227 was converted into the RB.50 Trent Propeller-Turbine testbed as part of the research programme under Specification N.11/43; this first flew with the 750shp + 1,250lbs Rolls-Royce RB.50 Trent I propeller-turbine engine on 20 September 1944 thereby becoming the world's first turboprop-powered aircraft.
In July 1944, the first Meteors were issued to an operational squadron for operational trials. [I do not consider them frontline fighters at this stage]
Dimensions; 43/ 41.3/ 13/ 374 sq ft; 2x 1,700lb Rolls-Royce RB.23 Welland I; max speed 415mph at 10,000ft; range 500 miles; service ceiling 40,000ft and MTOW 13,795lb. Armament: 4x 20mm Orkileon FFB cannon.
Meteor F.Mk.II
Planned as the de Havilland Goblin powered production mark.
Meteor F.Mk.III
Planned with improved fuel capacity. The first example should fly in January 1945.
Gloster G.45 Sea Meteor FSN.Mk.VI
Developed to meet Spec N.11/43 issued to Gloster for development of a navalised Meteor powered by two propeller-turbines. The eighteenth production Meteor, EE227, was fitted with two RB.50 Trent propeller-turbines, 7ft 11in five-blade Rotol propellers and a longer undercarriage. It first flew on 20 September 1944. EE227 became, in effect, the prototype G.45. A second, fully-navalised, prototype should fly in mid-1945.
De Havilland DH.100 Vampire
Two prototypes were ordered under Spec E.6/41, LZ548 and LZ551. The first prototype made its maiden flight at Hatfield on 20 September 1943 followed by LZ551 two months later. A major problem, eventually overcome, was snaking during high-speed runs, which was cured by altering the fin shape and tail arrangement. In 1943 100 production fighters were ordered.
Vampire F.Mk.I
The first production F.Mk.I flew on 20 April 1944 powered by a 3,100lb Goblin II. [Initial production is slow and all are used on trials]
Dimensions; 38/ 30.9/ 8.10/ 262 sq ft; 1x 3,100lb de Havilland DGo.2 Goblin II; max speed 540mph; range 730 miles and service ceiling 42,800ft. Armament: 4x 20mm Orkileon FFB cannon.
Sea Vampire FN.Mk.II
Basically an F.Mk.I but with catapult spools and arrestor gear. The prototype LZ551 was converted with 40% extra flaps, long travel oleos and an arrestor hook. It first flew in this form in January 1944. 12 production aircraft were built during 1944 by Fairey and on 3 December 1944, LZ551 piloted by Captain Eric "Winkle" Brown became the first pure-jet aircraft to land on and take off from an aircraft carrier. [These are all for trials, not as frontline FAA fighters]
Vampire F.Mk.III
A planned improved variant with more fuel in extended wing tanks and revised tailplane. The prototype TG275 should fly during 1945.
Engines
Rolls-Royce RB.23 Welland
Diameter: 43 in (1,098 mm)
Dry weight: 850 lb (386 kg)
Maximum thrust: 1,700lbs
Rolls-Royce RB.26 Derwent
Derwent I 2,000lbs 1943
Derwent II 2,200lbs 1944
Derwent IV 2,400lbs 1944
The Rolls-Royce Derwent is essentially an improved version of the Rolls-Royce Welland. It was designed by a Rolls-Royce team and they dispensed with Whittle's reverse flow design, and instead designed an axial-flow design. This layout makes the engine longer but makes the gas flow simpler and improves reliability. Adding improved fuel and oil systems, the Derwent I entered production with 2,000lbs thrust. Further developments peak at 2,400lbs of thrust.
Length: 84 in (2,135 mm)
Diameter: 41.5 in (1,055 mm)
Dry weight: 975 lb (443 kg)
Compressor: Single-stage dual-entry centrifugal compressor with two-sided impeller
Combustors: 10 flow combustors with igniter plugs in chambers 3 and 10
Turbine: Single-stage axial flow with 54 blades
Oil system: 2.75 gal (12.5 L) capacity, circulation rate 215 gal/hr (976 L/hr), maximum inverted flying time 15 s
Maximum thrust:
120lbs (0.5 kN) at 6,000 rpm at idle.
2,000lbs (8.9 kN) at 16,500 rpm for take-off
1,550lbs (6.9 kN) at 15,000 rpm for cruise
Overall pressure ratio: 3.9:1
Fuel consumption:
470 lb/hr (215 kg/hr) at idle
1,820 lb/hr (830 kg/hr) at cruise power
2,360 lb/hr (1,070 kg/hr) at maximum power
Oil consumption: 0.125 gal/hr (0.57 L/hr)
Thrust-to-weight ratio: 2.1:1 (20.1 N/kg)
Rolls-Royce RB.41 Nene
The Rolls-Royce RB.41 Nene is essentially an enlarged version of the Derwent with minimal changes to deliver 5,000lbs of thrust, making it the most powerful jet engine in the world. The Nene was designed and built in an astonishingly short five-month period in 1944, first running on 27 October 1944. Although based on the axial version of the basic Whittle-style layout, the Nene uses a double-sided centrifugal compressor for improved pressure ratio and thus higher thrust.
Length: 96.8 in (2,459 mm)
Diameter: 49.5 in (1,257 mm)
Dry weight: 1,550 lb (700 kg) (less jet-pipe)
Compressor: Dual-entry centrifugal compressor with two-sided impeller
Combustors: 9 flow-combustion chambers
Turbine: Single-stage axial flow
Maximum thrust: 5,000 lbs (22.2 kN) at 12,400 rpm for take-off (early engines 4,500lbs thrust)
Overall pressure ratio: 4:1 static
Thrust-to-weight ratio: 3.125
Rolls-Royce RB.50 Trent
The Rolls-Royce RB.50 is the companys first propeller-turbine engine. The RB.50 is essentially a Derwent II turbojet engine with an additional turbine stage driving a reduction gearbox (designed by A. A. Rubbra) connected to a five-bladed Rotol propeller. The RB.50 ran for 633 hours on test during 1943, before being installed in a Gloster Meteor jet fighter which flew for the first time on 20 September 1944. The planned rating is 750shp + 1,250lbs residual thrust.
Rolls-Royce RB.39
The RB.39 is Rolls-Royce's first purpose-designed propeller-turbine engine. It uses a two-spool design, with an axial compressor for the low-pressure section, and a single-sided centrifugal compressor as the high-pressure stage, running on concentric shafts. The RB.39 is a long engine with the axial LP compressor in front of, in effect, a scaled down Derwent engine. Accessories are grouped around the axial. Cooling for turbines and turbine bearings comes from a small diffuser on the main shaft as well as tappings from the axial and centrifugal compressors. Began bench testing in late 1944.
De Havilland H-1 Goblin
H-1 Goblin I 2,700lbs 1943
H-1 Goblin II 3,100lbs 1944
The H-1 first ran on 13 April 1942, and quickly matured to produce its full design thrust within two months. It first flew on 5 March 1943 in the Gloster Meteor and on 20 September 1943 in the de Havilland Vampire.
Length: 107 in (2,718 mm)
Diameter: 50 in (1,270 mm)
Dry weight: 1,550 lb (703 kg)
Compressor: Single sided, centrifugal flow
Combustors: 16 chambers
Turbine: Single stage
Maximum thrust: 3,000lbs at 10,200 rpm
Overall pressure ratio: 3.3:1
Turbine inlet temperature: 790 °C
Fuel consumption: 3,720 lb/hr (465 imp.gal/hr) (1,687 kg/hr - 2,114 L/hr)
Specific fuel consumption: 1.3 lbs/lb/hr
Thrust-to-weight ratio: 1.9 lbs/lb
De Havilland H-2 Ghost
The de Havilland Ghost was originally the Halford H-2. The H-2 uses ten larger flame cans in place of the Goblin's sixteen smaller ones, using split intakes to each can to feed in more air (equal to twenty cans feeding off the compressor). The H-2 was renamed the Ghost when de Havilland took over the Halford company. The Ghost began bench testing in 1944 and should begin air tests in 1945.
Armstrong Siddeley ASX
An axial flow jet engine that first ran in April 1943. The ASX is unique in layout. The inlet to the 14-stage compressor is placed near the middle of the engine, the air flowing forward as it is compressed. From there it feeds into 11 flame cans arranged around the outside of the compressor, flowing back past the inlet, and finally through the turbine. This layout allows the compressor and combustion areas to be folded together to make the engine shorter. The ASX was flight tested fitted to the bomb bay of a modified Avro Lancaster, the first flight taking place on 28 September 1944.
At full power the engine runs at 8,000 rpm and develops 2,600lbs of thrust at sea level. For cruise the engine runs at 7,500 rpm and develops 2,050lbs.
Length: 13 ft 11 in (4,240 mm)
Diameter: 42 in (1,068 mm)
Dry weight: 1,900 lb (865 kg)
Compressor: Axial flow, 14-stage
Combustors: 11 chambers, Nimonic 75 steel.
Turbine: Two stage, axial flow
Maximum thrust: 2,600lbs at 8,000 rpm
Specific fuel consumption: 1.03 lb/lbf/hr
Thrust-to-weight ratio: 0.73:1
Armstrong Siddeley ASP
The experimental ASX axial turbojet was converted into a propeller-turbine with the addition of a second turbine stage, which was geared to the propeller and was named ASP. It first ran in April 1944 on the test bench. Flight-testing will be carried out using an Avro Lancaster, having the two outboard Rolls-Royce Merlins replaced by ASPs during 1945-46.
Length: 123.2 in (3129 mm)
Diameter: 54 in (1372 mm)
Dry weight: 3,450 lb (1565 kg)
Compressor: 14 stage axial
Combustors: 11 combustion chambers
Turbine: Two-stage turbine
Maximum power output: ASP 3,600ehp including 1,100lbs exhaust thrust
Overall pressure ratio: 5.35:1
Specific fuel consumption: 0.805 lb/hr/ehp
Power-to-weight ratio: 1.2:1
Bristol Theseus
The Theseus is the Bristol Aeroplane Company's first gas-turbine engine design. It is the third British propeller-turbine design. A novel feature is the use of a heat exchanger to transfer waste heat from the exhaust to the compressor exit. Trial engines have been extensively bench tested this year and hopefully a test certificate will be issued from the Air Ministry early in 1945 to allow the start of airborne trials on a converted Avro Lancaster.
Length: 81.85 in (2.07 m)
Diameter: 54 in (1.372 m)
Dry weight: 2,205 lb (1,000 kg)
Compressor: 8-stage axial, followed by a single centrifugal stage
Combustors: 8 combustion chambers
Turbine: Three-stage
Maximum power output: 2,220hp plus 825lbs exhaust thrust
Fuel consumption: 272 Imperial gallon (1,237 l) /hour
Power-to-weight ratio: 1.0 hp/lb