- Yes
- No
Introduction: Though not looking like it, the Gloster E.28/39 was one of the most advanced pieces of technology of its day, and represents a major milestone for the British aviation industry, as well as demonstrating Britain’s technological prowess.
Description:
The E.28/39 story started in the late 1930’s, when an engineer named Frank Whittle proposed a new form of propulsion for aviation, one which offered speeds and altitudes that were previously unfathomed. This piece of technology was completely different to the piston engines used up until then. Rather than using combustion to turn a propeller to create forward motion, this new form of propulsion used sets of compressors, which would bring air into a combustion chamber, before sending it out the back at high velocities. As mentioned, such an engine offered great advancements that were previously not thought possible. This engine was the jet engine. Though there was Government opposition, Whittle and his team persevered, and continued work. A prototype was built, and ground tests ran through 1937 to 1939. These tests showed that the engine had promise. Now all that was left was for it to be test flown.
Development began in 1939 with the utmost secrecy, with the codename “Weaver” being given to the type. On the 29th of April, Whittle visited the Gloster works, meeting designer George Carter and test pilots Michael Daunt and Gerry Sayer. He was familiar with all of these men, discussing with the latter two the greatest details regarding the performance of the jet engine. He also briefed Carter about the necessary design features an aircraft with a jet engine would require. It must be remembered that this was truly at the cutting edge of technology, and that the project was truly stepping beyond what was known at the time. It was agreed that a completely new aircraft would have to be designed, as no existing type would be able to be modified to carry the new type of powerplant. It was also agreed that an official Air Ministry contract was necessary. By this time, it became clear that Gloster was the best candidate for such a project, since they had the available space to work on it. The deal was also sweetened by the good relationship between Carter and Whittle.
On 13th October, 1939, a meeting was held at Farnborough to discuss the upcoming aircraft. During this meeting, Carter presented two possible configurations. The first had a long tailpipe, which ended aft of the tail. The second had a shorter jetpipe, with the tail and elevators being supported on a boom. The latter configuration allowed for easy access to the jet engine, as well as keeping the engine bay clear of any supporting structure and increased performance, but introduced the risk of creating airflow disturbances in the rear of the aircraft. The overall configuration of both types remained much the same; mid-wing monoplane, with the pilot in the front, who sat in front of the engine which was in the middle. Despite its pioneering nature, the E.28/39 was quite simple in design terms, with a rather conventional layout and a tricycle undercarriage. The military potential of such a design was also analysed, with provision for guns being fitted. The specification for the Gloster design was approved on 21st January, 1940, and construction was ordered to go ahead.
To fully test the uniqueness of jet propulsion, it was necessary to satisfy all strength and structural rigidity questions in order to verify the methods of proper construction of future aircraft. Control and stability were also of the utmost importance. Another challenge was rate of flow into the jet engine, which require 26lb (11.8kg) of air per second, the velocity of which was not meant to exceed 200ft/sec (61m/sec). This was solved by creating an air duct 18in (45.7cm) wide. One interesting thing to note was the need for a steerable nosewheel, since props generally used the slipstream from the propeller over the rudder to change direction on the ground.
A contract for the construction of two prototypes was placed on the 3rd of February 1940, with the registrations of W4041 and W4046 being placed. The mock-ups were shown on the 22nd April, with construction rapidly progressing at Gloster’s Experimental Shop in Brockworth. The threat of bombing meant that the airframes were moved to Regent Motors Garage, Cheltenham. By 8th July, assembly of the fuselage was completed and various other parts were moving along very well. By January 1941, the airframe was ready. Cranwell was chosen for the first flight, due to its conditions. This momentous achievement was completed on 15th May, 1941, when W4041 made the first ever flight by a British jet aircraft. After witnessing this occasion, Sir Henry Tizard wrote:
Blockquote
“In my opinion, we have now reached a stage when the odds against the jet propulsion engine of the Whittle type being developed to a successful issue in the near future have disappeared”*
*The Centrifugal type jet engine
A new dawn was appearing over the horizon. The Dawn of the Jet Age approached, an Age which pushed the limits of what was known. All boundaries would be pushed to their limits and beyond, those of speed, materials and aircraft design. This was a truly ground-breaking moment.
W4041:
W4041 was first fitted with a Power Jets W1X engine, which was meant for use in ground tests as it was not intended for flight. Despite this, the aircraft did make it into the air, albeit briefly for a distnce of 200 yards (183m) at a height of 6 feet (1.85m). As mentioned above, the first true flight occurred on 15th May, 1941, with a W.1 engine. Flight tests showed that the aircraft performed favourably against the Spitfire of the time. In January 1942, a new engine was fitted, the W.1A, giving the performance characteristics below. It was found during tests that surging became an issues, as well as high landing speeds due to high engine thrust during short final. The latter was compounded by the fact that descent from high altitude occurred at much higher altitudes than in a prop, with the lack of a propeller, which would normally slow down the aircraft, being a major cause behind this. However, the latter issue was quickly overcome with experience, as stated above, the aircraft was pushing beyond the boundaries of what was previously known, and thus both test pilot and engineer had to learn on the go.
After the crash of W4046, W4041 was given some improvements. Firstly, improvements to the ailerons were made to prevent the aircraft from suffering a similar fate to W4046. Secondly, the aircraft given endplate fins on the horizontal stabilisers, which were added to reduce the zigzagging which had occurred on W4046. Finally, the engine was replace with a more powerful W2/500 engine. In addition to these changes, metal-covered control surfaces were added, and the original NACA section wing was replaced by a new one from Gloster, specifically aimed at higher-speed flight. Engine surges were found to occur at 25,000ft (7,620m) with the new engine, which required it to be modified. These modifications were finished by April 1944. An altitude of 43,000ft (12,860m) was reached that summer, and though the aircraft kept climbing, the lack of pressurisation in the cockpit meant that the aircraft could not go any further. The final part of the aircraft’s career was in the use of gathering performance data. A new engine, the W.2/700 was also tested, but there is little to no information that I could find regarding this type. After a number of shows and displays in 1945, the aircraft was given to the Science Museum in London, where the aircraft is on display today.
Performance:
Spoiler
The type has been split into "Early and “Late” below, depending on the engine type installed, due to each engine giving different performances, as can be seen in the table below. Overall dimensions remain the same.
The “Early” has the W.1A engine, the “Late” has the W.2/500.
| Type: | Single-seat jet-powered Research aircraft |
|---|---|
| Powerplant: | Early: Power Jets W.1A |
Late: Power Jets W.2/500|
|Span:|29ft 0in (8.84m)|
|Length:|25ft 3.75in (7.71m)|
|Gross Wing Area:|146.5sq ft (13.62m2)|
|All-up Weight:|Early: 3,748 lb (1,700 kg)
Late: 4,200lb (1,905kg)|
|Rate of Climb:|Early: 23,500ft (7163m) in 12.5min
Late: Over 3,000ft/min (914m/min) at 1,000ft|
|Maximum Speed:|Early: 365mph (587km/h)
Late: 446mph (750km/h)|
|Service Ceiling:|Early: 32,000 ft (9,800m)
Late: 43,000 ft (12,680m)|
|Armament:|None fitted,
Provision for four Browning .303in (7.7mm) machine guns, as specified under Specification E.28/39|
Addition to the game: Due to the type having two different engines at different periods, with many different modifications, it can be argued that the Early and Late configurations are almost completely different to one another, and thus they can be added as different aircraft. However, there is also the option of only adding one aircraft, with the ability to choose between the modifications based on the engine they want.
Conclusion: With such an intriguing history, and leaving behind such a great impact on aviation, I think that this would be a highly interesting addition to the game. I must admit it was quite interesting researching this aircraft, and I realised how little I knew about this type, uncovering more interesting details the further I dug. For instance, I had never known that the type had tested such a wide variety of engines, which gave such different performances; Tony Buttler’s works proving to be a God-send during my research. Anyways, I hope you enjoyed this suggestion, and I hope to see you in the next one.
Sources:
Spoiler
“British Experimental Combat Aircraft of World War II: Prototypes, Research Aircraft and Failed Production Designs” by Tony Buttler
“British Secret Projects 3: Fighters 1935-1950” by Tony Buttler
https://www.baesystems.com/en/heritage/gloster-e-28-39
Gloster-Whittle E.28/39 | This Day in Aviation
Air Warfare: an International Encyclopedia: A-L - Google Books
Technology and the Air Force: A Retrospective Assessment - Google Books
Sources: