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116-639: The Mikulin AM-3 (also called RD-3M ) was a turbojet engine developed in the Soviet Union by Alexander Mikulin . The development of the high-performance single-shaft engine began in 1948. The engine was used in different versions for the Tupolev Tu-16 and Tu-104 , as well as the Myasishchev M-4 . It had a single-stage low-pressure and an eight-stage high-pressure compressor, powered by

232-416: A i r + m ˙ f ) V j − m ˙ a i r V {\displaystyle F_{N}=({\dot {m}}_{air}+{\dot {m}}_{f})V_{j}-{\dot {m}}_{air}V} where: If the speed of the jet is equal to sonic velocity the nozzle is said to be " choked ". If the nozzle is choked, the pressure at the nozzle exit plane

348-562: A turboshaft engine, a development of the gas turbine engine where an additional turbine is used to drive a rotating output shaft. These are common in helicopters and hovercraft. Turbojets were widely used for early supersonic fighters , up to and including many third generation fighters , with the MiG-25 being the latest turbojet-powered fighter developed. As most fighters spend little time traveling supersonically, fourth-generation fighters (as well as some late third-generation fighters like

464-625: A 35° swept wing ( Pfeilflügel II , literally "arrow wing II") to the Me 262, the same wing-sweep angle later used on both the North American F-86 Sabre and Soviet Mikoyan-Gurevich MiG-15 fighter jets. Though this was not implemented, he continued with the projected HG II and HG III ( Hochgeschwindigkeit , "high-speed") derivatives in 1944, designed with a 35° and 45° wing sweep, respectively. Interest in high-speed flight, which led him to initiate work on swept wings starting in 1940,

580-545: A B.6 gun detachment of 2809 Squadron RAF Regiment shot down another Me 262 over the airfield of Volkel . The final appearance of Me 262s over Volkel was in 1945 when yet another fell to 2809's guns. By January 1945, Jagdgeschwader 7 (JG 7) had been formed as a pure jet fighter wing, partly based at Parchim , although it was several weeks before it was operational. In the meantime, a bomber unit—I Gruppe , Kampfgeschwader 54 (KG(J) 54)—redesignated as such on 1 October 1944 through being re-equipped with, and trained to use

696-742: A defensive interceptor. The configuration of a high-speed, light-payload Schnellbomber ("fast bomber") was intended to penetrate enemy airspace during the expected Allied invasion of France. His edict resulted in the development of (and concentration on) the Sturmvogel variant. Hitler's interference helped to extend the delay in bringing the Schwalbe into operation; (other factors contributed too; in particular, there were engine vibration problems which needed attention). In his memoirs , Albert Speer , then Minister of Armaments and War Production, claimed Hitler originally had blocked mass production of

812-440: A feature shared with the first four Me 262 V-series airframes, caused its jet exhaust to deflect off the runway, with the wing's turbulence negating the effects of the elevators , and the first takeoff attempt was cut short. On the second attempt, Wendel solved the problem by tapping the aircraft's brakes at takeoff speed, lifting the horizontal tail out of the wing's turbulence. The first four prototypes (V1-V4) were built with

928-585: A gas turbine to power an aircraft was filed in 1921 by Frenchman Maxime Guillaume . His engine was to be an axial-flow turbojet, but was never constructed, as it would have required considerable advances over the state of the art in compressors. In 1928, British RAF College Cranwell cadet Frank Whittle formally submitted his ideas for a turbojet to his superiors. In October 1929 he developed his ideas further. On 16 January 1930 in England, Whittle submitted his first patent (granted in 1932). The patent showed

1044-542: A landing field, lengthening flights. The increase in reliability that came with the turbojet enabled three- and two-engine designs, and more direct long-distance flights. High-temperature alloys were a reverse salient , a key technology that dragged progress on jet engines. Non-UK jet engines built in the 1930s and 1940s had to be overhauled every 10 or 20 hours due to creep failure and other types of damage to blades. British engines, however, utilised Nimonic alloys which allowed extended use without overhaul, engines such as

1160-421: A prototype Me 262 fitted with FuG 218 Neptun radar . Another candidate for top ace on the aircraft was Oberstleutnant Heinrich Bär , who is credited with 16 enemy aircraft while flying Me 262s out of his total of 240 aircraft shot down. The Me 262 was so fast that German pilots needed new tactics to attack Allied bombers. In a head-on attack, the combined closing speed of about 320 m/s (720 mph)

1276-644: A retractable tricycle landing gear from its beginnings and flew on jet power alone as early as the end of March 1941. The V3 third prototype airframe , with the code PC+UC, became a true jet when it flew on 18 July 1942 in Leipheim near Günzburg , Germany, piloted by test pilot Fritz Wendel . This was almost nine months ahead of the British Gloster Meteor 's first flight on 5 March 1943. Its retracting conventional tail wheel gear (similar to other contemporary piston-powered propeller aircraft),

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1392-459: A second generation SST engine using the 593 core were done more than three years before Concorde entered service. They evaluated bypass engines with bypass ratios between 0.1 and 1.0 to give improved take-off and cruising performance. Nevertheless, the 593 met all the requirements of the Concorde programme. Estimates made in 1964 for the Concorde design at Mach 2.2 showed the penalty in range for

1508-418: A shallow dive that took them through the escort fighters with little risk of interception. When they were about 1.5 km (0.93 mi) astern and 450 m (1,480 ft) below the bombers, they pulled up sharply to reduce speed. On levelling off, they were one km (1,100 yd) astern and overtaking the bombers at about 150 km/h (90 mph) relative speed, well placed to attack them. Since

1624-411: A significant impact on commercial aviation . Aside from giving faster flight speeds turbojets had greater reliability than piston engines, with some models demonstrating dispatch reliability rating in excess of 99.9%. Pre-jet commercial aircraft were designed with as many as four engines in part because of concerns over in-flight failures. Overseas flight paths were plotted to keep planes within an hour of

1740-408: A similar type, helped increase the overall lift produced by the wing by as much as 35% in tight turns or at low speeds, greatly improving the aircraft's turn performance as well as its landing and takeoff characteristics. As many pilots soon found out, the Me 262's clean design also meant that it, like all jets, held its speed in tight turns much better than conventional propeller-driven fighters, which

1856-551: A slow pace; it was not until August 1944 that initial operational missions were flown against the Allies; the unit made claims for 19 Allied aircraft in exchange for six Me 262s lost. Despite orders to stay grounded, Nowotny chose to fly a mission against an enemy bomber formation flying some 9,100 m (30,000 ft) above, on 8 November 1944. He claimed two P-51Ds destroyed before suffering engine failure at high altitude. Then, while diving and trying to restart his engines, he

1972-405: A small helicopter engine compressor rotates around 50,000 RPM. Turbojets supply bleed air from the compressor to the aircraft for the operation of various sub-systems. Examples include the environmental control system , anti-icing , and fuel tank pressurization. The engine itself needs air at various pressures and flow rates to keep it running. This air comes from the compressor, and without it,

2088-435: A steep right-hand turn, his pale blue underside standing out against the purple sky. Another banked right in front of the Me's nose. Violent jolt as I flew through his airscrew eddies. Maybe a wing's length away. That one in the gentle left-hand curve! Swing her round. I was coming from underneath, eye glued to the sight (pull her tighter!). A throbbing in the wings as my cannon pounded briefly. Missed him. Way behind his tail. It

2204-525: A tactic known to the Tempest-equipped No. 135 Wing RAF as the "Rat Scramble": Tempests on immediate alert took off when an Me 262 was reported airborne. They did not intercept the jet, but instead flew towards the Me 262 and Ar 234 base at Hopsten air base . The aim was to attack jets on their landing approach, when they were at their most vulnerable, travelling slowly, with flaps down and incapable of rapid acceleration. The German response

2320-439: A test unit ( Jäger Erprobungskommando Thierfelder , commanded by Hauptmann Werner Thierfelder ) to introduce the Me 262 into service and train a corps of pilots to fly it. On 26 July 1944, Leutnant Alfred Schreiber , while flying over Munich, with the 262 A-1a W.Nr. 130 017, encountered a Mosquito PR Mark XVI reconnaissance aircraft, of No. 540 Squadron RAF , piloted by Fl. Lt. A.E. Wall. Schreiber attempted to shoot down

2436-513: A turbojet application, where the output from the gas turbine is used in a propelling nozzle, raising the turbine temperature increases the jet velocity. At normal subsonic speeds this reduces the propulsive efficiency, giving an overall loss, as reflected by the higher fuel consumption, or SFC. However, for supersonic aircraft this can be beneficial, and is part of the reason why the Concorde employed turbojets. Turbojet systems are complex systems therefore to secure optimal function of such system, there

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2552-512: A turbojet engine is always subsonic, regardless of the speed of the aircraft itself. The intake has to supply air to the engine with an acceptably small variation in pressure (known as distortion) and having lost as little energy as possible on the way (known as pressure recovery). The ram pressure rise in the intake is the inlet's contribution to the propulsion system's overall pressure ratio and thermal efficiency . The intake gains prominence at high speeds when it generates more compression than

2668-494: A turbojet is high enough at higher thrust settings to cause the nozzle to choke. If, however, a convergent-divergent de Laval nozzle is fitted, the divergent (increasing flow area) section allows the gases to reach supersonic velocity within the divergent section. Additional thrust is generated by the higher resulting exhaust velocity. Thrust was most commonly increased in turbojets with water/methanol injection or afterburning . Some engines used both methods. Liquid injection

2784-487: A two-stage axial compressor feeding a single-sided centrifugal compressor . Practical axial compressors were made possible by ideas from A.A. Griffith in a seminal paper in 1926 ("An Aerodynamic Theory of Turbine Design"). Whittle later concentrated on the simpler centrifugal compressor only, for a variety of practical reasons. A Whittle engine was the first turbojet to run, the Power Jets WU , on 12 April 1937. It

2900-421: A two-stage high-pressure turbine. Comparable engines Related lists Turbojet Turbojets have poor efficiency at low vehicle speeds, which limits their usefulness in vehicles other than aircraft. Turbojet engines have been used in isolated cases to power vehicles other than aircraft, typically for attempts on land speed records . Where vehicles are "turbine-powered", this is more commonly by use of

3016-438: Is a call for the newer models being developed to advance its control systems to implement the newest knowledge from the areas of automation, so increase its safety and effectiveness. Messerschmitt Me 262 The Messerschmitt Me 262 , nicknamed Schwalbe (German: " Swallow ") in fighter versions, or Sturmvogel (German: " Storm Bird ") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that

3132-413: Is a component of a turbojet used to divert air into the intake, in front of the accessory drive and to house the starter motor. An intake, or tube, is needed in front of the compressor to help direct the incoming air smoothly into the rotating compressor blades. Older engines had stationary vanes in front of the moving blades. These vanes also helped to direct the air onto the blades. The air flowing into

3248-557: Is evident from the advanced developments Messerschmitt had on his drawing board in 1944. While the Me 262 V9 Hochgeschwindigkeit I (HG I) flight-tested in 1944 had only small changes compared to combat aircraft, most notably a low-profile canopy —tried as the Rennkabine (literally "racing cabin") on the ninth Me 262 prototype for a short time—to reduce drag, the HG II and HG III designs were far more radical. The projected HG II combined

3364-523: Is greater than atmospheric pressure, and extra terms must be added to the above equation to account for the pressure thrust. The rate of flow of fuel entering the engine is very small compared with the rate of flow of air. If the contribution of fuel to the nozzle gross thrust is ignored, the net thrust is: F N = m ˙ a i r ( V j − V ) {\displaystyle F_{N}={\dot {m}}_{air}(V_{j}-V)} The speed of

3480-573: Is modelled approximately by the Brayton cycle . The efficiency of a gas turbine is increased by raising the overall pressure ratio, requiring higher-temperature compressor materials, and raising the turbine entry temperature, requiring better turbine materials and/or improved vane/blade cooling. It is also increased by reducing the losses as the flow progresses from the intake to the propelling nozzle. These losses are quantified by compressor and turbine efficiencies and ducting pressure losses. When used in

3596-559: The 357th Fighter Group was one of the first American pilots to shoot down an Me 262, which he caught during its landing approach. On 7 October 1944, Lt. Urban Drew of the 365th Fighter Group shot down two Me 262s that were taking off, while on the same day Lt. Col. Hubert Zemke , who had transferred to the Mustang equipped 479th Fighter Group , shot down what he thought was a Bf 109, only to have his gun camera film reveal that it may have been an Me 262. On 25 February 1945, Mustangs of

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3712-567: The 55th Fighter Group surprised an entire Staffel of Me 262As at takeoff and destroyed six jets. The British Hawker Tempest scored several kills against the new German jets, including the Me 262. Hubert Lange, a Me 262 pilot, said: "the Messerschmitt Me 262's most dangerous opponent was the British Hawker Tempest—extremely fast at low altitudes, highly manoeuvrable and heavily armed." Some were destroyed with

3828-621: The F-111 and Hawker Siddeley Harrier ) and subsequent designs are powered by the more efficient low-bypass turbofans and use afterburners to raise exhaust speed for bursts of supersonic travel. Turbojets were used on Concorde and the longer-range versions of the Tu-144 which were required to spend a long period travelling supersonically. Turbojets are still common in medium range cruise missiles , due to their high exhaust speed, small frontal area, and relative simplicity. The first patent for using

3944-656: The Gloster Meteor , entered service in 1944, towards the end of World War II , the Me 262 in April and the Gloster Meteor in July. Only about 15 Meteor saw WW2 action but up to 1400 Me 262s were produced, with 300 entering combat, delivering the first ground attacks and air combat victories of jet planes. Air is drawn into the rotating compressor via the intake and is compressed to a higher pressure before entering

4060-588: The Heinkel HeS 3 ), or an axial compressor (as in the Junkers Jumo 004 ) which gave a smaller diameter, although longer, engine. By replacing the propeller used on piston engines with a high speed jet of exhaust, higher aircraft speeds were attainable. One of the last applications for a turbojet engine was Concorde which used the Olympus 593 engine. However, joint studies by Rolls-Royce and Snecma for

4176-527: The North American XB-70 Valkyrie , each feeding three engines with an intake airflow of about 800 pounds per second (360 kg/s). The turbine rotates the compressor at high speed, adding energy to the airflow while squeezing (compressing) it into a smaller space. Compressing the air increases its pressure and temperature. The smaller the compressor, the faster it turns. The (large) GE90-115B fan rotates at about 2,500 RPM, while

4292-488: The Rolls-Royce Welland and Rolls-Royce Derwent , and by 1949 the de Havilland Goblin , being type tested for 500 hours without maintenance. It was not until the 1950s that superalloy technology allowed other countries to produce economically practical engines. Early German turbojets had severe limitations on the amount of running they could do due to the lack of suitable high temperature materials for

4408-531: The Sukhoi Su-9 (1946) and Nakajima Kikka . Many captured Me 262s were studied and flight-tested by the major powers, and influenced the designs of production aircraft such as the North American F-86 Sabre , MiG-15 , and Boeing B-47 Stratojet . Several aircraft have survived on static display in museums. Some privately built flying reproductions have also been produced; these are usually powered by modern General Electric CJ610 engines. Before World War II,

4524-424: The Tu-144 , also used afterburners as does Scaled Composites White Knight , a carrier aircraft for the experimental SpaceShipOne suborbital spacecraft. Reheat was flight-trialled in 1944 on the W.2/700 engines in a Gloster Meteor I . The net thrust F N {\displaystyle F_{N}\;} of a turbojet is given by: F N = ( m ˙

4640-618: The 13 Mosquitoes lost over Berlin in the first three months of 1945. Intercepts were generally or entirely made using Wilde Sau methods, rather than AI radar-controlled interception. As the two-seat trainer was largely unavailable, many pilots made their first jet flight in a single-seater without an instructor. Despite its deficiencies, the Me 262 clearly marked the beginning of the end of piston-engined aircraft as effective fighting machines. Once airborne, it could accelerate to speeds over 850 km/h (530 mph), about 150 km/h (93 mph) faster than any Allied fighter operational in

4756-765: The Allied fighters could be effectively done the same way as the U.S. fighters fought the more nimble, but slower, Japanese fighters in the Pacific. Allied pilots soon found that the only reliable way to destroy the jets, as with the even faster Me 163B Komet rocket fighters, was to attack them on the ground or during takeoff or landing. As the Me 262A's pioneering Junkers Jumo 004 axial-flow jet engines needed careful nursing by their pilots, these jet aircraft were particularly vulnerable during takeoff and landing. Luftwaffe airfields identified as jet bases were frequently bombed by medium bombers , and Allied fighters patrolled over

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4872-486: The British jet-powered Gloster Meteor . The Allies countered by attacking the aircraft on the ground and during takeoff and landing. One of the most advanced WWII combat aircraft, the Me 262 operated as a light bomber , reconnaissance aircraft , and experimental night fighter . The Me 262 proved an effective dogfighter against Allied fighters; German pilots claimed 542 Allied aircraft were shot down, data also used by

4988-492: The European Theater of Operations. The Me 262's top ace was probably Hauptmann Franz Schall with 17 kills, including six four-engine bombers and ten P-51 Mustang fighters, although fighter ace Oberleutnant Kurt Welter claimed 25 Mosquitos and two four-engine bombers shot down by night and two further Mosquitos by day. Most of Welter's claimed night kills were achieved by eye, even though Welter had tested

5104-746: The German capital, the Wehrmacht's 9th Army (with elements from the 12 Army and 4th Panzer Army ) was assaulting the Red Army's 1st Ukrainian Front . To support this attack, on 24 April, JG 7 dispatched thirty-one Me 262s on a strafing mission in the Cottbus - Bautzen area. Luftwaffe pilots claimed six lorries and seven Soviet aircraft, but three German jets were lost. On the evening of 27 April, thirty-six Me 262s from JG 7, III.KG(J)6 and KJ(J)54 were sent against Soviet forces that were attacking German troops in

5220-538: The Germans saw the potential for aircraft powered by the jet engine constructed by Hans von Ohain in 1936. After the successful test flights of the world's first jet aircraft—the Heinkel He 178 —within a week of the invasion of Poland which started the conflict, they adopted the jet engine for an advanced fighter aircraft. As a result, the Me 262 was already under development as Projekt 1065 (or P.1065) before

5336-520: The Jumo 004A engine had passed several 100-hour tests, with a time between overhauls of 50 hours being achieved. However, the Jumo 004A engine proved unsuitable for full-scale production because of its considerable weight and its high utilization of strategic materials (nickel, cobalt, molybdenum), which were in short supply. Consequently, the 004B engine was designed to use a minimum amount of strategic materials. All high heat-resistant metal parts, including

5452-508: The Me 262 V1 example, bearing its Stammkennzeichen radio code letters of PC+UA, but since its intended BMW 003 turbojets were not ready for fitting, a conventional Junkers Jumo 210 engine was mounted in the V1 prototype's nose, driving a propeller, to test the Me 262 V1 airframe. When the BMW 003 engines were installed, the Jumo was retained for safety, which proved wise as both 003s failed during

5568-564: The Me 262 had little effect on the war because of its late introduction and the small numbers that entered service. Although German use of the Me 262 ended with World War II, the Czechoslovak Air Force operated a small number until 1951. Also, Israel may have used between two and eight Me 262s. These were supposedly built by Avia and supplied covertly, and there has been no official confirmations of their use. The aircraft heavily influenced several prototype designs, such as

5684-440: The Me 262 was quite maneuverable despite its high wing loading and lack of low-speed thrust, especially if attention was drawn to its effective maneuvering speeds. The controls were light and effective right up to the maximum permissible speed and perfectly harmonised. The inclusion of full span automatic leading-edge slats , something of a "tradition" on Messerschmitt fighters dating back to the original Bf 109's outer wing slots of

5800-522: The Me 262, before agreeing in early 1944. Similar criticisms were voiced by Lieutenant General Adolf Galland. Hitler rejected arguments that the aircraft would be more effective as a fighter against the Allied bombers destroying large parts of Germany and wanted it as a bomber for revenge attacks. According to Speer, Hitler felt its superior speed compared to other fighters of the era meant it could not be attacked, and so preferred it for high altitude straight flying. Test flights began on 18 April 1941, with

5916-489: The Me 262, ten of them American North American P-51 Mustangs . Me 262 aces included Georg-Peter Eder , with twelve enemy fighters (including nine P-51s) to his credit , Erich Rudorffer also with twelve enemy fighters to his credit, Walther Dahl with eleven (including three Lavochkin La-7s and six P-51s) and Heinz-Helmut Baudach with six (including one Spitfire and two P-51s) amongst many others. Pilots soon learned that

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6032-525: The Me ;262A-2a fighter-bomber for use in a ground-attack role. However, the unit lost 12 jets in action in two weeks for minimal returns. Jagdverband 44 (JV 44) was another Me 262 fighter unit, of squadron ( Staffel ) size given the low numbers of available personnel, formed in February 1945 by Lieutenant General Adolf Galland , who had recently been dismissed as Inspector of Fighters . Galland

6148-548: The US Navy although higher claims have sometimes been made. The aircraft had reliability problems because of strategic materials shortages and design compromises with its Junkers Jumo 004 axial-flow turbojet engines. Late-war Allied attacks on fuel supplies also reduced the aircraft's readiness for combat and training sorties. Armament production within Germany was focused on more easily manufactured aircraft. Ultimately,

6264-463: The World War II era shared, was the high risk of compressor stall and if throttle movements were too rapid, the engine(s) could suffer a flameout. The coarse opening of the throttle would cause fuel surging and lead to excessive jet pipe temperatures. Pilots were instructed to operate the throttle gently and avoid quick changes. German engineers introduced an automatic throttle regulator later in

6380-464: The aircraft decreases the efficiency of the engine because it has been compressed, but then does not contribute to producing thrust. Compressor types used in turbojets were typically axial or centrifugal. Early turbojet compressors had low pressure ratios up to about 5:1. Aerodynamic improvements including splitting the compressor into two separately rotating parts, incorporating variable blade angles for entry guide vanes and stators, and bleeding air from

6496-485: The change in the centre of gravity and to position the centre of lift properly relative to the centre of mass. (The original 35° sweep, proposed by Adolf Busemann , was not adopted.) Initially the inboard leading edge retained the straight profile as did the trailing edge of the midsection of the wing. Based on data from the AVA Göttingen and wind tunnel results, the inboard section's leading edge (between

6612-407: The cockpit; and a 200-litre (44-imperial-gallon; 53-US-gallon) ventral fuselage tank beneath, the Me 262 would have a total flight endurance of 60 to 90 minutes. Fuel was usually J2 ( derived from brown coal ), with the option of diesel or a mixture of oil and high octane B4 aviation petrol . Fuel consumption was double the rate of typical twin-engine fighter aircraft of the era, which led to

6728-401: The combustion chamber, were changed to mild steel (SAE 1010) and were protected only against oxidation by aluminum coating. The engine represented a design compromise to minimize the use of strategic materials and to simplify manufacture. With the lower-quality steels used in the 004B, the engine required overhaul after just 25 hours for a metallurgical test on the turbine. If it passed the test,

6844-410: The combustion chamber. Fuel is mixed with the compressed air and burns in the combustor. The combustion products leave the combustor and expand through the turbine where power is extracted to drive the compressor. The turbine exit gases still contain considerable energy that is converted in the propelling nozzle to a high speed jet. The first turbojets, used either a centrifugal compressor (as in

6960-432: The combustor and pass through to the turbine in a continuous flowing process with no pressure build-up. Instead, a small pressure loss occurs in the combustor. The fuel-air mixture can only burn in slow-moving air, so an area of reverse flow is maintained by the fuel nozzles for the approximately stoichiometric burning in the primary zone. Further compressed air is introduced which completes the combustion process and reduces

7076-421: The compressor enabled later turbojets to have overall pressure ratios of 15:1 or more. After leaving the compressor, the air enters the combustion chamber. The burning process in the combustor is significantly different from that in a piston engine . In a piston engine, the burning gases are confined to a small volume, and as the fuel burns, the pressure increases. In a turbojet, the air and fuel mixture burn in

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7192-401: The compressor is passed through these to keep the metal temperature within limits. The remaining stages do not need cooling. In the first stage, the turbine is largely an impulse turbine (similar to a pelton wheel ) and rotates because of the impact of the hot gas stream. Later stages are convergent ducts that accelerate the gas. Energy is transferred into the shaft through momentum exchange in

7308-536: The compressor stage. Well-known examples are the Concorde and Lockheed SR-71 Blackbird propulsion systems where the intake and engine contributions to the total compression were 63%/8% at Mach 2 and 54%/17% at Mach 3+. Intakes have ranged from "zero-length" on the Pratt & Whitney TF33 turbofan installation in the Lockheed C-141 Starlifter , to the twin 65 feet (20 m) long, intakes on

7424-454: The conventional gear configuration. Changing to a tricycle arrangement—a permanently fixed undercarriage on the fifth prototype (V5, code PC+UE), with the definitive fully retractable nosewheel gear on the V6 (with Stammkennzeichen code VI+AA, from a new code block) and subsequent aircraft corrected this problem. Test flights continued over the next year, but engine problems continued to plague

7540-482: The end of the war. And on 8 May, at around 4:00 p.m. Oblt. Fritz Stehle of 2./JG 7, while flying a Me 262 on the Ore Mountains , attacked a formation of Soviet aircraft. He claimed a Yakovlev Yak-9 , but the aircraft shot down was probably a P-39 Airacobra . Soviet records show that they lost two Airacobras, one of them probably downed by Stehle, who would thus have scored the last Luftwaffe air victory of

7656-501: The engine nacelles—approached from the side of a bomber formation, where their silhouettes were widest and while still out of range of the bombers' machine guns, fired a salvo of rockets. One or two hits with these rockets could shoot down even the famously rugged Boeing B-17 Flying Fortress , from the "metal-shattering" brisant effect of the fast-flying rocket's 520 g (18 oz) explosive warhead. The much bigger BR 21 large-calibre rockets, fired from their tubular launchers under

7772-489: The engine was refitted for a further 10 hours of usage, but 35 hours marked the absolute limit for the turbine wheel. Frank Whittle concludes in his final assessment over the two engines: "it was in the quality of high temperature materials that the difference between German and British engines was most marked" Operationally, carrying 2,000 litres (440 imperial gallons; 530 US gallons) of fuel in two 900-litre (200-imperial-gallon; 240-US-gallon) tanks, one each fore and aft of

7888-474: The engines, Messerschmitt moved the engines from the wing roots to underwing pods, allowing them to be changed more readily if needed. That turned out to be important, both for availability and maintenance. When it became apparent that the BMW 003 jets would be significantly heavier than anticipated, on 1 March 1940, it was decided that instead of moving the wing backward on its mount, the outer wing would be swept slightly rearwards to 18.5 degrees, to accommodate

8004-665: The fields to attack jets trying to land. The Luftwaffe countered by installing extensive " Flak alleys" of anti-aircraft guns along the approach lines to protect the Me 262s from the ground—and by providing top cover during the jets' takeoff and landing with the most advanced Luftwaffe single-engined fighters, the Focke-Wulf Fw 190 D and (just becoming available in 1945) Focke-Wulf Ta 152 H. Nevertheless, in March–April 1945, Allied fighter patrol patterns over Me 262 airfields resulted in numerous jet losses. Lt. Chuck Yeager of

8120-399: The first flight and the pilot had to land using the nose-mounted engine alone. The V1 through V4 prototype airframes all possessed what would become an uncharacteristic feature for most later jet aircraft designs, a fully retracting conventional gear setup with a retracting tailwheel—indeed, the very first prospective German "jet fighter" airframe design ever flown, the Heinkel He 280 , used

8236-461: The first kill by a 262, of a reconnaissance Mosquito, PR.IX LR433, of 540 squadron, over Munich, killing the pilot, Fl. Lt. Desmond Laurence Mattewman and navigator Flight Sergeant William Stopford. Major Walter Nowotny was assigned as commander after the death of Thierfelder in July 1944, and the unit redesignated Kommando Nowotny . Essentially a trials and development unit, it mounted the world's first jet fighter operations. Trials progressed at

8352-431: The forests north-east of Baruth . They succeeded in strafing 65 Soviet lorries, after which the Me 262s intercepted low flying Il-2 Sturmoviks searching for German tanks. The jet pilots claimed six Sturmoviks for the loss of three Messerschmitts. During operations between 28 April and 1 May Soviet fighters and ground fire downed at least ten more Me 262s from JG 7. However, JG 7 managed to keep its jets operational until

8468-449: The high-speed convergence allowing Me 262 pilots little time to line up their targets or acquire the appropriate amount of deflection . This problem faces any aircraft that approaches another from behind at much higher speed, as the slower aircraft in front can always pull a tighter turn, forcing the faster aircraft to overshoot. I passed one that looked as if it was hanging motionless in the air (I am too fast!). The one above me went into

8584-475: The high-temperature materials used in their turbosuperchargers during World War II. Water injection was a common method used to increase thrust, usually during takeoff, in early turbojets that were thrust-limited by their allowable turbine entry temperature. The water increased thrust at the temperature limit, but prevented complete combustion, often leaving a very visible smoke trail. Allowable turbine entry temperatures have increased steadily over time both with

8700-442: The installation of a low-fuel warning indicator in the cockpit that notified pilots when remaining fuel fell below 250 L (55 imp gal; 66 US gal). Unit cost for an Me 262 airframe, less engines, armament, and electronics, was 87,400  ℛ︁ℳ︁ . To build one airframe took around 6,400-man-hours. On 19 April 1944, Erprobungskommando 262 was formed at Lechfeld just south of Augsburg , as

8816-441: The introduction of superior alloys and coatings, and with the introduction and progressive effectiveness of blade cooling designs. On early engines, the turbine temperature limit had to be monitored, and avoided, by the pilot, typically during starting and at maximum thrust settings. Automatic temperature limiting was introduced to reduce pilot workload and reduce the likelihood of turbine damage due to over-temperature. A nose bullet

8932-401: The jet V j {\displaystyle V_{j}\;} must exceed the true airspeed of the aircraft V {\displaystyle V\;} if there is to be a net forward thrust on the airframe. The speed V j {\displaystyle V_{j}\;} can be calculated thermodynamically based on adiabatic expansion . The operation of a turbojet

9048-593: The jets. Aiming was difficult because the jets closed into firing range quickly and remained in firing position only briefly, using their standard attack profile, which proved more effective. A prominent Royal Navy test pilot, Captain Eric Brown , chief naval test pilot and commanding officer of the Captured Enemy Aircraft Flight Royal Aircraft Establishment , who tested the Me 262 noted that: This

9164-518: The loss of three Me 262s. Although a 4:1 ratio was exactly what the Luftwaffe would have needed to make an impact on the war, the absolute scale of their success was minor, as it represented only 1% of the attacking force. In the last days of the conflict, Me 262s from JG 7 and other units were committed in ground assault missions, in an attempt to support German troops fighting Red Army forces. Just south of Berlin, halfway between Spremberg and

9280-401: The low-drag canopy with a 35° wing sweep and a V-tail (butterfly tail). The HG III had a conventional tail, but a 45° wing sweep and turbines embedded in the wing roots . Messerschmitt also conducted a series of flight tests with the series production Me 262. Dive tests determined that the Me 262 went out of control in a dive at Mach  0.86, and that higher Mach numbers would cause

9396-526: The nacelle and wing root) was later swept to the same angle as the outer panels, from the "V6" sixth prototype onward throughout volume production. The shallow leading edge sweep of 18.5° may have inadvertently provided an advantage by slightly increasing the critical Mach number however, its Tactical (useable) Mach number remained a relatively modest at Mach 0.82 and both German and British test pilots found that it suffered severe controllability problems as it approached Mach 0.86. The jet engine program

9512-436: The nose of the Me 262A (one either side of the nosewheel well) were only as fast as MK 108 rounds. Though this broadside-attack tactic was effective, it came too late to have a real effect on the war and only small numbers of Me 262s were equipped with the rocket packs; most were Me 262A-1a models, of Jagdgeschwader 7 . This method of attacking bombers became the standard and mass deployment of Ruhrstahl X-4 guided missiles

9628-402: The opposite way to energy transfer in the compressor. The power developed by the turbine drives the compressor and accessories, like fuel, oil, and hydraulic pumps that are driven by the accessory gearbox. After the turbine, the gases expand through the exhaust nozzle producing a high velocity jet. In a convergent nozzle, the ducting narrows progressively to a throat. The nozzle pressure ratio on

9744-421: The original design was very different from the aircraft that eventually entered service. Specifically, it featured wing-root-mounted engines, rather than podded ones. The progression of the original design was delayed greatly by technical problems with the new jet engine. Originally designed with straight wings, problems arose when the long delayed engines proved heavier than originally promised. While waiting for

9860-459: The piston-powered, 1935-origin Bf 109 and the projected Me 209 . Major General Adolf Galland had supported Messerschmitt through the early development years, flying the Me 262 himself on 22 April 1943. By that time, the problems with engine development had slowed production of the aircraft considerably. One particularly acute problem was the lack of an alloy with a melting point high enough to endure

9976-558: The project, the Jumo 004 being only marginally more reliable than the lower-thrust (7.83 kN/1,760 lbf) BMW 003. Early engines were so short-lived that they frequently needed replacement after only a single flight. Airframe modifications were complete by 1942 but, hampered by the lack of engines, serial production did not begin until 1944, and deliveries were low, with 28 Me 262s in June, 59 in July, but only 20 in August. By mid-1943,

10092-432: The root to 1 mm (0.039 in) at the tip. To expedite construction, save weight, and use fewer strategic materials late in the war, the wing interiors were not painted. The wings were fastened to the fuselage at four points, using a pair of 20 mm (0.79 in) and forty-two 8 mm (0.31 in) bolts. During mid-1943, Adolf Hitler envisioned the Me 262 as a ground-attack / bomber aircraft rather than

10208-497: The short barrels of the MK 108 cannon and low muzzle velocity - 540 m/s (1,800 ft/s) - rendered it inaccurate beyond 600 m (660 yd), coupled with the jet's velocity, which required breaking off at 200 m (220 yd) to avoid colliding with the target, Me 262 pilots normally commenced firing at 500 m (550 yd). Gunners of Allied bomber aircraft found their electrically powered gun turrets had problems tracking

10324-537: The start of the war. The project had originated with a request by the Reichsluftfahrtministerium (RLM, Ministry of Aviation) for a jet aircraft capable of one hour's endurance and a speed of at least 850 km/h (530 mph; 460 kn). Woldemar Voigt headed the design team, with Messerschmitt's chief of development, Robert Lusser , overseeing. During April 1939, initial plans were drawn up and, following their submission in June 1939,

10440-468: The supersonic airliner, in terms of miles per gallon, compared to subsonic airliners at Mach 0.85 (Boeing 707, DC-8) was relatively small. This is because the large increase in drag is largely compensated by an increase in powerplant efficiency (the engine efficiency is increased by the ram pressure rise which adds to the compressor pressure rise, the higher aircraft speed approaches the exhaust jet speed increasing propulsive efficiency). Turbojet engines had

10556-446: The temperature of the combustion products to a level which the turbine can accept. Less than 25% of the air is typically used for combustion, as an overall lean mixture is required to keep within the turbine temperature limits. Hot gases leaving the combustor expand through the turbine. Typical materials for turbines include inconel and Nimonic . The hottest turbine vanes and blades in an engine have internal cooling passages. Air from

10672-421: The temperatures involved, a problem that had not been adequately resolved by the end of the war. After a November 1941 flight (with BMW 003s) ended in a double flameout , the aircraft made its first successful flight entirely on jet power on 18 July 1942, propelled by a pair of Jumo 004 engines. Ludwig Bölkow was the principal aerodynamicist assigned to work on the design of the Me 262. He initially designed

10788-548: The thrust from a turbojet engine. It was flown by test pilot Erich Warsitz . The Gloster E.28/39 , (also referred to as the "Gloster Whittle", "Gloster Pioneer", or "Gloster G.40") made the first British jet-engined flight in 1941. It was designed to test the Whittle jet engine in flight, and led to the development of the Gloster Meteor. The first two operational turbojet aircraft, the Messerschmitt Me 262 and then

10904-412: The turbines would overheat, the lubricating oil would leak from the bearing cavities, the rotor thrust bearings would skid or be overloaded, and ice would form on the nose cone. The air from the compressor, called secondary air, is used for turbine cooling, bearing cavity sealing, anti-icing, and ensuring that the rotor axial load on its thrust bearing will not wear it out prematurely. Supplying bleed air to

11020-471: The turbines. British engines such as the Rolls-Royce Welland used better materials giving improved durability. The Welland was type-certified for 80 hours initially, later extended to 150 hours between overhauls, as a result of an extended 500-hour run being achieved in tests. General Electric in the United States was in a good position to enter the jet engine business due to its experience with

11136-537: The unarmed Mosquito, though Wall evaded Schreiber's three attack runs, to land safely at Fermo, Italy, after the first air-to-air use of a jet fighter. Sources state the Mosquito had a hatch fall out, during the evasive manoeuvres, though the aircraft returned to RAF Benson on 27 July 1944, and remained in service till it was lost in a landing in October 1950. On 8 August 1944, Lt. Joachim Weber of EKdo 262 claimed

11252-421: The war but it only partly alleviated the problem. The aircraft had, by contemporary standards, a high wing loading (294.0 kg/m , 60.2 lbs/ft ) that required higher takeoff and landing speeds. Due to poor throttle response, the engines' tendency for airflow disruption that could cause the compressor to stall was ubiquitous. The high speed of the Me 262 also presented problems when engaging enemy aircraft,

11368-719: The war. Several two-seat trainer variants of the Me 262, the Me 262 B-1a, had been adapted through the Umrüst-Bausatz 1 factory refit package as night fighters , complete with on-board FuG 218 Neptun high-VHF band radar, using Hirschgeweih ("stag's antlers") antennae with a set of dipole elements shorter than the Lichtenstein SN-2 had used, as the B-1a/U1 version. Serving with 10. Staffel Nachtjagdgeschwader 11 , near Berlin, these few aircraft (alongside several single-seat examples) accounted for most of

11484-538: The wing using NACA airfoils modified with an elliptical nose section. Later in the design process, these were changed to AVL derivatives of NACA airfoils, the NACA 00011-0.825-35 being used at the root and the NACA 00009-1.1-40 at the tip. The elliptical nose derivatives of the NACA airfoils were used on the horizontal and vertical tail surfaces . Wings were of single-spar cantilever construction, with stressed skins , varying from 3 mm (0.12 in) skin thickness at

11600-490: Was a Blitzkrieg aircraft. You whack in at your bomber. It was never meant to be a dogfighter , it was meant to be a destroyer of bombers ... The great problem with it was it did not have dive brakes . For example, if you want to fight and destroy a B-17, you come in on a dive. The 30mm cannon were not so accurate beyond 600 metres [660 yd; 2,000 ft]. So you normally came in at 600 yards [550 m; 1,800 ft] and would open fire on your B-17. And your closing speed

11716-419: Was a great potential advantage in a dogfight as it meant better energy retention in manoeuvres. Too fast to catch for the escorting Allied fighters, the Me 262s were almost impossible to head off. As a result, Me 262 pilots were relatively safe from the Allied fighters, as long as they did not allow themselves to get drawn into low-speed turning contests and saved their maneuvering for higher speeds. Combating

11832-427: Was able to draw into the unit many of the most experienced and decorated Luftwaffe fighter pilots from other units grounded by lack of fuel. During March, Me 262 fighter units were able, for the first time, to mount large-scale attacks on Allied bomber formations. On 18 March 1945, thirty-seven Me 262s of JG 7 intercepted a force of 1,221 bombers and 632 escorting fighters. They shot down 12 bombers and one fighter for

11948-414: Was attacked by other Mustangs, forced to bail out, and died. The Kommando was then withdrawn for further flight training and a revision of combat tactics to optimise the Me 262's strengths. On 26 November 1944, a Me 262A-2a Sturmvogel of III. Gruppe / KG 51 'Edelweiß' based at Rheine-Hopsten Air Base near Osnabrück was the first confirmed ground-to-air kill of a jet combat aircraft. The Me 262

12064-467: Was cancelled. Some nicknamed this tactic the Luftwaffe's Wolf Pack , as the fighters often made runs in groups of two or three, fired their rockets, then returned to base. On 1 September 1944, USAAF General Carl Spaatz expressed the fear that if greater numbers of German jets appeared, they could inflict losses heavy enough to force cancellation of the Allied bombing offensive by daylight. The Me 262

12180-408: Was delayed by problems with engines, metallurgy , and interference from Luftwaffe chief Hermann Göring and Adolf Hitler . The German leader demanded that the Me 262, conceived as a defensive interceptor, be redesigned as ground-attack / bomber aircraft. The aircraft became operational with the Luftwaffe in mid-1944. The Me 262 was faster and more heavily armed than any Allied fighter, including

12296-502: Was designed and produced by the German aircraft manufacturer Messerschmitt . It was the world's first operational jet-powered fighter aircraft and "the only jet fighter to see air-to-air combat in World War Two". The design of what would become the Me 262 started in April 1939, before World War II . It made its maiden flight on 18 April 1941 with a piston engine , and its first jet-powered flight on 18 July 1942. Progress

12412-404: Was difficult to counter because its high speed and rate of climb made it hard to intercept. However, as with other turbojet engines at the time, the Me 262's engines did not provide sufficient thrust at low airspeeds and throttle response was slow, so that in certain circumstances such as takeoff and landing the aircraft became a vulnerable target. Another disadvantage that pioneering jet aircraft of

12528-476: Was exasperating. I would never be able to shoot one down like this. They were like a sack of fleas. A prick of doubt: is this really such a good fighter? Could one in fact, successfully attack a group of erratically banking fighters with the Me 262? Luftwaffe pilots eventually learned how to handle the Me 262's higher speed and the Me 262 soon proved a formidable air superiority fighter, with pilots such as Franz Schall managing to shoot down seventeen enemy fighters in

12644-424: Was liquid-fuelled. Whittle's team experienced near-panic during the first start attempts when the engine accelerated out of control to a relatively high speed despite the fuel supply being cut off. It was subsequently found that fuel had leaked into the combustion chamber during pre-start motoring checks and accumulated in pools, so the engine would not stop accelerating until all the leaked fuel had burned off. Whittle

12760-471: Was shot down by a Bofors gun of B.11 Detachment of 2875 Squadron RAF Regiment at the RAF forward airfield of Helmond, near Eindhoven . Others were lost to ground fire on 17 and 18 December when the same airfield was attacked at intervals by a total of 18 Me 262s and the guns of 2873 and 2875 Squadrons RAF Regiment damaged several, causing at least two to crash within a few miles of the airfield. In February 1945,

12876-594: Was still high and since you had to break away at 200 metres [220 yd; 660 ft] to avoid a collision, you only had two seconds firing time. Now, in two seconds, you can't sight. You can fire randomly and hope for the best. If you want to sight and fire, you need to double that time to four seconds. And with dive brakes, you could have done that. Eventually, German pilots developed new tactics to counter Allied bombers. Me 262s, equipped with up to 24 unguided folding-fin R4M rockets —12 in each of two underwing racks, outboard of

12992-640: Was tested on the Power Jets W.1 in 1941 initially using ammonia before changing to water and then water-methanol. A system to trial the technique in the Gloster E.28/39 was devised but never fitted. An afterburner or "reheat jetpipe" is a combustion chamber added to reheat the turbine exhaust gases. The fuel consumption is very high, typically four times that of the main engine. Afterburners are used almost exclusively on supersonic aircraft , most being military aircraft. Two supersonic airliners, Concorde and

13108-425: Was the construction of a "flak lane" of over 150 emplacements of the 20 mm Flakvierling quadruple autocannon batteries at Rheine-Hopsten to protect the approaches. After seven Tempests were lost to flak at Hopsten in a week, the "Rat Scramble" was discontinued. Adolf Busemann had proposed swept wings as early as 1935; Messerschmitt researched the topic from 1940. In April 1941, Busemann proposed fitting

13224-470: Was too high for accurate shooting with the relatively slow firing 30mm MK 108 cannon - at about 650 rounds/min this gave around 44 rounds per second from all four guns. Even from astern, the closing speed was too great to use the short-ranged cannon to maximum effect. A roller-coaster attack was devised, the Me 262s approached from astern and about 1,800 m higher (5,900 ft) than the bombers. From about five km (3.1 mi) behind, they went into

13340-427: Was unable to interest the government in his invention, and development continued at a slow pace. In Germany, Hans von Ohain patented a similar engine in 1935. His design, an axial-flow engine, as opposed to Whittle's centrifugal flow engine, was eventually adopted by most manufacturers by the 1950s. On 27 August 1939 the Heinkel He 178 , powered by von Ohain's design, became the world's first aircraft to fly using

13456-463: Was waylaid by a lack of funding, which was primarily due to a prevailing attitude amongst high-ranking officials that the conflict could be won easily with conventional aircraft. Among these was Hermann Göring , head of the Luftwaffe, who cut the engine development program to just 35 engineers in February 1940 (the month before the first wooden mock-up was completed). The aeronautical engineer Willy Messerschmitt sought to maintain mass production of

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