An aircraft engine , often referred to as an aero engine , is the power component of an aircraft propulsion system . Aircraft using power components are referred to as powered flight . Most aircraft engines are either piston engines or gas turbines , although a few have been rocket powered and in recent years many small UAVs have used electric motors .
190-565: The Allison V-1710 aircraft engine designed and produced by the Allison Engine Company was the only US -developed V-12 liquid-cooled engine to see service during World War II . Versions with a turbocharger gave excellent performance at high altitude in the twin-engined Lockheed P-38 Lightning , and turbo-superchargers were fitted to experimental single-engined fighters with similar results. The United States Army Air Corps (USAAC) preference for turbochargers early in
380-515: A compression ratio of 6.65:1. The valvetrain has a single overhead camshaft per bank of cylinders and four valves per cylinder. The engine design benefited from the General Motors philosophy of built-in production and installation versatility, embracing a philosophy of modular design for aviation powerplants. The engine was constructed around a basic power section , from which different installation requirements could be met by fitting
570-443: A gas turbine engine offered. Thus was born the idea to mate a turbine engine to a traditional propeller. Because gas turbines optimally spin at high speed, a turboprop features a gearbox to lower the speed of the shaft so that the propeller tips don't reach supersonic speeds. Often the turbines that drive the propeller are separate from the rest of the rotating components so that they can rotate at their own best speed (referred to as
760-593: A 9.6:1 blower ratio. This allowed the P-51A to reach a maximum speed of 415 mph (668 km/h; 361 kn) at 10,400 ft (3,200 m) and maintain 400 mph (640 km/h; 350 kn) at 23,000 ft (7,000 m). This was more than 70 mph (110 km/h; 61 kn) faster than the Merlin 45-powered Spitfire V at 10,000 ft (3,000 m), and more than 30 mph (48 km/h; 26 kn) faster at 25,000 ft (7,600 m). Its speed impressed
950-618: A better efficiency. A hybrid system as emergency back-up and for added power in take-off is offered for sale by Axter Aerospace, Madrid, Spain. Small multicopter UAVs are almost always powered by electric motors. Reaction engines generate the thrust to propel an aircraft by ejecting the exhaust gases at high velocity from the engine, the resultant reaction of forces driving the aircraft forwards. The most common reaction propulsion engines flown are turbojets, turbofans and rockets. Other types such as pulsejets , ramjets , scramjets and pulse detonation engines have also flown. In jet engines
1140-504: A center wing mounted pod housing an array of recon cameras, and was assigned to the 3200th Photo Test Squadron, being designated, unofficially, the RF-82B. On 27 February 1947, P-82B, named Betty Jo and flown by Colonel Robert E. Thacker , made history when it flew nonstop from Hawaii to New York without refueling, a distance of 5,051 mi (8,129 km) in 14 hr 32 min. It averaged 347.5 mph (559.2 km/h). This flight tested
1330-419: A combustion section where fuel is added and ignited, one or more turbines that extract power from the expanding exhaust gases to drive the compressor, and an exhaust nozzle that accelerates the exhaust gases out the back of the engine to create thrust. When turbojets were introduced, the top speed of fighter aircraft equipped with them was at least 100 miles per hour faster than competing piston-driven aircraft. In
1520-564: A common crankshaft. The vast majority of V engines are water-cooled. The V design provides a higher power-to-weight ratio than an inline engine, while still providing a small frontal area. Perhaps the most famous example of this design is the legendary Rolls-Royce Merlin engine, a 27-litre (1649 in ) 60° V12 engine used in, among others, the Spitfires that played a major role in the Battle of Britain . A horizontally opposed engine, also called
1710-783: A complete redesign, and did not share many components with the earlier engine series. Almost all components were interchangeable with later series engines and the V-3420, and could be assembled as right hand or left hand turning engines in either pusher or tractor applications. "F" series engines were designed for late model pursuit aircraft, and are identified by the compact external spur gear-type reduction gear box. Military models were V-1710-27, -29, -39, -45, -49, -51, -53, -55, -57, -61, -75, -77, -81, -87, -89, -91, -95, -99, -101, -105, -107, -111, -113, -115, -119, producing 1,150–1,425 hp (858–1,063 kW) at 3000 rpm. The V-1710-101, -119 and -121 models has an auxiliary supercharger, some with
1900-490: A cooling system into the air duct of a hydrogen jet engine permits greater fuel injection at high speed and obviates the need for the duct to be made of refractory or actively cooled materials. This greatly improves the thrust/weight ratio of the engine at high speed. It is thought that this design of engine could permit sufficient performance for antipodal flight at Mach 5, or even permit a single stage to orbit vehicle to be practical. The hybrid air-breathing SABRE rocket engine
2090-649: A coordinated flyover. Most of the Strategic Air Command's bombers were to participate, along with its only "Long Range" fighter group, the 27th. The weather in Nebraska was horrible, with most airports in the Midwest forced to close on the day of the display. Kearney Air Force Base was hit with a blizzard, and paths were cut through the snow allowing the F-82s to take off and rendezvous with the bombers. This
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#17327800657052280-440: A cylinder on the other side. Opposed, air-cooled four- and six-cylinder piston engines are by far the most common engines used in small general aviation aircraft requiring up to 400 horsepower (300 kW) per engine. Aircraft that require more than 400 horsepower (300 kW) per engine tend to be powered by turbine engines . An H configuration engine is essentially a pair of horizontally opposed engines placed together, with
2470-491: A drag racing engine, being unable to accelerate rapidly, but "could taxi all day at 150". Unlimited hydroplane racing also became a big sport across the U.S. at this time and V-1710s were often tuned for racing at up to 3,200 hp (2,400 kW)—power levels that were beyond design criteria and significantly reduced durability. Later, as purpose-built V8 engines became available for drag racing and unlimited boats shifted to turboshaft power, tractor pullers began using
2660-522: A feature of the V-1710-F series. The accessory end had a one- or two-speed engine-driven supercharger that might have a second stage with or without an intercooler , the ignition magnetos and the customary assortment of oil and fuel pumps, all dictated by the application requirements. The front of the engine could have one of a number of different output drives. The drive might be a "long-nose" or close coupled propeller reduction gear, an extension drive to
2850-711: A few instances of eye-to-eye contact with Soviet aircraft. The slower F-82s had a longer range than the F-94s, and the Twin Mustangs constantly patrolled over many Alaskan villages and towns. Periodically, the F-82s were used for long-range visual reconnaissance near several known rough airstrips on the Chukchi Peninsula that the Soviets had used during World War II as landing fields for lend-lease aircraft and checking for any activity. In addition, flights around
3040-408: A flat or boxer engine, has two banks of cylinders on opposite sides of a centrally located crankcase. The engine is either air-cooled or liquid-cooled, but air-cooled versions predominate. Opposed engines are mounted with the crankshaft horizontal in airplanes , but may be mounted with the crankshaft vertical in helicopters . Due to the cylinder layout, reciprocating forces tend to cancel, resulting in
3230-613: A flight which was deployed from the 4th F(AW)S in Okinawa to Japan and a full squadron of F-80s for air defense. On 30 June, FEAF requested HQ USAF for an additional 21 F-82 aircraft, which was denied. In addition, the projected level of support which could be provided at the level of combat usage FEAF was experiencing was no more than 60 days due to a shortage of parts. The fact was that, when F-82 production ended in April 1948, no provision had been made for an adequate supply of spare parts, as
3420-572: A fraction of the cost of traditional engines. Such conversions first took place in the early 1970s; and as of 10 December 2006 the National Transportation Safety Board has only seven reports of incidents involving aircraft with Mazda engines, and none of these is of a failure due to design or manufacturing flaws. The most common combustion cycle for aero engines is the four-stroke with spark ignition. Two-stroke spark ignition has also been used for small engines, while
3610-407: A free-turbine engine). A turboprop is very efficient when operated within the realm of cruise speeds it was designed for, which is typically 200 to 400 mph (320 to 640 km/h). Turboshaft engines are used primarily for helicopters and auxiliary power units . A turboshaft engine is similar to a turboprop in principle, but in a turboprop the propeller is supported by the engine and the engine
3800-456: A handful of types are still in production. The last airliner that used turbojets was the Concorde , whose Mach 2 airspeed permitted the engine to be highly efficient. A turbofan engine is much the same as a turbojet, but with an enlarged fan at the front that provides thrust in much the same way as a ducted propeller , resulting in improved fuel efficiency . Though the fan creates thrust like
3990-465: A large number of enemy troops killed when the B-26s destroyed a bridge at Pyongtaek , causing a massive jam. On 5 July, the 339th Squadron was pulled out of combat and returned to Johnson AB. Shortly afterwards, the 4th Squadron returned to Okinawa, with the 347th Provisional Group being inactivated and control of the 68th Squadron being turned over to the 8th Fighter Group . The 339th had been in combat
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#17327800657054180-408: A liquid-cooled aftercooler. Supercharger gear ratios were: 6.44:1, 7.48:1, 8.10:1, 8.80:1 and 9.60:1 depending on altitude rating. These engines had either a six or twelve weight crankshaft, revised vibration dampeners that combined to allow higher engine speeds, SAE #50 propeller shaft, and higher horsepower ratings. The "E" series and "F" series engines were very similar, the primary difference being
4370-657: A long-range escort fighter. Radar-equipped F-82s were used extensively by the Air Defense Command as replacements for the Northrop P-61 Black Widow as all-weather day/night interceptors. During the Korean War , Japan-based F-82s were among the first USAF aircraft to operate over Korea. The first three North Korean aircraft destroyed by U.S. forces were shot down by F-82s, the first being a North Korean Yak-11 downed over Gimpo Airfield by
4560-536: A maximum of about 15,000 feet (4,600 m) they were available in comparatively large numbers and were the mainstay of some Allied Air Forces in all but the European theater of war. The engines proved to be robust and little affected by machine-gun fire. In total, over 60 percent of the post-June 1941 USAAF 's pursuit aircraft operated during WWII were powered by the V-1710. Allison slowly but continuously improved
4750-465: A mechanical glitch. This remains the longest nonstop flight ever made by a propeller-driven fighter, and the fastest time in which such a distance has ever been covered in a piston-engine aircraft. The aircraft chosen was an earlier "B" model powered by Rolls-Royce Merlin engines (see "Surviving aircraft" below). The Twin Mustang was developed at the end of the prop-driven fighter era and at the dawn of
4940-430: A newly designed center wing section containing the same six .50 caliber (12.7mm) M3 Browning machine guns as a single-engine Mustang, but with more concentrated fire. The first XP-82 prototype was equipped with a removable centerline gun pod housing eight additional .50 caliber M2 Brownings, but this did not feature on production aircraft. An even more powerful centerline gun pod containing a 40 mm (1.6 in) cannon
5130-527: A number, starting with number 1. The last letter, which was introduced when both right hand turning and left hand turning engines were built, identified by the letter R or L respectively. The military model numbers were identified by a "dash number" following the engine description "V-1710". The USAAC/USAAF models were the odd numbers, starting with "-1" and the USN models were the even numbers, starting with "-2". "A" series engines were early development engines for
5320-465: A pair of Soviet-built aircraft (the exact aircraft type has never been determined) came out of the clouds. Orders given to the F-82 pilots prohibited any aggressive action; however, gun switches were activated when the enemy leader tightened up his turn and peeled off at the F-82s with his wing man in close tail. The F-82s dropped their external tanks, turned on combat power and started a climbing turn towards
5510-569: A peak pressure of 30 MPa (300 bar). Although engine weight increases by 30%, aircraft fuel consumption is reduced by 15%. Sponsored by the European Commission under Framework 7 project LEMCOTEC , Bauhaus Luftfahrt, MTU Aero Engines and GKN Aerospace presented the concept in 2015, raising the overall engine pressure ratio to over 100 for a 15.2% fuel burn reduction compared to 2025 engines. On multi-engine aircraft, engine positions are numbered from left to right from
5700-478: A piston-engine with two 10 piston banks without a high-pressure turbine, increasing efficiency with non-stationary isochoric - isobaric combustion for higher peak pressures and temperatures. The 11,200 lb (49.7 kN) engine could power a 50-seat regional jet . Its cruise TSFC would be 11.5 g/kN/s (0.406 lb/lbf/hr) for an overall engine efficiency of 48.2%, for a burner temperature of 1,700 K (1,430 °C), an overall pressure ratio of 38 and
5890-461: A position to shoot them down. Furthermore, when they did so, the bombers had already made their runs over intended targets. The radar-equipped wartime Northrop P-61 Black Widow night fighter was found to be effective in locating and attacking the incoming SAC bombers, and also had the range to attack the bombers far from their intended targets. With no suitable jet interceptors, the P-61 transitioned to
Allison V-1710 - Misplaced Pages Continue
6080-424: A propeller, the surrounding duct frees it from many of the restrictions that limit propeller performance. This operation is a more efficient way to provide thrust than simply using the jet nozzle alone, and turbofans are more efficient than propellers in the transsonic range of aircraft speeds and can operate in the supersonic realm. A turbofan typically has extra turbine stages to turn the fan. Turbofans were among
6270-748: A purely American and stronger engine than the foreign-designed P-51's V-1650 (built at Packard plants, dismantled after the war). In addition, the licensing costs paid to Rolls-Royce for each V-1650 were being increased by Britain after the war. It therefore negotiated in August 1945 with the Allison Division of the General Motors Corporation for a new version of the Allison V-1710 -100 engine. This forced North American to switch subsequent production P-82C and later models to
6460-410: A remote gearbox, or a gearbox that could drive two wing-mounted propellers from a fuselage-mounted engine. Another key feature of the V-1710 design was its ability to turn the output shaft clockwise or counter-clockwise by assembling the engine with the crankshaft turned end-for-end, by installing an idler gear in the drive train to the supercharger, camshafts, and accessories, installing a starter turning
6650-425: A search for replacement fuels for general aviation aircraft a priority for pilots’ organizations. Turbine engines and aircraft diesel engines burn various grades of jet fuel . Jet fuel is a relatively less volatile petroleum derivative based on kerosene , but certified to strict aviation standards, with additional additives. Model aircraft typically use nitro engines (also known as "glow engines" due to
6840-614: A single power lever to regulate engine performance, reducing the pilot's workload when managing this very complex engine. "H" series engines were to use a two-stage supercharger driven by a two-stage air-cooled power recovery turbine. The engine was to have an aftercooler and port-type fuel injection. This variant, however, was never built. Data from Aircraft Engines of the World 1946 and Jane's Fighting Aircraft of World War II. Related development Comparable engines Related lists Aircraft engine In commercial aviation
7030-691: A single production line to build engines for various fighters and bombers . The United States Navy (USN) hoped to use the V-1710 in its rigid airships Akron and Macon , but both were equipped with German-built Maybach VL II engines as the V-1710 was still in testing when the Macon was lost in February 1935 (the Akron having been lost in April 1933). The USAAC purchased its first V-1710 in December 1932. The Great Depression slowed development, and it
7220-404: A smooth running engine. Opposed-type engines have high power-to-weight ratios because they have a comparatively small, lightweight crankcase. In addition, the compact cylinder arrangement reduces the engine's frontal area and allows a streamlined installation that minimizes aerodynamic drag. These engines always have an even number of cylinders, since a cylinder on one side of the crankcase "opposes"
7410-508: A strategic target ended after the Korean War . Strategic bombing became a one-plane, one target mission, with the jet-powered Boeing B-52 Stratofortress flying higher and faster than most enemy interceptors. The escort fighter became redundant, and by 1957 SAC had inactivated the last of its strategic fighter escort wings. The appearance of the Soviet Tupolev Tu-4 in 1947 posed a new threat to postwar USAAF planners, and with
7600-451: A stronger crankshaft, SAE #50 propeller shaft, and Bendix pressure carburetors. "D" series engines were designed for pusher applications using propeller-speed extension shafts and remote thrust bearings mounted to the airframe. The military models were V-1710-9, -13, -23, and -41, producing 1,000–1,250 hp (750–930 kW) at 2600 rpm. Supercharger ratios were 6.23:1, 8.0:1 or 8.77:1, depending on altitude rating. These engines had
7790-465: A thick overcast when they received an urgent request for air support from some hard-pressed ground troops. Darkness was approaching when they reached the area and found UN ground troops pinned down by a concentration of mortars. The F-82 pilots made several passes to get set up with the ground controller, and as soon as the enemy target was pinpointed, the heavily armed aircraft commenced an attack that would last 45 minutes and use up all their ordnance. When
Allison V-1710 - Misplaced Pages Continue
7980-428: A total of 10 days (26 June – 5 July), flying a total of 44 combat sorties for which they had been given no training. The 68th Squadron was left to carry on the battle. Throughout July and August 1950, F-82s from the 68th Squadron attacked enemy trains, vehicles, and numerous buildings, and constantly strafed North Korean troops on the roads. On the night of 27 August, an element of F-82s was patrolling over South Korea over
8170-561: A total of 27 F-82s available for combat duty. This was commendable, considering that on 31 May 1950 a total of 32 F-82s existed within FEAF. With these combined squadrons, the 347th Provisional Fighter Group (AW) was formed. Before dawn on 27 June, the 347th Provisional Group was up in the air over Korea, with a mission to provide cover for the Douglas C-54 Skymaster transports flying in and out of Kimpo Airfield as they moved
8360-417: A total of 682 civilians being transported to Sasebo, Japan . Once the bulk of U.S. civilians had been evacuated out of South Korea by ship, the priority of FEAF changed to a military nature. The 339th F(AW)S received orders from Fifth Air Force to move all available aircraft, along with crews and equipment, to Itazuke Air Base to assist the 68th in providing air cover for the evacuation of Seoul. However,
8550-514: A total of twelve operational F-82Gs. This, combined with what the 339th could contribute, was insufficient to meet the combat needs thrust upon FEAF. The F-80 Shooting Star was available, but its thirsty jet engine meant it could only remain over the airfield for a few minutes before having to return to base and it could not reach the forward combat area from Japan. No USAF P-51 Mustangs were available. FEAF ordered Twentieth Air Force to send eight F-82s from its 4th F(AW)S from Okinawa to Itazuke, making
8740-481: Is a pre-cooled engine under development. At the April 2018 ILA Berlin Air Show , Munich -based research institute de:Bauhaus Luftfahrt presented a high-efficiency composite cycle engine for 2050, combining a geared turbofan with a piston engine core. The 2.87 m diameter, 16-blade fan gives a 33.7 ultra-high bypass ratio , driven by a geared low-pressure turbine but the high-pressure compressor drive comes from
8930-449: Is a twin-spool engine, allowing only two different speeds for the turbines. Pulsejets are mechanically simple devices that—in a repeating cycle—draw air through a no-return valve at the front of the engine into a combustion chamber and ignite it. The combustion forces the exhaust gases out the back of the engine. It produces power as a series of pulses rather than as a steady output, hence the name. The only application of this type of engine
9120-490: Is above and behind. In the Cessna 337 Skymaster , a push-pull twin-engine airplane, engine No. 1 is the one at the front of the fuselage, while engine No. 2 is aft of the cabin. Aircraft reciprocating (piston) engines are typically designed to run on aviation gasoline . Avgas has a higher octane rating than automotive gasoline to allow higher compression ratios , power output, and efficiency at higher altitudes. Currently
9310-453: Is bolted to the airframe : in a turboshaft, the engine does not provide any direct physical support to the helicopter's rotors. The rotor is connected to a transmission which is bolted to the airframe, and the turboshaft engine drives the transmission. The distinction is seen by some as slim, as in some cases aircraft companies make both turboprop and turboshaft engines based on the same design. A number of electrically powered aircraft, such as
9500-533: Is considered to be the first United States air combat mission of the Korean War. With this information, along with other intelligence reports available to them, FEAF confirmed that the Korean People's Army had, indeed, launched a full-scale invasion of South Korea. FEAF's first priority, however, was to evacuate United States citizens. On the morning of 26 June, the nearby Norwegian freighter Reinholte
9690-400: Is located above the cylinders, it is called an inverted inline engine: this allows the propeller to be mounted high up to increase ground clearance, enabling shorter landing gear. The disadvantages of an inline engine include a poor power-to-weight ratio , because the crankcase and crankshaft are long and thus heavy. An in-line engine may be either air-cooled or liquid-cooled, but liquid-cooling
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#17327800657059880-720: Is more common because it is difficult to get enough air-flow to cool the rear cylinders directly. Inline engines were common in early aircraft; one was used in the Wright Flyer , the aircraft that made the first controlled powered flight. However, the inherent disadvantages of the design soon became apparent, and the inline design was abandoned, becoming a rarity in modern aviation. For other configurations of aviation inline engine, such as X-engines , U-engines , H-engines , etc., see Inline engine (aeronautics) . Cylinders in this engine are arranged in two in-line banks, typically tilted 60–90 degrees apart from each other and driving
10070-400: Is not limited to engines with a single row of cylinders. This is typically to differentiate them from radial engines . A straight engine typically has an even number of cylinders, but there are instances of three- and five-cylinder engines. The greatest advantage of an inline engine is that it allows the aircraft to be designed with a low frontal area to minimize drag. If the engine crankshaft
10260-430: Is of lesser concern, rocket engines can be useful because they produce very large amounts of thrust and weigh very little. A rocket turbine engine is a combination of two types of propulsion engines: a liquid-propellant rocket and a turbine jet engine. Its power-to-weight ratio is a little higher than a regular jet engine, and works at higher altitudes. For very high supersonic/low hypersonic flight speeds, inserting
10450-695: Is the last American piston-engined fighter ordered into production by the United States Air Force . Based on the North American P-51 Mustang , the F-82 was originally designed as a long-range escort fighter for the Boeing B-29 Superfortress in World War II . The war ended well before the first production units were operational. In the postwar era, Strategic Air Command used the aircraft as
10640-588: The Beaufort Sea , near the most northerly tip of Alaska, about 1,000 min (60,000 s) south of the North Pole. The F-82H made a brief but memorable appearance in the movie "Top of the World" (1955). Another mission of the 449th was to act as a simulated invasion force during U.S. Army combat maneuvers during the summer months. Army ground units in Alaska were very limited in their movements due to
10830-567: The Bell P-63 and North American P-82 E/F/G series. In addition, it was tried or studied as the powerplant for many experimental and test aircraft such as the Curtiss XP-55 Ascender , North American XP-51J "lightweight Mustang ", Boeing XB-38 Flying Fortress , and Republic XP-47A (AP-10), both of the latter with turbo-superchargers. The V-1710-powered F-82 did not arrive in time for World War II, but did see brief action in
11020-725: The Cold War brought on the challenge of B-29, Boeing B-50 or Convair B-36 missions into the Soviet Union . The size of the Soviet Union dictated long bombing missions there and back from bases in Europe or Alaska, most of it over Soviet territory. Also the weather, which was bad enough in Western Europe, would make bombing missions exceptionally difficult between October and May. With no long-range jet fighters to escort
11210-834: The Eighth Air Force . A few P-38s would remain in the European theater as the F-5 for photo reconnaissance. The P-38 had fewer engine failures in the Pacific Theater, where operating techniques were better developed (such as those recommended by Charles Lindbergh during his development work in the theater),) and the Japanese did not operate at such high altitudes. Using the same P-38Gs which were proving difficult to maintain in England, Pacific-based pilots were able to use
11400-627: The Korean War , although the type was completely withdrawn from Korea by the end of 1950. It had a short service life that was probably due to a combination of factors: poor reliability from the G-series V-1710 engines, low numbers of F-82s produced, and the arrival of jet fighters. The initial production P-82B had Merlin engines, but North American was forced to use the Allison V-1710 for the E/F/G models when Packard stopped production of
11590-635: The Lockheed P-38 , Bell P-39 and Curtiss P-40 . When war material procurement agents from the United Kingdom asked North American Aviation to build the P-40 under license, NAA instead proposed their own improved aircraft design, using the V-1710 in their NA-73 . The V-1710 has 12 cylinders with a bore and stroke of 5.5 by 6 in (139.7 by 152.4 mm) in 60° V format, for a displacement of 1,710.6 cu in (28.032 L), with
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#173278006570511780-617: The Nome area and along the western Alaskan coastline were made. Squadron records show the Twin Mustangs were flown over some of the most remote areas of the Territory, along what today is known as the "North Slope" and over very rugged interior regions. The Twin Mustangs in Alaska operated further north than any other USAF aircraft at the time. In April 1952, they were flying escort duty for SAC B-36 Peacemaker bombers near Barter Island in
11970-527: The QinetiQ Zephyr , have been designed since the 1960s. Some are used as military drones . In France in late 2007, a conventional light aircraft powered by an 18 kW electric motor using lithium polymer batteries was flown, covering more than 50 kilometers (31 mi), the first electric airplane to receive a certificate of airworthiness . On 18 May 2020, the Pipistrel E-811 was
12160-684: The Rutan Quickie . The single-rotor engine was put into a Chevvron motor glider and into the Schleicher ASH motor-gliders. After the demise of MidWest, all rights were sold to Diamond of Austria, who have since developed a MkII version of the engine. As a cost-effective alternative to certified aircraft engines some Wankel engines, removed from automobiles and converted to aviation use, have been fitted in homebuilt experimental aircraft . Mazda units with outputs ranging from 100 horsepower (75 kW) to 300 horsepower (220 kW) can be
12350-570: The Soviet Union after having been forced to land there during bombing raids against Japan in WWII. Since the USSR was expected to have nuclear weapons sooner or later, the appearance of the Soviet Tu-4 was a shock to U.S. military planners, since it meant that the U.S. mainland might be vulnerable to a Soviet nuclear attack from the air. Until jet interceptors could be developed and put into service,
12540-424: The gyroscopic effects of the heavy rotating engine produced handling problems in aircraft and the engines also consumed large amounts of oil since they used total loss lubrication, the oil being mixed with the fuel and ejected with the exhaust gases. Castor oil was used for lubrication, since it is not soluble in petrol, and the resultant fumes were nauseating to the pilots. Engine designers had always been aware of
12730-424: The oxygen necessary for fuel combustion comes from the air, while rockets carry an oxidizer (usually oxygen in some form) as part of the fuel load, permitting their use in space. A turbojet is a type of gas turbine engine that was originally developed for military fighters during World War II . A turbojet is the simplest of all aircraft gas turbines. It consists of a compressor to draw air in and compress it,
12920-472: The 318th FIS at McChord AFB in late 1951. Some went to Alaska, where they were modified into F-82H but most were scrapped. After World War II, the Northrop P-61 Black Widow was the Far East Air Forces (FEAF) main interceptor. However, a lack of spare parts and maintenance issues made it difficult to keep the war-weary aircraft in the air. Until an all-weather jet interceptor became available,
13110-498: The 339th F(AW)S, shot down another La-7. The C-54 was able to escape safely. Three of the five North Korean aircraft had been shot down, with pilot Lt. William G. "Skeeter" Hudson and radar operator Lt. Carl Fraiser scoring the first United States aerial "kill" of the Korean War. In the following weeks, the F-82 pilots would exceed all expectations in aerial combat. On 28 June, orders came down for all F-82s to be used in heavy ground support against any North Korean activity found between
13300-590: The 339th flying similar numbers of missions. During those early days, the stress and strain of combat put on the crews was intense. However, by early July the chances of F-82s engaging in air-to-air combat was significantly reduced, as the F-80 Shooting Stars had effectively stopped North Korea's air force from coming below the 38th parallel. The F-82s began flying strike and escort missions, along with night intruder sorties. Several F-82s took hits in their radar radomes, which were difficult to replace, and
13490-419: The 339th's complement of aircraft were scattered over several bases at the time. Seven F-82s at Yokota AB were flyable and two were in the hangar undergoing maintenance for major repairs. Four other F-82s were at Misawa AB on TDY. The three at Yokota were dispatched immediately to Itazuke, as well as the four at Misawa, making a total of seven combat ready F-82Gs present for duty on 27 June. The 68th F(AW)S had
13680-561: The 35 in Japan answered the call. Arriving in the early morning, they orbited Kimpo Airfield in three flights, each above the other. Suddenly, at 1150 hours, a mixed group of five North Korean fighters (Soviet-built Yak-9s , Yak-11s and La-7s ) appeared, heading for the airfield. One of the Yak-11s immediately scored several hits on 68th F(AW)S pilot Lt. Charles Moran's vertical stabilizer. Moments later, Lt. William G. "Skeeter" Hudson, also of
13870-589: The 449th began receiving the F-94 Starfire jet interceptor, and the F-82s were assigned to a separate detachment within the squadron. With the outbreak of the Korean War, tensions were high in Alaska, as it was feared that it would become a "back door" to Soviet aircraft striking North America. The Soviets were repeatedly testing the Alaskan air defenses, with the F-94s responding when radar stations alerted them to incoming aircraft. Intercepts were rare, with only
14060-537: The 68th F(AW)S, initiated a high-G turn to engage the Yak, and soon was closing in on the Yak's tail. He then fired a short burst at close range, scoring hits with his six .50 inch machine guns. The Yak banked hard to the right, with the F-82G in close pursuit. A second burst hit the Yak's right wing, setting the gas tank on fire and knocking off the right flap and aileron. The North Korean pilot bailed out, but his observer, who
14250-655: The 68th to start flying armed reconnaissance missions to check roads over southern North Korea as UN forces were rapidly withdrawing south before the Chinese onslaught. This was a nightmare as the Chinese were pouring south, and it appeared that the situation was becoming as it had been the previous June. On 26 January, the armed reconnaissance missions were discontinued and the F-82s were placed on continuous combat air patrols over Kandong Airfield near Pyongyang and over both of Pyongyang's main airfields, ( K-23, Pyongyang and K-24, Pyongyang East ) to monitor enemy air activity. This
14440-598: The ADC interceptor mission. Available F-61s were war-weary and night fighter F-82C/D models were modified into all-weather interceptors to replace them. The production interceptor versions of the Twin Mustang were designated the F-82F and F-82G; the distinguishing feature between the F and G models was largely the nacelle beneath the center-wing that housed radar equipment (F-82F's AN/APG-28 and F-82G's SCR-720C18). In addition,
14630-618: The Alaska Air Defense mission. The Twin Mustang was well-suited for the air defense mission in Alaska due to its long-range flying ability. In March 1949, the squadron was reassigned to Ladd AFB , near Fairbanks , where an additional eight (14 total) arrived. In Alaska, the squadron would patrol over wide areas of Alaska as the Soviets flying from airfields in Siberia would often test the air defenses. Beginning in August 1950,
14820-679: The Allison engine, again developing unimagined power. Finally, the warbird movement began to restore and return to the air examples of the classic fighters of the war and many V-1710-powered pursuit airplanes began to fly again, with freshly overhauled engines. The reliability, maintainability, and availability of the engine has led others to use it to power flying examples of aircraft whose original engines are unobtainable. This includes newly manufactured Russian Yak-3 and Yak-9 airplanes, originally powered by Klimov V-12s in World War II and
15010-892: The British, and the RAF quickly realized the airplane would possess excellent high altitude performance if the Allison V-1710 engine were replaced by the 60-Series Merlin . A similar proposal to cure the P-38's problems by replacing its Allisons with Merlins was quashed by the USAAF, after protests from Allison. Starting with the V-1710-45 around 1943 (after the P-51 had been fitted with a Merlin 61 by Rolls-Royce), Allison attached an auxiliary supercharger to some of its engines in an effort to improve high-altitude performance. The two-stage supercharged Allison
15200-764: The Clerget 14F Diesel radial engine (1939) has the same power to weight ratio as a gasoline radial. Improvements in Diesel technology in automobiles (leading to much better power-weight ratios), the Diesel's much better fuel efficiency and the high relative taxation of AVGAS compared to Jet A1 in Europe have all seen a revival of interest in the use of diesels for aircraft. Thielert Aircraft Engines converted Mercedes Diesel automotive engines, certified them for aircraft use, and became an OEM provider to Diamond Aviation for their light twin. Financial problems have plagued Thielert, so Diamond's affiliate — Austro Engine — developed
15390-811: The Continental United States, the Caribbean Air Command 319th FIS at France Field in the Panama Canal Zone received 15 F-82Fs in December 1948 to replace Black Widows for defending the Panama Canal but remained there only briefly before being reassigned to McChord AFB in May 1949. The Twin Mustang was replaced in ADC service during 1950–1951 by the Lockheed F-94 Starfire , the last being with
15580-459: The F-82 for escorting B-26 Invaders deep into North Korea and for searching out ground targets along the Han River . Making do with what they had was the order of the day, and maintenance crews were cannibalizing everything in sight in order to keep the maximum number of F-82s airborne. During the period 26–30 June, the 68th squadron flew 35 combat sorties, averaging five hours per sortie, with
15770-704: The F-82Es were largely surplus, with the last examples being phased out by September. A few were sent to Far East Air Forces for combat in Korea and some were sent to Alaska for bomber escort missions over the Arctic from Ladd AFB until 1953. The majority went to reclamation and were gone by 1952. With the appearance of the Mikoyan-Gurevich MiG-15 over North Korea in late 1950, the B-29, as well as all of
15960-489: The F-82G Twin Mustang was seen as the interim solution. The last operational P-61s were sent by the 68th and 339th Fighter (All Weather) Squadrons to the reclamation yard at Tachikawa Air Base in February 1950, with Twin Mustangs arriving as replacement aircraft. In Far East Air Forces, there were three squadrons operating the Twin Mustang, consisting of 45 aircraft. The 4th Fighter (All Weather) Squadron
16150-557: The Japanese home islands , which was forestalled by the surrender of Japan after the atomic bombings of Hiroshima and Nagasaki and the opening of Soviet attacks on Japanese-held territory in Manchuria. In October 1943, the North American Aircraft design team began work on a fighter design that could travel over 2,000 mi (3,200 km) without refueling. It consisted of a twin-fuselage design, parallel to
16340-431: The Merlin 60 series engines consumed some 330–380 hp (250–280 kW) at 25,000 ft (7,600 m). General Electric was the sole source for research and production of American turbo-superchargers during this period, from its four decades worth of steam turbine engineering experience. Turbo-superchargers were highly successful in U.S. bombers, which were exclusively powered by radial engines. The P-47 fighter had
16530-559: The Merlin engine. In total, 69,305 V-1710s were built by Allison during the war, all in Indianapolis, Indiana . The V-1710's useful life continued, as thousands were available on the surplus market. In the 1950s, many drag racers and land speed racers , attracted by its reliability and good power output, adopted the V-1710; Art Arfons and brother Walt in particular used one, in Green Monster . It proved unsuccessful as
16720-625: The Merlin. The P-40F, a Lend Lease export to Britain, was one of the first American fighters to be converted to a Packard-Merlin engine. However, the installed engine was the V-1650-1 (a Packard-produced Merlin XX ) with a slightly improved single-stage, two-speed supercharger, yielding only modest gains over the Allison V-1710. The last Allison powered P-51, the Mustang I(II)/P-51A, used the single-stage, single-speed Allison V-1710-81, with
16910-539: The North Korean aircraft. For some reason, the North Korean leader fired while too far away, with his bullets falling short of the F-82s which then pulled up into the clouds and above the overcast, putting them in a position to return fire if the North Koreans followed them. However, they did not, and no further contact was made for the rest of the day. The evacuation at Inchon was successfully carried out with
17100-505: The P-38 Lightning, which accounted for much of the extensive production run. The Allison Division of General Motors began developing an ethylene glycol -cooled engine in 1929 to meet a USAAC need for a modern, 1,000 hp (750 kW), engine to fit into a new generation of streamlined bombers and fighters. To ease production, the new design could be equipped with different propeller gearing systems and superchargers, allowing
17290-627: The P-82 pre-production aircraft already manufactured went into storage, with an uncertain future. However, during the 1947 Soviet Aviation Day display at Tushino Airport , a surprise appearance was put in by what looked like three Boeing B-29s, followed by a fourth, passenger version, the Tu-70. The first three were examples of the Tupolev Tu-4 , which was a reverse-engineered B-29 Superfortress, three examples of which were known to have been interned in
17480-436: The P-82's range. The aircraft carried a full internal fuel tank of 576 US gal (2,180 L; 480 imp gal), augmented by four 310 US gal (1,200 L; 260 imp gal) tanks for a total of 1,816 US gal (6,870 L; 1,512 imp gal). Colonel Thacker did not drop three external tanks when their fuel was expended, either because of an oversight, or because they were stuck due to
17670-833: The P-for-pursuit category with F-for-fighter. All P-82s were then re-designated F-82. The F-82E was the first operational model and its initial operational assignment was to the Strategic Air Command 27th Fighter (later Fighter-Escort) Wing at Kearney Air Force Base , Nebraska in March 1948. During World War II, the P-51 Mustang had escorted Boeing B-17 Flying Fortress and Consolidated B-24 Liberator bombers from bases in England and Southern Italy to targets in Nazi-occupied Europe. However,
17860-566: The Twin Mustangs already built were seen as an interim solution to SAC's fighter escort mission for its strategic bomber force and also as an all-weather air defense interceptor. Early attempts to develop jet-powered all-weather fighters ran into a series of delays. The Curtiss-Wright XF-87 Blackhawk was ordered in December 1945, but it ran into development difficulties and the project was abandoned in October 1948. The Northrop P-89 Scorpion had greater promise, but it too had teething troubles and
18050-570: The USAAC, and are easily identified by the long reduction gear case. The military models were V-1710-3, -5, -7, -11. -13, -15, -19, -21, -23, -33, producing between 750–1,050 hp (560–780 kW) at 2600 rpm. These engines came in two groups, one group rated at full power at sea level, the other rated at full power at high altitude. The altitude rating difference was in the supercharger gear ratio, four of which were used: 6.23:1, 6.75:1, 8.0:1 and 8.77:1. These engines received heavier crankcases,
18240-606: The USAF 68th Fighter Squadron . Initially intended as a very long-range (VLR) escort fighter , the F-82 was designed to escort Boeing B-29 Superfortress bombers on missions exceeding 2,000 mi (3,200 km) from the Solomon Islands or Philippines to Tokyo, missions beyond the range of the Lockheed P-38 Lightning and conventional P-51 Mustangs. Such missions were part of the planned U.S. invasion of
18430-531: The USN and USAAC. The first military model was a single V-1710-2, which was first sold to the USN on June 26, 1930. The "A" engines had no counterweights on the crankshaft, 5.75:1 compression ratio, 2:1 internal spur gear-type reduction gear boxes, 8.77:1 supercharger ratio, 9.5 in (240 mm) impeller, SAE #50 propeller shaft, a float-type carburetor, and produced 1,070 hp (800 kW) at 2800 rpm on 92 octane gasoline. "B" series engines were designed for USN airships. The military model
18620-479: The V-1710 was to be a single-stage supercharged engine and, if a higher altitude capability was desired, the aircraft could use their newly developed turbo-supercharger as was featured in the XP-37(YP-37), P-38, and XP-39. The benefits of a two-stage supercharger eventually became so clear that Allison did make some efforts in this direction. Allison attached an auxiliary supercharger in various configurations to
18810-621: The V-1710's development program meant that less effort was spent on developing suitable mechanically driven centrifugal superchargers for the Allison V-12 design, as other V-12 designs from friendly nations like the British Rolls-Royce Merlin were already using. When smaller-dimensioned or lower-cost versions of the V-1710 were desired, they generally had poor performance at higher altitudes. The V-1710 nevertheless gave excellent service when turbocharged, notably in
19000-574: The Wankel engine has been used in motor gliders where the compactness, light weight, and smoothness are crucially important. The now-defunct Staverton-based firm MidWest designed and produced single- and twin-rotor aero engines, the MidWest AE series . These engines were developed from the motor in the Norton Classic motorcycle . The twin-rotor version was fitted into ARV Super2s and
19190-482: The Western European air war – flying for long hours in intensely cold weather at 30,000 feet (9,100 m) – revealed several problems with these engines. They had a poor manifold fuel-air distribution and poor temperature regulation of the turbo-supercharger air, which resulted in frequent engine failures ( detonation occurred as the result of persistent uneven fuel-air mixture across the cylinders caused by
19380-622: The air war on the Eastern Front in Europe was primarily short ranged, tactical, and conducted at lower altitudes. In the P-39, Soviet pilots scored the highest number of individual kills made on any American, or British fighter type. The P-40, which also had only the single-stage, single-speed-supercharged V-1710, had similar problems with high-altitude performance. The P-38 was the only fighter to make it into combat during World War II with turbo-supercharged V-1710s. The operating conditions of
19570-525: The aircraft from either position, alternating control on long flights, while later night fighter versions kept the cockpit on the left side only, placing the radar operator in the right position. Although some P-82B airframes were completed before the end of World War II, most remained at the North American factory in California waiting for engines until 1946. As a result, none saw service during
19760-466: The aircraft pulled up for the last time, the mortar positions were silent and ground forces later showed over 300 enemy dead. Beginning in October 1950, F-82s would start flying weather reconnaissance pre-dawn missions over North Korea. At the same time, the squadron would also be responsible for keeping at least three aircraft on alert on airfields in the Seoul area ( K-13 (Suwon) and K-14 (Kimpo)) during
19950-600: The aircraft to good advantage including, in April 1943, Operation Vengeance , the interception and downing of the Japanese bomber carrying Admiral Isoroku Yamamoto . New P-38 models with ever-increasing power from more advanced Allisons were eagerly accepted by Pacific air groups. When Packard started building Merlin V-1650 engines in America in 1942, certain American fighter designs using the Allison V-1710 were changed to use
20140-550: The aircraft was not expected to remain in operational service once jet-powered aircraft were available. Further, the Air Force simply did not have that many F-82s in the first place (182 total operational aircraft), and did not want to weaken the F-82 units committed to the Pacific Northwest or Atlantic coast, or to draw from the fourteen F-82Hs in Alaska. This was a heavy blow to FEAF planners, as they wanted to use
20330-563: The aircraft's performance seriously. Additionally the unit could be jettisoned in an emergency, or for belly landings and was sometimes even lost during high-G maneuvers. F-82F models were designated for ADC units in the United States, while the F-82G models were deployed to Far East Air Forces for air defense of Japan and Okinawa . F-82s were not deployed to Europe. The first F-82Fs began reaching ADC squadrons in September 1948. By
20520-444: The appropriate accessories section at the rear, and an appropriate power output drive at the front. A turbo-supercharger could be used, if desired. The P-39, P-63, and Douglas XB-42 Mixmaster used V-1710-Es, exchanging the integral reduction gear for an extension shaft driving a remotely located reduction gear and propeller. Aircraft such as the P-38, P-40, P-51A, and North American P-82E used close-coupled propeller reduction gears,
20710-570: The bombers it was designed to protect. The first production F-82Es reached the 27th in early 1948, and almost immediately the group was deployed to McChord AFB , Washington , in June, where its squadrons stood on alert on a secondary air defense mission due to heightened tensions over the Berlin Airlift . It was also believed that the 27th would launch an escort mission, presumably to the Soviet Union, if conflict broke out in Europe. From McChord,
20900-436: The case when the aircraft refused to become airborne during its first flight attempt. After a month of work, North American engineers finally discovered that rotating the propellers to meet in the center on their upward turn created sufficient drag to cancel out all lift from the center wing section, one quarter of the aircraft's total wing surface area. The engines and propellers were then exchanged, with their rotation meeting on
21090-420: The clouds using radar and broke out at 2,000 ft (610 m), heading for Kimpo Airfield near Seoul . The pilots observed huge convoys of North Korean trucks and other vehicles, including 58 tanks, which had crossed into South Korea. The crews flew back through the clouds to Itazuke Air Base, where they were debriefed by a U.S. Army colonel from General Douglas MacArthur 's staff. This reconnaissance flight
21280-464: The command. With the outbreak of the Korean War in June 1950, the F-82 was pressed into combat duty. On 25 June 1950, 68th Fighter Squadron F-82 aircrews on alert at Itazuke Air Base were told that North Korea had crossed the 38th Parallel . They were ordered to fly to the area and report any activity on the main roads and railroads. They arrived to find overcast conditions, with cloud tops at 8,000 ft (2,400 m). The Twin Mustangs flew through
21470-923: The compression ratio increased to 6.65:1. Marvel MC-12 fuel injection, which was unsatisfactory and quickly replaced by a float-type carburetor on -9 and -13 models. Later dash number engines used Bendix pressure carburetors. These engines were being designed at the same time as the V-3420 engine, and shared many assemblies as they were developed. The "D" series engines were the last of the "early" V-1710 engines. "E" series engines were designed for remote gearbox applications using crankshaft-speed extension shafts and remote 1.8:1 gearboxes with SAE #60 hollow propeller shafts. The military models were V-1710-6, -17, -31, 35, -37, -47, -59, -63, -83, -85, -93, -103, -109, -117, -125, -127, -129, -133,-135 and -137, producing 1,100–2,830 hp (820–2,110 kW) at 3000 rpm. Supercharger gear ratios were: 6.44:1, 7.48:1, 8.10:1, 8.80:1 and 9.6:1 depending on altitude rating. These engines were
21660-500: The compression-ignition diesel engine is seldom used. Starting in the 1930s attempts were made to produce a practical aircraft diesel engine . In general, Diesel engines are more reliable and much better suited to running for long periods of time at medium power settings. The lightweight alloys of the 1930s were not up to the task of handling the much higher compression ratios of diesel engines, so they generally had poor power-to-weight ratios and were uncommon for that reason, although
21850-442: The cost to produce each engine from $ 25,000 down to $ 8,500 and allowed the installed lifetime of the engine to be increased from 300 hours to as much as 1,000 hours for the less-stressed power-plants. Weight increases needed to accomplish this were minimal, with the result that all models were able to produce more than 1 hp/lb (1.6 kW/kg) at their takeoff rating. There was also a high degree of commonality of parts throughout
22040-593: The cylinders arranged evenly around the crankshaft, although some early engines, sometimes called semi-radials or fan configuration engines, had an uneven arrangement. The best known engine of this type is the Anzani engine, which was fitted to the Bleriot XI used for the first flight across the English Channel in 1909. This arrangement had the drawback of needing a heavy counterbalance for the crankshaft, but
22230-486: The cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks. The first practical rotary engine
22420-414: The design during a period of time when Kelsey's attention was focused elsewhere, and Bell engineers, NACA aero-dynamic specialists and the substitute fighter project officer determined that dropping the turbocharger would be among the drag reduction measures indicated by borderline wind tunnel test results; an unnecessary step, according to aviation engineer and historian Warren M. Bodie. The production P-39
22610-621: The downward turn, and the problem was fully solved. The first XP-82 prototype ( 44-83886 ) was completed on 25 May 1945, and made the type's first successful flight on 26 June 1945. This aircraft was accepted by the Army Air Forces on 30 August 1945, whose officials were so impressed by the aircraft, while still in development, that they ordered the first production P-82Bs in March 1945, fully three months before its first flight. The XP-82 prototypes, and production P-82Bs and P-82Es, retained both fully equipped cockpits so that pilots could fly
22800-402: The end of September, ADC had 29 F-82Fs. By the middle of 1949 the F-82 was replacing Black Widows in service with Air Defense Command along the west coast at Hamilton AFB , California (317th FIS) and McChord AFB , Washington (318th FIS, 319th FIS). East coast defense was the mission of the Twin Mustangs assigned to McGuire AFB , New Jersey (2d FIS, 5th FIS). In addition to the forces in
22990-581: The engine core is the bypass ratio. Low-bypass engines are preferred for military applications such as fighters due to high thrust-to-weight ratio, while high-bypass engines are preferred for civil use for good fuel efficiency and low noise. High-bypass turbofans are usually most efficient when the aircraft is traveling at 500 to 550 miles per hour (800 to 890 kilometres per hour), the cruise speed of most large airliners. Low-bypass turbofans can reach supersonic speeds, though normally only when fitted with afterburners . The term advanced technology engine refers to
23180-600: The engine could produce full power) ratings ranging from 8,000 to 26,000 feet (2,400 to 7,900 m). The V-1710 has often been criticized for not having a "high-altitude" supercharger. The comparison is usually to the later, two-stage, versions of the Rolls-Royce Merlin 60-series engines also built by Packard as the V-1650 and used in the P-51B Mustang and subsequent variants. The USAAC had specified that
23370-652: The engine during the war. The initial rating of 1,000 hp (750 kW) was incrementally increased; the final V-1710-143/145(G6R/L) was rated for 2,300 hp (1,700 kW). By 1944, the War Emergency Power rating on the P-38L was 1,600 hp (1,200 kW). The most powerful factory variant was the V-1710-127, designed to produce 2,900 hp (2,200 kW) at low altitude and 1,550 hp (1,160 kW) at 29,000 feet (8,800 m). This engine
23560-542: The engine exhaust and so do not draw much power from the engine crankshaft, whereas displacement superchargers are coupled directly by shafts and gears to the engine crankshaft. Turbo-superchargers do increase the exhaust back-pressure and thus do cause a very small decrease in engine power, but the power increase due to increased induction pressures more than makes up for that decrease. Crankshaft-driven superchargers require an increase in directly driven percentage of engine power as altitude increases (the two-stage supercharger of
23750-438: The engine works by having a coiled pipe in the combustion chamber that superheats the fuel (propane) before being injected into the air-fuel inlet. In the combustion chamber, the fuel/air mixture ignites and burns, creating thrust as it leaves through the exhaust pipe. Induction and compression of the fuel/air mixture is done both by the pressure of propane as it is injected, along with the sound waves created by combustion acting on
23940-415: The engine's heat-radiating surfaces to the air and tends to cancel reciprocating forces, radials tend to cool evenly and run smoothly. The lower cylinders, which are under the crankcase, may collect oil when the engine has been stopped for an extended period. If this oil is not cleared from the cylinders prior to starting the engine, serious damage due to hydrostatic lock may occur. Most radial engines have
24130-581: The existing engine-mounted supercharger and carburetor. Early versions of these two-stage supercharger engines were used on the P-63. No intercooler, aftercooler, or backfire screen (flame trap) were incorporated into these two-stage V-1710 engines (except for the V-1710-119 used on the experimental P-51J, which had an aftercooler). The two-stage Merlin engines had all of these features, which were designed to prevent detonation from charge heating and backfire into
24320-520: The experimental German Messerschmitt Bf 109Z "Zwilling." Although based on the lightweight experimental XP-51F, which would later become the P-51H Mustang, it was actually a new design. North American Design Chief Edgar Schmued incorporated two P-51H Mustang fuselages lengthened by the addition of a 57 in (1,400 mm) fuselage plug located behind the cockpit where additional fuel tanks and equipment could be installed. These were mounted to
24510-474: The fighter version. In 1948, the 3200th Proof Test Group at Eglin AFB , Florida, fitted the 4th F-82B Twin Mustang with retractable pylons under the outer wings capable of mounting 10 High-Velocity Air Rockets (HVAR) each, which folded into the wing undersurface when not in use. This installation was not adopted on later models, the standard "tree" being used instead. The 13th aircraft was experimentally fitted with
24700-570: The first Allison engines appearing over Berlin belonged to a group of P-38Hs of 55th Fighter Group , engine troubles contributing to a reduction of the force to half strength over the target. It was too late to correct these problems in the production lines of Allison or GE, and as the numbers of Merlin-engined P-51 Mustangs based in England mounted up through the end of 1943 and into 1944, the P-38s were steadily withdrawn from Europe until October 1944 when they were no longer used for bomber escort duty with
24890-606: The first electric aircraft engine to be awarded a type certificate by EASA for use in general aviation . The E-811 powers the Pipistrel Velis Electro . Limited experiments with solar electric propulsion have been performed, notably the manned Solar Challenger and Solar Impulse and the unmanned NASA Pathfinder aircraft. Many big companies, such as Siemens, are developing high performance electric engines for aircraft use, also, SAE shows new developments in elements as pure Copper core electric motors with
25080-399: The first engines to use multiple spools —concentric shafts that are free to rotate at their own speed—to let the engine react more quickly to changing power requirements. Turbofans are coarsely split into low-bypass and high-bypass categories. Bypass air flows through the fan, but around the jet core, not mixing with fuel and burning. The ratio of this air to the amount of air flowing through
25270-490: The first part of WWII, including a cruise setting that ran the engine at high RPM and low manifold pressure with a rich mixture. These settings can contribute to over-cooling of the engine, fuel condensation problems, accelerated mechanical wear, and the likelihood of components binding or "freezing up." Details of the failure patterns were described in a report by General Doolittle to General Spatz in January 1944. In March 1944,
25460-546: The front crankcase cover, which was interchangeable between the two series engines. "G" series engines were designed for high-altitude pursuit aircraft, and are identified by the auxiliary supercharger with a Bendix "Speed-Density" fuel control. Military models were V-1710-97, -131, -143, -145, and -147, producing 1,425–2,000 hp (1,063–1,491 kW) at 3000 rpm. Supercharger gear ratios were: 7.48:1, 7.76:1, 8.10:1, 8.80:1 and 9.60:1 depending on altitude rating. These engines were equipped with an SAE #50 propeller shaft and
25650-399: The front lines and the 38th Parallel. Every F-82 which could be made ready for flight was pressed into combat service. Although Fifth Air Force needed every available aircraft to slow down the North Korean invasion force, it was hard to justify the release of all F-82s from their defensive responsibilities for the many key bases in Japan. It was decided to release all F-82s for combat except for
25840-495: The group flew its Twin Mustangs on weather reconnaissance missions over the northwest Pacific, but problems were encountered with their fuel tanks. Decommissioned F-61 Black Widow external tanks were found at Hamilton AFB , California, which could be modified for the F-82; fitted on the pylons of the Twin Mustang, these solved the problem. With a reduction in tension, the 27th returned to its home base in Nebraska during September. Four F-82s were deployed from McChord to Alaska, where
26030-661: The hours of darkness and bad weather. This would become the main mission for the F-82s for the balance of 1950, as the F-51s, F-80s and F-84s took on most of the combat ground attack missions which the F-82s had been pressed into at the beginning of the war. With the entry of the Chinese Communist forces into the war, the situation on the ground began to deteriorate rapidly. By late December, the 68th had begun flying two-aircraft missions during daylight and single-aircraft missions at night from Kimpo AB. On 7 January, FEAF ordered
26220-497: The intake stacks. It was intended as a power plant for personal helicopters and compact aircraft such as Microlights. A few aircraft have used rocket engines for main thrust or attitude control, notably the Bell X-1 and North American X-15 . Rocket engines are not used for most aircraft as the energy and propellant efficiency is very poor, but have been employed for short bursts of speed and takeoff. Where fuel/propellant efficiency
26410-441: The interceptor required numerous modifications. The right side cockpit was replaced with a radar operator's position without flight controls. A long radar pod, resembling a sausage and irreverently known as a "long dong", was attached to the underside of the wing center section, below the six .50 cal (12.7mm) machine guns and with its dish in front of the propellers to prevent interference. This unconventional arrangement did not affect
26600-432: The jet age. Its designed role as a long-range fighter escort was eliminated by the end of World War II. With the rapid draw-down of the armed forces after the war, the newly established United States Air Force had little money for new prop-driven aircraft, especially since jets, such as the Messerschmitt Me 262 , had been faster than P-51 Mustangs in the skies of Germany in late 1944. The completed airframes (minus engines) of
26790-436: The jet-powered F-94 Starfire. USAF claimed the Twin Mustangs destroyed 20 enemy aircraft, four in the air and 16 on the ground during the conflict. During the Korean war, 22 F-82s were lost, including 11 in combat missions and 11 non-combat losses. Modified F-82F/Gs for cold weather were designated as F-82H. Six were assigned initially to the 449th F(AW)S at Adak Island in December 1948 to replace their P-61 Black Widows in
26980-429: The last F-82G was sent for cold-weather modification, and then deployed to Alaska. By mid-April 1952, the F-82s in Okinawa were also sent to Japan for modification and were also sent to Alaska. All-weather responsibilities in FEAF were now in the hands of the F-94 and the jet era. F-82G operational losses during the Korean War 1951 was the last full year of F-82 operations in Korea, as they were gradually replaced by
27170-478: The last civilians out. Fearing that the North Korean Air Force might try to shoot down the transport (a C-54 had been destroyed on the ground at Kimpo by North Korean fighters on 25 June), the Air Force requested air cover to protect the aircraft during takeoff. Fortunately, 339th Fighter All Weather Squadron (F(AW)S) with their F-82Gs were based at Yokota AB and the 68th F(AW)S was based at Itazuke AB Japan. With Lieutenant Colonel John F. Sharp in command, 27 F-82Gs of
27360-434: The line was rapidly approaching for the F-82 in Korea. By the end of August 1951, there were only eight operational F-82s with the 68th, with its replacement, the Lockheed F-94 Starfire arriving in Japan, taking over missions previously flown by the Twin Mustangs. In March 1952, the Starfire-equipped 319th Fighter-Interceptor Squadron arrived from Moses Lake AFB , Washington and took up residence at K-13. On 28 March 1952,
27550-400: The lower-powered engines. It was found that Allison-powered P-82 models demonstrated a lower top speed and poorer high-altitude performance than the earlier Merlin-powered versions. The earlier P-82B models were designated as trainers, while the "C" and later models were employed as fighters, making the P-82 one of the few aircraft in U.S. military history to be faster in its trainer version than
27740-400: The major Western manufacturers of turbofan engines are Pratt & Whitney (a subsidiary of Raytheon Technologies ), General Electric , Rolls-Royce , and CFM International (a joint venture of Safran Aircraft Engines and General Electric). Russian manufacturers include the United Engine Corporation , Aviadvigatel and Klimov . Aeroengine Corporation of China was formed in 2016 with
27930-430: The many limitations of the rotary engine so when the static style engines became more reliable and gave better specific weights and fuel consumption, the days of the rotary engine were numbered. The Wankel is a type of rotary engine. The Wankel engine is about one half the weight and size of a traditional four-stroke cycle piston engine of equal power output, and much lower in complexity. In an aircraft application,
28120-462: The merger of several smaller companies. The largest manufacturer of turboprop engines for general aviation is Pratt & Whitney. General Electric announced in 2015 entrance into the market. In this section, for clarity, the term "inline engine" refers only to engines with a single row of cylinders, as used in automotive language, but in aviation terms, the phrase "inline engine" also covers V-type and opposed engines (as described below), and
28310-433: The modern generation of jet engines. The principle is that a turbine engine will function more efficiently if the various sets of turbines can revolve at their individual optimum speeds, instead of at the same speed. The true advanced technology engine has a triple spool, meaning that instead of having a single drive shaft, there are three, in order that the three sets of blades may revolve at different speeds. An interim state
28500-463: The most common Avgas is 100LL. This refers to the octane rating (100 octane) and the lead content (LL = low lead, relative to the historic levels of lead in pre-regulation Avgas). Refineries blend Avgas with tetraethyllead (TEL) to achieve these high octane ratings, a practice that governments no longer permit for gasoline intended for road vehicles. The shrinking supply of TEL and the possibility of environmental legislation banning its use have made
28690-404: The new AE300 turbodiesel , also based on a Mercedes engine. Competing new Diesel engines may bring fuel efficiency and lead-free emissions to small aircraft, representing the biggest change in light aircraft engines in decades. While military fighters require very high speeds, many civil airplanes do not. Yet, civil aircraft designers wanted to benefit from the high power and low maintenance that
28880-440: The newly dedicated Idlewild Airport in New York City soon followed, with the aircraft flying non-stop from Kearney AFB. In March 1949, Kearney AFB was closed and the 27th FEW was reassigned to Bergstrom Air Force Base , Texas . Other long-range missions were flown cross-country, including simulated dogfights with Lockheed F-80 Shooting Stars . The 27th FEW began transitioning to the Republic F-84 Thunderjet in March 1950, and
29070-401: The pilots provided transition training to the 449th Fighter (All Weather) Squadron, which used Twin Mustangs in the air defense mission. They remained in Alaska for about 45 days, returning to rejoin the rest of the group at the beginning of November 1948. In January 1949, Eighth Air Force planned a large celebration at Carswell Air Force Base . All of its assigned units were to participate in
29260-431: The point of view of the pilot looking forward, so for example on a four-engine aircraft such as the Boeing 747 , engine No. 1 is on the left side, farthest from the fuselage, while engine No. 3 is on the right side nearest to the fuselage. In the case of the twin-engine English Electric Lightning , which has two fuselage-mounted jet engines one above the other, engine No. 1 is below and to the front of engine No. 2, which
29450-472: The poor high-altitude performance of the V-1710 versus the increased problems brought on by addition of the turbo-supercharger. The fates of all of the V-1710 powered fighters of World War II would thus hinge on that choice. The original XP-39 was built with a V-1710 augmented by a General Electric Type B-5 turbo-supercharger as specified by Fighter Projects Officer Lieutenant Benjamin S. Kelsey and his colleague Gordon P. Saville . Numerous changes were made to
29640-542: The poor manifold design). Specially formulated fuels were a necessity for the P-38 as were specific spark plugs needed for specific cylinders. The turbo-supercharger had additional problems with getting stuck in the freezing air in either high or low boost mode; the high boost mode could cause detonation in the engine, while the low boost mode would be manifested as power loss in one engine, resulting in sudden fishtailing in flight. These problems were aggravated by sub-optimal engine management techniques taught to many pilots during
29830-432: The power-to-weight ratio is very important, making the Wankel engine a good choice. Because the engine is typically constructed with an aluminium housing and a steel rotor, and aluminium expands more than steel when heated, a Wankel engine does not seize when overheated, unlike a piston engine. This is an important safety factor for aeronautical use. Considerable development of these designs started after World War II , but at
30020-435: The propeller-driven bombers in the USAF inventory, were rendered obsolete as strategic offensive weapons. The straight-winged F-84Gs were ineffective against the MiG, and it took the swept-wing North American F-86 Sabre to counter them. It would take a new generation of swept-wing jet bombers, able to fly higher and faster, to survive the MiG-15 and subsequent Soviet interceptors. The era of large formations of bombers flying to
30210-504: The proper direction, and re-arranging the ignition wiring on the right side to accommodate a changed firing order. No change to the oil pump nor coolant pump circuits was needed. The ability to reverse the direction of rotation with a minimum of extra parts to achieve the task allowed the use of either a "tractor" or "pusher" propeller . This approach allowed easy changes of the supercharger(s) and supercharger drive-gear ratio. That gave different critical altitude (the maximum altitude at which
30400-449: The radomes were removed, turning the aircraft into day fighters. In the ground support role, the F-82s could reach any part of the Korean battlefield with a total ordnance load of over 4,000 lb (1,800 kg). Each of the six .50-inch machine guns carried 400 rounds. This firepower was well-used against numerous ground targets. The escort missions flown with the B-26s took F-82s deep into North Korea. Flying with external fuel tanks, it
30590-401: The same combination of radial engine ( R-2800 ) and turbo-supercharger and was also successful, apart from its large bulk, which was caused by the need for the ductwork for the aft-mounted turbo-supercharger. However, mating the turbocharger with the Allison V-1710 proved to be problematic. As a result, designers of the fighter planes that used the V-1710 were invariably forced to choose between
30780-452: The series. The individual parts of the Allison series were produced to a high degree of standardization and reliability, using the best technology available at the time. Even after the war, racing Merlins used Allison connecting rods. As stated previously, General Motors' policies regarding versatility meant that their Allison division would also employ modular design features on the V-1710 from its "long block" core V-12 unit outwards, so that it
30970-428: The start of the Cold War in 1948, led to the establishment of Air Defense Command (ADC) in the United States Air Force . In 1947, the embryonic ADC was not particularly effective. During a number of simulated raids on the United States carried out by Strategic Air Command during the period 1947–1949, defending F-51 Mustangs and F-47 Thunderbolts repeatedly failed to find the incoming bombers, and were seldom in
31160-414: The strategic bomber force, the 27th FEW was to fly these missions in F-82Es. The F-82E had a range of over 1,400 mi (2,300 km), which meant that with external fuel tanks it could fly from London to Moscow, loiter for 30 minutes over the target, and return, the only American fighter which could do so. It also had an operational ceiling of 40,000 ft (12,000 m), where it could stay close to
31350-412: The supercharger. The G-series V-1710s installed on the F-82 E/F/G models had only anti-detonation injection (ADI) to deal with these problems, and not surprisingly had severe reliability and maintenance problems. In one record, it was stated that the F-82 required 33 hours of maintenance for each hour of flight. Although the early V-1710 powered P-39, P-40 and P-51A were limited to combat operations at
31540-439: The time the aircraft industry favored the use of turbine engines. It was believed that turbojet or turboprop engines could power all aircraft, from the largest to smallest designs. The Wankel engine did not find many applications in aircraft, but was used by Mazda in a popular line of sports cars . The French company Citroën had developed Wankel powered RE-2 [ fr ] helicopter in 1970's. In modern times
31730-511: The two (so far) airworthy examples of the Ilyushin Il-2 , taking the place of the Mikulin V-12 it originally used, as well as ambitious projects such as a replica Douglas World Cruiser and Focke-Wulf Fw 190 D by Flug Werk of Germany . Allison's internal model designation for the V-1710 started with the letter A and proceeded to the letter H. Each letter designated a family of engines that shared major components, but differed in specific design details. Each of these designs were identified by
31920-414: The two crankshafts geared together. This type of engine has one or more rows of cylinders arranged around a centrally located crankcase . Each row generally has an odd number of cylinders to produce smooth operation. A radial engine has only one crank throw per row and a relatively small crankcase, resulting in a favorable power-to-weight ratio . Because the cylinder arrangement exposes a large amount of
32110-409: The use of a glow plug ) powered by glow fuel , a mixture of methanol , nitromethane , and lubricant. Electrically powered model airplanes and helicopters are also commercially available. Small multicopter UAVs are almost always powered by electricity, but larger gasoline-powered designs are under development. North American F-82 Twin Mustang The North American F-82 Twin Mustang
32300-421: The war, North American built 250 P-82 E/F for air defense roles into the early 1950s. This was the final military role for the V-1710. The USAAC had earlier decided to concentrate on turbo-superchargers for high altitude boost, believing that further development of turbo-superchargers would allow their engines to outperform European rivals using crankshaft driven superchargers. Turbo-superchargers are powered by
32490-404: The war. Like most versions of the P-51 Mustang, the first two prototype XP-82s as well as the next 20 P-82B models were powered by British-designed Rolls-Royce Merlin engines, re-engineered for increased durability and mass-production, and built under license by Packard . These provided the fighter with excellent range and performance; however, the Army had always wanted to give the Twin Mustang
32680-399: The years after the war, the drawbacks of the turbojet gradually became apparent. Below about Mach 2, turbojets are very fuel inefficient and create tremendous amounts of noise. Early designs also respond very slowly to power changes, a fact that killed many experienced pilots when they attempted the transition to jets. These drawbacks eventually led to the downfall of the pure turbojet, and only
32870-477: Was V-1710-4. They differed from the "A" series engines in that they did not have a supercharger, had two float-type down-draft carburetors were mounted directly to the intake manifold, an SAE #40 propeller shaft, and could be brought from full power to stop and back to full power in the opposite rotation in less than 8 seconds. They produced 600–690 hp (450–510 kW) at 2400 rpm. "C" series engines were developed for highly streamlined pursuit aircraft for
33060-446: Was attached to the 51st Fighter-Interceptor Wing at Naha Air Base , Okinawa, tasked with providing air defense within the Twentieth Air Force's area of responsibility during darkness and inclement weather. The 68th F(AW)S area would cover southern Japan from their base at Itazuke and the 8th Fighter Bomber Wing , with the 339th F(AW)S covering Tokyo and northern Japan from Johnson Air Base . FEAF had about 40 Twin Mustangs assigned to
33250-481: Was capable of being mated to many different styles of turbo-superchargers and various other accessories, although the variety of turbo-superchargers available for installation was limited due to the constraints of single-engine fighter design. Since it was produced in large numbers and was highly standardized, the engine has been used in many postwar racing designs. Its reliability and well-mannered operation allowed it to operate at high rpm for extended periods. Following
33440-449: Was considered, but was never built. The outer wings were reinforced to allow the addition of hard points for carrying additional fuel or 1,000 lb (450 kg) of ordnance. The two vertical tails were also from the XP-51F, but incorporated large dorsal fillets for added stability in case of an engine failure. The aircraft had conventional landing gear with both wheels retracting into bays under each fuselage center section. The XP-82
33630-428: Was either dead or badly wounded, remained in the doomed aircraft. Parachuting down to Kimpo Airfield, the North Korean pilot was immediately surrounded by South Korean soldiers. Surprisingly, he pulled out a pistol and began firing at them. The South Korean soldiers returned fire, killing him. Moments later, Lt. Moran shot down an La-7 over the airfield, while a few miles away, Major James W. Little, commanding officer of
33820-401: Was essential as any Chinese aircraft operating out of these bases would be in easy range of the UN front lines. The 68th's efforts claimed 35 trucks destroyed, with damage to many others. As 1951 progressed, the F-82s of the 68th Squadron continued its mission of air defense over Seoul and flying weather reconnaissance flights; however, its combat duties became more and more limited. The end of
34010-408: Was essentially developed as an "add on" to the single-stage engine, and required minimal changes to the base engine. While it lacked the refinement, compactness and after-cooler of the two-stage Merlin, the Allison used a pressure-altitude governed variable-speed first stage. Various configurations of this auxiliary supercharger were used in production versions of the V-1710 that powered aircraft such as
34200-457: Was necessary on many occasions for the Twin Mustangs to drop tanks, owing to the risk of fire or explosion if enemy fire hit one of the empty tanks. On 10 July, F-82s from the 4th and 68th squadrons participated in one of the biggest strikes of the war against ground targets. Joined by B-26s and F-80s, the aircraft hit massive amounts of North Korean road traffic. An estimated 117 trucks, 38 tanks and seven personnel carriers were destroyed, along with
34390-410: Was not expected to enter service until 1952 at the earliest. Due to the lack of a suitable jet-powered replacement, the wartime Northrop P-61 Black Widow night fighter was forced into this role, and in order to fill in the gap until the Scorpion became available, night fighter adaptations of the Twin Mustang were developed and deployed. On 11 June 1948, the newly formed United States Air Force replaced
34580-437: Was not until December 14, 1936, that the engine next flew in the Consolidated XA-11A testbed. The V-1710-C6 successfully completed the USAAC 150 hour Type Test on April 23, 1937, at 1,000 hp (750 kW), the first engine of any type to do so. The engine was then offered to aircraft manufacturers where it powered the prototype Curtiss XP-37s . All entrants in the new pursuit competition were designed around it, powering
34770-436: Was seen as proof of the F-82's capabilities in bad weather. In early 1949, the 27th began carrying out long-range escort profile missions. Flights to Puerto Rico , Mexico, the Bahamas and nonstop to Washington, D.C. were carried out. For President Truman 's 1949 inauguration, the 27th FEW launched 48 aircraft to fly in review, along with several other fighter units, in formation down Pennsylvania Avenue. Another flyover of
34960-427: Was sent to Inchon harbor to evacuate non-military personnel from Seoul, which lay directly in the invasion route. A flight of Twin Mustangs from the 68th F(AW)S was dispatched to the area, arriving at dawn to provide air protection for the evacuation. Two of the F-82s were dispatched to fly over the road from Seoul, while others flew top cover over the Inchon docks. The patrol went without incident until about 1300, when
35150-425: Was static tested at 2,800 hp (2,100 kW) and was planned for installation in an XP-63H aircraft. The end of the war ended this development, so this promising experiment never flew. The extra power of this version was derived from using exhaust turbines, not to drive a turbo-supercharger, but to return that energy to turning the crankshaft, called a turbo-compound engine . Improvements in manufacturing brought
35340-460: Was the Gnome Omega designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically. Before the first World War most speed records were gained using Gnome-engined aircraft, and in the early years of the war rotary engines were dominant in aircraft types for which speed and agility were paramount. To increase power, engines with two rows of cylinders were built. However,
35530-426: Was the German unmanned V1 flying bomb of World War II . Though the same engines were also used experimentally for ersatz fighter aircraft, the extremely loud noise generated by the engines caused mechanical damage to the airframe that was sufficient to make the idea unworkable. The Gluhareff Pressure Jet (or tip jet) is a type of jet engine that, like a valveless pulsejet, has no moving parts. Having no moving parts,
35720-453: Was thus stuck with poor high-altitude performance and proved unsuitable for the air war in Western Europe which was largely conducted at high altitudes. The P-39 was rejected by the British, but used by the U.S. in the Mediterranean and the early Pacific air war, as well as shipped to the Soviet Union in large numbers under the Lend Lease program . The Soviets were able to make good use of P-39s because of its excellent maneuverability and because
35910-474: Was to be powered by two Packard-built Rolls-Royce V-1650 Merlin engines. Initially, the left engine was a V-1650-23 with an additional gear in the propeller reduction box to allow the left propeller to turn opposite to the right propeller, which was driven by the more conventional V-1650-25. In this arrangement both propellers would turn upward as they approached the center wing, which in theory would have allowed better single-engine control. This proved not to be
36100-487: Was used to avoid the spark plugs oiling up. In military aircraft designs, the large frontal area of the engine acted as an extra layer of armor for the pilot. Also air-cooled engines, without vulnerable radiators, are slightly less prone to battle damage, and on occasion would continue running even with one or more cylinders shot away. However, the large frontal area also resulted in an aircraft with an aerodynamically inefficient increased frontal area. Rotary engines have
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