181-613: Over twenty variants of the North American P-51 Mustang fighter were produced from 1940, when it first flew, to after World War II , some of which were employed also in the Korean War and in several other conflicts. The prototype of the Mustang, designated NA-73X, was rolled out by North American Aviation on 9 September 1940, albeit without an engine, and was first flown the following 26 October. The Mustang
362-416: A turbocharger , which is powered by the kinetic energy of the exhaust gases. However, up until the mid-20th century, a turbocharger was called a "turbosupercharger" and was considered a type of supercharger. The first supercharged engine was built in 1878, with usage in aircraft engines beginning in the 1910s and usage in car engines beginning in the 1920s. In piston engines used by aircraft, supercharging
543-661: A better aircraft with the same Allison V-1710 engine in the air sooner than establishing a production line for the P-40. John Attwood of NAA spent much time from January to April 1940 at the British Purchasing Commission's offices in New York discussing the British specifications of the proposed aircraft with British engineers. The discussions consisted of free-hand conceptual drawings of an aircraft with
724-526: A car’s exhaust note, while a supercharged engine maintains the louder exhaust note of a normally aspirated car. Turbocharged engines are more prone to heat soak of the intake air (since turbocharging can place the hot exhaust components near the intake air system), although this can be overcome through the use of an intercooler . The majority of aircraft engines used during World War II used mechanically driven superchargers because they had some significant manufacturing advantages over turbochargers. However,
905-541: A development of the V-1710-39, driving a 10 ft 9 in (3.28 m)-diameter three-bladed Curtiss-Electric propeller. The armament was changed to four .50 in (12.7 mm) Browning machine guns, two in each wing, with a maximum of 350 rounds per gun (rpg) for the inboard guns and 280 rpg for the outboard. Other improvements were made in parallel with the A-36, including an improved, fixed air duct inlet replacing
1086-581: A development project known as the Rolls-Royce Mustang X , replaced the Allison engine with a Rolls-Royce Merlin 65 two-stage inter-cooled supercharged engine. During testing at Rolls-Royce's airfield at Hucknall in England , it was clear the engine dramatically improved the aircraft's performance at altitudes above 15,000 ft (4,600 m) without sacrificing range. Following receipt of
1267-409: A distinctive "kink" at the wing root 's leading edges. Other alterations to the wings included new navigation lights, mounted on the wingtips, rather than the smaller lights above and below the wings of the earlier Mustangs, and retractable landing lights which were mounted at the back of the wheel wells; these replaced the lights which had been formerly mounted in the wing leading edges. The engine
1448-469: A dorsal fin should be installed. Dorsal fin kits are being made available to overseas activities" The dorsal fin kits became available in August 1944, and available as retrofits for P-51Bs and P-51Cs (but rarely used on the "razorback" -B and -C Mustangs), and to early P-51Ds and P-51Ks that had not already been built with them. Also incorporated was a change to the rudder trim tabs , which would help prevent
1629-515: A dummy airfield about 0.62 mi (1 km) from the blast tower on which two low-yield bombs were detonated. The Mustangs survived intact. In 1967, A68-1 was bought by a U.S. syndicate, for restoration to flight status and is currently owned by Troy Sanders. After the USAF cancelled orders for P-51H variants, the RAAF followed suit, stopping 250 locally-built CAC CA-21s. The lightweight Mustangs had
1810-523: A dynamic compressor are: Common methods of driving a supercharger include: Fuels with a higher octane rating are better able to resist autoignition and detonation . As a result, the amount of boost supplied by the superchargers could be increased, resulting in an increase in engine output. The development of 100-octane aviation fuel, pioneered in the USA in the 1930s, enabled the use of higher boost pressures to be used on high-performance aviation engines and
1991-415: A limiting factor in engine performance. Extreme temperatures can cause pre-ignition or knocking , which reduces performance and can cause engine damage. The risk of pre-ignition/knocking increases with higher ambient air temperatures and higher boost levels. Turbocharged engines use energy from the exhaust gas that would normally be wasted, compared with a supercharger which mechanically draws power from
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#17327942460332172-501: A little tricky. It could not by any means out-turn a Spitfire. No way. It had a good rate-of-roll, better than the Spitfire, so I would say the plusses to the Spitfire and the Mustang just about equate. If I were in a dogfight, I'd prefer to be flying the Spitfire. The problem was I wouldn't like to be in a dogfight near Berlin, because I could never get home to Britain in a Spitfire! The U.S. Air Forces, Flight Test Engineering, assessed
2353-617: A more thorough conversion than the Mustang X, with a tailor-made engine installation and a complete redesign of the radiator duct. The airframe itself was strengthened, with the fuselage and engine mount area receiving more formers because of the 355 lb (161 kg) greater weight of the Packard V-1650-3 compared with the V-1710. The engine cowling was completely redesigned to house the Packard Merlin, which, because of
2534-573: A narrow range of load/speed/boost, for which the system must be specifically designed. Positive displacement pumps deliver a nearly fixed volume of air per revolution of the compressor (except for leakage, which typically has a reduced effect at higher engine speeds). The most common type of positive-displacement superchargers is the Roots-type supercharger . Other types include the rotary-screw , sliding vane and scroll-type superchargers. The rating system for positive-displacement superchargers
2715-503: A new wing design. The airfoil was switched to the NACA 66,2-(1.8)15.5 a=.6 at the root and the NACA 66,2-(1.8)12 a=.6 at the tip. These airfoils were designed to give less drag than the previous NAA/NACA 45-100. In addition, the planform was a simple trapezoid, with no leading edge extension at the root. In 1943, North American submitted a proposal to redesign the P-51D as model NA-105, which
2896-476: A nominal 150-octane rating. Using such fuels, aero engines like the Rolls-Royce Merlin 66 and Daimler-Benz DB 605 DC produced power outputs of up to 2,000 hp (1,500 kW). One disadvantage of forced induction (i.e. supercharging or turbocharging) is that compressing the intake air increases its temperature. For an internal combustion engine, the temperature of the intake air becomes
3077-452: A raised pilot's position, and the aircraft was given a new propeller with wider, uncuffed blades and rounded tips to allow the additional power to be better used. This propeller was similar to the one used on some later production P-51Ds and the majority of postwar F-51Ds. With a new airframe several hundred pounds lighter, extra power, and a more streamlined radiator, the P-51H was faster than
3258-456: A result of the crippling of the Luftwaffe fighter arm. Reichsmarschall Hermann Göring , commander of the Luftwaffe during the war, was quoted as saying, "When I saw Mustangs over Berlin, I knew the jig was up." On 15 April 1944, VIII Fighter Command began "Operation Jackpot", attacks on Luftwaffe fighter airfields. As the efficacy of these missions increased, the number of fighters at
3439-478: A result of these problems, a modification kit consisting of a dorsal fin was manufactured. One report stated: "Unless a dorsal fin is installed on the P-51B, P-51C and P-51D airplanes, a snap roll may result when attempting a slow roll. The horizontal stabilizer will not withstand the effects of a snap roll. To prevent recurrence, the stabilizer should be reinforced in accordance with T.O. 01-60J-18 dated 8 April 1944 and
3620-545: A series of independent ground-attack missions against targets in the home islands. The first of these operations took place on 16 April, when 57 P-51s strafed Kanoya Air Field in Kyushu. In operations conducted between 26 April and 22 June, the American fighter pilots claimed the destruction of 64 Japanese aircraft and damage to another 180 on the ground, as well as a further 10 shot down in flight; these claims were lower than
3801-564: A slight amount of jet thrust . Because NAA lacked a suitable wind tunnel to test this feature, it used the GALCIT 3.0 m (10 ft) wind tunnel at the California Institute of Technology . This led to some controversy over whether the Mustang's cooling system aerodynamics were developed by NAA's engineer Schmued or by Curtiss, as NAA had purchased the complete set of P-40 wind tunnel data and flight test reports. The NA-73X
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#17327942460333982-564: A test pilot for Rolls-Royce , suggested fitting a Merlin 61 , as fitted to the Spitfire Mk IX . The Merlin 61 had a two-speed, two-stage, intercooled supercharger, designed by Stanley Hooker of Rolls-Royce. Both the Merlin 61 and V-1710-39 were capable of about 1,570 horsepower (1,170 kW) war emergency power at relatively low altitudes, but the Merlin developed 1,390 horsepower (1,040 kW) at 23,500 feet (7,200 m) versus
4163-505: A total displacement of 426 cu in (7.0 L)). However, because 6–71 is the engine's designation rather than that of the blower, the actual displacement of the blower is less; for example, a 6–71 blower pumps 339 cu in (5.6 L) per revolution. Other supercharger manufacturers have produced blowers rated up to 16–71. Dynamic compressors rely on accelerating the air to high speed and then exchanging that velocity for pressure by diffusing or slowing it down. Major types of
4344-476: A two-stage inter-cooled supercharger with a more compact layout. Nonetheless, turbochargers were useful in high-altitude bombers and some fighter aircraft due to the increased high altitude performance and range. Turbocharged piston engines are also subject to many of the same operating restrictions as those of gas turbine engines. Turbocharged engines also require frequent inspections of their turbochargers and exhaust systems to search for possible damage caused by
4525-475: A variable-speed auxiliary supercharger and developed 1,150 horsepower (860 kW) at 22,400 feet (6,800 m). In November 1941, NAA studied the possibility of using it, but fitting its excessive length in the Mustang would require extensive airframe modifications and cause long production delays. In May 1942, following positive reports from the RAF on the Mustang I's performance below 15,000 ft, Ronald Harker,
4706-430: Is that the intake air is warmer than at high altitude. Warmer air reduces the threshold at which engine knocking can occur, especially in supercharged or turbocharged engines. Methods to cool the intake air at ground level include intercoolers/aftercoolers , anti-detonant injection , two-speed superchargers and two-stage superchargers. In supercharged engines which use a carburetor , a partially-open throttle reduces
4887-417: Is too large for the engine displacement. For this reason, supercharged engines are common in applications where throttle response is a key concern, such as drag racing and tractor pulling competitions. A disadvantage of supercharging is that the engine must withstand the net power output of the engine plus the power to drive the supercharger. Additionally, turbochargers provide sound-dampening properties to
5068-557: Is usually based on their capacity per revolution . In the case of the Roots blower, the GMC rating pattern is typical. The GMC rating is based on how many two-stroke cylinders - and the size of those cylinders - that it is designed to scavenge , with GMC's model range including 2–71, 3–71, 4–71 and 6–71 blowers. The 6–71 blower, for example, is designed to scavenge six cylinders of 71 cu in (1.2 L) each, resulting in an engine with
5249-663: The 1925 Delage , and the 1926 Bugatti Type 35C . Amongst the most famous supercharged cars is the Bentley 4½ Litre ("Blower Bentley"), which was introduced in 1929. In 1935, the development of screw-type superchargers reached a milestone when Swedish engineer Alf Lysholm patented a design for a rotary-screw compressor with five female and four male rotors. In the 21st century, supercharged production car engines have become less common, as manufacturers have shifted to turbocharging to achieve higher fuel economy and power outputs. For example, Mercedes-Benz's Kompressor engines of
5430-691: The 55th Fighter Group surprised an entire Staffel of Me 262As at takeoff and destroyed six jets. The Mustang also proved useful against the V-1s launched toward London. P-51B/Cs, using 150-octane fuel, were fast enough to catch the V-1 and operated in concert with shorter-range aircraft such as advanced marks of the Supermarine Spitfire and Hawker Tempest . By 8 May 1945, the 8th , 9th , and 15th Air Force 's P-51 groups claimed some 4,950 aircraft shot down (about half of all USAAF claims in
5611-565: The China Burma India Theater (CBI). The first group to fly the P-51 on operations was the 354th Operations Group ; their first long-distance escort mission was flown on January 15, 1944. Allied strategists quickly exploited the long-range fighter as a bomber escort. It was largely due to the P-51 that daylight bombing raids deep into German territory became possible without prohibitive bomber losses in late 1943. A number of
North American P-51 Mustang variants - Misplaced Pages Continue
5792-730: The Combined Chiefs of Staff issued the Pointblank Directive to destroy the Luftwaffe's capacity before the planned invasion of Europe, putting the CBO into full implementation. German daytime fighter efforts were, at that time, focused on the Eastern Front and several other distant locations. Initial efforts by the 8th met limited and unorganized resistance, but with every mission, the Luftwaffe moved more aircraft to
5973-557: The English Channel , but were thought to be of limited value as fighters due to their poor performance above 15,000 ft (4,600 m). RAF Mustangs (Mk Is, which were not drop tank capable) made history on October 22, 1942, when they escorted 22 Vickers Wellington medium bombers on a daylight raid to Germany, thus becoming the first RAF single-seat fighters to fly over the country during World War II. The first American order for 150 P-51s, designated NA-91 by North American,
6154-602: The Lockheed Constellation , and the C-124 Globemaster II . In the 1985 and 1986 World Rally Championships, Lancia ran the Delta S4 , which incorporated both a belt-driven supercharger and exhaust-driven turbocharger. The design used a complex series of bypass valves in the induction and exhaust systems as well as an electromagnetic clutch so that, at low engine speeds, a boost was derived from
6335-507: The Medal of Honor during World War II: Chief Naval Test Pilot and C.O. Captured Enemy Aircraft Flight Capt. Eric Brown , RN , tested the Mustang at RAE Farnborough in March 1944 and noted: The Mustang was a good fighter and the best escort due to its incredible range, make no mistake about it. It was also the best American dogfighter. But the laminar-flow wing fitted to the Mustang could be
6516-663: The Mustang Mk X with the Merlin 65. Apart from the engine installation, which utilized custom-built engine mounts designed by Rolls-Royce and initially the 10 ft 9 in (3.28 m)-diameter four-bladed Rotol propeller from a Spitfire Mk IX , the Mk X was a straightforward adaptation of the Mk I airframe, keeping the same radiator duct design. The Vice-Chief of the Air Staff , Air Marshal Sir Wilfrid R. Freeman , lobbied vociferously for Merlin-powered Mustangs, insisting two of
6697-698: The Nakajima Ki-84 Hayate against it. The P-51 was a relative latecomer to the Pacific theater, due largely to the need for the aircraft in Europe, although the P-38's twin-engined design was considered a safety advantage for long, over-water flights. The first P-51s were deployed in the Far East later in 1944, operating in close-support and escort missions, as well as tactical photoreconnaissance. As
6878-586: The Republic P-47 Thunderbolt and P-51B be considered for the roles of smaller escort fighters, and in July, a report stated that the P-51B was "the most promising plane" with an endurance of 4 hours 45 minutes with the standard internal fuel of 184 gallons plus 150 gallons carried externally. In August, a P-51B was fitted with an extra internal 85-gallon tank, but problems with longitudinal stability occurred, so some compromises in performance with
7059-449: The boundary layer on the lower surface of the wing was being ingested into the inlet and separating, causing the radiator to vibrate and producing the rumble. The production P-51B inlet was lowered even further, to give a separation of 2.63 in (67 mm) from the bottom of the wing. In addition, the shelf above the oil cooler face was removed and the inlet highlight swept back. It was decided new P-51Bs (NA-102s) would continue with
7240-528: The gas turbine and a pre-turbine section of the exhaust system. The size of the ducting alone was a serious design consideration. For example, both the F4U Corsair and the P-47 Thunderbolt used the same radial engine , but the large barrel-shaped fuselage of the turbocharged P-47 was needed because of the amount of ducting to and from the turbocharger in the rear of the aircraft. The F4U used
7421-416: The intercooler radiator mounted on the supercharger casing, was 5 in (130 mm) taller and used an updraft carburetor , rather than the downdraft variety of the Allison. The new engine drove a four-bladed 11 ft 2 in (3.40 m)-diameter Hamilton Standard propeller that featured cuffs of hard molded rubber. To cater for the increased cooling requirements of the Merlin, a new fuselage duct
North American P-51 Mustang variants - Misplaced Pages Continue
7602-426: The .50 cal (12.7 mm) "nostril"-mounted weapons. The British designated this model as Mustang Mk IA , and would fit a number with similar equipment. It was quickly evident the Mustang's performance, although exceptional up to 15,000 ft (4,600 m) (the supercharger's critical altitude rating), was markedly reduced at higher altitudes. This was because the single-speed single-stage supercharger fitted to
7783-398: The 1.6 litre Mercedes 6/25 hp and 2.6 litre Mercedes 10/40 hp , both of which began production in 1923. They were marketed as Kompressor models, a term which was used for various models until 2012. Supercharged racing cars from around this time included the 1923 Fiat 805-405 , the 1923 Miller 122 the 1924 Alfa Romeo P2 , the 1924 Grand Prix season car from Sunbeam,
7964-455: The 357th Fighter Group of the 8th Air Force with 565 air-to-air combat victories and the 9th Air Force's 354th Fighter Group with 664, which made it one of the top-scoring fighter groups. The top Mustang ace was the USAAF's George Preddy , whose final tally stood at 26.83 victories (a number that includes shared one half- and one third victory credits), 23 of which were scored with the P-51. Preddy
8145-508: The Air Corps' four-engine bombers. Most of the other uses for the Allison were for low-altitude designs, where a simpler supercharger would suffice. Fitting a turbocharger into the Mustang proved impractical, and Allison was forced to use the only supercharger available. In spite of this, the Mustang's advanced aerodynamics showed to advantage, as the Mk I was about 30 mph (48 km/h) faster than contemporary Curtiss P-40 Warhawks using
8326-656: The Air Member for Development and Production. Self also sat on the British Air Council Subcommittee on Supply (or "Supply Committee"), and one of his tasks was to organize the manufacturing and supply of American fighter aircraft for the RAF. At the time, the choice was very limited, as no U.S. aircraft then in production or flying met European standards, with only the Curtiss P-40 Tomahawk coming close. The Curtiss-Wright plant
8507-576: The Air National Guard in 1952. The P-51H was not used for combat in the Korean War despite its improved handling characteristics, since the P-51D was available in much larger numbers and was a proven commodity. North American P-51 Mustang The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War , among other conflicts. The Mustang
8688-406: The Allison's 1,150 horsepower (860 kW) at 11,800 feet (3,600 m), delivering an increase in top speed from 390 mph (340 kn; 630 km/h) at ~15,000 feet (4,600 m) to an estimated 440 mph (380 kn; 710 km/h) at 28,100 feet (8,600 m). In the end the Merlin 61 was never fitted to the Mustang X, (or any other Mustang). The 65 series (a medium altitude engine)
8869-419: The American planners had expected, however, and the raids were considered unsuccessful. USAAF losses were 11 P-51s to enemy action and seven to other causes. Due to the lack of Japanese air opposition to the American bomber raids, VII Fighter Command was solely tasked with ground-attack missions from July. These raids were frequently made against airfields to destroy aircraft being held in reserve to attack
9050-511: The Americans did not suffer any losses. Osaka was bombed for the fourth time that month, on 15 June, when 444 B-29s destroyed 1.9 square miles (4.9 km ) of the city and another 0.59 square miles (1.5 km ) of nearby Amagasaki ; 300,000 houses were destroyed in Osaka. This attack marked the end of the first phase of XXI Bomber Command's attack on Japan's cities. During May and June,
9231-896: The Army Air Corps to appreciate and push its good points. It does not fully satisfy good people on both sides of the Atlantic who seem more interested in pointing with pride to the development of a 100% national product..." Nevertheless, during the British service development program of the Mustang I at Rolls-Royce's airfield at Hucknall , a close relationship was developed between NAA, the RAF Air Fighting Development Unit and Rolls Royce Rolls-Royce Flight Test Establishment at Hucknall. Following extensive communication between Hitchcock (based in England), Rolls Royce engineers and Phillip Legarra at NAA regarding
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#17327942460339412-593: The B/C series when fitted with the tank, and led to the same fillet being added to -B, -C and initial -D-series versions in the field, to be quickly standardized as a normal rear-fuselage airframe component on later production blocks of the -D version. P-51Ds without fuselage fuel tanks were fitted with either the SCR-522-A or SCR-274-N Command Radio sets and SCR-695-A, or SCR-515 radio transmitters, as well as an AN/APS-13 rear-warning set; P-51Ds and Ks with fuselage tanks used
9593-720: The BPC and NAA, and did not involve the US Army or Wright Field in any way. In September 1940, a further 300 NA-73s were ordered by the MAP. To ensure uninterrupted delivery, Colonel Oliver P. Echols arranged with the Anglo-French Purchasing Commission to deliver the aircraft and NAA gave two examples (41-038 and 41-039) to the USAAC for evaluation. It is important to note that the Mustang I (NA-73 and NA-83) and
9774-806: The British Aircraft Purchasing Commission signed its first contract for the North American NA-73 on 24 April 1940, before Lend-Lease was in effect. Thus, the initial order for the P-51 Mustang (as it was later known) was placed by the British under the " cash and carry " program, as required by the US Neutrality Acts of the 1930s. After the arrival of the initial aircraft in the UK in October 1941,
9955-513: The British aircraft's more powerful engine (the Rolls-Royce Merlin 45, producing 1,470 hp (1,100 kW; 1,490 PS) at 9,250 ft (2,820 m). Although it has often been stated that the poor performance of the Allison engine above 15,000 ft (4,600 m) was a surprise and disappointment to the RAF and USAAF, this has to be regarded as a myth; aviation engineers of the time were fully capable of correctly assessing
10136-567: The British as the Mustang V ), and XP-51G to those with Merlin RM 14 SMs . A third lightweight prototype powered by an Allison V-1710 -119 was added to the development program. This aircraft was designated XP-51J . Since the engine was insufficiently developed, the XP-51J was loaned to Allison for engine development. None of these experimental lightweights went into production. The P-51H (NA-126)
10317-403: The British officials. Self was concerned that NAA had not ever designed a fighter, insisting they obtain the drawings and study the wind-tunnel test results for the P-40, before presenting them with detailed design drawings based on the agreed concept. NAA purchased the drawings and data from Curtiss for £56,000, confirming the purchase with the British Purchasing Commission. The commission approved
10498-497: The European theater, the most claimed by any Allied fighter in air-to-air combat) and 4,131 destroyed on the ground. Losses were about 2,520 aircraft. The 8th Air Force's 4th Fighter Group was the top-scoring fighter group in Europe, with 1,016 enemy aircraft claimed destroyed. This included 550 claimed in aerial combat and 466 on the ground. In air combat, the top-scoring P-51 units (both of which exclusively flew Mustangs) were
10679-518: The German airbases fell to the point where they were no longer considered worthwhile targets. On 21 May, targets were expanded to include railways, locomotives, and other rolling stock used by the Germans to transport materiel and troops, in missions dubbed "Chattanooga". The P-51 excelled at this mission, although losses were much higher on strafing missions than in air-to-air combat, partially because
10860-418: The German engines being significantly larger in displacement. Two-stage superchargers were also always two-speed. After the air was compressed in the low-pressure stage , the air flowed through a heat exchanger (" intercooler ") where it was cooled before being compressed again by the high-pressure stage and then possibly also aftercooled in another heat exchanger. While superchargers were highly used in
11041-530: The Ia (NA-91), produced for the British, were not equivalent to the P-51A which was a later model (NA-99). Two British Mustang Is were held back by the USAAF and given the provisional model number XP-51. The USAAF held back 57 Mustang Ia aircraft armed with 4 x 20mm Hispano cannon, from the third British order, converting most of them to tactical reconnaissance aircraft and designating them P-51-2/F6A. North American retained
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#173279424603311222-401: The Luftwaffe than to the Allies and was never a serious threat. The Me 262A was a serious threat, but attacks on their airfields neutralized them. The pioneering Junkers Jumo 004 axial-flow jet engines of the Me 262As needed careful nursing by their pilots, and these aircraft were particularly vulnerable during takeoff and landing. Lt. Chuck Yeager of the 357th Fighter Group was one of
11403-449: The Luftwaffe wherever it could be found. The aim was to achieve air supremacy . Mustang groups were sent far ahead of the bombers in a "fighter sweep" to intercept German fighters. Bomber crews complained, but by June, supremacy was achieved. The Luftwaffe answered with the Gefechtsverband ("battle formation"). This consisted of a Sturmgruppe of heavily armed and armored Fw 190As escorted by two Begleitgruppen of Bf 109s, whose task
11584-418: The Merlin that included Simmons automatic supercharger boost control with water injection, allowing War Emergency Power as high as 2,218 hp (1,500 kW). Differences between the P-51D included lengthening the fuselage and increasing the height of the tailfin, which reduced the tendency to yaw. Service access to the guns and ammunition was also improved. The canopy resembled the P-51D "bubble" style, over
11765-442: The Merlin, enabling long flights over water at 50 ft (15 m) altitude before approaching the enemy coastline. Over land, these flights followed a zig-zag course, turning every six minutes to foil enemy attempts at plotting an interception. During the first 18 months of Rhubarb raids, RAF Mustang Mk.Is and Mk.Ias destroyed or heavily damaged 200 locomotives, over 200 canal barges, and an unknown number of enemy aircraft parked on
11946-411: The Mustang B on 24 April 1944 thus: Supercharger In an internal combustion engine , a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement . The current categorization is that a supercharger is a form of forced induction that is mechanically powered (usually by a belt from the engine's crankshaft ), as opposed to
12127-467: The Mustang helped ensure Allied air superiority in 1944. The P-51 was also used by Allied air forces in the North African, Mediterranean , Italian , and Pacific theaters. During World War II, Mustang pilots claimed to have destroyed 4,950 enemy aircraft. At the start of the Korean War, the Mustang, by then redesignated F-51 , was the main fighter of the United States until jet fighters , including North American's F-86 Sabre , took over this role;
12308-509: The Mustang then became a specialized fighter-bomber. Despite the advent of jet fighters, the Mustang remained in service with some air forces until the early 1980s. After the Korean War, Mustangs became popular civilian warbirds and air racing aircraft. In 1938, the British government established a purchasing commission in the United States, headed by Sir Henry Self . Self was given overall responsibility for RAF production, research, and development, and also served with Sir Wilfrid Freeman ,
12489-505: The Mustang's liquid-cooled engine (particularly its liquid coolant system) was vulnerable to small-arms fire, unlike the air-cooled R-2800 radials of its Republic P-47 Thunderbolt stablemates based in England, regularly tasked with ground-strafing missions. Given the overwhelming Allied air superiority , the Luftwaffe put its effort into the development of aircraft of such high performance that they could operate with impunity, but which also made bomber attack much more difficult, merely from
12670-422: The P-51 or P-51-1). Two kept their P-51-1 designation and were used for testing by the USAAF. Two XP-51s (serials 41-038 and 41-039) set aside for testing arrived at Wright Field on 24 August and 16 December 1941 respectively. The small size of this first order reflected the fact that what had been known as the USAAC up until late June 1941 was still a relatively small, underfunded peacetime organization. After
12851-434: The P-51B and P-51C aircraft were fitted for photo reconnaissance and designated F-6C . Following combat experience the P-51D series introduced a "teardrop", or " bubble ", canopy to rectify problems with poor visibility to the rear of the aircraft. In the United States, new moulding techniques had been developed to form streamlined nose transparencies for bombers. North American designed a new streamlined plexiglass canopy for
13032-475: The P-51B which was later developed into the teardrop shaped bubble canopy. In late 1942, the tenth production P-51B-1-NA was removed from the assembly lines. From the windshield aft the fuselage was redesigned by cutting down the rear fuselage formers to the same height as those forward of the cockpit; the new shape faired in to the vertical tail unit. A new simpler style of windscreen, with an angled bullet-resistant windscreen mounted on two flat side pieces improved
13213-502: The P-51D, able to reach 472 mph (760 km/h; 410 kn) at 21,200 ft (6,500 m). The P-51H was designed to complement the Republic P-47N Thunderbolt as the primary aircraft for the planned invasion of Japan , with 2,000 ordered to be manufactured at Inglewood. Production was just gathering steam with 555 delivered when the war ended. Additional orders, already on the books, were canceled. With
13394-592: The RAAF from the USA. In late 1946, CAC was given another contract to build 170 (reduced to 120) more P-51Ds on its own; these, designated CA-18 Mustang Mark 21, Mark 22 or Mark 23, were manufactured entirely in-house, with only a few components being sourced from overseas. The 21 and 22 used the American-built Packard V-1650-3 or V-1650-7. The Mark 23s, which followed the 21s, were powered by Rolls-Royce Merlin 66 or Merlin 70 engines. The first 26 were built as Mark 21s, followed by 66 Mark 23s;
13575-533: The RAF 50 (as the Mustang II) before production converted to producing the Merlin-powered P-51B. The A-36A was the first aircraft based on the 'Mustang' airframe ordered by the U.S. Government specifically for use by the USAAF. NAA found an unfilled 'Dive Bomber' USAAF contract, which they got mainly by their own initiative. In so doing, NAA was able to keep the production bays open with the hope
13756-496: The SCR-522-A and AN/APS-13 only. The P-51D became the most widely produced variant of the Mustang. A Dallas-built version of the P-51D, designated the P-51K, was equipped with an 11 ft (3.4 m) diameter Aeroproducts propeller in place of the 11.2 ft (3.4 m) Hamilton Standard propeller. The hollow-bladed Aeroproducts propeller was unreliable, due to manufacturing problems, with dangerous vibrations at full throttle and
13937-499: The Spitfire and Hurricane planes powered by the Rolls-Royce Merlin engine were equipped largely with single-stage and single-speed superchargers. In 1942, two-speed two-stage supercharging with aftercooling was applied to the Rolls Royce Merlin 61 aero engine. The improved performance allowed the aircraft they powered to maintain a crucial advantage over the German aircraft they opposed throughout World War II, despite
14118-594: The USAAF had become so interested in the Merlin Mustang project that an initial contract for 400 aircraft was placed three months beforehand in August. The conversion led to production of the P-51B beginning at NAA's Inglewood, California, plant in June 1943, and P-51s started to become available to the 8th and 9th air forces in the winter of 1943–1944. Conversion to the two-stage supercharged and intercooled Merlin 60 series, over 350 lb (160 kg) heavier than
14299-549: The USAAF would place orders for it as a fighter. On 16 April 1942, Fighter Project Officer Benjamin S. Kelsey ordered 500 A-36A s, a redesign that included six .50 in (12.7 mm) M2 Browning machine guns , dive brakes, and the ability to carry two 500 lb (230 kg) bombs. Kelsey would rather have bought more fighters but was willing instead to initiate a higher level of Mustang production at North American by using USAAF funds earmarked for ground-attack aircraft when pursuit aircraft funding had already been allocated. It
14480-499: The United States patented the design for an air mover for use in blast furnaces and other industrial applications. This air mover and Birmingham's ventilation compressor both used designs similar to that of the later Roots-type superchargers . In March of 1878, German engineer Heinrich Krigar obtained the first patent for a screw-type compressor. The design was a two-lobe rotor assembly with identically-shaped rotors, however
14661-490: The V-1710 had been designed to produce maximum power at low altitude; above that, power dropped off rapidly. Prior to the Mustang project, the USAAC had Allison concentrate primarily on turbochargers in concert with General Electric ; the turbochargers proved to be reliable and capable of providing significant power increases in the Lockheed P-38 Lightning and other high-altitude aircraft, in particular in
14842-475: The V-1710-39. The RAF later operated 308 P-51Bs and 636 P-51Cs, which were known in RAF service as Mustang Mk IIIs; the first units converted to the type in late 1943 and early 1944. Mustang Mk III units were operational until the end of World War II, though many units had already converted to the Mustang Mk IV (P-51D) and Mk IVa (P-51K) (828 in total, comprising 282 Mk IV and 600 Mk IVa). As all except
15023-597: The XP-51 did not begin immediately. However, this did not mean it was neglected, or testing and evaluation mishandled. The 150 NA-91s were designated P-51 by the newly formed USAAF and were initially named Apache , although this was soon dropped and the RAF name, Mustang, adopted instead. The USAAF did not like the mixed armament of the British Mustang Is and instead adopted an armament of four long-barrelled 20 mm (.79 in) Hispano Mk II cannon, removing
15204-734: The XP-51B. Based on the Packard V-1650-3 duplicating the Merlin 61's performance, NAA estimated for the XP-78 a top speed of 445 mph (387 kn; 716 km/h) at 28,000 feet (8,500 m), and a service ceiling of 42,000 feet (13,000 m). Initial flights of what was known to Rolls-Royce as the Mustang X were completed at Hucknall in October 1942. The first flight of the US version, designated XP-51B took place in November 1942, but
15385-403: The air density at 30,000 ft (9,100 m) is 1 ⁄ 3 of that at sea level, resulting in 1 ⁄ 3 as much fuel being able to be burnt in a naturally aspirated engine, therefore the power output would be greatly reduced. A supercharger/turbocharger can be thought of either as artificially increasing the density of the air by compressing it or as forcing more air than normal into
15566-654: The amphibious Dieppe Raid on the French coast (19 August 1942), four British and Canadian Mustang squadrons, including 26 Squadron, saw action covering the assault on the ground. By 1943–1944, British Mustangs were used extensively to seek out V-1 flying bomb sites. The last RAF Mustang Mk I and Mustang Mk II aircraft were struck off charge in 1945. Army Co-operation Command used the Mustang's superior speed and long range to conduct low-altitude " Rhubarb " raids over continental Europe, sometimes penetrating German airspace. The V-1710 engine ran smoothly at 1,100 rpm, versus 1,600 for
15747-486: The angle of the reflector glass. Pilots were also given the option of having ring and bead sights mounted on the top engine cowling formers. This option was discontinued with the P-51D. The first XP-51B flew on 30 November 1942. Flight tests confirmed the potential of the new fighter, with the service ceiling being raised by 10,000 ft (3,000 m), with the top speed improving by 50 mph (43 kn; 80 km/h) at 30,000 ft (9,100 m). American production
15928-463: The attacks in May destroyed 94 square miles (240 km ) of buildings, which was equivalent to one-seventh of Japan's total urban area. The minister of home affairs , Iwao Yamazaki , concluded after these raids that Japan's civil defense arrangements were "considered to be futile". On the first day of June, 521 B-29s escorted by 148 P-51s were dispatched in a daylight raid against Osaka. While en route to
16109-593: The benefit to the operational range was given a much higher priority to American aircraft because of a less predictable requirement on the operational range and having to travel far from their home bases. Consequently, turbochargers were mainly employed in American aircraft engines such as the Allison V-1710 and the Pratt & Whitney R-2800 , which were comparably heavier when turbocharged, and required additional ducting of expensive high-temperature metal alloys in
16290-523: The bombers from England to Germany and back. By the time the Pointblank offensive resumed in early 1944, matters had changed. Bomber escort defenses were initially layered, using the shorter-range P-38s and P-47s to escort the bombers during the initial stages of the raid before handing over to the P-51s when they were forced to turn for home. This provided continuous coverage during the raid. The Mustang
16471-413: The bombers had destroyed much of the country's six largest cities, killing between 112,000 and 126,762 people and rendering millions homeless. The widespread destruction and high number of casualties from these raids caused many Japanese to realize that their country's military was no longer able to defend the home islands. American losses were low compared to Japanese casualties; 136 B-29s were downed during
16652-602: The bombers proved to be easy prey for the Mustangs, and had to be quickly withdrawn from combat. The Focke-Wulf Fw 190 A, already suffering from poor high-altitude performance, was outperformed by the Mustang at the B-17's altitude, and when laden with heavy bomber-hunting weapons as a replacement for the more vulnerable twin-engined Zerstörer heavy fighters, it suffered heavy losses. The Messerschmitt Bf 109 had comparable performance at high altitudes, but its lightweight airframe
16833-433: The boost pressure to rise exponentially with engine speed (above a certain threshold). Another family of supercharger, albeit rarely used, is the pressure wave supercharger . Roots blowers (a positive displacement design) tend to be only 40–50% efficient at high boost levels, compared with 70-85% for dynamic superchargers. Lysholm-style blowers (a rotary-screw design) can be nearly as efficient as dynamic superchargers over
17014-532: The campaign. In Tokyo, Osaka, Nagoya, Yokohama, Kobe, and Kawasaki, "over 126,762 people were killed ... and a million and a half dwellings and over 105 square miles (270 km ) of urban space were destroyed." In Tokyo, Osaka and Nagoya, "the areas leveled (almost 100 square miles (260 km )) exceeded the areas destroyed in all German cities by both the American and British air forces (about 79 square miles (200 km ))." P-51s also conducted
17195-535: The city, the Mustangs flew through thick clouds, and 27 of the fighters were destroyed in collisions. Nevertheless, 458 heavy bombers and 27 P-51s reached the city, and the bombardment killed 3,960 Japanese and destroyed 3.15 square miles (8.2 km ) of buildings. On 5 June, 473 B-29s struck Kobe by day and destroyed 4.35 square miles (11.3 km ) of buildings for the loss of 11 bombers. A force of 409 B-29s attacked Osaka again on 7 June; during this attack, 2.21 square miles (5.7 km ) of buildings were burnt out and
17376-617: The cutback in production, the variants of the P-51H with different versions of the Merlin engine were produced in either limited numbers or terminated. These included the P-51L , similar to the P-51H but utilizing the 2,270 hp (1,690 kW) V-1650-11 engine, which was never built; and its Dallas-built version, the P-51M , or NA-124, which used the V-1650-9A engine lacking water injection and therefore rated for lower maximum power, of which one
17557-410: The cylinder every time the piston moves down on the intake stroke. Since a supercharger is usually designed to produce a given amount of boost at high altitudes (where the air density is lower), the supercharger is often oversized for low altitude. To prevent excessive boost levels, it is important to monitor the intake manifold pressure at low altitude. As the aircraft climbs and the air density drops,
17738-503: The design did not reach production. Also in 1878, Scottish engineer Dugald Clerk designed the first supercharger which was used with an engine. This supercharger was used with a two-stroke gas engine. Gottlieb Daimler received a German patent for supercharging an internal combustion engine in 1885. Louis Renault patented a centrifugal supercharger in France in 1902. The world's first series-produced cars with superchargers were
17919-580: The earliest aircraft were obtained under Lend-Lease, all Mustang aircraft still on RAF charge at the end of the war were either returned to the USAAF "on paper" or retained by the RAF for scrapping. The last RAF Mustangs were retired from service in 1947. Prewar doctrine was based on the idea " the bomber will always get through ". Despite RAF and Luftwaffe experience with daylight bombing, the USAAF still incorrectly believed in 1942 that tightly packed formations of bombers would have so much firepower that they could fend off fighters on their own. Fighter escort
18100-780: The early 2000s (such as the C 230 Kompressor straight-four, C 32 AMG V6, and CL 55 AMG V8 engines) were replaced around 2010 by turbocharged engines in models such as the C 250 and CL 65 AMG models. However, there are exceptions, such as the Audi 3.0 TFSI supercharged V6 (introduced in 2009) and the Jaguar AJ-V8 supercharged V8 (upgraded to the Gen III version in 2009). In the 1930s, two-speed drives were developed for superchargers for aero engines providing more flexible aircraft operation. The arrangement also entailed more complexity of manufacturing and maintenance. The gears connected
18281-412: The engine. Therefore turbocharged engines usually produce more power and better fuel economy than supercharged engines. However, turbochargers can suffer from turbo lag (especially at lower RPM), where the exhaust gas flow is initially insufficient to spin the turbocharger and achieve the desired boost level, thus leading to a delay in the throttle response . This is often a result of a turbo charge which
18462-408: The escorts, the threat of mass attacks and later the "company front" (eight abreast) assaults by armored Sturmgruppe Fw 190As brought an urgency to attacking the Luftwaffe wherever it could be found, either in the air or on the ground. Beginning in late February 1944 , 8th Air Force fighter units began systematic strafing attacks on German airfields with increasing frequency and intensity throughout
18643-568: The expected Allied invasion fleet. While the P-51 pilots only occasionally encountered Japanese fighters in the air, the airfields were protected by antiaircraft batteries and barrage balloons . By the end of the war, VII Fighter Command had conducted 51 ground-attack raids, of which 41 were considered successful. The fighter pilots claimed to have destroyed or damaged 1,062 aircraft and 254 ships, along with large numbers of buildings and railway rolling stock. American losses were 91 pilots killed and 157 Mustangs destroyed. Two P-51 pilots received
18824-768: The extreme heat and pressure of the turbochargers. Such damage was a prominent problem in the early models of the American Boeing B-29 Superfortress high-altitude bombers used in the Pacific Theater of Operations during 1944–45. Turbocharged piston engines continued to be used in a large number of postwar airplanes, such as the B-50 Superfortress , the KC-97 Stratofreighter , the Boeing 377 Stratocruiser ,
19005-458: The first 14 Mark 21s were converted to fighter-reconnaissance aircraft, with two F24 cameras in both vertical and oblique positions in the rear fuselage, above and behind the radiator fairing; the designation of these modified Mustangs was changed from Mark 21 to Mark 22. An additional 14 purpose-built Mark 22s, built after the Mark 23s, and powered by either Packard V-1650-7s or Merlin 68s, completed
19186-536: The first American pilots to shoot down an Me 262, which he caught during its landing approach. On 7 October 1944, Lt. Urban L. Drew of the 361st 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
19367-483: The first order to be delivered to the USAAC for evaluation; these two airframes, 41-038 and 41-039 respectively, were designated XP-51 . The first RAF Mustang Mk Is were delivered to 26 Squadron at RAF Gatwick in February 1942 and made their combat debut on 10 May 1942. With their long range and excellent low-altitude performance, they were employed effectively for tactical reconnaissance and ground-attack duties over
19548-507: The first production aircraft by January 1941. In March 1940, 320 aircraft were ordered by Freeman, who had become the executive head of the Ministry of Aircraft Production (MAP) and the contract was promulgated on 24 April. The NA-73X , which was designed by a team led by lead engineer Edgar Schmued , followed the best conventional practice of the era, designed for ease of mass manufacturing. The design included several new features. One
19729-536: The first squadron of Mustang Mk Is entered service in January 1942, the first being No. 26 Squadron RAF . Due to poor high-altitude performance, the Mustangs were used by Army Co-operation Command , rather than Fighter Command, and were used for tactical reconnaissance and ground-attack duties. On 10 May 1942, Mustangs first flew over France, near Berck-sur-Mer . On 27 July 1942, 16 RAF Mustangs undertook their first long-range reconnaissance mission over Germany. During
19910-489: The five experimental Mustang Xs be handed over to Carl Spaatz for trials and evaluation by the U.S. Eighth Air Force in Britain. The high-altitude performance improvement was remarkable: one Mk X ( serial number AM208 ) reached 433 mph (376 kn; 697 km/h) at 22,000 ft (6,700 m) with full supercharger, and AL975 tested at an absolute ceiling of 40,600 ft (12,400 m). The two XP-51Bs were
20091-574: The flight velocities they achieved. Foremost among these were the Messerschmitt Me 163 B point-defense rocket interceptors, which started their operations with JG 400 near the end of July 1944, and the longer-endurance Messerschmitt Me 262 A jet fighter, first flying with the Gruppe -strength Kommando Nowotny unit by the end of September 1944. In action, the Me 163 proved to be more dangerous to
20272-415: The forward view while the new canopy resulted in exceptional all-round visibility. Wind tunnel tests of a wooden model confirmed that the aerodynamics were sound. The new model Mustang also had a redesigned wing; alterations to the undercarriage up-locks and inner-door retracting mechanisms meant that there was an additional fillet added forward of each of the wheel bays, increasing the wing area and creating
20453-412: The full tank were made. Since the fuel from the fuselage tank was used during the initial stages of a mission, the fuel tank would be fitted in all Mustangs destined for VIII Fighter Command . The P-51 Mustang was a solution to the need for an effective bomber escort. It used a common, reliable engine and had internal space for a larger-than-average fuel load. With external fuel tanks, it could accompany
20634-468: The fuselage behind the pilot, greatly increasing the aircraft's range over that of the earlier P-51A. NAA incorporated the tank in the production of the P-51B-10, and supplied kits to retrofit it to all existing P-51Bs. The Mustang was initially developed for the RAF, which was its first user. As the first Mustangs were built to British requirements, these aircraft used factory numbers and were not P-51s;
20815-761: The fuselage tanks would lead to the replacement of the fabric-covered elevators with metal-covered surfaces and a reduction of the tailplane incidence. With the fuselage and wing tanks, plus two 75 US gal (62 imp gal; 280 L) drop tanks, the combat radius was 880 mi (1,420 km). Despite these modifications, the P-51Bs and P-51Cs, and the newer P-51Ds and P-51Ks, experienced low-speed handling problems that could result in an involuntary "snap-roll" under certain conditions of air speed, angle of attack, gross weight, and center of gravity. Several crash reports tell of P-51Bs and P-51Cs crashing because horizontal stabilizers were torn off during maneuvering. As
20996-476: The ground, for a loss of eight Mustangs. At sea level, the Mustangs were able to outrun all enemy aircraft encountered. The RAF gained a significant performance enhancement at low altitude by removing or resetting the engine's manifold pressure regulator to allow overboosting, raising output as high as 1,780 horsepower at 70 in Hg. In December 1942, Allison approved only 1,570 horsepower at 60 in Hg manifold pressure for
21177-582: The late-June 1941 reorganization of the USAAC into the United States Army Air Forces , roughly six months before the attack on Pearl Harbor changed the outlook for the United States regarding involvement in global hostilities against the Axis overnight , priority had to be given to building as many existing fighters – P-38s, P-39s, and P-40s – as possible while simultaneously training pilots and other personnel, which meant evaluation of
21358-625: The limited scale of operations, no conclusive evidence showed American doctrine was failing. In the 26 operations flown to the end of 1942, the loss rate had been under 2%. In January 1943, at the Casablanca Conference , the Allies formulated the Combined Bomber Offensive (CBO) plan for "round-the-clock" bombing – USAAF daytime operations complementing the RAF nighttime raids on industrial centers. In June 1943,
21539-613: The majority continued to use the original framed canopies. P-51Bs and P-51Cs started to arrive in England in August and October 1943. The P-51B/P-51C versions were sent to 15 fighter groups that were part of the Eighth and Ninth Air Forces in England and the Twelfth and Fifteenth in Italy (the southern part of Italy was under Allied control by late 1943). Other deployments included
21720-444: The mid-1900s and during WWII , they have largely fallen out of use in modern piston-driven aircraft . This can largely be attributed to the higher temperature and lighter alloys that make turbochargers more efficient than superchargers, as well as the lower maintenance due to less moving parts. Due to the reduced air density at higher altitudes, supercharging and turbocharging have often been used in aircraft engines. For example,
21901-444: The movable fitting of previous Mustang models and the fitting of wing racks able to carry either 75 or 150 US gal (62 or 125 imp gal; 280 or 570 L) drop tanks, increasing the maximum ferry range to 2,740 mi (4,410 km) with the 150 US gal (120 imp gal; 570 L) tanks. The top speed was raised to 409 mph (658 km/h) at 10,000 ft (3,000 m). The USAAF received 310 and
22082-468: The order comprised 320 NA-73s, followed by 300 NA-83s, all of which were designated Mustang Mark I by the RAF. The first RAF Mustangs supplied under Lend-Lease were 93 Mk Ia designated as P-51s by the USAAF, followed by 50 P-51As used as Mustang Mk IIs. Aircraft supplied to Britain under Lend-Lease were required for accounting purposes to be on the USAAC's books before they could be supplied to Britain, but
22263-459: The order had been placed; it first flew on 26 October 1940, 149 days into the contract, an uncommonly short development period even during the war. With test pilot Vance Breese at the controls, the prototype handled well and accommodated an impressive fuel load. The aircraft's three-section, semi-monocoque fuselage was constructed entirely of aluminum to save weight. It was armed with four .30 caliber (7.62 mm) AN/M2 Browning machine guns in
22444-406: The others had 270 rpg, for a total of 1,880. The B/C subtypes' M2 guns were mounted with an inboard axial tilt, this angled mounting had caused problems with the ammunition feed and with spent casings and links failing to clear the gun-chutes, leading to frequent complaints that the guns jammed during combat maneuvers. The D/K's six M2s were mounted upright, remedying the jamming problems. In addition,
22625-583: The performance of an aircraft's engine and supercharger. As evidence of this, in mid-1941, the 93rd and 102nd airframes from the NA-91 order were slated to be set aside and fitted and tested with Packard Merlin (the US-built version of the Merlin) engines, with each receiving the designation XP-51B . On 23 June 1942, a contract was placed for 1,200 P-51As (NA-99s). The P-51A used the new Allison V-1710-81 engine,
22806-684: The pilot over-controlling the aircraft and creating heavy loads on the tail unit. One of the few remaining complaints with the Merlin-powered aircraft was a poor rearward view. The canopy structure, which was the same as the Allison-engined Mustangs, was made up of flat, framed panels; the pilot entered or exited the cockpit by lowering the port side panel and raising the top panel to the right. The canopy could not be opened in flight and tall pilots especially were hampered by limited headroom. In order to at least partially improve
22987-400: The pilot's seat, starting with P-51B-5-NA ("block 5"). When this tank was full, the center of gravity of the Mustang was moved dangerously close to the aft limit. As a result, maneuvers were restricted until the tank was down to about 25 US gal (21 imp gal; 95 L) and the external tanks had been dropped. Problems with high-speed "porpoising" of the P-51Bs and P-51Cs with
23168-616: The primary USAAF fighter in the theater. It was produced in larger numbers than any other Mustang variant. Nevertheless, by the end of the war, roughly half of all operational Mustangs were still P-51B or P-51C models. In November 1944 the Australian government decided to order Australian-built Mustangs, to replace its Curtiss Kittyhawks and CAC Boomerangs in the South West Pacific theatre . The Commonwealth Aircraft Corporation (CAC) factory at Fishermans Bend , Melbourne
23349-568: The production run. All of the CA-17s and CA-18s, plus the 84 P-51Ks, used Australian serial numbers prefixed by A68. In October 1953, six Mustangs, including A68-1 , the first Australian built CA-17 Mk 20, were allotted to the Long Range Weapons Development Establishment at Maralinga, South Australia , for use in experiments to gauge the effects of low-yield atomic bombs . The Mustangs were placed on
23530-422: The promising outlook of a Merlin Mustang, along with the subsequent work in progress by Rolls Royce on the Mustang X, NAA representatives including Mustang designer Schmued visited the UK to examine and discuss the project in detail. The promising calculations and modification progress by Rolls Royce led in July 1942 to a contract being let for two NAA Merlin prototypes, briefly designated XP-78, but soon to become
23711-497: The resulting detailed design drawings, signing the commencement of the Mustang project on 4 May 1940, and firmly ordering 320 on 29 May 1940. Prior to this, NAA only had a letter of intent for an order of 320 aircraft. Curtiss engineers accused NAA of plagiarism. The British Purchasing Commission stipulated armament of four .303 in (7.7 mm) machine guns (as used on the Tomahawk), a unit cost of no more than $ 40,000, and delivery of
23892-485: The same V-1710-39 (producing 1,220 hp (910 kW ; 1,240 PS ) at 10,500 ft (3,200 m), driving a 10 ft 6 in (3.20 m) diameter, three-blade Curtiss-Electric propeller). The Mk I was 30 mph (48 km/h) faster than the Supermarine Spitfire Mk Vc at 5,000 ft (1,500 m) and 35 mph (56 km/h) faster at 15,000 ft (4,600 m), despite
24073-493: The same armament and ammunition load of the P-51A, while the bomb rack/external drop tank installation was adapted from the A-36 Apache; the racks were rated to carry up to 500 lb (230 kg) of ordnance and were also piped for drop tanks. The machine guns were aimed using the electrically illuminated N-3B reflector sight fitted with an A-1 head assembly which allowed it to be used as a gun or bomb sight through varying
24254-467: The second aircraft of this batch to help develop the P-51A. The Allison engine in the Mustang I had a single-stage supercharger that caused power to drop off rapidly above 15,000 feet (4,600 m). This made it unsuitable for use at the altitudes where combat was taking place in Europe. Allison's attempts at developing a high-altitude engine were underfunded, but produced the V-1710-45, which featured
24435-423: The sides and rear. Because the new structure slid backward on runners, it could be slid open in flight. The aerial mast behind the canopy was replaced by a "whip" aerial which was mounted further aft and offset to the right. Most British Mk IIIs were equipped with Malcolm hoods. Several American service groups "acquired" the necessary conversion kits and some American P-51B/P-51Cs appeared with the new canopy, although
24616-431: The single-stage Allison, driving a four-bladed Hamilton Standard propeller, required moving the wing slightly forward to correct the aircraft's center of gravity . After the USAAF, in July 1943, directed fighter aircraft manufacturers to maximize internal fuel capacity, NAA calculated the P-51B's center of gravity to be forward enough to include an additional 85 US gal (320 L; 71 imp gal) fuel tank in
24797-526: The spring, with the objective of gaining air supremacy over the Normandy battlefield. In general, these were conducted by units returning from escort missions, but beginning in March, many groups also were assigned airfield attacks instead of bomber support. The P-51, particularly with the advent of the K-14 gyro gunsight and the development of "Clobber Colleges" for the training of fighter pilots in fall 1944,
24978-452: The supercharger to the engine using a system of hydraulic clutches, which were initially manually engaged or disengaged by the pilot with a control in the cockpit. At low altitudes, the low-speed gear would be used, to prevent excessive boost levels. At higher altitudes, the supercharger could be switched to a higher gear to compensate for the reduced intake air density. In the Battle of Britain
25159-500: The supercharger. In the middle of the rev range, a boost was derived from both systems, while at the highest revs the system disconnected the drive from the supercharger and isolated the associated ducting. This was done in an attempt to exploit the advantages of each of the charging systems while removing the disadvantages. In turn, this approach brought greater complexity and affected the car's reliability in WRC events, as well as increasing
25340-521: The superiority of the wing designed with the NAA/NACA 45–100 airfoils . The other feature was a new cooling arrangement positioned aft (single ducted water and oil radiators assembly) that reduced the fuselage drag and effects on the wing. Later, after much development, they discovered that the cooling assembly could take advantage of the Meredith effect , in which heated air exited the radiator with
25521-589: The test results and after further flights by a number of USAAF pilots, the results were so positive that North American began work on converting several aircraft developing into the P-51B/C (Mustang Mk III) model, which became the first long range fighter to be able to compete with the Luftwaffe 's fighters. The definitive version, the P-51D , was powered by the Packard V-1650-7 , a license-built version of
25702-457: The throttle can be progressively opened to obtain the maximum safe power level for a given altitude. The altitude at which the throttle reaches full open and the engine is still producing full rated power is known as the critical altitude . Above the critical altitude, engine power output will reduce as the supercharger can no longer fully compensate for the decreasing air density. Another issue encountered at low altitudes (such as at ground level)
25883-573: The two-speed, two-stage- supercharged Merlin 66 , and was armed with six .50 caliber (12.7 mm) AN/M2 Browning machine guns . From late 1943, P-51Bs and P-51Cs (supplemented by P-51Ds from mid-1944) were used by the USAAF's Eighth Air Force to escort bombers in raids over Germany , while the RAF's Second Tactical Air Force and the USAAF's Ninth Air Force used the Merlin-powered Mustangs as fighter-bombers, roles in which
26064-492: The use of drop tanks enabled the Merlin-powered Mustang to be introduced as a bomber escort with a combat radius of 750 mi (1,210 km) using two 75 US gal (62 imp gal; 280 L) 2-piece, sheet-metal stamped construction drop tanks. The range would be further increased with the introduction of an 85 US gal (71 imp gal; 320 L) self-sealing fuel tank aft of
26245-480: The various components and equipment fitted to Spitfires. In the course of this NAA found that British load factors were less than American ones. Working to the lower load factors helped them reduce structure weight. In test flights, the NA-105 achieved 491 mph (790 km/h) at 21,000 ft (6,400 m). The designation XP-51F was assigned to prototypes powered with V-1650 engines (a small number were passed to
26426-566: The view from the Mustang, the British had field-modified some Mustangs with clear, sliding canopies called Malcolm hoods (designed by R Malcolm & Co ), and whose design had also been adopted by the U.S. Navy's own F4U-1D version of the Vought F4U Corsair in April 1944. The new structure was a frameless plexiglas moulding which ballooned outwards at the top and sides, increasing the headroom and allowing increased visibility to
26607-581: The war in Europe wound down, the P-51 became more common. With the capture of Iwo Jima , USAAF P-51 Mustang fighters of the VII ;Fighter Command were stationed on that island starting in March 1945, being initially tasked with escorting Boeing B-29 Superfortress missions against the Japanese homeland . The command's last major raid of May was a daylight incendiary attack on Yokohama on 29 May conducted by 517 B-29s escorted by 101 P-51s. This force
26788-563: The weapons were installed along the line of the wing's dihedral , rather than parallel to the ground line as in the earlier Mustangs. The wing racks fitted to the P-51D/P-51K series were strengthened and were able to carry up to 1,000 lb (450 kg) of ordnance, although 500 lb (230 kg) bombs were the recommended maximum load. Later models had removable under-wing 'Zero Rail' rocket pylons added to carry up to ten T64 5.0 in (127 mm) HVAR rockets per plane. The gunsight
26969-546: The weight of engine ancillaries in the finished design. Twincharged engines have occasionally been used in production cars, such as the 2005-2013 Volkswagen 1.4 litre and the 2017-present Volvo B4204T43/B4204T48 2.0 litre four-cylinder engines. In 1849, G. Jones of Birmingham, England began manufacturing a lobe pump compressor to provide ventilation for coal mines. In 1860, the Roots Blower Company (founded by brothers Philander and Francis Marion Roots) in
27150-414: The west and quickly improved their battle direction. In fall 1943, the 8th Air Force's heavy bombers conducted a series of deep-penetration raids into Germany, beyond the range of escort fighters. The Schweinfurt–Regensburg mission in August lost 60 B-17s of a force of 376, the 14 October attack lost 77 of a force of 291—26% of the attacking force. For the US, the very concept of self-defending bombers
27331-460: The wings and two .50 caliber (12.7 mm) AN/M2 Browning machine guns mounted under the engine and firing through the propeller arc using a gun-synchronizing gear . While the USAAC could block any sales it considered detrimental to the interests of the US, the NA-73 was considered to be a special case because it had been designed at the behest of the British and all dealings were directly between
27512-572: Was a decisive element in Allied countermeasures against the Jagdverbände . The numerical superiority of the USAAF fighters, superb flying characteristics of the P-51, and pilot proficiency helped cripple the Luftwaffe ' s fighter force. As a result, the fighter threat to the US, and later British, bombers was greatly diminished by July 1944. The RAF, long proponents of night bombing for protection, were able to reopen daylight bombing in 1944 as
27693-467: Was a low priority, but when the concept was discussed in 1941, the Lockheed P-38 Lightning was considered to be most appropriate, as it had the speed and range. Another school of thought favored a heavily up-armed "gunship" conversion of a strategic bomber . A single-engined, high-speed fighter with the range of a bomber was thought to be an engineering impossibility. The 8th Air Force started operations from Britain in August 1942. At first, because of
27874-659: Was a wing designed using laminar flow airfoils, which were developed co-operatively by NAA and the National Advisory Committee for Aeronautics (NACA). These airfoils generated low drag at high speeds. During the development of the NA-73X, a wind-tunnel test of two wings, one using NACA five-digit airfoils and the other using the new NAA/NACA 45–100 airfoils, was performed in the University of Washington Kirsten Wind Tunnel. The results of this test showed
28055-416: Was accepted by the USAAF. Modifications included changes to the cowling, a simplified undercarriage with smaller wheels and disc brakes, a larger canopy, and an armament of four .50 Brownings. In total the design was some 1,600 lb (730 kg) lighter than the P-51D. Schmued described how it came from an enquiry by the USAAF as to why British aircraft were lighter than American ones. NAA engineers examined
28236-472: Was also one of the first aircraft to have a fuselage lofted mathematically using conic sections ; this resulted in smooth, low-drag surfaces. To aid production, the airframe was divided into five main sections—forward, center, rear fuselage, and two wing halves— all of which were fitted with wiring and piping before being joined. The prototype NA-73X was rolled out in September 1940, just 102 days after
28417-419: Was built out of the original 1629 ordered, serial number 45-11743. Although some P-51Hs were issued to operational units, none saw combat in World War II and, in postwar service, most were issued to reserve units. One aircraft was provided to the RAF for testing and evaluation. Serial number 44-64192 was designated BuNo 09064 and used by the U.S. Navy to test transonic airfoil designs and then returned to
28598-406: Was called into question, but instead of abandoning daylight raids and turning to night bombing, as the RAF suggested, they chose other paths; at first, bombers converted to gunships (the Boeing YB-40 ) were believed to be able to escort the bomber formations, but when the concept proved to be unsuccessful, thoughts then turned to the Lockheed P-38 Lightning. In early 1943, the USAAF also decided that
28779-438: Was carried out by inserting the airplane, with the outer wing panels removed, into the 16-foot wind tunnel. A test engineer would sit in the cockpit with the wind tunnel running and listen for the duct rumble. It was eventually found that the rumble could be eliminated by increasing the gap between the lower surface of the wing and the upper lip of the cooling system duct from 1 to 2 in (25 to 51 mm). They concluded part of
28960-424: Was changed from the N-3B to the N-9 before the introduction in September 1944 of the K-14 or K-14A gyro-computing sight . Apart from these changes, the P-51D and K series retained V-1650-7 engine used in the majority of the P-51B/C series. The addition of the 85 US gallon (322 l) fuselage fuel tank, coupled with the reduction in area of the new rear fuselage, exacerbated the handling problems already experienced with
29141-466: Was completed on 9 September 1940, 102 days after contract signing, achieving its first flight on 26 October. The Mustang was designed to use the Allison V-1710 engine without an export-sensitive turbosupercharger or a multi-stage supercharger, resulting in limited high-altitude performance. The aircraft was first flown operationally and very successfully by the RAF and as a tactical-reconnaissance aircraft and fighter-bomber (Mustang Mk I). In mid 1942,
29322-428: Was designed in 1940 by a team headed by James H. Kindelberger of North American Aviation (NAA) in response to a requirement of the British Purchasing Commission . The commission approached NAA to build Curtiss P-40 fighters under license for the Royal Air Force (RAF). Rather than build an old design from another company, NAA proposed the design and production of a more modern fighter. The prototype NA-73X airframe
29503-427: Was designed. This housed a larger radiator, which incorporated a section for the supercharger coolant, and, forward of this and slightly lower, an oil cooler was housed in a secondary duct which drew air through the main opening and exhausted via a separate exit flap. A "duct rumble" heard by pilots in flight in the prototype P-51B resulted in a full-scale wind-tunnel test at NACA 's Ames Aeronautical Laboratory . This
29684-401: Was even more greatly affected by increases in armament. The Mustang's much lighter armament, tuned for antifighter combat, allowed it to overcome these single-engined opponents. At the start of 1944, Major General James Doolittle , the new commander of the 8th Air Force, released most fighters from the requirement of flying in close formation with the bombers, allowing them free rein to attack
29865-465: Was eventually replaced by the Hamilton Standard. By the time of the Korean War, most F-51s were equipped with "uncuffed" Hamilton Standard propellers with wider, blunt-tipped blades. The photo reconnaissance versions of the P-51D and P-51K were designated F-6D and F-6K respectively. The RAF assigned the name Mustang Mk IV to the P-51D model and Mustang Mk IVA to P-51K models. The P-51D/P-51K started arriving in Europe in mid-1944 and quickly became
30046-424: Was fitted to all Mustang X prototypes. Initially, the Mustang's steadfast champion, USAAC/F Assistant Air Attaché Major Thomas Hitchcock, was concerned that the USAAF had little or no interest in the potential of the P-51A and its development with the Merlin engine. He wrote: "Its development in this theatre has suffered for various reasons. Sired by the English out of an American mother, the Mustang has no parent in
30227-410: Was intercepted by 150 A6M Zero fighters, sparking an intense air battle in which five B-29s were shot down and another 175 damaged. In return, the P-51 pilots claimed 26 "kills" and 23 "probables" for the loss of three fighters. The 454 B-29s that reached Yokohama struck the city's main business district and destroyed 6.9 square miles (18 km ) of buildings; over 1000 Japanese were killed. Overall,
30408-533: Was often used to compensate for the lower air density at high altitudes. Supercharging is less commonly used in the 21st century, as manufacturers have shifted to turbochargers to reduce fuel consumption and increase power outputs. There are two main families of superchargers defined according to the method of gas transfer: positive displacement and dynamic superchargers. Positive displacement superchargers deliver an almost constant level of boost pressure increase at all engine speeds, while dynamic superchargers cause
30589-552: Was originally designed to use a low-altitude rated Allison V-1710 engine. Unlike later models, Allison-powered Mustangs were characterized by the carburetor air intake placed on the dorsal surface of the nose, immediately behind the propeller. The first production contract was awarded by the British for 320 NA-73 fighters, named Mustang Mk I by the British Purchasing Commission ; a second British contract soon followed, which called for 300 more (NA-83) Mustang Mk I fighters. Contractual arrangements were also made for two aircraft from
30770-465: Was placed by the US Army on 7 July 1940. This was on behalf of the RAF in a Lend-Lease deal. All but the last 57 went to the British. After the attack on Pearl Harbor , the USAAF 'held back' these Mustang Mk IAs for their own use. Fifty-five of these P-51-1s were outfitted with a pair of K.24 cameras in the rear fuselage for tactical low-level reconnaissance and re-designated F-6A (the "F" for photographic, although confusingly also still referred to as
30951-453: Was running at capacity, so P-40s were in short supply. North American Aviation (NAA) was already supplying its T-6 Texan (known in British service as the "Harvard") trainer to the RAF, but was otherwise underused. NAA President "Dutch" Kindelberger approached Self to sell a new medium bomber , the North American B-25 Mitchell . Instead, Self asked if NAA could manufacture P-40s under license from Curtiss. Kindelberger said NAA could have
31132-425: Was shot down and killed by friendly fire on Christmas Day 1944 during the Battle of the Bulge . In early 1945, P-51C, D, and K variants also joined the Chinese Nationalist Air Force . These Mustangs were provided to the 3rd, 4th, and 5th Fighter Groups and used to attack Japanese targets in occupied areas of China. The P-51 became the most capable fighter in China, while the Imperial Japanese Army Air Force used
31313-443: Was so clearly superior to earlier US designs that the 8th Air Force began to steadily switch its fighter groups to the Mustang, first swapping arriving P-47 groups to the 9th Air Force in exchange for those that were using P-51s, then gradually converting its Thunderbolt and Lightning groups. By the end of 1944, 14 of its 15 groups flew Mustangs. The Luftwaffe's twin-engined Messerschmitt Bf 110 heavy fighters brought up to deal with
31494-401: Was started in early 1943 with the P-51B (NA-102) being manufactured at Inglewood, California , and the P-51C (NA-103) at a new plant in Dallas, Texas, which was in operation by summer 1943. The RAF named these models Mustang Mk III . In performance tests, the P-51B reached 441 mph (383 kn; 710 km/h) at 30,000 ft (9,100 m). In addition, the extended range made possible by
31675-447: Was the Packard V-1650-7, a licence-built version of the Rolls-Royce Merlin 60 series, fitted with a two-stage, two-speed supercharger . The armament was increased with the addition of two more .50 in (12.7 mm) AN/M2 "light-barrel" M2 Browning machine guns , the standard heavy machine gun used throughout the American air services of World War II, bringing the total to six. The inner pair of machine guns had 400 rounds per gun, and
31856-401: Was the final production Mustang, embodying the experience gained in the development of the XP-51F and XP-51G aircraft. This aircraft, with minor differences as the NA-129, came too late to participate in World War II, but it brought the development of the Mustang to a peak as one of the fastest production piston-engine fighters to see service. The P-51H used the new V-1650-9 engine, a version of
32037-448: Was the first airframe of the Mustang "family" to be drop-tank capable. The 500 aircraft were designated A-36A (NA-97). This model became the first USAAF Mustang to see combat. One aircraft (British serial EW998 ) was passed to the British who gave it the name Mustang Mk I (Dive Bomber) . In April 1942, the RAF's Air Fighting Development Unit (AFDU) tested the Mustang and found its performance inadequate at higher altitudes. As such, it
32218-473: Was the only non-U.S. production line for the P-51. In 1944, 100 P-51Ds were shipped from the U.S. in kit form to inaugurate production. From February 1945, CAC assembled 80 of these under the designation CA-17 Mustang Mark 20, with the first Australian-built aircraft flying on the 29 April 1945 and the first aircraft was handed over to the RAAF on 31 May 1945. The remaining 20 were kept unassembled as spare parts. In addition, 84 P-51Ks were also shipped directly to
32399-484: Was to be used to replace the P-40 in Army Cooperation Command squadrons, but the commanding officer was so impressed with its maneuverability and low-altitude speeds, he invited Ronnie Harker (from Rolls-Royce 's Flight Test establishment) to fly it. Rolls-Royce engineers rapidly realized equipping the Mustang with a high altitude Merlin 61 engine with its two-speed two-stage supercharger would substantially improve performance. The company started converting five aircraft as
32580-541: Was to keep the Mustangs away from the Fw 190s as they attacked the bombers. This strategy proved to be problematic, as the large German formation took a long time to assemble and was difficult to maneuver. It was often intercepted by the P-51 "fighter sweeps" before it could attack the bombers. However, German attacks against bombers could be effective when they did occur; the bomber-destroyer Fw 190As swept in from astern and often pressed their attacks to within 90 m (100 yd). While not always able to avoid contact with
32761-430: Was used to vastly increase the power output for several speed record airplanes. Military use of high-octane fuels began in early 1940 when 100-octane fuel was delivered to the British Royal Air Force fighting in World War II. The German Luftwaffe also had supplies of a similar fuel. Increasing the octane rating became a major focus of aero engine development for the remainder of the war, with later fuels having up to
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