The P-51 Mustang 1 The Inspiration, Design and Legacy Behind the P-51 Mustang Matthew Hundt English 11 Ms. Morris Lake Mills High School February 25, 2013 The P-51 Mustang 2 The Inspiration, Design, and Legacy Behind the P-51 Mustang The year is 1940. Britain’s Royal Air Force (RAF), and later the American Army Air Force (AAF), were in dire need of a long-range escort fighter that would be capable of fending off the Luftwaffe, which “was a potent force” (Ludwig, 2003, p.94). In his 1982 work, Jablonski concluded that the only way for bombers to survive the hazardous trip to and from Germany was to have fighter escort that could accompany them round trip (p. 103). The response to that limitation was the P-51 Mustang, which became a major factor in the Allies’ triumph in the air war in the European Theater of Operations (ETO). During World War II, the British, due to extreme shortages of fighter aircraft, contacted North American Aviation (NAA), an American aircraft company, and asked them to design and subsequently manufacture an innovative fighter plane that would be superior to all German opposition. The ensuing plane, the P-51 Mustang, became the most revered and feared escort fighter of the war because of its extensive range, impressive aerodynamics that afforded maneuverability and speed, and the deadly armament it possessed (Jablonski, 1982, p. 97). The Mustang may be the most important and innovative fighter plane in history due to its impeccable combat record and sleek design. After France had been successfully defeated by Nazi Germany, the British realized that they needed to strengthen defense measures. In Haggerty’s 2010 work, he noted that by the time the Battle of Britain began, the RAF was "critically short" of fighter planes to fend off the German advances (p. 511). Haggerty also stated that since the British economy was already strained, the Air Ministry needed to look elsewhere (America) for a plane manufacturer that would build bomber escorts for the RAF (p. 511). “RAF agents initially approached the dominant U.S. aircraft supplier, the Curtiss-Wright Corporation, with a request to place an order for more than 300 of their best fighters the P-40 The P-51 Mustang 3 Warhawk – which was also the main fighter in U.S. Army Air Corps service. Curtiss-Wright turned the order down due to lack of factory capacity" (Haggerty, 2010, p. 511). Ludwig (2003) stated that "on 11 April 1940 the BPC [British Purchasing Commission] signed a Letter of Intent to purchase '...400 aircraft, type NA-50B'" from NAA. One of the few provisions that the British made was that the plane be built around the same Allison V-1710-39 engine that the Warhawk utilized. Naturally, NAA, which was a small company at the time, accepted the offer (Ludwig, 2003, p. 35). According to Haggerty (2010), Mr. Dutch Kindelberger, NAA’s president, stated that NAA could design and produce a high-performing aircraft from scratch (p. 511). Haggerty (2010) also declared that the British gave NAA exactly 120 days to produce their first prototype a very difficult task to complete for a small and inexperienced company like NAA (p. 513). Despite the time limits that were imposed by the British, NAA’s young and accomplished team of engineers was able to meet the deadline with the NA-73 (later changed to XP-51). In 2003, Ludwig stated that Kindelberger gave “[Edgar] Schmued credit for designing the Mustang” (p. 35). When the first Mustang prototype rolled out of the factory in 1940, it was virtually “ignored [by the United States Army Air Force] because it was a British project” (Ludwig, 2003, p. 32). Ludwig stated in 2003 that the USAAF did not favor the XP-51 because it never was properly examined by AAF officials operating with an American set of standards (p. 85). Due to this serious obstacle, even when the XP-51 outperformed all other newly designed American fighter aircraft; it was not employed by the AAF until much later in the war (Ludwig, 2003, P. 32). The P-51 Mustang 4 Jablonski (1982) stated that when the British first acquired the Mustang in mid to late 1940, they were duly impressed by the low level capabilities of this aircraft, and used it for cross channel low-level reconnaissance and strafing missions (p. 98). In fact, Gadney (2013), a former World War II veteran, proposed that the P-51’s early role favored low-level anti-German personnel dive bombing and strafing more than high-altitude air-to-air combat (p. 10). Among the many early problems that plagued the Mustang was its inefficiency as an all altitude combat fighter. In fact, Jablonski (1982) wrote that “the plane struck both British and American experts as being unfitted for work as a high-altitude fighter -– it lacked sufficient power” (p. 98-99). As Kennedy (2013) verified, the problem was that the engine was not an adequate performer; it did not have enough power to compete with the top Luftwaffe fighters (121). Kennedy (2013) even stated that the Mustang could have been discontinued: while it flew well and had extensive potential as a low-level interceptor, both the RAF and AAF had superior planes that they preferred (p. 121). Later on, the British would find a remedy to the serious problem of an underpowered engine. Amid the other major problems incurred were many deadly complications that could have resulted in the death of the pilot. According to Rogers (2011) the Mustang unfortunately had an uncanny tendency for its guns to jam when forced into a high G (gravity felt as weight) maneuver (p. 23). As Jablonski (1972) noted, this could have been fatal in a dogfight against an experienced adversary because it left the Mustang defenseless (51). Another serious design flaw, as Rogers (2011) observed, was the long nose and high cowling of the Mustang. This forced a zigzag takeoff at low speeds, which fouled up spark plugs. In turn, this resulted in chronic engine failure forcing many missions to be aborted. The last straw was the reoccurrence of more engine failures in flight, which was potentially lethal to the pilot (p. 27). The P-51 Mustang 5 The British must have seen serious potential in order to patiently stay committed to such a problematic plane as the Mustang. Not only did the British tolerate the plane due to need, but they actually thought rather highly of it. Jablonski (1982) mentions that the British favored the Mustang because of “its clean design, extensive protective armor for the pilot, large and leak- proof fuel tanks, and good performance at low altitudes” (p. 98). As indicated by Rogers (2011) the self-sealing tanks were truly a Godsend: pilots would never have to worry about getting their fuel tanks holed (p. 50). In addition, Kennedy (2013) alludes to the fact that while the aerodynamics of the Mustang puzzled the British, they were deeply interested in its potential. Jablonski (1982) observed that the immense firepower of the Mustang was very satisfying for the British; the P-51 was equipped with six wing mounted .50 caliber machine guns (p. 110). The British were mystified by the Mustang’s performance, but they were determined to exploit the plane’s full potential. According to Kennedy (2013) the British contacted Rolls- Royce’s test pilot, Ronnie Harker, and asked him to “test a problematic U.S. plane, designated Pursuit Fighter 51 (P-51)” (p. 121). Harker loved the plane even when he compared it to many of the other top-notch British fighters he had flown. He especially favored the Mustang because aerodynamically the plane was superb, and “it turned easily, never stalled, and was fine at low to medium altitudes” (Kennedy, 2013, p. 121). His report concluded “The point that strikes me is that with a powerful and good engine like the Merlin 61, its performance should be outstanding, as it is 35 m.p.h. faster than the Spitfire 5 at roughly the same power" (Kennedy, 2013, p. 122). Essentially Harker had just recommended the imperative component that the plane was missing. This idea would prove to be the Mustang’s savior because both the RAF and the AAF heavily preferred other planes at the moment. As Michel (2008) states, “Fortunately, because of a serendipitous series of events, the P-51 was developed and survived" (p. 53). The P-51 Mustang 6 Once the Merlin Packard 61 engine had been installed into the P-51, the effects on the performance of the Mustang were instantaneous. Kennedy (2013) states that after the first Merlin 61 engine had been positioned in the Mustang, it became an entirely new plane (p. 126). Tests showed that “while the Mustang was considerably heavier than the Spitfire, it (the Spitfire) needed far more revs per minute to attain the same altitude and speed” (Kennedy, 2013, p. 127). That engine, coupled with the Mustang’s “astounding fuel capacity” (Kennedy, 2013, p. 127), which totaled approximately 269 gallons when all internal tanks were full (p. 127), more than doubled the range of the Spitfire, an astounding feat during World War II (Kennedy, 2013, p. 127). Hull (2013) mentions that when the Mustang entered the fray in its modified state, its exceptional range, speed, and armament quickly made it the scourge of Luftwaffe pilots flying the inferior Me-109 (p. 58). The British then produced another object that would further revolutionize the air war – the drop tank (an external gas tank slung beneath the airplane). When the aluminum drop tank first appeared in the ETO, it had the desired effect on Allied aircraft of significantly extending their range of flight.