Emergency fighter An emergency fighter is an aircraft designed or adapted for use as a fighter during an emergency period in war . While useful as a broad concept or definition , it is not easy to make the category of emergency fighter clear cut , as many aircraft designs are produced under pressure in wartime , and aircraft which were hastily adapted for use as fighters may then go on to have a mainstream career . The context . The crisis which gives rise to an emergency fighter may have been the sudden outbreak of war , which resulted in a country lacking sufficient fighter aircraft . This was the case for Australia at the beginning of the Pacific War in World War II ; with both the UK and the USA committing its production capacity to supplying their own needs , they had to create their own indigenous design resulting in the Commonwealth Boomerang . An emergency fighter may also have been produced to meet a need for a particular sort of fighter aircraft . For instance , Britain ’ s RAF used hastily converted Bristol Blenheim light bomber s as twin engined heavy fighters . A materials shortage arising in the course of conflict may have led to experiments with new kinds of fighters , like the Finnish VL Humu , which was based on the American Brewster F2A , but with a higher proportion of wood in its construction . Emergency fighters were also designed to a tight time scale in a crisis situation , in the hope that a new aircraft might be able to change a nation ’ s fortunes . Most famous of these was undoubtedly the Heinkel He 162 jet aircraft of Germany . Many examples of the emergency fighter concept date from the Second World War . In that global conflict , situations of strategic national emergency arose in several nations due to total war . At the same time , fighter design was still sufficiently simple that an aircraft designed and produced in a matter of months had some chance of being effective . Types of solution . Some emergency fighters were aircraft designed for other purposes but pressed into service to meet an immediate need . In early 1942 eight Australian Wirraway trainer and general purpose military aircraft were used to intercept a Japanese raid on Rabaul , with disastrous effects when all the defenders were shot down . Some Russia n Sukhoi Su - 2 light bombers were used as fighters during the opening days of Operation Barbarossa when nothing else was available . To meet the challenge posed by a shortage of strategic material s like the light alloy s used in aircraft construction , several prototype emergency fighters were designed to use more readily available materials . For example , the British Martin - Baker MB 2 used a simple design made from steel tubes , while the VL Myrsky used much plywood . However , less strategically important materials like steel or wood tended to affect the performance of the aircraft adversely . Adaptation of existing aircraft . The advantage of adapting existing aircraft was that the emergency fighter could be produced quickly . A variety of aircraft types were used : the Bristol Blenheim light bomber lacked performance in its intended role as a heavy day fighter , but found a useful niche as a strike fighter in Coastal Command and as a night fighter , pioneering the use of airborne intercept radar ; the Russian Ilyushin Il - 2 was occasionally used to escort other Shturmoviks on ground attack missions ; and 26 British Miles Master s were produced , but never used , as the M . 24 Master fighter with a single seat and six wing guns . Modern attack aircraft are usually equipped to carry short range air - to - air missile s for self - defense , some airforces because of inventory shortages will task their attack aircraft with a secondary air to air role , for example as with the Portuguese A - 7 attack squadrons . During the late 1980s and early 1990s the United Kingdom planned to use their BAe Hawk trainer aircraft as point - defence fighters . New designs . Very few new emergency fighter designs progressed beyond the prototype stage . Of those that did , the Commonwealth Boomerang was probably the most successful , but even then it was most effectively used in the ground support role . The Heinkel He 162 entered mass production and even squadron service , shooting down some opponents , but its effectiveness was limited by a dire shortage of fuel in the collapsing Reich . Other designs which did not enter service included the British Miles M . 20 , which had a similar performance to the contemporary Hawker Hurricane ; and the American Bell XP - 77 . Emergency fighters by country of origin . Germany . In the final years of the war , Nazi Germany produced a wide array of radical aircraft concepts . Some of these did not progress beyond initial design stages . An emergency fighter competition was also launched to develop jet aircraft with great performance advantages over Allied aircraft . Sweden . Neutral Sweden built up its airforce during World War II , in an effort to deter potential aggressors . It was difficult to obtain foreign built aircraft , so new designs were built locally . United Kingdom . The crisis point for the British RAF came at the Battle of Britain , and British use of emergency fighters centres on this time . United States of America . The vast manufacturing resources of the USA , and its lack of vulnerability to invasion , meant that emergency fighters were not extensively developed . Only the Bell XP - 77 lightweight fighter using non - strategic materials could be considered akin to an emergency fighter . However , the United States Navy did use the SBD Dauntless dive - bomber as combat air patrol aircraft in emergencies , including during the Battle of Coral Sea . On 8 May 1942 , Pilot Stanley " Swede " Vejtasa claimed three A6M Zeroes shot down when his scouting squadron was pressed into service to defend the USS Yorktown . Assessment . Very few emergency fighters entered service , and of those that did , even fewer types achieved effectiveness in operations . Two main factors can be identified for this failure : Overall therefore it can be seen that the lack of operational effectiveness of emergency fighters stemmed from the inherent limitations of the concept .