Military Aircraft

I. Introduction

Military Aircraft, the use of airplanes and other flying machines for military purposes. Since the beginning of the 20th century the military airplane has evolved from a frail contraption of wood, wire, and fabric into a sophisticated weapons system of enormous complexity that revolutionized the conduct of warfare. Air power has provided military commanders with new means of gathering intelligence, dominating a battlefield, striking the enemy over great distances, and forging global lines of supply and communication. Aviation redefined old notions of war, rendering civilians on the homefront as vulnerable to attack as soldiers on the battlefield.

II. The Airplane and World War I

The American aviators Wilbur and Orville Wright made the world's first powered, controlled, heavier-than-air flights on December 17, 1903. Within six years, however, leadership in the new technology had passed to Europe, where government leaders supported aviation through the sponsorship of races and competitions, subsidized programs of research and development, the purchase of aircraft, and the establishment of the earliest military flying units.

Within a month of the outbreak of World War I in August 1914, pioneer military aviators had demonstrated their value as aerial scouts and observers. The need to prevent enemy fliers from observing activity behind the lines led to the development of the first fighter aircraft. The appearance in 1915 of the German Fokker E-2, which featured a machine gun synchronized to shoot through the arc of the spinning propeller, opened the era of air combat.

The fight for control of the airspace over the trenches fueled rapid technical development. Comparative advantage shifted back and forth across the lines as new aircraft were introduced. By 1918, the skies were contested by superb fighter aircraft such as the German Fokker D.VII, French Spad 13, and British S.E.5 and Sopwith Camel, which operated at speeds of up to 200 km/h (125 mph), and altitudes of 6100 m (20,000 ft).

The pilots who flew these aircraft became the best-known fighters of the war. The German ace Manfred von Richthofen, known as the "Red Baron," ran up a total of 80 victories before his death on April 21, 1917. Rene Fonck, a French pilot with 75 victories, was the highest-ranking ace to survive the war. Other top fighter pilots of the war were Major Edward "Mick" Mannock (Britain, 73 victories); Major William "Billy" Bishop (Canada, 72 victories); Captain Ernst Udet (Germany, 62 victories); and Captain Edward V. Rickenbacker (United States, 25 victories).

While public attention focused on the fighter pilots, other fliers were exploring a variety of military roles for the airplane. Throughout the war, observation and artillery spotting were the most critical tasks performed by aircraft. Specialized ground attack machines also became a major factor shaping military operations. Large flying boats conducted antisubmarine patrols and long range ocean reconnaissance.

German zeppelin airships bombed cities in Belgium, England, and France during the years 1914 to 1917. During the final year of the war, German fliers continued the air attacks on London and other cities with twin-engine Gotha aircraft and giant four-engine bombers like the Zeppelin R-6, with a wingspan of more than 42 meters (138 ft) and a bomb load of 2040 kg (4500 lbs).

III. Military Aviation 1919-1939

The world's military air services faced difficult times during the years immediately following World War I. The German air force was disbanded by the Treaty of Versailles, while air power advocates in the victorious Allied nations struggled to prove that the airplane was the weapon of the future. Brigadier General Billy Mitchell, who had commanded United States Air Service combat units during World War I, launched a controversial drive for the creation of an independent air force. Court-martialed in 1925 following a series of attacks on U.S. military policy, Mitchell resigned from the service, but not from the fight for increased American air strength.

Military aircraft technology evolved slowly during a period of reduced government spending after World War I. By the mid-1930s, however, increased funding, the availability of improved engines and propellers, the introduction of drag-reducing features such as retractable landing gear, and the imaginative use of duralumin (a strong, lightweight aluminum alloy) in aircraft construction led to radical breakthroughs in design. The American-built prototype Boeing B-17, a superior four-engine bomber, made its first flight in 1932. In similar fashion, first-generation all-metal pursuit aircraft such as the Soviet Polikarpov I-16 and the American Curtiss P-36 set the stage for the fighters that would contest the skies in a conflict already looming.

IV. Aviation in World War II

From beginning to end, World War II was an air war. Germany opened the conflict with a stunning drive across Poland, Belgium, Luxembourg, the Netherlands, and France during 1939 and 1940, demonstrating the power of a coordinated effort between land and air forces. Attempts to obtain air superiority over Britain in preparation for an invasion began with German attacks on shipping in the English Channel in July 1940, followed by aerial raids on British coastal installations and Royal Air Force (RAF) bases, and day and night bombing attacks on London and other British cities.

The fighter pilots of Britain's Royal Air Force won the Battle of Britain in 1940 by a narrow margin. The quality of their Hawker Hurricane and Supermarine Spitfire interceptors, the short range of the German Messerschmitt Bf 109 escort fighters, and the vulnerability of other German aircraft such as the Heinkel He 111, Junkers Ju 88, and Dornier Do 17 bombers were all factors in the victory. Just as important, however, was the network linking radar stations to command centers that plotted the position of German aircraft and guided British fighter pilots toward their targets by radio. Electronic weaponry had emerged as a major factor in aerial warfare.

The high losses resulting from early attempts to bomb targets in Germany convinced the leaders of RAF Bomber Command to discontinue daylight precision attacks on specific targets in favor of night area raids conducted against entire cities. The United States Army Air Forces (USAAF) began a daylight precision bombing campaign from Britain against Germany with Boeing B-17 and Consolidated B-24 aircraft in 1943. The appearance of long-range escort fighters like the Republic P-47, North American P-51, and Lockheed P-38 helped turn the tide of the great air battles fought high over Germany in favor of the Allied forces. During 1944 and early 1945, the USAAF struck Germany during the day, while the RAF attacked at night. One by one, Germany's cities were reduced to rubble.

Tactical air power also played a major role. Allied air forces had swept German aircraft from the skies over the Normandy (Normandie) beaches prior to the D-Day invasion of June 6, 1944, and would maintain battlefield air superiority for the remainder of the conflict. Medium bombers like the Martin B-26, and fighter aircraft doing double duty as ground attack machines, paved the way for advancing Allied armies.

Japan opened the Pacific war with air attacks on Pearl Harbor, Hawaii, and other United States and British bases in the Pacific on December 7 and 8, 1941. Japanese land-based aircraft already dominated the skies over China and Southeast Asia, except in those sections of Burma (now known as Myanmar) and China patrolled by the Curtiss P-40s of the American Volunteer Group, commanded by Brigadier General Claire Lee Chennault. The real turning point of the Pacific war came on June 4, 1942, when American carrier-based aircraft sank four Japanese carriers and a heavy cruiser in the waters northwest of Midway Island.

For the next three years, Allied forces pushed the enemy back across the Pacific. Japan entered the war with the world's finest torpedo bomber (Nakajima B5N2 Type 97) and long-range fighter aircraft (Mitsubishi A6M2 Type 0). By 1944 the arrival of Grumman F6F Hellcats and Chance Vought F4U Corsairs had tipped the technological balance in favor of United States naval aviators. The P-40 and P-39 aircraft flown by the U.S. Army during the early months of the war were replaced by superior P-38, P-47, and P-51 fighters. B-17 and B-24 bombers attacked Japanese island bases, while B-25 bombers sunk Japanese merchant ships.

Aircraft such as the American-built Douglas C-47, Douglas C-54, and Curtiss C-46 were the aerial workhorses of the war effort, ferrying personnel and supplies to the far corners of the globe. Consolidated PBY Catalina flying boats patrolled the waters of the Atlantic for U-boats, maintained communication and supply lines, and rescued downed pilots.

The final phase of the war in the Pacific was underway by 1944, when Boeing B-29 Superfortress bombers began to attack targets in Japan from bases in China. The capture of the islands of Saipan and Tinian enabled the B-29s to range even farther over the Japanese islands. When high altitude precision bombing techniques yielded disappointing results, Army Air Force planners sent the B-29s in low and at night to conduct area fire raids of the sort pioneered by the RAF. The results were devastating–more than 83,000 residents of Tokyo lost their lives during a single raid on the night of March 10, 1945. The dropping of two atomic bombs on Hiroshima and Nagasaki was quickly followed by the Japanese surrender on August 14, 1945 (see Nuclear Weapons).

V. The Turbojet and the Helicopter

Two important technical developments changed the face of aviation after World War II. The turbojet engine was developed almost simultaneously by the German engineer Hans von Ohain and the English engineer Frank Whittle (see Jet Propulsion). On August 27, 1939, the German Heinkel He 178 became the first purely jet-powered aircraft to fly. The German Messerschmitt Me 262, the first operational jet, entered service in the fall of 1944.

The Russian-born American aeronautical engineer Igor Sikorsky inaugurated the age of practical vertical flight when he flew his VS-300 helicopter on September 14, 1939. Over the next half-century, the helicopter would perform as an air-sea rescue vehicle, an air freight and passenger carrier, and in a host of other roles. The introduction of small gas turbojet engines in the 1950s greatly improved helicopter performance.

During the 1960s, the United States Army and Marine Corps pioneered the use of the helicopter to move troops in and out of combat. The UH-1D Huey helicopter was used to deliver troops to combat zones or other difficult-to-reach areas during the Vietnam War (1959-1975). Helicopter gunships like the Bell AH-1G Cobra revolutionized the conduct of air-ground battles.

VI. Research and Development in Military Aviation

Research and development have been the keys to aviation progress since 1945. In the United States, flight research is conducted by the military services and the National Aeronautics and Space Administration (NASA). The first generation of dedicated post-war research aircraft, like the Bell X-1 and Douglas D-558-2 Skyrocket, explored the problems of flight beyond the speed of sound. Later X-series airplanes continued to probe the limits of speed and altitude. The North American X-15, the best known of the post-war research aircraft, flew to speeds in excess of 6400 km/h (4000 mph) and reached altitudes of up to 107,000 m (350,000 ft). No aircraft designed to operate solely within the atmosphere has ever flown faster.

VII. Military Aviation in the Modern World

The United States and the Union of Soviet Socialist Republics (USSR) emerged as rival superpowers after 1945. American postwar strategy required a fleet of bombers capable of delivering nuclear weapons anywhere in the world. The B-29 and B-50 bombers were replaced by Consolidated's ten-engine (six-piston, four-jet) B-36 Peacemaker. The Boeing B-47, which used a revolutionary swept-wing design, was the first successful United States strategic jet bomber. The Boeing B-52 Stratofortress became one of the most remarkable military airplanes of all time. First flown on October 3, 1952, it remained in service more than forty years later.

Efforts to develop a supersonic replacement for the B-52 have not succeeded. The Convair B-58 Hustler, the world's first operational supersonic bomber, was phased out of service after only four years because of high maintenance costs. The Rockwell International B-1 was dropped from production because of threatened cost overruns. A modified version of the airplane finally entered service as the B-1B.

The Northrup B-2 stealth bomber, designed to penetrate enemy radar networks without detection, has been a costly and controversial program. In 1994, the Convair F-111, designed to meet a variety of needs for both the United States Air Force (USAF) and United States Navy (USN), remains the only supersonic bomber in the United States inventory.

The jet revolution also produced some remarkable fighter and attack aircraft. The Lockheed P-80 Shooting Star was the first jet delivered to combat units of the USAAF. The North American F-86 Sabre was the weapon of choice for USAF pilots contesting Korean airspace with the Soviet-built MiG-15. A new generation of supersonic fighter aircraft appeared after 1953. The North American F-100 Super Sabre; the Convair F-102 Delta Dagger; the British Electric Lightning; and the twin-engine MiG-19 were typical of the era. Few military aircraft of the 1960s were as commercially successful as the French-built Dassault-Mirage III, which served with 15 of the world's air forces.

More powerful jet engines and new aerodynamic concepts provided the foundation for larger, multi-purpose aircraft. The McDonnell-Douglas F4 Phantom II served the U.S. Navy, Marine Corps and USAF as a fighter, fighter-bomber, and reconnaissance aircraft. The Chance-Vought A-7 Crusader, the Republic F-105 Thunderchief, and the Grumman A6E Intruder were among the other leading U.S. aircraft during the Vietnam War.

In terms of absolute performance, few operational airplanes can match the record established by Lockheed's U-2 and SR-71 reconnaissance aircraft. Introduced in 1955, the U-2 was capable of climbing to very high altitudes, remaining in the air for almost 11 hours, and covering up to 7644 km (4750 mi) on 3800 l (1000 gallons) of fuel. On May 1, 1960, a U-2 flown by the United States military officer Francis Gary Powers crashed in the USSR. The incident grew into one of the great confrontations of the Cold War when Powers was placed on trial and sentenced to prison.

The Lockheed SR-71 Blackbird, the first version of which flew in 1958, operated at sustained speeds in excess of Mach 3 (see Mach Number) and at altitudes of more than 26,000 m (85,000 feet). The Blackbird performed all of the reconnaissance tasks assigned to it before retirement from the operational USAF inventory in 1989 as a cost-saving measure.

VIII. Today and Tomorrow

The Persian Gulf crisis of 1990 and 1991 illustrates the extent to which military aviation dominates the conduct of modern war. During the weeks and months following the Iraqi invasion of Kuwait in 1990, Lockheed C-130 Hercules, C-141 Starlifter, and C-5A Galaxy aircraft transported combat and support troops and mountains of equipment and supplies into the Middle East. Lockheed F-117 stealth fighters launched Operation Desert Storm early on the morning of January 17, 1991, with devastating attacks on Iraqi communications centers and command posts. With its ability to evade detection by radar and deliver a variety of guided weapons precisely on target, the F-117 is currently the most effective United States strike aircraft.

Throughout the air campaign, coalition forces maintained an umbrella of reconnaissance and electronic countermeasures aircraft over enemy territory, disrupting Iraqi communications, identifying targets, and directing air strikes. Ship and air-launched cruise missiles struck pre-selected targets. F-15C Eagles and U.S. Navy F-14 Tomcats maintained air superiority, while F-16 Falcons, F-18 Hornets, and British and French Jaguars attacked air defense installations. B-52G bombers pounded front-line troop emplacements. F-15Es, F-111Fs, A-6E Intruders, and RAF Tornadoes struck Iraqi air fields, missile sites, and other key targets. Pilots of the Free Kuwaiti and Royal Saudi Air Forces, operating Northrup F-5Es and Mirage F-1s, played important roles in the air campaign.

Operation Desert Storm concluded with a classic air-ground advance against Iraqi troops. Reconnaissance aircraft reported enemy troop positions and movements to coalition ground forces. Advancing troops were supported by helicopter gunships and specialized ground attack craft like the Fairchild A-10 Thunderbolt II. Close air support cleared the way for the infantry and armored units that drove the enemy from Kuwaiti territory in only four days.

The application of air power in the Persian Gulf was by no means perfect: precision guided weapons did not always strike their intended targets, mobile missile launchers proved difficult to locate, and human error led to a tragic loss of life from friendly aerial fire. Nevertheless, Operation Desert Storm underscored the critical importance of air power.

The latest military aircraft can intercept enemy intruders, or deliver powerful guided weapons with extraordinary precision. Continued improvements in aircraft design, propulsion and control systems will result in levels of performance beyond the tolerance of a human pilot.

Contributed By:

Tom D. Crouch, B.A., M.A., Ph.D.

Chairman, Department of Aeronautics, National Air and Space Museum at the Smithsonian Institution. Author of The Eagle Aloft: Two Centuries of the Balloon in America and other books. Editor of Charles A. Lindbergh: An American Life.

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"Military Aircraft," Microsoft® Encarta® Online Encyclopedia 2001

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