The Douglas DC-3 was produced in 21-passenger day planes, 14-passenger de luxe Skylounges, and 14-passenger Skysleepers. The DC-3 put “sleeper planes” on an acceptable basis. Coast-to-coast schedules were cut to three stops and an overnight trip. Fares were cut in half and air travel became an accepted fact.
While the DC-3’s were cutting to an overnight hop the air journey from coast to coast, Captain Eddie Rickenbacker had pushed his Eastern Air Lines from New York to Miami, Florida. Here it connected with Juan Trippe’s Pan American Airways. By this time Trippe’s Pan American Clipper planes regularly were covering a route from Miami down through the West Indies to Rio de Janeiro, Brazil, and to Buenos Aires in the Argentine. At Buenos Aires Pan American Airways connected with Harold R. Harris’ Pan American-Grace Airways to complete a route over the Andes and back up the west coast of South America.
The story of Harold Harris and his airway is a book in itself. Harris, a veteran flier of World War I, had been an Army test pilot. In 1922 he became the first member of the “Caterpillar Club” when he used a parachute to escape from a plane which had failed. Later, as a crop-dusting pilot in Peru, he visualized and founded the Pan American-Grace air route.
By the time Juan Trippe’s Pan American Clippers were flying over every country in Central and South America, his active mind was busy planning another “survey.” Though his company at that time was operating the world’s largest airline, Trippe was planning new worlds to conquer.
Pan American had been using Igor Sikorsky’s four-engined flying boats on his route to Rio and Buenos Aires, and Trippe sent one of them, with veteran Edwin Misick in command, on a “survey” flight westward across the Pacific.
On November 22, 1935, Pan American Airways’ China Clipper took off from San Francisco Bay on its first scheduled trans-Pacific flight to Manila, Philippine Islands. One hundred years before, to the day, the first Yankee clipper ship had sailed into the same bay. Twenty-five years before, a young man had made America’s first trans-Pacific flight—a flight of 33 miles from the California shore to Catalina Island. The 26-ton China Clipper heading into its 8,000-mile trans-Pacific flight was a Martin 130 flying boat built by Glenn L. Martin, the young fellow of the Catalina flight. In just 59 hours and 48 minutes of flying time the first China Clipper landed in Manila Bay.
With the sweep of its wings the first China Clipper ripped out weeks of slow surface travel to the rich markets of the Far East. By 1936 a trip from this country to China was measured by a matter of sixty or seventy flight hours instead of by weeks.
It was not the big clipper planes alone that built the far-flung Pan American Airways. Juan Trippe visualized his world airways system and then picked the finest experts in every field to carry out his plans. Former diplomats covered the proposed routes long before the Clippers flew them. There was, of course, no freedom of the air. No plane could fly over a foreign country without permission. Trippe’s emissaries had to get franchises. Germany, France, Britain, and Holland were after franchises in South America too. There, as in the Far East, they got the rights to fly, not by government pressure, but by selling aviation as a valuable business asset to any nation.
Once Trippe had his franchises, he sent experts to explore and lay out routes. They carved airports out of jungles and Arctic wastes, and in places where no white man ever had penetrated. The supply problems overcome and the engineering marvels performed by Trippe’s advance men would furnish plots for a dozen movie thrillers. In laying out the bases at Wake and Guam on the Pacific route, more than one million separate items were bought, shipped, and installed before the first China Clipper took off from San Francisco.
Pan American’s map added another blue line after the Pacific route was under way. This time it was to Alaska, and another distant travel time could be reckoned in flight hours rather than ocean days.
Then came the Atlantic and the giant Boeing 314 Pan American Clippers.
Boeing achieved such excellent results with its two-engined planes that its engineers went on to plan four-engined super-planes. When Juan Trippe wanted a plane for his Atlantic service, Boeing was ready with the 41-ton Boeing 314. The 314 Atlantic Clippers carried 74 passengers and boasted of compartments that could be converted into berths, dressing rooms, a dining salon, and a real kitchen for serving hot meals aloft. On May 20, 1939, just twenty years after the first transatlantic flight of the Navy NC’s, the Atlantic Clipper took off on the trip that inaugurated Pan American Airways service to Europe. Juan Trippe’s dream was reaching around the world.
In the very early days of aviation, before the start of World War I, most of the airplanes, with the exception of a few military ships, were sold to private owners. Those buyers were either barnstormers or wealthy sportsmen. Some advertising in national magazines even tried to create sales, for private planes. This activity ceased with the beginning of the war in 1914, and owners turned their planes over to the Government for training purposes.
At the end of the war there were hundreds of young men who had learned to fly. This situation brought about a considerable amount of private flying. However, most of the ex-service men bought surplus war equipment, such as the Curtiss Jenny, so that there was not a large market for the manufacturers of new private planes.
Following the Lindbergh flight to Paris and other spectacular aviation achievements, the American public really became air-conscious. It was at that time that the private plane came into its own.
People began to find that airplanes were of practical value, and business firms began to use them in various ways. Sales and service representatives could cover vast areas in a short time. Essential equipment could be carried swiftly by airplanes over stretches of country which before had been almost inaccessible. Ranchers used planes to cover far-flung ranges. Explorers and scientists alike used the airplane to search for hidden treasure and precious minerals in spots which before had been impossible to reach by land transportation.
All this activity brought about the development of more comfortable cabin planes and led to a demand for large and small private ships. The small, light plane field expanded with amazing speed once there was a demand. In the late twenties Aëronca, Taylor, and Piper began to bring out safe, comfortable, and inexpensive planes. By the middle thirties flying schools and private landing fields were a common sight throughout America.
As the light planes became popular, the training of private pilots developed into a big business. Flying lessons became an important source of income to aviators who heretofore had operated their little airfields on the revenue derived from sightseeing hops and an occasional charter trip. Student pilots became logical prospects for
light planes and the more successful flying schools became sales agencies for the aircraft manufacturers. Students became expert fliers and graduated to instructors’ jobs. A number of these young instructors in turn bought light planes and started flying schools of their own. Thus, light plane flying spread like wildfire over the country.
The light planes of the late thirties were mainly high-wing monoplanes. They were powered with light, air-cooled engines and were so designed that they had a high factor of safety. They were sturdily built and easy to fly. The average student was able to solo after eight or ten lessons, though real flying ability came only through constant practice. Light planes cost from $1,500 to $2,000. Many of them were equipped with accessories such as heaters, radios, navigation lights, and flight instruments. All of them had comfortably upholstered, enclosed cabins. In the years just before World War II light plane flying for business and pleasure was an accepted mode of travel for boys and girls as well as men and women of all ages.
High above the earth, 14,000 to 20,000 feet, lies a region of smooth air called the substratosphere.
Pioneer fliers had reached this region years before, but its thin, rare air made life and movement impossible. Men had long looked to this smooth-air region as the ideal flight path—a path without rough air, or fog, or storm to slow their progress. But both they and their engines needed plenty of air for operation.
It was not until 1939, when Dr. Sanford Moss invented the turbo-supercharger, that high engine performance at altitudes above 30,000 feet became a matter of fact. The turbo-supercharger, a simple machine driven by the force of the engine exhausts, pumped air into the engines to give them sea-level pressure at high altitudes. This took care of the engines in the smooth-air substratosphere regions.
Next came the human element. Human beings, like engines, cannot live without sufficient air. This brought about the development of the supercharged cabin for airplanes. In 1936 “Tommy” Tomlinson, a brilliant ex-Navy flier, started making experimental substratosphere flights for TWA in a specially designed plane. He found that the speed of a properly equipped airplane would increase some 36 per cent at 30,000 feet. At the same time Army engineers were experimenting with a Lockheed plane having a supercharged cabin.
The Boeing Company, working in co-operation with Tomlinson, Transcontinental and Western Airways, and Pan American, developed the Boeing 307. The 307 was a big all-metal, low-wing monoplane with a pressurized, high-altitude cabin, which made possible flight at altitudes up to 20,000 feet. This was accomplished in a manner similar to that used in supercharging the engines. Engine-driven superchargers pumped air into the cabin-ventilating system and the atmosphere in the plane was kept at normal low-level pressure regardless of how high the plane flew. The Boeing 307 Stratoliner was put into service by TWA and Pan American Airways in 1940 and marked a tremendous step forward in the speed and comfort of modern air travel.
In 1941, fifteen years after the operation of the nation’s airlines had been turned over to private firms, air transport was approaching perfection. The first single-engined, two-passenger mail planes, cruising at 100 miles per hour, took thirty-three hours to make the coast-to-coast trip. Now giant luxury airliners were doing it in fifteen hours. In contrast to the frequent stops of the low-flying plane of the early days, the high-flying air transports of 1941 were making the journey with only three stops. Where the air traveler of the twenties rode in an uncomfortable seat in a cold, gas-smelling plane, and was lucky if he got a box lunch, the modern passenger rode in luxuriously upholstered chairs in a heated salon, and dined on hot fried chicken or steak with all the “trimmings.”
Even more significant was the change in flight and safety aids. No longer did the pilot fly with his eyes on the railroad tracks and the family wash on the line below. Radio communication with the ground, continual weather information, and precision navigation and flight instruments changed all that and brought safety to air transport.
With domestic airline routes covering America from coast to coast and from border to border, and with the wings of Pan American’s Clippers casting their shadows over 75,000 miles of the earth’s surface, the Japs struck at Pearl Harbor.
In September, 1939, when the first Nazi Stukas screamed down on Poland, we produced only 117 military aircraft. Our Army Air Corps could muster only some 21,000 officers and men, and the Navy could not boast of even that many. Neither the Army nor Navy had more than a thousand planes each. That meant all types: trainers, transport planes, and fighters. The Nazi Luftwaffe at that time was composed of more than a million men and 15,000 warplanes, and the Japanese had many more planes than we ever had thought they could build. This was the beginning not only of World War II, but of Air War I.
This was not the first time that the United States got off to a late start. The same thing was true in World War I. Nevertheless, with typical American confidence, we thought we could do it again. Consequently, in 1940, we set as our goal the building of 50,000 warplanes.
We lost the first rounds of the fight while we were getting started. In the South Pacific it was ten Jap planes to our one; at Wake Island, four obsolete Marine Corps fighters flew gallantly to meet a hundred of the foe. At Pearl Harbor hangars full of planes were caught on the ground. At Corregidor there was a cry of “No planes!”
But a typical American once said, “We have not yet begun to fight.” As in World War I, our military and industrial aviation leaders “rolled up their sleeves” and began to fight. As a result, in less than three years, they produced the greatest aërial fighting force that the world ever has known.
Let us go back to 1920 and review the progress of our Army and Naval aviation up to the start of World War II. We shall find out why we were able to create unbeatable air power when the crisis came.
From its earliest beginnings United States naval aviation made progress far out of proportion to the small amount of money appropriated by the Government. But it was a young and eager organization with a constant desire to do things—to stretch its wings. An aërial world remained unexplored and naval aviators were an inquisitive lot.
The first carrier, the Langley, with a complement of six airplanes, became the training ground for the young naval aviators who were to lay the foundation for the world’s greatest seagoing aërial task force. While the Langley was primitive by today’s standards, experiments with it pointed the way for the development of improved types of carrier-based fighting planes. However, the enthusiasm of the young naval aviators was not shared entirely by other Navy men based on surface craft. To them airplanes were just something to be fished out of the sea when an engine failed. It was some time before the aviators were able to convince these others of the exceptional value of planes in spotting gunfire and scouting for an enemy.
Regardless of the fact that they were the Navy’s orphans, the young pioneers kept at it. They flew the crude machines available and developed tactics for carrier-based airplanes. They improved the arresting gear and solved many technical problems in ways that enabled aircraft builders to design airplanes especially suitable for use on carriers. At the same time, it was natural that flying boats should appeal to Navy men. The flight of the NC flying boats inspired the development of long-range patrol boats. Naval aviators also went ahead with experiments which were to lead to the creation of flying boats with a range of 2,000 miles and more.
While the naval aviators were busy with their early experiments on the Langley, the Disarmament Conference of 1922 had changed this country’s plans for the construction of new battleships. However, the United States and Great Britain were permitted, by the terms of the conference agreement, each to have 135,000 tons of airplane carriers. Two of the big cruisers under construction at that time were converted into carriers. These two, our first specifically designed-aircraft carriers, were the Lexington and the Saratoga. When commissioned in 1927, the Lexington and the Saratoga were the biggest and best aircraft carriers in the world. Weighing about 35,000 tons and capable of carrying sixty to eighty airplanes,
they were the fastest ships of their type afloat. The ships—the “Lex” and the “Sara,” as airmen called them—became the twin mothers of carrier fighter tactics and operational techniques.
The U. S. Navy pioneered in the development of aircraft as a military weapon and spared no effort to develop it and fit it into naval organization. The Lexington and the Saratoga were the proving grounds for the ideas of our imaginative leaders of naval aviation. The lessons learned in maneuvers with the Lexington and Saratoga were well embedded in the minds of the men who were someday to command the greatest carrier task force the world has ever seen. The old Lexington and Saratoga were in the thick of the fight in the Pacific from the day after Pearl Harbor. The “Lex” went down in the gallant fight that stopped the Japs in the Coral Sea. Within two years a new and more powerful Lexington was hammering the Japs in the Pacific. The Saratoga, damaged severely several times, lived through the heroic struggle to see victory. The “Lex” and the “Sara” will always live in the hearts of the Navy’s veteran airmen.
The Curtiss TS-1 was the first carrier fighter built to Navy specification. It was followed by the Boeing FB-l. Carrier fighters offered one of aviation’s most difficult problems. A carrier fighter had to have a short takeoff run, necessitated by the carrier’s short deck. Another requirement was a short wingspan to permit the storage of a number of planes in the limited space of the carrier’s hangar deck. As a result, small light biplanes were used on the carriers for many years. The Curtiss BFC-l and BF2C-l were the first carrier-based aircraft to be equipped with retractable landing gear. The Boeing F4B-4, though it did not have a retractable landing gear, was a very fast, all-metal fighter and was popular as a carrier-based fighter. Grumman came into the picture in 1935 with a stubby, fast, two-place fighter, the FF-1. It was highly successful, but was later re-designed as a scout plane, the SF-1. The FF-1 was the fastest fighter yet to appear in service and, after several modifications, it became the F3F-1, a design standardized by the Navy and used throughout by the carriers’ fighter squadrons.
In line with its strategic policy the Army Air Corps continued to develop aviation around long-range bombardment. Long-range bombers would stop an invader far from our shores and therefore the aim of our Air Corps leaders was to develop a bomber that could be used for that purpose.
The Martin BM-1, the Barling bomber, and the Keystone LB-6, developed in the twenties, were all biplanes made of wood, metal, and fabric. What the Army airmen really wanted was an all-metal, low-wing, multi-engined bomber capable of flying far out to sea, dropping its bombs, and returning to its base on land. Naturally at that time our only thoughts were of weapons for defense and the protection of our coastline from an invader.
The Martin B-10 two-engined bomber seemed to fill the Army requirements. It was a low-wing monoplane capable of carrying a ton of bombs a thousand miles at a speed of nearly 200 miles per hour. It became the Army’s standard bomber in 1934.
In the same year ten Martin B-10’s, under the command of (then) Lieutenant Colonel Henry H. Arnold, made an historic flight to Alaska. This Alaskan trip was climaxed by a nonstop flight from Juneau, Alaska, to Seattle, Washington, 943 miles over water in five hours and forty minutes. Alaska’s nearness became apparent and American airpower was needed to defend it. Army officials and top air strategists went to work. The answer was a call for bigger bombers with greater range, greater bomb capacity, and greater speed.
The Boeing Company, whose B-9 all-metal, low-wing, two-engined bomber had proved sensational in 1932, produced the answer to the Army’s problem of 1935. The answer was the giant four-engined model 299, America’s first four-engined bomber. It was a mid-wing, all-metal monoplane with a wingspan of 104 feet. With a top speed of over 250 miles per hour its performance was more than sensational.
The pioneering of unusual airplanes like the Monomail, the B-9, and the 247 transport were steps toward the Boeing 299. It was a courageous step from two-engined to four-engined bombers, but the Boeing Company made it so successfully that almost instantly the United States Army Air Corps won world leadership in long-range, heavy bombardment aviation.
The exceptional speed, range, armament, and bomb capacity of the 299 quickly resulted in the dramatic name Flying Fortress. As the B-17 it flew across the country at 232 miles per hour. In 1938, six B-17 Flying Fortresses set unofficial world records for speed and range in a mass flight from Langley Field, Virginia, to Buenos Aires, Argentina, and return.
From 1930 to 1940 the small but efficient air arm of the United States Navy continued to make progress. Since the introduction of the radial engine, the Navy had worked closely with manufacturers of this type of power plant. All types of Navy airplanes were powered with either Wright or Pratt & Whitney air-cooled, radial engines. Many problems peculiar to naval aircraft were worked out through the close co-operation of Navy technicians and manufacturers. Corrosion-resistant metals were developed for cylinders. Stronger engine parts were introduced to withstand the stress of dive-bombing. Continual progress was made in increasing the power of the engine without increasing its weight per horsepower. Thus engine power increased from 200 horsepower in 1925 to 1,000 horsepower in 1940.
Naval aviators, encouraged by pioneer flying officers such as Jack Towers, Marc Mitscher, Reeves, Bellinger, Read, and others, flew continually to improve their flying and tactical techniques. They flight-tested experimental planes, invented and perfected the technique of dive-bombing, and improved their skill in the difficult task of carrier operations. A young lieutenant, Frank D. Wagner, who invented dive-bombing almost twenty years ago, a rear admiral in World War II, had the satisfaction of seeing his invention, at the peak of perfection, operating with deadly effect against our enemies in the Pacific. In fact, many of the young naval aviators who fifteen years before were conducting a continual competition to see whose squadron could excel the rest in flying, dive-bombing, and gunnery, commanded the greatest naval air force in the world.
In addition to the development of carrier-based aircraft operation, the Navy perfected a catapult device which simplified the launching of planes from all types of surface vessels. In 1912 the air-minded Captain Chambers had made a successful experiment with a catapult-launching device. This device, made of material salvaged from a scrap heap, laid the foundation for catapult-launching of aircraft from surface vessels. In Captain Chambers’ device the plane rested on a small car running on the catapult rail. A cylinder filled with compressed air contained a piston. When a valve was opened, the escaping air pushed the piston against the car with a force that sent the car down the catapult rail and the plane into the air.
The basic idea developed by Captain Chambers is still used in Navy catapults. In the modern device, the airplane rests on a car riding on a catapult rail which can be mounted on all types of surface craft. The rail is so constructed that it can be swung in any direction, permitting the plane to be launched into the wind. The power that shoots the catapult car and sends the plane off the rail is furnished by a five-inch shell fired in a mechanism at the rear of the rail. It was this idea of Captain Chambers’ that originally gave the Navy a start on the device enabling our battleships, cruisers, and destroyers to take observation planes to sea with them. This was the idea which furnished the “eyes of the fleet” and gave admirals and captains the power to see what lay beyond the horizon.
The development of naval aviation marched step by step with the development of aircraft. The year 1940 saw the introduction of one of the best carrier-based fighters ever built, the Grumman F4F Wildcat. This stubby-winged craft was a radical departure from previous carrier-fighter design and became the first successful monoplane to go to sea on the carriers. Wing-flaps lowered landing speeds and shortened take-off runs. This permitted the use on the carriers of the fast fighter, since the flaps acted as brakes and reduced the plane’s speed for deck landings. The F4F had a wingspan of 38 feet but this was decreased by the folding of its wings to 14 feet 6 inches. This device reduced the space necessary for storage in the carrier’s hangar deck and permitted the use of additional fighters on the ship. The F4F’s landing gear retracted completely into the fuselage, thus aiding in streamlining and increasing the speed of the fighter. It was powered with a 1,200-horsepower Pratt 81 Whitney air-cooled radial engine and had a speed of about 350 miles per hour.
Experiments with the use of aërial torpedoes brought about the development of the Douglas TBD-1 torpedo plane. Though not so fast as a fighter, the three-place TBD-1 Devastator carried a deadly torpedo load. The Douglas SBD Dauntless was designed for dive-bombing and was the first low-wing monoplane to be used as the standard dive-bomber on our carriers.
The Douglas SBD Dauntless was the first Navy dive-bomber to get into action in World War II. In fact it went into action a few minutes after the first Jap shot was fired at Pearl Harbor, on the morning of December 7th, 1941. SBD’s from the carrier Enterprise, steaming toward Hawaii, were the first planes in action on that fateful morning. From that day on our war in the Pacific was one of attack. The dive-bomber is an attack weapon and the sturdy SBD’s led the attack from Pearl Harbor down to Guadalcanal and on up the Pacific to the Philippines and victory.
While other types of planes were under consideration at the beginning of the war, the airplanes just discussed were the ones that bore the brunt of the fighting in the early months following the attack on Pearl Harbor. Their work in the hands of gallant Navy airmen in the heartbreaking first year of our struggle against terrific odds in the Pacific would in itself furnish material for a book many times the size of this one.
In the early twenties the memories of the famous transatlantic flight of the NC flying boats persisted in the minds of naval aviators. Much of the Navy’s interest was centered in the Pacific, and the vision of flying boats that could quickly link Hawaii to the mainland was an enticing one.
On a trial flight from San Francisco, California, to Honolulu, Hawaii, in 1925, Commander John Rogers, flying a Navy patrol plane, was forced down after twenty-five hours in the air. He was within four hundred miles of Hawaii when he landed on the sea. After drifting for nine days, Rogers was picked up by a submarine. Although the flight had failed, it had established a seaplane record of over 1,800 miles, and the trail was blazed.
It was the development of the famous Consolidated PBY flying boats that eventually put our West Coast within twenty-four hours’ flying distance of Hawaii. You will remember the Army officer who had charge of our first air mail service back in 1918—Major Reuben H. Fleet. Major Fleet resigned from the service in 1922 and in the year following organized the Consolidated Aircraft Corporation. His firm manufactured many types of airplanes, including the Army’s PB-2A fighter and the 0-19 observation plane. In 1928 Consolidated built the XBY-1, a flying boat with a wingspan of 100 feet. This was the first Consolidated flying boat purchased by the United States Navy. Following this came the big thirty-two-place Consolidated Commodore flying boat.
The Commodore led to the development of the P2Y type of flying boat. This was a two-engined plane with a wingspan of 100 feet and a length of 62 feet. This was the plane which was to lead to the world-famous PBY Catalina flying boats. In January, 1934, six P2Y’s in the service of the United States Navy made the first successful mass flight from San Francisco to Pearl Harbor, Hawaii, a distance of 2,414 miles.
First introduced in 1934, the Consolidated PBY Catalina was one of the world’s first all-metal flying boats. Powered with two 600-horsepower radial engines, the PBY was for six years the fastest airplane of its class. In January, 1937, twelve Navy PBY’s flew in nonstop formation from San Diego, California, to Pearl Harbor, Hawaii, a distance of 2,553 miles, in 21 hours and 43 minutes. In June of the same year twelve PBY’s flew in nonstop formation from San Diego to Coco Solo, Canal Zone, or 3,087 miles in 27 hours and 21 minutes. In 1937 Sir Hubert Wilkins flew a commercial version of the PBY over 19,000 miles of Arctic wastes.
Although prevented from any great expansion in the years following World War I, the Army led the way in many phases of aviation. United States Army planes were the first to fly around the world. Army aviation also pioneered night flying and the use of the lighted airfield, refueling in the air, and radio communication between ground and plane. It made great advances in aërial photography. In 1929, Captain Albert W. Stevens photographed Mount Rainier from an airplane 227 miles away, establishing a record of long-distance aërial photography. The same year, Lieutenant “Jimmy” Doolittle, in a demonstration of instrument-flying, accomplished a take-off and a landing solely through the use of instruments. This was the beginning of “blind flying.” The Army Fokker Question Mark under the command of Carl Spaatz and Ira Eaker, generals commanding our heavy bomber forces in Europe in World War II, established an endurance record by staying aloft for 150 hours. Their plane was refueled in the air during the record flight. Army aviators were trained in the use of oxygen at high altitudes and in the use of instruments for “blind flying.”
In 1927 the great Matériel Division of the Air Corps was established in its new home at Wright Field, Dayton, Ohio, close by the birthplace of Orville and Wilbur Wright. The Air Corps Matériel Division was the testing laboratory for all Army aviation equipment. Here all types of new engines, planes, and instruments were developed and tested. Aircraft manufacturers co-operated closely with Army technicians in developing ideas which would help to further the advancement of military aviation. New types of planes were taken to Wright Field, where Army technicians and test pilots put them through grueling tests before releasing them for Army service. Here the Army research engineers worked with oil companies to develop fuels which would increase the performance of aircraft engines. Clothing and equipment for pilots were tested. High-speed aërial cameras were developed, and it was through the efforts of the men at Wright Field that aërial photography in general was perfected to so high a degree.
Many of the features developed for the Army at Wright Field also were applied to commercial aviation and contributed greatly to the safety of air travel. From the earliest postwar days, Army aviation leaders had been insistent that safety was the most important factor in the development of airplanes and of aviation equipment. The experts at Wright Field have contributed greatly to the high record of safety which consistently has prevailed in Army aviation.
THE ALLISON ENGINE
For several years after World War I, all Army airplanes were powered with water-cooled, in-line engines. In the majority of cases it was the Liberty engine developed during the war, but some water-cooled Wright engines also were used. As late as 1927 the Army still was experimenting with the Liberty engine and trying to increase its horsepower. James A. Allison became interested in this project and, when the job was given up as hopeless, went on to create his own engine. He died before he had completed his engine, but his assistant, Norman H. Gilman, continued its development in conjunction with General Motors. The first successful Allison engine was completed in 1932, and the following year the Navy used it to power the dirigibles Akron and Macon.
The Army became very much interested in the Allison engine. Although a number of Army fighters were equipped with radials following the early successes of that type of engine, Air Corps men believed that, due to its narrow frontal area, the in-line engine could help to streamline fighters. Finally, in 1939, after many changes, the first Allison engines were installed in Curtiss P-40 Army fighters. The first Allison engine had developed 1,090 horsepower. By 1940 its horsepower was increased to 1,150 and the Army adopted it as standard. It was installed in all P-40’s and later in Lawrence Bell’s P-39 Airacobra. In the P-39 the engine was installed in the fuselage behind the pilot. A ten-foot shaft carried the power to the propeller in the nose of the ship. This installation permitted the housing of a 37-millimeter cannon and two machine guns in the nose of the Airacobra. The Lockheed P-38 Lightning was powered with two Allison engines, making it the first fighter with more than two thousand horsepower.
Regardless of the fact that this country was at peace and our military policy a defensive one, our farseeing Air Corps leaders continued to build American air power around the heavy, long-range bomber. As the heavy bomber was primarily an offensive weapon, many Americans believed the Army’s development of it to be contrary to our declared policy. As a result, we did not build great numbers of bombers. However, with the small number that we did have, our Army aviators made great progress in the technique of high-altitude bombing.
As in all branches of the United States Army, great stress was laid on good marksmanship. Army aviators were trained to hit the mark with their bombs just as the infantryman does with his rifle. Other countries developing heavy bombers were satisfied if their airmen dropped a great many bombs in a given target area. In this country the development of the bombsight enabled our aviators to hit a target with great accuracy from high altitudes. This is called precision bombing. It was also known as pin-pointing a target, because of the ability of our bombardiers to score direct hits on small targets. It was the B-17 Flying Fortress that gave Army airmen the greatest help in perfecting high-altitude, precision bombing. The broad wings of the Fortress furnished a steady platform from which to aim the bombs, and the great plane was able to fly smoothly in the higher altitudes. The bombardier riding in its transparent nose could carefully line up his target and drop his bombs with precision accuracy.
It was not until the outbreak of World War II that most Americans came to realize the value of the airplane in modern conflict. As the fighting grew to global proportions, Americans began in particular to appreciate the farsightedness of our Air Corps leaders in developing the long-range bomber.
By 1940 the original Boeing 299 or B-17 had grown from a sixteen-ton ship to a giant twenty-two-ton bomber. The new version, the B-17D, was powered with two 1,200-horsepower radial engines, giving it a speed of more than 300 miles per hour. Continual improvements were made on it and by the spring of 1942 a still more formidable member of the Fortress family, the B-17F, was in production.
The B-17F was the most powerful bomber yet produced. It was armed with eleven .50-caliber machine guns and manned by a crew of ten. It could carry more than three tons of bombs to targets over seven hundred miles distant. Its oxygen system permitted its crew to fly the Fortress at altitudes above 35,000 feet. With its eleven heavy machine guns in the hands of a perfectly trained crew, the Fortress was capable of defending itself with deadly effectiveness.
The first Flying Fortresses went into action with the United States Army on the day after the attack on Pearl Harbor. Although this country had then only a limited number of Fortresses, they and their successors quickly began to distinguish themselves on the battlefronts of the world.
By the summer of 1942 Flying Fortresses had begun what was to be the greatest sustained aërial invasion the world had ever known. Starting with a small group of Fortresses, the United States Army Air Forces went to work to wreck Adolf Hitler’s “Fortress Europe” and clear the path for an Allied invasion.
From small raids by a dozen Fortresses the number of bombers grew until the raids became huge aërial invasions involving hundreds of bombers and thousands of airmen. That the path for invasion was cleared and victory brought nearer was due in no small measure to our big bombers and the farsighted American airmen who had brought them into being against almost insurmountable obstacles.
Although the airplane in World War I had been used mainly as an observation and a plane-to-plane combat weapon, wise American airmen, such as General “Billy” Mitchell, visualized the craft as a means of destroying the enemy’s ability to fight. These men saw his weapons destroyed as they were being built and his transport stopped before it reached the battlefield. As the result of this thinking, our doctrine of air power was established.
With this much accomplished, the need for various types of airplanes was clearly defined. It called for three distinct types of warplanes: the long-range bomber, the observation plane, and the pursuit plane. Air strategy was built around the long-range bomber. This was the weapon which would destroy the enemy’s war plants and military establishments on his home grounds. The observation plane was to be used to seek out the enemy’s movements and to locate his installations. As aërial photography was perfected, the observation planes were to be equipped to bring back a record of their findings. These records would establish the targets for the long-range bombers. In the beginning, the pursuit plane was considered a weapon to protect our own military establishments, our cities, and our war plants. Its mission was to intercept any enemy planes attempting to attack us.
On the preceding pages we have seen the bomber develop from a single-engined DH-4 into the giant four-engined B-17. This development was the result of the careful study of aërial strategy by our Army airmen. When the big bombers with a range of thousands of miles were built, our strategists saw them as weapons to be used only against an enemy’s most distant military establishments. The smaller two-engined bombers which had once been our long-range bombers