Chapter III: Part 3

Tony Fokker’s tri-motors and Wright radial engines predominated in the famous flights of the late twenties, but other American planes and engines were coming into prominence. The first Wright 200-horsepower radial engine was called the _Whirlwind_. It was soon followed by a more powerful Wright radial, the 400-horsepower _Cyclone_. At the same time the Pratt & Whitney organization of Hartford, Connecticut, made the 425-horsepower air-cooled _Wasp_ radial engine. Wright _Cyclones_ and Pratt & Whitney _Wasps_ were destined to power American airplanes for many years to come.

During 1927 and 1928 the map of the United States showed a continually increasing number of lines marked “Air Mail Route.” In 1926, the sixteen companies holding air mail contracts flew about 1,700,000 air miles. Much of this mileage was flown in single-engined, open-cockpit airplanes. Mail was the principal source of revenue. The few passengers who first braved the rigors of early air transport either rode on mail sacks or in small, cramped cockpits. Pilots and Operation men alike frankly admitted they were not keen about carrying passengers.

The Boeing Aircraft Company of Seattle, Washington, set up the Boeing Air Transport and took over the operation of the air mail service from Chicago to San Francisco. National Air Transport handled the Chicago-New York route, to complete the transcontinental route. Jack Frye and others established an air mail and transport service between Los Angeles, California, and Phoenix, Arizona. Western Air Express operated between Los Angeles and Salt Lake City, Utah. A number of short lines operating routes from the Great Lakes and down through the south were soon to be merged to create American Airlines.

In 1928, an air traveler making an extensive trip would be likely to fly in seven or eight different types of planes. He might step into a Fokker tri-motor, change to a single-engined Boeing, ride for some distance in a Ford tri-motor or a Whirlwind-powered _Travel Air_, and finish his trip in a Curtiss _Carrier Pigeon_. The planes usually flew low, at between one and two thousand feet. Here the air was usually rough and a good percentage of air travelers were troubled with airsickness. The planes landed every few hundred miles to refuel. They were noisy and heated only by exhaust gases from the engines, which usually furnished more sickly fumes than heat. Little food, if any, was served, and a coast-to-coast journey took thirty-three hours.

Though 1926 was the official start of American air transport, the first two years of its existence were years of experimentation. It was not until the country’s imagination had been fired by the flights of Lindbergh, Byrd, Chamberlain, and others that air transport emerged from its experimental stage. By 1927 the bigger minds in airline services had realized that the time was coming when provisions must be made to carry passengers on a large scale. It was not until 1928, with the arrival of powerful radial engines and better airplane designs, that air transport began to show real prospects. It was two years after the first beginnings of air transport that John Monk Saunders, the author, paid over $400 for an air passage from Los Angeles to New York, and became the first transcontinental air passenger.

Although its aircraft production had been mainly for the Army and Navy, the Boeing Aircraft Company also was in the air transport business through its Chicago-San Francisco air mail route. Boeing’s inventive genius was turned to air transport problems and created, first, the Boeing 40-B4 four-passenger and mail plane. Then came the big twelve-passenger, radial-powered, tri-motor plane, called the “Pioneer Pullman of the Air.” This ship, Boeing 80-A, helped to reduce the coast-to-coast transport time to twenty-seven hours. When the 80-A was introduced the Boeing Air Transport and the National Air Transport had been merged to form United Air Lines, the first transcontinental airline.

With air transport five years old, by 1930 the speed of planes was only about 100 miles per hour. Engineers and transport men agreed that the air transport plane must be faster. The planes of that day still had a considerable amount of external bracing and many of them were biplanes with strut and wire wing bracings. This caused the drag that was holding down the speed of the transport. Many of these planes had so many bracings that they whistled as they flew. To make a profit, the air transport operators had to have faster, quieter, and yet more comfortable airplanes. They must also be more easily maintained.

In 1921, Boeing came up with a plane that, while not the final answer to the air transport problem, was to point the way to the modern all-metal, monoplane type of air transports. This plane was the Boeing _Monomail_. The _Monomail_ was big, fast, and comfortable, and it carried a big pay load. It was the first practical low-wing, all-metal transport to be put into service in this country. It carried five passengers, their baggage, and 1,750 pounds of mail or cargo, at a cruising speed of 140 miles per hour. The _Monomail_ was the sensation of air transport in 1931, and set the pace for future transport planes.

DONALD DOUGLAS’ DREAM COMES TRUE

The Boeing people, though pleased with the reception and performance of the _Monomail_, knew that the single-engine plane was not the final answer. If the engine failed, the plane must land. If the plane was over rough or mountainous country, forced landings meant danger. A big plane must have two engines, one of which could keep the plane flying if the other failed. Boeing went to work with this in mind.

Near Los Angeles, the young man who had been dreaming of big commercial transport planes since the Wright Brothers’ trials at Fort Meyer, also was thinking of two-engined transports that could fly on one engine. From the time Donald Douglas’ _World Cruisers_ had circled the globe, his aircraft had grown larger and larger. His orders, however, were for Army, Navy, and Coast Guard planes; not for great commercial airliners.

Although Donald Douglas had achieved a great deal of international fame as the result of the round-the-world flight and was highly respected in military circles, few other people knew him. A quiet, industrious young man, he had put all his earnings back into his business and had continued to work on his dream of big, roomy, smooth-flying airliners. He visualized air transport flying from coast to coast and from country to country in a great network of airlines that would link the whole world.

On a hot, dry day in the summer of 1933, in Winslow, Arizona, a new two-engined transport took off from one of the highest airports on the Transcontinental & Western Airways route. Gaining altitude, the pilot cut off one of its two engines, then flew more than 200 miles over the Rockies to Albuquerque, New Mexico. Returning, the pilot cut off one engine on the take-off. With one _Cyclone_ radial roaring, the transport took off easily and climbed steadily. The first Douglas DC-1 transport had proved itself and a dream had come true.

WINGSPAN 85 FEET LENGTH 62 FEET

THE DOUGLAS DC-2, THE FIRST OF THE WORLD’S LUXURY AIR TRANSPORTS, WAS A LOW-WING, ALL-METAL PLANE WITH RETRACTABLE LANDING GEAR.

POWER TWO 9-CYLINDER 700-HP. RADIAL ENGINES

THE DC-2’s WRIGHT _CYCLONE_ ENGINES RAN ON HIGH OCTANE GAS AND WERE COVERED WITH METAL COWLING TO REDUCE _DRAG_.

SPEED ONE HOUR 180 MILES

RANGE 1,200 MILES

THE DC-2 USHERED IN A NEW PHASE OF AIR TRANSPORT. IT CRUISED AT 180 MILES PER HOUR AND CROSSED THE COUNTRY WITH ONLY A FEW STOPS FOR REFUELING.

CEILING 12,500 FEET

IT COULD FLY AT HIGHER ALTITUDES THAN PREVIOUS TRANSPORTS, THUS AVOIDING THE MORE TURBULENT AIR OF THE LOWER ALTITUDES. IT WAS EQUIPPED WITH A GOOD HEATING AND VENTILATING SYSTEM.

PAYLOAD 14 PASSENGERS PLUS 1,000 POUNDS OF MAIL AND CARGO.

THE DC-2 WAS SOUND-PROOFED AND THE PASSENGERS RODE IN ADJUSTABLE UPHOLSTERED SEATS THAT GAVE THEM PULLMAN-LIKE COMFORT.

THE DC-2 TRANSPORT PLANE COMBINED PASSENGER COMFORT WITH ECONOMICAL OPERATION COSTS AND HELPED TO LAY THE FOUNDATION FOR FASTER, SAFER, AND CHEAPER AIR TRAVEL. MANY OF THE EARLY DC-2’S ARE STILL IN SERVICE WITH AIRLINES AND THE U.S. ARMY AIR TRANSPORT COMMAND.]

The DC-l was an experimental model of the new Douglas two-engined luxury air transport plane. On the night of February 18, 1934, six months after the first DC-l was tested over the Rockies near Winslow, a new Cyclone-powered Douglas took off from Los Angeles for Newark, New Jersey. This plane was the first of the famous DC-2’s. It was flown by Jack Frye of TWA (Transcontinental & Western Airways) and Captain Eddie Rickenbacker of Eastern Air Lines. They roared into Newark ahead of a snowstorm which had blotted out all the airports along the route, and were three hours ahead of schedule for a new transcontinental record of 13 hours, 4 minutes. This flight made obsolete all existing transport planes.

SAFETY IN FLIGHT

The new Douglas DC-2 transport plane combined all the knowledge of thirty years of flight. In the early “thirties” air transport began to come into its own. Plane-to-ground radio was put into use. The radio range, or radio beam, pioneered by “Shorty” Schroeder with Henry Ford in 1927, was guiding our airliners on their course. The radio beam flashed the Morse code letters “A” and “N” along the flight path of the airliner. The dot-dash of the “A” signal was flashed on one side of the route and the dash-dot of the “N” signal was on the other. In the center of the flight path the two signals blended into a steady hum. This hum notified the pilot that he was “on course.” Regardless of fog, rain, or darkness the pilot got his course through his earphones.

The application of the gyroscope to aircraft instruments was a great step in the advancement of flying. First experimented with by Lawrence Sperry in the early days of the airplane, the constant action of the gyroscope was used to register the changes of attitude of aircraft in flight. It was first used in the Turn and Bank Indicator, then in the _Gyro-Horizon_ and _Directional Gyro_. Power-driven gyros constantly whirled in the direction in which they were set. They were attached to dials on the instrument panel and to the plane itself. The position or attitude of the gyro was indicated on the dial in relation to the attitude of the airplane. As the plane changed, the constantly spinning gyro remained in its correct attitude. The gyro position and the position of the plane shown on the dial told the pilot the actual attitude of the plane in the air so that he could correct in relation to the true position indicated by the gyro. This allowed the pilot to keep his plane on a true compass course and in the proper flight attitude without having to see the horizon. Thus a pilot could fly through fog or total darkness with both ease and safety.

CONTROL CABLES

THE GYRO UNIT CONTROLS MOTORS THAT OPERATE THE CONTROLS OF THE
PLANE.

THE GYRO PILOT AUTOMATICALLY FLIES A PLANE IN ANY POSITION THAT THE
PILOT DESIRES. WHEN THE GYRO IS SET TO FLY A PLANE IN A LEVEL
POSITION, IT WILL RESIST ALL ATTEMPTS TO CHANGE ITS POSITION. IF
THE SHIP SHOULD NOSE DOWN, THE GYRO STARTS THE CONTROLS TO WORK, TO
BRING THE NOSE UP. THIS IS TRUE IN ALL FLIGHT MOVEMENTS.]

The gyro instruments soon proved their value and were installed in the cockpits of transport planes the world over. The Sperry Gyropilot then was perfected. This remarkable instrument, based on the gyroscope movement, was developed actually to manipulate automatically the controls of even the largest airplane, keeping it directly on the desired course and leaving the human pilots free for their many other duties.

In 1933, Wiley Post flew around the world alone, but the Gyropilot piloted the _Winnie Mae_ over most of the route. This relieved the fatigue of constant flying and allowed Wiley to keep a continual check on his maps. His successful use of the automatic pilot soon caused its adoption by most of the major airlines of the country.

Thus, with the aid of the radio beam, better flight instruments, special octane gasoline, two-way radio, sound-proofing, wheel brakes, and adjustable pitch propellers, the airlines of America were fast emerging into a safe and comfortable means of travel.

While the DC-2 was coming into prominence in the air transport field, Boeing engineers had gone on with their idea of a two-engined plane and had built an all-metal bomber for the Army.

In building the two-engined, all-metal B-9, Boeing engineers learned how to build another plane with a more peaceful purpose. This ship was the famous Boeing 247-D commercial transport plane. The 247-D was an all-metal, low-wing monoplane, powered with two 550-horsepower Pratt & Whitney Wasp radial engines. It had a top speed of 200 miles per hour and a cruising speed of 180 miles per hour. It was America’s first three-mile-a-minute air transport plane.

In designing the speedy 247-D, the Boeing did not forget the comfort of the passengers. The plane was fully heated and ventilated. Its seats were deeply upholstered and had reclining backs. There were broad windows at each chair. There were dome lights and individual reading lamps; and the plane was equipped with a tiny galley and a complete lavatory. Insulation kept the 247-D quiet and comfortable in any sort of weather.

The 247-D carried ten passengers, a pilot, co-pilot, and stewardess, plus baggage and mail. It was first put into service by the United Air Lines in 1933, on their coast-to-coast route. Incidentally, it was United who had introduced to the airlines the third member of the air transport’s crew, the stewardess. The pretty young stewardesses were all trained nurses. They looked after air-sick passengers, served food en route, and looked after the comfort of the air travelers.

POWERED WITH TWO 550-HP. PRATT & WHITNEY RADIAL ENGINES, THE 247
CRUISED AT 180 MILES PER HOUR. ITS TEN PASSENGERS RODE IN DEEPLY
CUSHIONED SEATS WITH RECLINING BACKS. ITS WELL-VENTILATED, HEATED
CABIN WAS SOUND-PROOFED TO DEADEN THE ROAR OF THE ENGINES, AND THE
PASSENGERS RODE IN QUIET COMFORT.]

LUXURY AIRLINERS AND SKYSLEEPERS MAKE AIR TRAVEL AN ACCEPTED FACT

With the Boeing 247’s, United Air Lines in 1933 cut the coast-to-coast air trip to twenty-two hours. As DC-2’s and the fast two-engined Lockheed _Electras_ were speeding up air transport schedules on the airlines throughout the country, differences arose between the government and some air transport firms over mail contracts. The result was the cancellation in February, 1934, of all air mail contracts.

The air mail revenue was the life of the air transport operators and the cancellation of the mail contracts suddenly darkened their future. An attempt to put the transportation of air mail into the hands of the United States Army resulted in a tragic failure. This was due mainly to the unfamiliarity of Army pilots with air mail routes and their lack of proper equipment. In June, 1934, the air mail was turned back to the airlines.

The return of the air mail contracts to private operators saw the introduction of the new Douglas DC-3. This was the plane that brought Donald Douglas’ dream to complete fulfilment. His big, all-metal, low-wing, two-engined DC-3 completely revolutionized air transport. By 1935, the name Douglas had come to mean fast, comfortable, and safe air transport.

WINGSPAN 95 FEET LENGTH 64 FEET

THE DC-3, A LARGER AND MUCH IMPROVED VERSION OF THE DC-2, ACHIEVED INSTANT POPULARITY ON ITS INTRODUCTION IN 1934.

POWER TWO 9-CYLINDER 800-HP. RADIAL ENGINES

THE FIRST DC-3’S WERE POWERED WITH 800-HP. ENGINES, BUT LATER MODELS USED RADIALS UP TO 1150 HORSEPOWER.

SPEED ONE HOUR 180 MILES

THE DC-3 HAD A TOP SPEED OF 212 MILES PER HOUR, BUT ITS MOST PRACTICAL CRUISING SPEED WAS 180 MILES PER HOUR.

RANGE 1680 MILES

ITS LONG CRUISING RANGE MADE IT POSSIBLE FOR THE DC-3 TO MAKE THE COAST-TO-COAST TRIP WITH ONLY THREE STOPS.

CEILING 21,000 FEET

ITS MOST PRACTICAL ALTITUDE WAS FROM 8,000 TO 10,000 FEET, THOUGH THE DC-3 WAS CAPABLE OF REACHING AN ALTITUDE OF OVER 21,000 FEET.

PAYLOAD 21 PASSENGERS PLUS 2,000 POUNDS OF MAIL AND CARGO.

THE DC-3 WAS STEAM-HEATED AND SOUND-PROOFING MADE IT AS QUIET AS A PULLMAN CAR. IT WAS EQUIPPED WITH EVERY KNOWN SAFETY DEVICE.

NOW, THIRTY-ONE YEARS AFTER THE INVENTION OF THE AIRPLANE, WE BEGIN TO SEE THE RESULTS OF THE EFFORTS OF AMERICAN ENGINEERS AND AIRCRAFT BUILDERS. LIGHTWEIGHT, POWERFUL ENGINES; LIGHTWEIGHT, METAL CONSTRUCTION; RETRACTABLE LANDING GEAR AND SAFETY DEVICES PLAYED A VITAL PART IN MAKING THE DC-3 A SUCCESS.]

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.

PAN AMERICAN CLIPPERS CONQUER PACIFIC SKIES

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.

WINGSPAN 130 FEET LENGTH 90 FEET

THE GIANT MARTIN 130 WAS DESIGNED AND BUILT FOR THE LONG-RANGE FLIGHTS THAT WERE NECESSARY ON PAN AMERICAN’S TRANS-PACIFIC ROUTES.

POWER FOUR 14-CYLINDER 750-HP. RADIAL ENGINES

IT WAS POWERED WITH PRATT & WHITNEY TWIN-ROW, WASP RADIAL ENGINES AND HAD A TOP SPEED OF 180 MILES PER HOUR.

SPEED ONE HOUR 130 MILES

RANGE 3,200 MILES

CEILING 10,000 FEET

PAYLOAD

46 DAY PASSENGERS OR 26 SLEEPING BERTHS, A CREW OF SIX, AND A TON OF MAIL OR CARGO.

THE MARTIN 130, CALLED THE _CHINA CLIPPER_, WAS THE FIRST OF A GROUP OF MARTIN FLYING BOATS THAT PIONEERED PAN AMERICAN’S TRANS-PACIFIC MAIL, PASSENGER, AND CARGO SERVICE FROM AMERICA TO HAWAII, THE PHILIPPINES, CHINA, AND AUSTRALIA. THE GIANT, ROOMY PLANE WAS EQUIPPED WITH EVERY LUXURY FOR AIR TRAVELERS. IT COULD CLIMB TO AN ALTITUDE OF OVER 17,000 FEET, BUT CRUISED MORE ECONOMICALLY AND COMFORTABLY AT 10,000 FEET.

THE MARTIN 130 WAS THE LARGEST FLYING BOAT OF ITS TIME. IT WAS OF VERY RUGGED CONSTRUCTION AND WAS EQUIPPED WITH TWO-WAY RADIO AND OTHER SAFETY DEVICES. THE ORIGINAL _CHINA CLIPPER_ BUILT UP A RECORD OF 12,000,000 MILES OF OCEAN FLYING FROM 1935 TO 1945.]

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.

PAN AMERICAN CLIPPER INAUGURATES AMERICA’S FIRST TRANSATLANTIC AIR TRANSPORT SERVICE

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_.

WINGSPAN 152 FEET LENGTH 106 FEET

THE HUGE LONG-RANGE BOEING _CLIPPER_ WEIGHED 41-TONS.

POWER FOUR 14-CYLINDER 1,500 HP. RADIAL ENGINES

FOUR 3-BLADED PROPELLERS WITH A DIAMETER OF 14 FEET FURNISHED THE _THRUST_ FOR THE PLANE.

SPEED ONE HOUR 175 MILES

RANGE 3,100 MILES

CEILING 15,000+ FEET

PAYLOAD

PAYLOAD 74 DAY PASSENGERS. OR 40 SLEEPER PASSENGERS, A CREW OF 8 TO 15 PLUS 2 TONS OF MAIL

THE BOEING _CLIPPER_ HAD A TOP SPEED OF 190 MILES PER HOUR AND COULD FLY NONSTOP FOR 3,100 MILES WITH 40 PASSENGERS. IT WAS OF ALL-METAL CONSTRUCTION AND DIVIDED INTO ELEVEN SECTIONS BY BULKHEADS. IT HAD AN UPPER DECK FOR THE FLIGHT CREW AND STORAGE SPACE. THE MAIN DECK WAS DIVIDED INTO TEN COMPARTMENTS FOR PASSENGERS. BELOW THIS DECK WERE A SERIES OF WATERTIGHT COMPARTMENTS. A PASSAGE THROUGH THE WINGS PERMITTED THE SERVICING OF THE ENGINES DURING FLIGHT.

THE FIRST BOEING _CLIPPER_ TO SPAN THE ATLANTIC WAS THE LARGEST COMMERCIAL AIRPLANE IN THE WORLD. THE _CLIPPER_ WAS EQUIPPED WITH EVERY AVAILABLE SAFETY DEVICE AND LUXURIOUSLY FITTED FOR THE DAY AND NIGHT COMFORT OF THE PASSENGERS. THE STURDY, SAFE _CLIPPERS_ OPENED A NEW ERA OF AIR TRAVEL.]

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.

PRIVATE PLANES

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

LAMINATED BIRCHWOOD PROPELLER

FOUR-CYLINDER AIR-COOLED ENGINE

METAL COWLING

DUAL CONTROLS

LANDING GEAR

METAL WHEEL “PANTS”

LIFT STRUTS

WELDED STEEL TUBE FUSELAGE FRAME

FABRIC FUSELAGE COVERING

TAIL WHEEL

RUDDER ELEVATOR

ALUMINUM RIBS

FABRIC COVERING

STABILIZER]

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.

SUPERCHARGERS AND SUPER-AIRLINERS

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.

AIR POWER FOR WORLD WAR II

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.

NAVAL AVIATION 1922-1935

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.

SHIPBOARD FIGHTERS

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.

BATTLESHIP OF THE AIR

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.

WINGSPAN 105 FEET LENGTH 70 FEET

THE BOEING 299. THE _FLYING FORTRESS_, WAS AMERICA’S FIRST ALL-METAL, LONG-RANGE, HIGH-ALTITUDE, FOUR-ENGINED “BATTLESHIP OF THE AIR.”

POWER FOUR 9-CYLINDER 750-HP. RADIAL ENGINES

THE FIRST _FORTRESS_ WAS POWERED WITH PRATT & WHITNEY 750-HP. RADIAL ENGINES. LATER MODELS USED 1,000-HP. WRIGHT CYCLONES.

SPEED ONE HOUR 230 MILES

RANGE 2,000 MILES

CEILING 20,000 FEET

PAYLOAD 9 CREW MEMBERS, ONE TON OF BOMBS, AND FIVE 30-CALIBER MACHINE GUNS.

THE 299, OFFICIALLY DESIGNATED THE XB-17, WEIGHED 16 TONS. ITS GREAT WINGS WERE CONSTRUCTED OF ALUMINUM ALLOY METAL BRACED INTERNALLY BY A BRIDGE-LIKE TRUSS STRUCTURE. THE 299 WAS HIGHLY STREAMLINED AND ITS LANDING GEAR RETRACTED INTO WELLS IN THE ENGINE NACELLES. ITS ENGINES WHIRLED 3-BLADED CONSTANT-SPEED PROPELLERS. IT WAS EQUIPPED WITH WING FLAPS TO REDUCE ITS LANDING SPEED. GUNNERS WERE PROTECTED BY PLASTIC GUN BLISTERS AND BOMBS WERE CARRIED INSIDE THE FUSELAGE.

THE INTRODUCTION OF THE _FLYING FORTRESS_ MARKED A GREAT STEP FORWARD IN THE DESIGN OF BIG MILITARY AIRPLANES. IT CAME AS THE RESULT OF THE BOEING COMPANY’S DEVELOPMENT OF LOW-WING, ALL-METAL, MULTI-ENGINED PLANES. IT ALSO PROVED THAT PROPER STREAMLINING REDUCED _DRAG_ AND INCREASED SPEED.]

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.

NAVAL AVIATION GETS READY

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.

SBD _DAUNTLESS_ DIVE BOMBER

TBD _DEVASTATOR_ TORPEDO PLANE]

THE U. S. NAVY’S FIRST LONG-RANGE FLYING BOATS

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.

WINGSPAN 104 FEET LENGTH 65 FEET

THE _CATILINA_ WAS THE FIRST LONG-RANGE FLYING BOAT TO BE BUILT IN QUANTITY FOR THE U.S. NAVY.

POWER TWO 9-CYLINDER RADIAL ENGINES

THE FIRST MODELS WERE POWERED WITH 600-HP. ENGINES, LATER THEIR POWER WAS INCREASED TO 1050 HP.

SPEED ONE HOUR 198 MILES

RANGE 2,000+ MILES

THE _CATALINA_, WITH A RANGE OF OVER 2,000 MILES, GAVE THE NAVY A LONG-RANGE PATROL BOAT CAPABLE OF CONNECTING OUR MAINLAND WITH THE CANAL ZONE, HAWAII, AND ALASKA.

CEILING 18,000+ FEET

PAYLOAD A CREW OF SEVEN TO NINE MEN AND A TON OF BOMBS.

THE POWERFUL, STURDY _CATALINA_, WITH ITS ABILITY TO CRUISE FAR OUT OVER THE OCEAN, GAVE THE NAVY A VALUABLE DEFENSE WEAPON. SCOUTING FAR OUT FROM OUR SHORES, IT COULD PROTECT OUR COASTLINE.

WHEN THE _CATALINAS_ WENT INTO SERVICE IN 1934, NOT EVEN THEIR STAUNCHEST ADMIRERS VISUALIZED THAT, YEARS LATER, THEY WOULD BE ONE OF THE NAVY’S MOST DEPENDABLE WEAPONS IN DEFEATING THE NAZIS AND THE JAPS IN WORLD WAR II.]

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.

BOEING P-26 A FIGHTER]

TECHNICAL PROGRESS IN THE U. S. ARMY AIR CORPS IN THE THIRTIES

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.”

CURTISS P-36 _HAWK_

CURTISS P-40 _HAWK_]

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_.