he set up his own engineering laboratory in Detroit, Michigan. He
decided that wood and fabric were not suitable to stand the strain
required in a modern plane. His first all-metal plane, a Navy torpedo
bomber, flew successfully in test flights, but a Navy pilot wrecked it
on its official trial. The Navy would not order another one, so Bill had
to raise more money. He got it and built America’s first all-metal
transport plane. It carried eight passengers in addition to the two-man
crew. Bill knew it was a good plane and he was satisfied with it, but he
did not want to be a manufacturer. He wanted instead to stay at his
engineering work, so he sold his airplane company to Henry Ford, and the
famous Stout-designed, Ford tri-motor, “Tin Goose” was born.
[Illustration: 1925-1929
WINGSPAN 70 FEET
LENGTH 40 FEET
THE FORD TRI-MOTOR WAS AMERICA’S FIRST ALL-METAL TRANSPORT PLANE. IT
PROVED THE VALUE OF METAL IN AIRCRAFT CONSTRUCTION.
POWER
THREE 9-CYLINDER 200-H.P. RADIAL ENGINES
POWER FOR THE FORD PLANE WAS FURNISHED BY WRIGHT _WHIRLWIND_
AIR-COOLED, RADIAL ENGINES.
SPEED
ONE HOUR
100 MILES
RANGE
500 MILES
CEILING
8,000 FEET
PAYLOAD
8 PASSENGERS OR A CARGO LOAD OF EQUAL WEIGHT.
ALTHOUGH THE FORD DID NOT INCREASE THE RATE OF SPEED OF AIR
TRANSPORT, ITS ROOMY, ENCLOSED CABIN DID OFFER GREATER COMFORT FOR
AIR TRAVELERS. ITS THREE ENGINES GAVE IT A GREATER FACTOR OF
SAFETY. AS THE CABIN WAS HEATED ONLY BY ENGINE EXHAUST GASES, ITS
PRACTICAL SERVICE CEILING WAS UNDER 4,000 FEET. IN ADDITION TO ITS
PASSENGERS THE FORD CARRIED SEVERAL HUNDRED POUNDS OF AIR MAIL IN
ITS WING COMPARTMENTS.
THE _WHIRLWIND_-POWERED FORD TRANSPORT WAS ONE OF THE MOST SUCCESSFUL
EARLY PASSENGER AND CARGO CARRIERS. ONLY A FEW OF THEM WERE BUILT, AS
HENRY FORD DID NOT WISH TO CONTINUE IN THE AIRPLANE BUSINESS. MANY 1926
FORD TRANSPORTS ARE STILL IN USE IN VARIOUS PARTS OF THE WORLD.]
[Illustration]
Just about the time the Ford tri-motors were proving themselves in tests
an important law was passed by Congress. It was the Kelly Air Commerce
Act of 1925. It authorized the Post Office Department to contract with
private firms to fly the air mail routes maintained by the Department of
Commerce. This law was designed to encourage private capital to enter
the aviation field, with the objective of carrying not only mail but
passengers. In February, 1926, officials of one of the newly formed air
transport firms proudly watched their first big air transport plane take
off from the Detroit airport. The big plane was a Stout-designed,
all-metal Ford, the first of a series of airliners that were destined to
make aviation history.
[Illustration: WATER-COOLED IN-LINE ENGINE]
By the end of 1926, there were sixteen air transport operators holding
air mail contracts. Most of the flying was still done in single-engined
planes. Up to that time the weight of the big water-cooled engines in
multi-engined transports left little to spare for pay loads. It was not
until the development of the radial engine that commercial aviation
really started.
[Illustration: AIR-COOLED RADIAL ENGINE]
The in-line engine required a long, heavy crankshaft with sections for
each cylinder. This required that separate crankshaft bearings be used
for each cylinder. The whole crankshaft assembly was heavy and
cumbersome. When extra cylinders were added, the engine’s weight
increased and it became longer. In the radial engine a single crankshaft
hearing was used.
The radial air-cooled engine immediately showed many advantages over the
in-line, water-cooled engines of that time. The use of aluminum in its
construction made it lighter. It was cooled by allowing air to rush
through finely spaced fins on cylinder heads and barrels. The weight of
the cooling liquid (water) and the pump and mechanism to circulate it
was avoided.
[Illustration:
THE ACTION OF THE CRANKSHAFT IS THE SAME AS WINDING UP THE WELL
ROPE THAT HOISTED THE OLD OAKEN BUCKET. THE CRANKSHAFT’S JOB IS TO
TRANSLATE STRAIGHT-LINE MOTION INTO ROTARY MOTION.
IN THE RADIAL ENGINE, ALL HANDS TRANSMIT THEIR POWER TO ONE MASTER
ROD
IN THE IN-LINE ENGINE THE POWER OF EACH CYLINDER IS TRANSMITTED BY
A SEPARATE CRANK. THIS MAKES THE CRANKSHAFT GROW LONGER WITH EACH
ADDITIONAL CYLINDER.
SHORT, LIGHT, 9-CYLINDER, RADIAL CRANKSHAFT
LONG, HEAVY CRANKSHAFT OF A FOUR-CYLINDER IN-LINE ENGINE
EACH ADDITIONAL CYLINDER NOT ONLY INCREASES THE LENGTH OF THE
CRANKSHAFT, BUT IT ALSO MAKES IT NECESSARY TO CONSTRUCT A HEAVIER
BASE TO SUPPORT THE CYLINDERS, CRANKSHAFT, AND CRANKSHAFT BEARINGS.
THE RADIAL ENGINE, THE POWER OF ALL CYLINDERS IS TRANSLATED INTO
ROTARY MOTION BY RODS CONNECTED TO THE MASTER ROD, WHICH TURNS THE
SHORT CRANKSHAFT.]
[Illustration: LINDBERGH’S RYAN MONOPLANE _SPIRIT OF ST. LOUIS_]
BETTER POWER FOR AMERICA’S AIRPLANES
The Wright Brothers’ first airplane engine had weighed 170 pounds and
had produced 12 horsepower. It had used twenty-five per cent of its
energy propelling itself. With the introduction of the air-cooled,
radial engine twenty years later, a pound and a half of engine had been
made to produce one horsepower. Thus the new 350-pound radial engine of
200 horsepower put all but a fraction of weight into load-carrying
power.
While we are discussing horsepower, it might be well to find out just
what we mean by the term. In connection with steam and gasoline engines
it is used for the reason that the horse had for years been man’s most
common power plant. One horsepower represents the power ascribed to a
heavy dray horse in the days of horse-drawn vehicles. This “standard”
one-horse’s-power includes the three factors, time, weight, and
distance, or the length of time it takes to move a certain weight a
certain distance. One horsepower in these factors amounts to the ability
to lift 33,000 pounds one foot in one minute. Actual brake tests, where
an experimental engine shows its ability to lift a certain number of
pounds so high in one minute, gives the engineer a series of tables to
be used in designing other engines. Each cylinder produces an equal
share of the engine’s total horsepower. Thus each cylinder of the
nine-cylinder, 200-horsepower, Wright radial engine produced slightly
over 22 horsepower, or eight more than the entire four cylinders of the
Wright Brothers’ 1903 engine.
With the introduction of the first practical, light-weight, air-cooled,
radial engine, American aviation underwent a great change for the
better.
The Lawrance-designed Wright J engines promptly began to put a long
succession of famous fliers and famous airplanes in the books for one
record after another. The Stout-designed Ford tri-motor transport plane
was powered with Wright J3 radials. The J3 was adapted for use by the
United States Navy and led the Navy to discontinue entirely its use of
liquid-cooled power plants in favor of air-cooled radial engines for all
its service airplanes. Wright J4 engines powered the flight of Admiral
Richard E. Byrd and Floyd Bennett over the North Pole in 1926. Tony
Fokker, who had designed Germany’s fighters in World War I, began to
make records with his American-built planes powered with Wright radials.
With the arrival of a suitable engine, fliers all over the country began
to think of the Raymond Orteig prize of $25,000 for the first nonstop
flight from New York to Paris. This offer had been standing since 1919.
Admiral Byrd was ready to try for it when a slim, quiet, young air mail
pilot hopped off from Long Island, N. Y. Flying a Ryan monoplane powered
with a Wright J5 radial, this young fellow flew the Atlantic nonstop to
land, some thirty-three hours and thirty-nine minutes later, in Paris
with the quiet announcement, “I am Charles Lindbergh.”
RECORD-MAKING FOKKER TRI-MOTOR TRANSPORT PLANE
The best fighter planes used by the Germans in World War I were not of
German design. They were designed and built under the supervision of a
young man from Holland. Tony Fokker had offered his airplane designs to
his native Holland. They were refused. In turn, Fokker tried to interest
the British, French, and Belgians in his airplanes, but none of them
took him seriously. Just before World War I, the Germans “tied up”
Fokker with a contract that kept him practically their prisoner until
the war was over.
After the Armistice, Fokker fled from Germany with much of his equipment
and established himself in an airplane factory in his homeland. The
United States bought some of his airplanes, and in 1923 he established
an aircraft factory in this country.
In April of the same year, two Army lieutenants, Oakley Kelly and John
Macready, flying a Fokker T-2 powered by a _Liberty_ engine, set a
world’s endurance record by remaining in the air for thirty-six hours.
Later, in the same Fokker, they flew nonstop from Long Island to
California at a speed of nearly one hundred miles an hour. In 1925,
Fokker began building his famous Fokker tri-motor transport plane.
Among the first private firms that were successful in winning an air
mail contract was the Colonial Air Transport, operating between New York
and Boston. This airline was started in 1925 by a young ex-Navy flyer
named Juan Trippe, descendant of an old New England whaling family.
Young Trippe’s airline used a small fleet of Tony Fokker’s tri-motor
transport planes. In December, 1925, Juan Trippe, Tony Fokker, Harry
Bruno, and George Pond, the pilot, climbed into one of the Fokker
tri-motors on what Trippe called a survey flight. The “survey” included
some flying around the Florida coast and climaxed with a record nonstop
flight from Miami, to Havana, Cuba.
[Illustration: 1925-1928
WINGSPAN 70 FEET
LENGTH 40 FEET
THE FOKKER WAS ONE OF THE FIRST MULTI-ENGINED TRANSPORTS AND THE FIRST
TO USE WOOD VENEER FOR WING AND FUSELAGE COVERING.
POWER
THREE 9-CYLINDER 200-HP., RADIAL ENGINES.
ANY TWO OF THE FOKKER’S THREE ENGINES WOULD ENABLE IT TO STAY IN THE
AIR, A STEP FORWARD IN SAFETY.
SPEED
ONE HOUR
100 MILES
EVEN WITH THREE 200-HP. ENGINES, THE BIG FUSELAGE CAUSED A _DRAG_ THAT
HELD ITS CRUISING SPEED DOWN TO 100 MILES PER HOUR.
RANGE
500 MILES
ITS NORMAL RANGE WAS 500 MILES, BUT WITH EXTRA GAS TANKS INSTEAD OF
PAYLOAD IT COVERED RECORD DISTANCES.
CEILING
8,000 FEET
THOUGH CAPABLE OF HIGHER ALTITUDES, ITS MOST PRACTICAL CRUISING ALTITUDE
WAS FROM 2,000 TO 4,000 FEET, DUE TO THE LACK OF A GOOD HEATING SYSTEM.
PAYLOAD
8 PASSENGERS OR
A CARGO LOAD OF
EQUAL WEIGHT.
THE FOKKER TRI-MOTOR WAS DEFINITELY AN ADVANCEMENT IN THE DEVELOPMENT OF
LARGE MULTI-ENGINED TRANSPORT PLANES. THOUGH FAR FROM PERFECT, IT WAS A
GREAT IMPROVEMENT OVER THE SINGLE-ENGINED, OPEN-COCKPIT SHIPS THAT WERE
FIRST USED IN AIR TRANSPORT.]
[Illustration]
The idea behind Juan Trippe’s “survey” flight to Florida and Havana was
to extend Colonial Air Transport’s route from Boston to Florida, then on
southward. His board of directors could not see his point, so Trippe
left Colonial. In a matter of weeks he had rounded up a few ex-war flier
friends with money, and had organized his own airline under the title,
Pan American Airways. Before it was completely set up Trippe had a
contract to fly the mail from Key West, Florida, to Havana, Cuba. That
was in 1928. From that time on, Juan Trippe’s Pan American Airways
continued to move just as fast as it had in its first few weeks of
organization. Less than two years after the first Key West-Havana
flight, Pan American was flying the mail to the Argentine.
[Illustration: STEARMAN AJ-5]
AIR TRANSPORT GROWS
While Tony Fokker was producing his famous tri-motor transports for
budding airlines like Juan Trippe’s Pan American Airways, Admiral Byrd
and three companions had flown a tri-motored Fokker to France. Clarence
Chamberlain and Charles Levine flew a Bellanca radial-powered monoplane
to Germany; Army Lieutenants Maitland and Hegenberger flew 2,400 miles
nonstop from Oakland, California, to Honolulu, Hawaii, in a
radial-powered Fokker; Amelia Earhart and Wilmer Stultz flew a Fokker
from Newfoundland to England. Amelia thus became the first woman to
cross the Atlantic in an airplane. Later she was to fly the Atlantic
alone.
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.
[Illustration: BOEING 40-B4]
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.
[Illustration: BOEING 80-A]
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.
[Illustration: THE BOEING _MONOMAIL_ WEIGHED 4 TONS EMPTY AND CARRIED A
1,750-POUND PAYLOAD. IT HAD A SMOOTH ALUMINIUM COVERING AND THE LANDING
GEAR RETRACTED INTO THE WINGS.]
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.
[Illustration: 1933-1934
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.]
[Illustration]
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.
[Illustration: WILEY POST’S LOCKHEED WINNIE MAE]
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.
[Illustration: WHEN THE GYROSCOPE IS SET SPINNING WITH ITS AXIS POINTED
TO THE CENTER OF THE EARTH IT WILL RESIST ANY FORCE THAT ATTEMPTS TO
CHANGE ITS POSITION.]
[Illustration: THE GYROSCOPE AUTOMATIC PILOT
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.]