Early Flying Wings (1870 - 1920)
by E.T. Wooldridge
For more than a century, there have been
countless patents, projects, and concepts relating to tailless airplanes.
Many models and prototypes were constructed; most enjoyed only a brief
period of development and public interest, and then quickly disappeared.
From an engineering viewpoint, a high percentage of these short-lived
projects were possibly well founded and deserving of serious consideration
and further development. The lack of adequate financial backing, lack of
government or public interest, and politics often contributed to the
premature end of a worthwhile project. For the most part, these projects
were pursued by independent promoters who made little attempt to
coordinate their investigations. Gradually, however, a large body of
technical data on tailless aircraft was accumulated. Although no organized
data-exchange program appeared to have existed during the 1920s and 1930s,
articles on tailless projects could be read frequently in aviation
journals, both in the United States and abroad. Whether these articles
inspired or assisted the competition is conjectural.
Engineers and enthusiasts who developed versions of the tailless airplane
had very different conceptions of what it should be. Some found their
inspiration in the flight of birds. Surely the earliest example of
tailless flight would be the
Quetzalcoatlus northropi, a giant
flying reptile that roamed the skies over North America some 70 million
years ago. The winged seeds of the maple and the Zanonia plant
served as the basis for designs of experimental models and gliders for
others.
Whatever the source of inspiration, most designers
persevered with their experiments and research despite the lack of
experimental facilities and financial backing. The critical period was
when experiments passed from the model and glider stages to powered
flight. For the reasons previously cited, projects were often terminated
altogether at this stage. In other cases, the problems of stability and
control associated with the absence of the tail and addition of an engine
proved insurmountable, so a conventional tail was added.
The history of tailless aircraft is replete with
frustrated, brilliant men to whom the description "neglected genius" could
have applied. Perhaps none would better qualify than Alphonse Penaud, an
imaginative young Frenchman who, for one brief decade, astounded his
contemporaries with concepts too advanced for his time.
Penaud was born in Paris in 1850, the son of a French
admiral and seemingly bound for a Navy career himself. When a childhood
illness precluded that option, Penaud turned to a brief but brilliant
career in aeronautics, developing many theories concerning airfoils and
the problems of stability and control in flight. He applied his theories
to a succession of creative models of helicopters, ornithopters, and
airplanes powered by rubber-band motors. In 1871, Penaud demonstrated the
possibility of sustained flight by an airplane by flying a rubber-band
powered monoplane a distance of 131 feet. His Planophore had
lateral and longitudinal stability; the tail assembly, located some
distance behind the wings, became known as the "Penaud tail."
In 1876, assisted by mechanic Paul Gauchot, Penaud
synthesized several years of intensive research and experimentation with
aerodynamics, materials, and engines in the design of a revolutionary
airplane. By strict definition, the machine was not tailless, though at
first glance it appeared to be almost a flying wing. But it incorporated
many advanced concepts that were used by engineers and enthusiasts in
flying wing designs for the next 100 years.
The drawings that accompanied Penaud's Patent No.
111574 show a high-wing, twin-tractor, monoplane amphibian with a
retractable four wheel undercarriage. The rudder and elevators were moved
by means of a single control column in a cockpit with a glass canopy. The
engine was buried in elliptical wings covered with varnished silk. The
wings had dihedral, high aspect ratio, reverse camber at the trailing
edge, washout, taper, and bent-up wing tips. Although the wings were
braced by upper and lower stays, the inventor planned to eliminate these
wires eventually, which would result in a cantilever construction.
Elevators were balanced by counterweights or springs.
Some of the unusual features of the radical 1876 design
of Alphonse Penaud and Paul Gauchot (above) are apparent in this 1940s
model (right) by Paul K. Guillow. The two castoring nose wheels and two
main wheels were fully retractable, folding backward and upward. The
Penaud wing was equipped with horizontal brake rudders at the wing tips
Since the airplane was an amphibian, the nacelle was
watertight, with portholes in the cabin for passengers. Propellers were
entirely metal and had variable pitch; they were connected by crankshafts
to the engine in the wings, where the flight crew could have direct access
for repairs. The list of innovations even extended to aircraft
instruments, including angle-of-attack indicators, airspeed indicators,
and aneroid altimeters.
Whether the airplane was capable of flight or not,
given the fact that contemporary power plants were inadequate, is
obviously pure conjecture. Penaud was unable to raise the necessary funds
to continue his research, and his radical concepts were met with
scepticism and ridicule by officials and fellow aeronautical enthusiasts.
Discouraged and depressed, Alphonse Penaud committed suicide in October
1880, at the age of 30, leaving many of his ideas to be "rediscovered"
years later.
Clement Ader
Ten years after Penaud's tragic death, another Frenchman, Clement Ader,
established his niche in aviation history. Ader succeeded in taking off in
an aircraft of his own design under its own power on October 9, 1890, at
Armainvilliers, France. The aircraft, named Eole, was once
described as "a chaos of mechanisms."' Penaud's practical genius, combined
with just a small amount of Ader's imagination, probably would have
produced a practical contribution to aeronautical science. Unfortunately,
in the Eole, and his only other completed machine, the Avion
III, Ader allowed his imagination to run rampant.
The Eole was described as a single engine
(steam) tractor monoplane, with a four-bladed bamboo propeller made in the
form of bird feathers. The wings were bat-like, with extreme canopied
curvature. There were no elevator, no rudder, and no conventional flight
controls. Each wing could be swung forward and aft separately by a
hand-operated crank, thus changing the position of the centre of pressure
and consequently the pitch of the airplane. Wings could be flexed up and
down by foot pedal; wing area and camber could also be changed by crank
action. In all, six hand-operated cranks, two foot pedals, and engine
controls had to be operated by the pilot in flight!
Despite the Herculean efforts that must have been
required to become airborne and remain in that state for any period of
time, Ader did accomplish his takeoff; the subsequent flight of about 165
feet was not considered controlled or sustained, however. Encouraged by
his craft's performance, and subsidized by the French government, Ader
started but never completed a second machine.
A third aircraft was completed in 1897, the Avion
III. It was generally similar in concept and appearance to Eole,
but significant changes had been effected. The airplane now had two
engines; wing structure had been simplified, as had the swing-wing
arrangement, although the latter remained a dangerous and virtually
unworkable system. Ader would have been well advised to study the Penaud
tail, details of which had been published in contemporary aeronautical
journals. The only additional flight control was a small rudder connected
to the tail wheel, and operated by pedals. A mechanism was also provided
to effect differential speed of the two propellers, giving some additional
control in yaw.
Two tests of the Avion III were conducted on a
circular track. These trials were witnessed by the proper officials, who
prepared a written report stating that the Avion III did not fly.
The report was kept secret until 1910, at which time it was made public.
In the interim, however, in the absence of official statements to the
contrary, Ader claimed to have flown a distance of 300 meters at the 1897
trials. The publication of the official report in 1910 did little to
settle a controversy that has persisted to the present day.
Avion III marked the end of Ader's practical work
in aeronautics, although he did considerable research on the principle of
the air-cushion hydrofoil, applying for a British patent on such a machine
in 1904.
The credit for designing and flying the first tailless
aircraft in Europe goes to the distinguished Danish inventor, Jacob
Christian Ellehammer. Born in 1871, Ellehammer experimented during his
youth with large kites capable of lifting heavy loads. As a young man, he
developed an interest in electricity during his early days as an
apprentice, journeyman, and later employee in an electro-mechanical shop.
He became a tinkerer, experimenter, and soon, a serious inventor with an
extraordinary understanding of mechanical devices.
Clement Ader's controversial 1897 Avion III is still preserved in the
Musee du Conservatoire des Arts et MEtiers in Paris. Two steam engines,
generating 20 hp each, drove two, four-bladed, bamboo propellers
resembling eight gigantic quill pens.
Perched precariously in the pendulum-like seat of his
homebuilt flying machine, Jacob Christian Ellehammer became the first
flying Dane. This photograph was taken by Ellehammer's cousin, Lars, as
the aircraft skimmed over a circular, concrete runway a distance of 140
feet
It was quite logical that Ellehammer's attention would eventually turn
to the design and construction of a practical reciprocating engine. At the
turn of the century he produced a successful motor scooter and built his
first airplane engine in 1904. It was a three-cylinder, air-cooled radial
engine of 9 hp, the forerunner of the same type of engine that was to
become so popular in the 1930s and beyond.
In 1906, after unsuccessful attempts to fly with his
own underpowered monoplane, Ellehammer paired an 18 hp engine with a
tailless biplane, both of his own design. The craft appeared as two
enormous kites, one mounted above the other, with pilot, engine, and a
reverse tricycle landing gear suspended underneath. The lower wing was
fixed, with a movable elevator attached to the trailing edge center
section. The upper wing was a smaller, non-rigid wing, much like a sail to
be held in shape by the slipstream of the tractor propeller. The elevator
was connected by wire to the pilot's seat at the forward part of the
airplane. The seat was hinged, so that the pendulum action resulting from
the pilot's movement forward and aft caused a corresponding vertical
movement of the elevator. There was no vertical fin and no rudder, but
some directional stability and control may have been afforded by the large
steerable tail wheel.
Assisted by his brother Vilhelm and cousin Lars,
Christian set up facilities on the small, barren Danish island of Lindholm
in 1905 to test the monoplane and then the biplane. After many changes in
configuration, and tethered, unmanned flights around a circular track,
Ellehammer confounded the skeptics on September 12,1906, when he
personally flew the airplane a distance of 140 feet at an altitude of
about one and a half feet.
Many people gave Ellehammer credit for the first flight
ever made in Europe, discounting the officially recognized flight of the
Brazilian Alberto Santos-Dumont, near Paris, France, on November 12 of
that same year. The latter flight, however, was officially sanctioned by
the Federation Aeronautique Internationale; a diary entry by Lars
Ellehammer duly noting the particulars of Christian's flight was not
considered sufficient evidence of the historic event. Detractors of
Ellehammer's accomplishment also criticized his use of a circular runway
with a pole at its centre, to which the aircraft was tethered by a fine
wire. The eminent aviation historian, Charles H. Gibbs-Smith, commented:
Tentative as Santos' flights were, Ellehammer-in his
second machine-did not even achieve the free flight which his admirers
have so often claimed for him ... the pilot was only a passive passenger,
the machine having a fixed rudder and automatic (pendulum) longitudinal
control, to say nothing of the advantage of centrifugal control. If
Ellehammer had concentrated on his excellent engines, he might have
played a major role in history.'
Notwithstanding Gibbs-Smith's rather brusque dismissal
of Ellehammer's flight, the importance of the event should be recognized.
The marvel is not that Ellehammer flew before or after anyone else of that
era; it is that he and others like him ever flew at all.
Ellehammer continued his aeronautical experiments for a number of
years, developing an improved biplane, which became the first
heavier-than-air craft to fly in Germany, in 1908. He later experimented
with a flying boat, a wheeled monoplane that flew repeatedly in 1909, and
a successful helicopter that was completed in 1912-the last of his
aeronautical developments. He eventually took out more than 400 patents on
a variety of electromechanical devices.
Early aviation pioneers studied the flight
characteristics of every conceivable type of flying animal-birds, insects,
bats, flying fish, even flying foxes. Elsewhere in nature, flying seeds
also provided the inspiration for serious investigations into the theory
of flight; one of these was the Zanonia macrocarpa seed. This
kidney-shaped seed came from a vine native to Java, and was a member of
the family that included such familiar plants as ground watermelon,
cucumber, and cantaloupe. The Zanonia seed could perform amazingly
long glides, during which it demonstrated basic inherent stability. The
seed was flat and about six inches long, with a central seed kernel
surrounded by light, tough tissue stiffened by fibers. A number of the
early experimenters with tailless aircraft were inspired by the
Zanonia's flying qualities. Igo Etrich adapted the principles he
gleaned from his observation of the Znnofzia seed to the hard
realities of powered, sustained flight in heavier-than-air machines.
Igo and his father, Ignaz Etrich, became aware of the
qualities of this seed through the theoretical papers of German naturalist
Dr. Frederick Ahlborn, published at the turn of the century. The Etriches
were amateur flyers and industrialists from Bohemia (now Czechoslovakia).
The younger Etrich had begun his practical investigations of unpowered
flight with the purchase of a Lilienthal glider in 1898. Igo Etrich soon
became a serious student of aeronautics, and, with the advice and
assistance of Dr. Ahlborn and in collaboration with Austrian aviation
enthusiast Franz Wels, built a tailless glider in the shape of the
Zanonia seed in 1904. An unwieldy contraption of bamboo, canvas, and
wire, the craft still had a graceful quality about it that eventually
justified Igo Etrich's faith in the Zanonia concept.
By 1906, practice glides with sandbags for passengers
had been successfully conducted, and the first Etrich-Wels manned glider
was ready for test flights. Several sandbag flights were conducted with
the glider being launched from a trolley after a run down an inclined
track. After the successful unmanned flights, one of which continued for
over 900 feet, pilot Fran-r Wels flew the glider on its first
manned flight in October 1906. Because of the craft's unique Zanonia
design, this was perhaps the first successful flight of an inherently
stable, manned aircraft.
Impressed with his glider's performance, Igo Etrich
decided to add power. In 1907, a small 24-hp engine with pusher propeller
was added to the 1906 Etrich-Wels glider, now heavily modified with a
rectangular stabilizing surface in front, cutaway wing to provide
visibility for a seated pilot, and provisions for wing warping for roll
control. The airplane would not fly because it was underpowered.
A tractor version followed in 1908, using the same
24-hp engine without the horizontal stabilizer. Called Etrich I, this
machine too was a failure, due to directional instability. After
dissolution of the Etrich-Wels partnership because of differences of
opinion on aircraft design, Etrich further modified the 1907 Etrich I,
installing a 40-hp engine. Finally, on November 29, 1909, Etrich flew his
first sustained powered flight.
Zanonia seed
At this juncture in his early career as an aircraft
designer, Igo Etrich made a radical departure from the design path that he
had pursued thus far. It became obvious to Etrich that simply adding a
power plant to the Zanonia wing was not the solution to his
problems. In fact, the problems that resulted from this mismatch
necessitated severe modifications to his basic design. Again, Etrich
turned to nature for the solution. To the wing of the Zanonia seed
he added the tail of a bird. The aircraft that evolved was the Tai be
(dove), a class of aircraft that was produced in a bewildering number
of versions for both civil and military use. Between 1910 and 1914, 54
manufacturers produced over 500 of these aircraft, including 137 different
configurations. All were easily recognized by their distinctive Zanonia-shaped
wings and dove-like tail, and all possessed the inherent stability
that had originally attracted Etrich to the Zanonia design. The
Taube was so stable that it could literally fly itself.'
The Taube marked the end of Igo Etrich's
experimentations with tailless aircraft. Etrich's aviation activities
continued in the post-World War I years, although he eventually turned his
considerable talents as an inventor to other industrial fields,
particularly textiles. Although Etrich's involvement with tailless craft
was relatively short, he proved the effectiveness of the stable
characteristics of the Zanonia seed, and he must rank with his
contemporaries, Jose Weiss and J.W. Dunne of England, as a serious
investigator of stability problems.
These problems were also being investigated on the
other side of the English Channel; for Jose Weiss, however, the soaring
flight of birds provided the inspiration. A Frenchman by birth, but a
long-time resident of Great Britain, Weiss was a keen student of birds
since childhood, and for years had speculated on their remarkable ability
to soar on seemingly motionless wings. Weiss devoted much of his time to
studies of the theory of flight. Between 1902 and 1907 he designed,
constructed, and flew hundreds of models, gradually developing his own
theory of inherent stability based on bird forms.
Finally satisfied that his theories were fundamentally
sound, A\kiss constructed his first full-sized, man-carrying glider in
1909. Weiss's answer to the problem of inherent stability was in the
curvature of the wings, which were thick at the roots but tapered outward
until the tips were flexible. Positive incidence at the fuselage decreased
gradually along the span until negative incidence, or washout, was
produced at the tips, and the trailing edge was turned upward. Hinged
elevators extended along part of the trailing edge. Christened Olive
after one of Weiss's five daughters the tailless craft was flown quite
successfully by test pilot Gordon England. Subsequent attempt to fly the
aircraft with power, however, were unsuccessful.
Later in the same year, Weiss built a powered,
single-seat tailless monoplane (Madge) on the same general lines as
his 1909 glider. Powered only b\ - a 12-hp Anzani engine driving two
pusher propellers through chains, the frail cloth-covered bamboo craft was
incapable of flight.
Elsie, Weiss's first tractor monoplane, still
tailless, appeared in 1910, but apparently enjoyed little success. A
second monoplane, Sylvia, was also tested in 1910, but by now Weiss
had abandoned the tailless configuration. The airplane was fitted with a
Penaud tail, but still retained the distinctive curved, twisted wings
designed by Weiss. The craft had a few successful flights, but a
structural failure in flight resulted in a crash in late 1910.
One of the hundreds of
models and gliders designed and constructed by Jose Weiss between 1902 and
1907. Although this model had some semblance of 'a tail, many o f Weiss's
successful flights were made with tailless gliders.
Although Weiss's attempts at powered flight did not
meet with notable success, his theories on wing design for inherent
stability were recognised and respected in aviation circles of the day. In
describing Jose Weiss's contributions to aeronautical lore, one aviation
historian compared his universal genius to that of Leonardo da Vinci.
'In this type the mind and the eye of the artist are conjoined with
the scientific mind. They think with the eye and the soul as well as with
the brain. Such men have the joy of great vision, of peering into the
mysteries; but often others, inspired by them, accomplish the practical
work '
John William Dunne was a soldier, author, pilot, and
designer. This thoughtful Englishman was totally dedicated to the
principle of inherent stability. Inspired by a Jules Verne story at the
age of 13, Dunne dreamed of a flying machine that needed no steering, that
would right itself regardless of wind or weather. Like Igo Etrich of
France, Dunne had studied the Zanortia seed, and was well aware of
its amazing flying qualities. Like his countryman Jose Weiss, he had
closely observed birds in flight. But both of those early pioneers had
encountered problems when they attempted to add an engine to their
successful tailless gliders. Dunne persisted, and produced a design which,
though controversial, was the first successful tailless aircraft with
swept back wings.
Dunne became seriously involved in the problems of
flight in 1901, as an army lieutenant home on sick-leave from the Boer
War. He began to plan, sketch, and make models, and he was encouraged in
these endeavours by the science fiction writer H.G. Wells, who urged Dunne
to concentrate on the problems of control and balance. Dunne's
model-building efforts were temporarily interrupted by another tour to
South Africa, from which he returned in 1903, now suffering from heart
disease that would force his early retirement from aeronautical activities
10 years later.
Despite poor health, however, John Dunne resumed his
aeronautical investigations, and by 1904 was ready to progress from the
model phase to experiments with gliders and later, powered aircraft. Dunne
sought an experienced engineer to assist him in the difficult job of
putting theory into practice. His problem was solved when he was assigned
in 1905 to the Army Balloon Factory at South Farnborough, England, then
under the able leadership of Colonel John Capper. With Capper's guidance
and support, Dunne began the design and construction of the the first
British military airplane.
Months of tests with model gliders were followed in the
spring of 1907 by the first passenger-carrying glider. It was the first of
many craft with the distinctive V-shaped wing designed by Dunne,
frequently described as an arrowhead minus a shaft.
Construction and flight testing of the first Dunne
aircraft, the D.1-A, were conducted under great secrecy. The flimsy craft
was shipped by rail in July 1907, to the village of Blair Atholl in the
Scottish Highlands. In the hills north of the village, the D.1-A flew one
successful eight-second flight, with Colonel Capper along for the ride.
Although Colonel Capper was slightly injured in the crash that terminated
the flight, the experimental glider had demonstrated the stability Dunne
considered so essential.
Dunne's design experiments during 1907 and 1908 can be
summarized as follows: the D.1-A glider, built in 1907, had limited
success in its one flight; the D.1-B powered airplane (modified D.1-A),
also of 1907, crashed in its first flight; the D.2 training glider,
designed in 1907, was not constructed; the Dunne-Huntington powered
triplane, designed in 1907-1908, was flown successfully in 1911; the D.3
man-carrying glider was flown successfully in 1908; the D.4 powered
airplane, flown in 1908, had partial success (in Dunne's words, "more a
hopper than a flyer").
By 1908, the British Army Council could no longer
tolerate the limited potential demonstrated by Dunne's machines. Dunne
left the Balloon Factory, and friends formed a small company, the Blair
Atholl Aeroplane Syndicate, to finance his experiments. By 1910, a new
aircraft was ready to be tested. The Dunne D.5 was a vast improvement over
previous designs and one that would bring international acclaim to its
designer.
Like previous models, the D.5 was a tailless biplane,
with sharply swept back wings. A boat-like nacelle housed the pilot, with
additional room for a passenger. An engine located at the rear of the
nacelle drove two pusher propellers. The keys to the inherent stability
demonstrated by the D.5, and the rest of Dunne's designs, were the twist
and the camber designed into his swept wings. The angle of incidence
changed gradually from root to tip so that the angle at the tip was less
than that at the root. The camber (curvature of the top surface of the
wing) also varied, so that near the wing root there was little curvature,
while at the tips the wings were curved for the greater part of the chord.
The British aviation historian Percy B. Walker, in his accounts of early
aviation at the Royal Aircraft Establishment, Farnborough, explained
Dunne's unusual swept wing design.
For stability in pitch, which is the primary
consideration, the same basic principles apply to the Dunne design as for
the more usual tailplane at the rear end of a fuselage. Although the
Dunne aeroplane is rightly regarded as tailless in the ordinary sense,
there are in effect two tails, corresponding to the wing tips on either
side. The essential characteristic of the wings in these tip regions is
the presence of washout or reduction in the angle of incidence relative
to the main portions inboard. Thus when an aeroplane of this design is
flying steadily on a level course there is only a small vertical force
acting on the outer portion of each wing, and this small force is
usually, and preferably, acting downwards. The combination of reduced or
slightly negative incidence at the tips, and the backward inclination of
the wings as a whole, ensures stability in pitch and acts as a substitute
for the tailplane of the more conventional types.
On December 20, 1910, John Dunne, in the role of test
pilot, demonstrated the extraordinary stability of the D.5 to an amazed
audience that included Orville Wright. Taking off from Eastchurch, the
site of many previous successful flights in the D.5, Dunne proved that an
airplane could be flown for an extended period of time without handling
any controls. Using both hands, Dunne scribbled a note on a flimsy piece
of paper as he motored over the countryside, narrowly missing a windmill,
and, despite a momentary failure to recognize the ground below, executing
a successful landing for the appreciative audience.
Dunne continued his design efforts for another three
years, until ill health finally forced his retirement from a life of total
devotion to his stability experiments. Beginning with the 1911 D.6
monoplane, Dunne's designs progressed in sequence through the D.10. He
reverted to the biplane format for the D.8 and D.10, and probably enjoyed
the most publicity and some limited commercial success with the D.8.
Following a successful D.8 cross-Channel flight and demonstration tour in
France, the Nieuport Company ordered a biplane, and W. Starling Burgess of
the United States was given the manufacturing rights in that country.
Burgess produced a number of successful land and seaplane variations of
the Dunne machines, continuing to demonstrate the remarkable stability of
the original aircraft.
Although two aircraft were ordered by the Royal Flying
Corps, it was becoming increasingly obvious to those concerned with
designing, building, and testing military aircraft that the inherent
stability so coveted by Dunne was incompatible with the handling
characteristics desired by military pilots. Manoeuvrability, ease of
handling, and superior performance determined an airplane's acceptability
by the military. Dunne's craft were relatively inefficient compared to
conventional aircraft of equal horsepower; excessive stability did not
result in ease of control and manoeuvrability. A reasonable compromise
between control and stability was required.
The 1910 Dunne D.6 monoplane was quite different from his well-known
tailless biplanes. The monoplane's wing was set high in parasol fashion.
The wing tips had pronounced washout, and the final few feet curved
sharply downward outboard of the centre of the ailerons to provide side
area in the absence of fins or rudders.
Assessing John Dunne's impact on aeronautical history
is difficult. Many of his theories on stability are valid and many
designers have benefited from his far-sighted experiments. England's G.T.R.
Hill and America's John K. Northrop, two of the more renowned
investigators of tailless aircraft, often referred to Dunne when
discussing the basic problems of stability and control. He was a true
pioneer-the first to create a practical tailless airplane.
The Dunne D.8 of 1911-1912 was representative of the
tailless pusher biplanes that Lieutenant J.W.Dunne designed as inherently
stable aircraft.
Dunne's tailless aircraft were successful because of
his brilliant use of aerodynamic innovation in wing design. A totally
different approach was taken in France by Rene Arnoux, who produced a
series of tailless designs from 1909 to 1923 that included
monoplanes, biplanes, pushers, tractors, low-wing, and mid-wing
arrangements. A typical Arnoux wing resembled a straight board with no
sweepback, dihedral, wing tip droop, or the like-a wing so simple it was
called the Arnoux "flying plank."
The Stablavion monoplane of Rene Arnoux is shown on display
at the Paris Aero Salon in October 1912. The secret of the success of the
Arnoux "flving plank" aircraft was the upturned trailing edge of the wing,
called reflex camber, which prevented instability caused by excessive aft
travel of' the centre of pressure
Arnoux first applied his "no frills" approach to a
tailless biplane in 1909, a design about which little has been
written. Two monoplanes followed in 1912, one of which, named Le
Stablavion, was placed on display at the Paris Aero Salon in October
1912. This two-seater pusher model attracted the attention of
visiting technical experts, and at least one aviation writer, Alexander
Dumas, gave the airplane extensive coverage in the well-known aviation
journal L'Aerophi1e. The aircraft had not been flown
before the exposition but was scheduled to begin tests in the near future.
Arnoux's experiments were interrupted by World War I. He resumed his
investigations after the war, however, and his attempts to adapt the
"flying plank" to racing aircraft in the 1920s will be discussed
later.
Professor Hugo Junkers of Germany was frequently
mentioned in aeronautical journals in connection with the evolution of the
so-called all-wing airplane. Much of the publicity stems from a famous
1910 Junkers patent for an airplane with a thick, hollow wing in which
non-lift-producing components such as engines, crew, and passengers could
be housed. Junkers's preoccupation with this "thick wing" concept was
evident in many of his aircraft designs that evolved over the next 30
years. The idea was even applied to a World War II design for a large
military transport glider, the Ju Mammut (mammoth). This huge
wooden aircraft, with a wingspan of 203 feet, carried most of its
payload inside the wing. Although it flew successfully, it was not
produced in quantity. Other than in some conceptual designs, such as his
1924 J 1000 giant airplane, or occasional wooden tailless models,
there is little physical evidence that Junkers's ideas extended to the
elimination of the tail section. Junkers applied his "all-wing" concepts
only to the extent that they were economically feasible.
Hugo Junkers's 1924 design for a giant airplane closely approximated a
true flying wing in concept. The wing was lo accommodate 26 cabins for 100
passengers, carry a crew of 10, and have enough fuel for 10 hours of
flight.
Although Junkers never received the necessary support
to develop his ideal airplane, he did provide the aeronautical community
with the perception that parasite drag could be substantially reduced by
placing most components and loads inside a thick cantilever wing.
When the prototype G 38a D-2000 made its maiden flight on November 6,
1929, it was billed as the largest landplane in the world, featuring a
mammoth wing with a chord of almost 33 feet and 6 feet thick at the root.
Although by no means a true flying wing, it incorporated some of the
desirable characteristics of such a design by locating the payload
compartments and engines in an unbraced cantilever wing.
Before World War I the majority of design work on
tailless aircraft took place in Europe. There were, however, two series of
designs by Americans during those early years that deserve mention-one a
modest commercial success based on John Dunne's developments in England,
the other a "home-grown" product developed by three brothers from New
Jersey with nothing to build on but intuition, common sense, and natural
ability.
Operating his own boat yard at Marblehead,
Massachusetts, prepared W. Starling Burgess for an equally successful
career as aircraft builder. In an age when aircraft construction
techniques and materials were rudimentary at best, Burgess found the high
standards of workmanship and construction that helped him build fast
racing yachts were in high demand by sportsmen and military aviators
alike. By the time he acquired the license to build and continue to
develop Dunne-style aircraft in 1913, he had become involved in the design
and construction of aircraft for four years, primarily in partnership with
his close friend Greely S. Curtis (not related to Glenn H. Curtiss). They
built Wright airplanes under license for sport and for the U.S. Army
Signal Corps. Flying schools were operated by the Burgess Company and
Curtis, as the organization was named, and Burgess himself gradually
became a pilot of considerable skill. By 1913, Burgess and Curtis had had
considerable success developing seaplanes for both civil and military use.
They also had become disenchanted with their arrangement with the Wright
brothers, and consequently dissolved their firm and reorganized as the
Burgess Company in early 1914.
Burgess had also acquired the exclusive American
manufacturing rights for the Dunne aircraft in 1913. He refined the Dunne
design, simplifying construction, cutting weight, and increasing engine
horsepower. Not surprisingly for a yachtsman turned flyer, Burgess
immediately undertook the task of modifying the Dunne design for
operations hardly envisioned by the English designer. During 1914, Burgess
and Curtis produced the first Burgess Dunne Hydro, equipped with a single
float underneath the centre nacelle and a small pontoon under each wing
tip. Test pilot Clifford L. Webster flew a successful first flight from
Marblehead Harbour, Massachusetts, in March 1914. Subsequent flight tests
and demonstrations elicited ecstatic reviews in the press and considerable
interest by the U.S. Army and Navy, and later, by several wealthy
sportsmen.
Despite favourable publicity accorded the Burgess-Dunne
types, the fact of the matter is that virtually only a handful of the
models were ever bought. The Army's only Burgess-Dunne, S.C. No. 36, was
accepted in December 1914. Capable of operation from land or, with minor
modification, from water, the airplane was used mostly for experimental
work with the Coast Artillery rather than in its intended role as tactical
reconnaissance scout. It was condemned on October 18, 1916, ending a
rather brief and unglamorous service life.
The Navy acquired two Burgess-Dunnes, the AH-7 and
AH-70. Both were hydroplanes. The AH-7 was an open, side-by-side cockpit
craft that was distinguished not only by its unusual Dunne design but by a
beautiful camouflage of lavender and green. In its sister ship, the AH-10,
which had a 100-hp Curtiss engine, Lieutenant Patrick Bellinger
established a new American altitude record for seaplanes by flying to
10,000 feet on April 23,1915. Three similar aircraft were ordered by the
Navy, and designated A-54, A-55, and A-56, but these aircraft never went
into active service.
Burgess enjoyed some success in the civil aviation
market, receiving considerable publicity with sales of hydroplanes to
financiers Vincent Astor and Harold Payne Whitney. The enterprising
Burgess also included a floating hangar of his own design in his aviation
package for the millionaire flyer interested in "water plane sports." The
media had a field day with the whole idea:
"It does not confine the activity of the machine to
one particular locality, but enables moves to be made to suit the desires
of the owner. If he so wishes, the summer months may be spent in the
North, either on the Atlantic Coast or on one of the many inland lakes,
whilst when winter makes climactic conditions uncomfortable for flying,
the machine and its hangar may be sent down to the smiling Florida
waters. What infinite possibilities for the future of the sport of
aviation are here foreshadowed! "
There were other orders for the Dunne derivative: a
warplane for Canada was delivered but then abandoned after it was damaged
in shipment; and allegedly, a military aircraft for Russia. The Burgess
catalogue listed an attractive flying boat with a Curtiss hull, designed
"primarily for sportsmen who do not wish to lose the sensations of the
speed boat." There was a BD Sportsman's Seaplane, as well as a Model BDH
Reconnaissance Type which, because of its inherent stability, enabled the
pilot "to fly long distances without fatigue and make observations at his
leisure." Prototypes for all of these were built, but the market was
limited.
In 1913, W. Starling Burgess secured American patent rights to build
aircraft in the United States under the Dunne patents covering inherent
stability. The U.S. Army's BurgessDunne S.C. No. 36 shown here was
delivered in 1914 and was one of a number of Dunne
aircraft produced front 1914 to 1917. The airplane was initially equipped
with a single square, flat-bottomed pontoon that was alternated with
conventional landing gear during test flights.
Perhaps the high point of Starling Burgess's romance
with the Dunne design was his winning of the 1915 Collier Trophy for
development of the Burgess-Dunne hydro-aeroplane. With the outbreak of
World War I, however, the market for purely civilian aircraft disappeared,
and there was no military requirement for the Dunne machine."
Starling Burgess accepted a commission in the U.S. Navy
in 1917, and in the process severed all ties with the company that bore
his name. The Burgess Company continued to produce conventional trainers,
flying boat hulls, and airship cars for the Navy during the war, but a
disastrous fire on November 7, 1918, destroyed one Burgess plant. The
fire, and the end of the war a few days later, spelled the end of the
Burgess Company. Burgess returned to the boat business, in which he worked
with considerable success until his death in 1947.
Shortly before Burgess shifted his interest from boats
to airplanes, the Boland brothers of Rahway, New Jersey, began their
investigations into tailless designs in a manner which, on the surface,
appeared to be something less than scientific. In 1904, Frank and Joseph,
the more mechanically inclined of the three brothers, established a
service garage for bicycles, motorcycles, and automobiles in Rahway, with
brother James running the business and taking care of the finances. In
1907, Frank tried unsuccessfully to build his own airplane without
drawings, knowledge, or advice.
In 1908, Frank was joined by his brothers, with Joseph
applying his considerable talent to designing and building a suitable
eight-cylinder water-cooled engine for their next venture. A series of
designs for tailless aircraft evolved in a process which one aviation
writer of the day described as "flying, smashing, altering, with the one
object in view of proving that rudders as generally used are unnecessary,
that ailerons and warping wings are only two methods of keeping right side
up." Frank Boland acted as test pilot and, through trial and error,
ingenuity, and no little courage, finally did prove to the aviation world
that the fledgling Boland Airplane and Motor Company could produce
aircraft that could fly.
The key to the Boland airplane's ease of handling and
manoeuvrability was a patented system of lateral control long known to
sailors, called a jib. Rudders, ailerons, and wing warping were not part
of this design. Lateral control was provided by elliptically shaped
surfaces, or jibs, mounted between the outer ends of the top and bottom
wings. Each jib was pivoted on an oblique axis from the lower front strut
to the upper rear strut and was movable inward, in one direction only. The
operation was similar to steering an automobile: a control wheel was
turned in the desired direction, the jib on that side was pulled in, and
the aircraft banked and turned. Control in elevation was provided by a
curved control surface located 14 feet in front of the wings. Moving the
control column forward caused the craft to go downward, and vice versa.
As the Bolands continued to test and improve their
designs, word of their success spread. Orders for aircraft and engines
began to arrive, as did the curiosity seekers and the serious
investigators. In 1911, Wilbur Wright paid a visit to the Rahway shop to
determine if the jib control infringed on Wright patents. It did not, and
apparently Wilbur Wright praised the Bolands for their original work.
After two years of experimenting, the Boland brothers produced this
tailless biplane, which flew quite successfully in 1910. Jibs used for
turning the airplane can be seen at the wing tips. Since the pilot's
feet were not used for any purpose during flight, they were inserted in
"stirrups" on the outrigger, so that the pilot sat with knees high, like
the driver of a racing automobile.
Frank Boland was killed in 1913 during an exhibition
flight in Trinidad, a crushing blow to the Boland Company. Joseph took
over control of the venture, concentrating on development and
manufacturing, while using other available talent for test flights and
demonstrations. A tailless flying boat appeared in 1913, and in 1914 the
newly formed Aeromarine Plane and Motor Company of Avondale, New Jersey,
took over the exclusive manufacturing rights of Boland airplanes and
engines. Joseph and James remained with the new organization for a time,
Joseph continuing to work on engine and airplane developments.
Unfortunately, little more was heard of the Boland tailless airplane and
its unique jib control.
An improved version of the 1910 Boland /1e-v at the Mineola fair grounds
in 1914. A fabric-covered nacelle was added to protect pilot and
passenger. An 8-cvlinder, 60-hp Boland engine powered the biplane, which
was made in both land- and seaplane versions.
The Boland brothers were a relatively small, but
extraordinary, part of early aviation history in the United States. Frank
supplied the enthusiasm, ingenuity, and self-taught flying ability; Joseph
provided the mechanical genius to transform ideas into some tangible,
workable form; and James had the business sense so often lacking in
ventures of that sort. Unfortunately, with Frank Boland's death, many of
the ingredients necessary for success went with him.
With World War I came a temporary hiatus in the
experimentation with tailless aircraft as nations turned to the more
practical business of adapting the airplane to full scale warfare for the
first time. In the decades that followed, however, the impetus provided by
the tremendous growth in military aviation and associated technology
contributed to a resurgence of interest in the tailless airplane,
initially in Europe, then in the United States.
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