The
Area Rule: Richard Whitcomb Concept
Raul Colon
e-mail:rcolonfrias@yahoo.com
PO Box 29754
Rio Piedras, Puerto Rico 00929
This is the story of a brilliant young engineer who would radically change
the way aircraft were to be designed in the future. A story about a
radical new idea in aircraft development: the Area Rule Concept. More
importantly, this is the story of a man and a concept that combined, would
revolutionise the aircraft designs forever. Richard T. Whitcomb was born
in the small town of Evanston, Illinois on February 21st, 1921. Since
early in his childhood, Whitcomb was influenced by his paternal
grandfather who had known the great American inventor Thomas A. Edison. He
would sit with his grandfather for hours and hear him tell story after
story about the great inventor’s life. Such was the influence of Mr.
Edison in young Whitcomb life that he decided to study mechanical
engineering right after high school. He enrolled at Worcester Polytechnic
Institute. He proceeded to graduate with honours with a degree in the
complex field of mechanical engineering. In the summer of 1943 Whitcomb
was hired to perform data gathering tests on the famous National Advisory
Committee for Aeronautics, Langley Aeronautical Laboratory at Hampton,
Virginia. Young Whitcomb did not know it at the time, but his work at the
prestigious laboratory would eventually lead him to become one of
America’s premier aerodynamic engineers. His innovating designs would
launch a new era in America’s aircraft design.
The late 1940s saw Langley’s wind tunnels used extensively on high speed
research. Test pilot Chuck Yeager broke the sound barrier in 1947 with a
Bell X-I test aircraft, first tested on Langley’s wind tunnel facility.
His accomplishment ushered in the era of supersonic flight, it also pushed
speed as a dominating factor in a combat aircraft’s design. It was at this
time that Whitcomb was assigned to the Laboratory’s secret eight foot
transonic wind tunnel. Within a few years of labouring there, young
Whitcomb developed a reputation as an innovating thinker, a man that
thought “outside the box” when it came to the aircraft’s aerodynamic
characteristics. In the early part of 1950, Whitcomb submerged himself in
drag aerodynamic research. He soon realized that the physics of airflow
changed violently as it expands from subsonic to supersonic speeds. By
late 1950, after extensive research, Whitcomb developed a theory that
directly related to the wing structure design as it related to the
aircraft’s overall drag profile. The wing area, he proclaimed, should be
reduced in an effort to smooth the expanding airflow and mitigate the
formation of shock waves that produced a high drag profile. To better
explain his concept, Whitcomb studied extensively the design of artillery
shells and machine guns bullets. Their smooth distribution, of what is
known as the Cross Sectional Area in order to reduce the drag profile at
supersonic speeds, appealed to him. Whitcomb came away from this
unorthodox study with a clear vision: in order to reduce the drag profile
of an aircraft, the plane needed to maintain a smooth distribution of area
in the proximities of the wing structure, thus reducing the drag profile
of the aircraft. The fuselage structure would have to be reduced
accordingly, thus giving the airframe a “coke bottle” shape. This
breakthrough idea will later be known as the Area Rule Concept.
As
with many new theories, the Area Rule Concept encountered its fair amount
of skepticism in aerodynamics engineering circles. As a result, Whitcomb’s
research began to encounter a barrage of obstacles from colleagues and
upper management, fortunately for him and the US Air Force, Adolph
Busemann stepped in. Busemann, a well respected German aerodynamicist who
was also working at NACA at the time, gave its full support to the newly
presented area rule concept. With this impressive backing, Whitcomb was
once again free to pursue his idea. He carried out a number of wind tunnel
experiments during the fall of 1952 that validated his theory. Indeed,
much of the collected data from these tests showed that the large drag
profile encountered near Mach 1 operational speed was reduced almost 60
percent when the airframe was sufficiently reduced in the neighborhood of
the wing structure. Although impressive as they were, these results were
not immediately embraced by the US aircraft industries. With his research
testing almost stopped by outside interference, Whitcomb again received
unexpected help. This time in the form of Convair’s YF-102 supersonic
fighter. The 102 design aircraft applied a delta wing configuration in an
effort to reduce the plane’s drag profile at supersonic speeds. Initial
testing of the completed sample plane demonstrated that although designed
to fly at speeds above Mach 1, the aircraft simply could not achieve its
intended threshold because the transonic drag profile was too great for
even the powerful Pratt & Whitney J-57 turbojet engine to overcome. It was
at this moment that Whitcomb’s concept raised to prominence. Convair’s
engineers began to research ways to improve the aircraft’s drag profile.
Their research, lead them directly to NACA and Whitcomb. They meet with
Whitcomb and, after careful examination of the area rule concept’s wind
tunnel data, the engineers modified the original 102 airframe with an area
rule fuselage. The new aircraft, YF-102Amade its maiden flight on the
morning of December 20th, 1954. The aircraft out-performed all
expectations. The area rule concept had increased the fighter top speed by
an astonishing 25 percent. The US Air Force was so impressed with new
aircraft speed and characteristics, that they placed an order for 870
102As.
The success of Whitcomb’s concept also meant that it would become
classified material. It remained a classified project until September
1955. Two months later, with his work in the public light, Whitcomb was
awarded the prestigious Collier Trophy.
Skunk Works, Ben R. Rich & Leo Janos; Back Bay Books 1994
Alpha, Bravo, Delta Guide to the U.S. Air Force, Walter J. Boyne; Penguin
Group 2003
U.S. Air Force: A Complete History, Lieutenant Colonel Dick Allan Daso
USAF (Ret); The Air Force Historical Foundation 2006
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