By Scott Schwartz
With the end of World War Two, the Lockheed Company
already had an advanced airliner in production in the form of a military
variant, which was used by the Army Air Corps under the designation C-69. Most readers will know this aircraft as the Constellation.
The Lockheed Constellation,
however, was not designed as a military airplane, and in truth, relatively
few C-69’s were produced for the Army.
The aircraft was intended from the outset to be an airliner, and its
origins lay in design studies that were begun in 1938. At the time, the twin-engine Douglas DC-3
reigned supreme in the airline market, which left competing Lockheed aircraft
in the shadows. What’s more, Douglas was
about to unveil its DC-4 (which was eventually referred to as the DC-4E – “E”
for “Experimental”), which was a four-engine aircraft that could carry forty
two passengers. The DC-4E also featured three short vertical stabilizers that
enabled the aircraft to fit into most airline maintenance hangars of the time. Those who are familiar with the DC-4 may be
scratching their heads, at this point.
Three vertical stabilizers? Well,
the DC-4E was not a resounding success, so it was not put into production (the
single-fin derivative was). In fact, the
Japanese bought the DC-4E (the Pearl Harbor attack was still a few years in the
future) and, with a little reverse-engineering, converted the design into the
Nakajima G5N Shinzan bomber. The G5N wasn’t a resounding success, either.
Nevertheless, four-engine airliners were on the
horizon, and Lockheed didn’t want to be left behind. The company began with the design of aircraft
known as the Model 44 Excalibur. The Excalibur
was supposed to be able to carry twenty-one passengers and hit a top speed of
262 mph. Since this was hardly an
improvement over the DC-3, the airlines weren’t interested. Lockheed engineers went back to the drawing
boards and came up with an improved Model 44 that could carry forty passengers
at 300 mph. Further, its pressurization
system allowed it to cruise at 15,000 feet.
Pan American Airways (“Pan Am”) was sufficiently interested in this
incarnation of the Model 44 that it actually entered into contract negotiations
with Lockheed. The negotiations were
under way, when one of the annoying characteristics of the free market
system-competition-slowed things down.
Boeing unveiled its Model 307 Stratoliner
– which was essentially a B-17C with a large, circular, pressurized
fuselage. The Stratoliner’s pressurization system enabled it to cruise at 18,000
feet, albeit at a slower speed than that of the Model 44.
While all of this was going on, the airline TWA’s
long-standing interest in high-altitude, “above-the-weather” passenger
transportation had coalesced into a set of requirements, which it presented to
Lockheed in the summer of 1939. One of
the “presenters” was a major TWA stockholder by the name of Howard Hughes. Hughes and TWA wanted Lockheed to come up
with an aircraft that exceeded the Excalibur’s
design parameters. Specifically, the
new aircraft had to be able to fly non-stop from coast to coast, fly at 250
mph, and to be able to carry six thousand pounds of cargo. And, of course, the cabin had to be
pressurized. By this time, models of the
Excalibur were being tested in wind
tunnels, but Lockheed suspended development of this aircraft. Now, the name Excalibur was used to identify the aircraft being designed to TWA’s
specifications. This new design was
called the Model 49 Excalibur A, with
Kelly Johnson and Hall Hibbard as the chief engineers on the project.
Like the DC-4E, the Model 49 was to be built with three
short vertical stabilizers. Further, the
Model 49 would have hydraulically boosted control services, a wing that was
essentially a scaled-up version of the P-38’s wing, and tricycle landing gear.
What set the Model 49 (later to be known as the Constellation) apart from other
airliners (even modern ones) was the “flattened-S” shape of the fuselage. This was the result of engineer Ward Beman’s
desire to have the air flow along the fuselage in such as way that it did not interfere
with the lift being generated by the wing.
His original design would have required a really long nose wheel strut,
so his final design has the nose of the aircraft tapering downward.
The design process progressed steadily, although
slowly. By late 1939, Lockheed was
marketing the design to the airlines (having received permission to sell the
aircraft to other airlines from TWA). As
a result, TWA and Pan Am bought forty Constellations
each.
With a top speed of 360 mph and the ability to
cruise at twenty thousand feet, the Constellation
was on the cutting edge of airliner development. As mentioned previously, the design process
was a slow one, and war was looming on the horizon.
TO BE CONTINUED…
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