Flight of the Spruce Goose

Published on November 2, 2012

The giant flying boat is the largest ever built.  On November 2, 1947, it taxied out into Long Beach Harbor.  Inside were 32 people, including the pilot and crew.  There were eight engines to run up.  Verifying performance was important.  Conditions on the water were perfect.  The plane was lightly fueled and far under its maximum gross weight.  Yet there were many who thought it would never fly — it was just another example of a government-funded project that was over budget, late on delivery and unable to perform.  Yet this wasn’t just any project, it was Howard Hughes’ baby — the Hughes H-4 Hercules, more commonly known as the Spruce Goose.  With all of the checks completed, Hughes advanced the power on all eight engines.  The great ship of the air began to accelerate over the waves.


Howard Hughes in the cockpit of the Spruce Goose, wearing his trademark hat.

The Origin of the Spruce Goose

At the height of the war in the Atlantic, U-Boats were strangling England of supplies.  It was extraordinarily challenging to move troops and equipment to England to help with the build-up.  Thus, in 1942, a developmental contract was awarded to Hughes Aircraft and the shipbuilder Henry Kaiser to develop an aerial supply ship that could move one M4 Sherman Tank or as many as 750 soldiers in a single flight with all their equipment.  It was the dream of strategists to be able to rapidly deploy entire divisions of ground troops in a single day — or maybe two — anywhere in the world.  A fleet of H-4 Hercules aircraft seemed to be just the right formula.

The size of the plane to meet that requirement was extraordinary.  Designers laid out a plan for a plane with a wingspan that was the greatest ever designed (it has yet to be surpassed, in fact), measuring in at 320 feet.  To put this in perspective, the wingspan equated to ten Bell P-39 Airacobras, lined up wingtip to wingtip.  The aircraft’s rudder alone was bigger than the wing of DC-3.  Eight Pratt & Whitney R-4360 Wasp Major radial engines, each boasting 4,000 hp, lined the front of the wing.  Put simply, it was a monster-sized aircraft.  Yet despite all this, the plane was built largely of birch wood.  Due to restrictions on the use of metals, the H-4 was entirely made of wood, hence its nickname, the Spruce Goose (the term goose being applied not only because it rhymed but because it was meant to question whether the aircraft could or would ever fly).


The Hughes H-4 Hercules Spruce Goose taxiing out for its first and only flight.

The First Flight

Over budget and vastly behind schedule, the reputation of Hughes Aircraft and Howard Hughes himself was at stake.  The plane had to fly.  And so, on November 2, 1947, more than two years after the war for which it had been built had been won, the plane was ready for take-off.  Given that it was Howard Hughes himself whose reputation was on the line, it was he, not his chief test pilot, who sat at the controls — he would fly the plane or die trying, though he knew that it would fly.

Pointing the H-4 Hercules into the wind, Hughes completed two taxi runs.  On board were Hughes and his copilot, Dave Grant, as well as two flight engineers (Don Smith and Joe Petrali).  To watch over the other aspects of the flight and engines, a total of 16 mechanics were in attendance plus two others.  As the test was to be a demonstration, seven members of the press were invited as well as seven members of the defense industry.  This meant that a total of 36 were on the Spruce Goose when it completed its two taxi tests.  Afterward, two of the press would depart to write and post their stories in the news.


The Spruce Goose in its one and only flight, quite nearly at the maximum altitude of 70 feet that it achieved during its 1 mile flight.

Finally, he began his take-off run with 34 on board.  Accelerating to take off speed, the Spruce Goose was gliding smoothly across the waves.  Finally, it lifted off.  Once airborne, it accelerated to 135 mph.  Keeping the aircraft well within ground effect (which is usually defined as half the wingspan), Hughes nursed it to an altitude of 70 feet before retarding the power an settling slowly back to the surface of the waves.  He executed no turns and never deviated from a perfectly level configuration — it was smooth, carefully managed and perfectly landed.  Once back on the waves, Hughes pulled the power back to taxi back to the dock.

The Final Word

For Howard Hughes, he had proved that the H-4 Hercules could fly.  Without a war, the plane was no longer needed, however, and so no further tests were required.  The plane was shelved and the Department of Defense was finished with the project.  The expectation was that the plane would be scrapped.  Yet Howard Hughes was concerned that others might again question the airworthiness of the Hercules — and he was emotionally attached to it, since it had been a major part of his life for five years.  Thus, he set up a team of engineers and maintenance to keep the plane in airworthy condition in a specially-built, climate-controlled secret hangar.


The Hughes H-4 Hercules Spruce Goose, the centerpiece of the Evergreen Aviation & Space Museum. Photo Credit: Drew Wallner

There the Hughes H-4 Hercules remained with full staff, ready to be rolled out and flown on a moment’s notice if ever the need arose.  Finally, in 1962, the staff was reduced — new heavy cargo planes like the C-5 and C-141 were entering service.  Even then, a limited crew kept the plane in good condition, a sort of enhanced mothballed status.  Finally, with the death of the by then reclusive Hughes in 1976, the effort was terminated.

Today, the Hughes H-4 Hercules Spruce Goose can be seen on display at the Evergreen Aviation & Space Museum in McMinnville, Oregon.  Beneath its great wings, dwarfed by the size of the aircraft, many other planes are also on display.  It remains to this day an awe-inspiring sight.


One More Bit of Aviation History

The idea of flying a single tank to Europe remains on the driving requirements of heavy cargo aircraft design.  Even if the lifting capabilities of a Lockheed C-5 Galaxy might be greater than the Spruce Goose, the size of America’s main battle tank has also increased dramatically.  The old M4 Sherman tank of World War II weighed 30.3 tons.  Today’s M1A1 Abrams tank weighs an incredible 67.6 tons — about 134,000 pounds, more than twice the weight.  A C-5 Galaxy’s maximum load across the Atlantic, such as to Ramstein, Germany, is about 150,000 pounds.


Today’s Aviation Trivia Question

Russia too built large flying boats — what was the largest and what was its lifting capacity?


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