Museum review: Evergreen Aviation & Space Museum

Reviewing the best military history exhibitions with Christopher Warner.

Evergreen Aviation & Space Museum
Open 9am-5pm daily
500 NE Captain Michael King Smith Way, McMinnville, OR 97128
+1 503 434 4180

The Pacific Northwest, renowned for its majestic mountain peaks and towering forests, is also home to the colossal ‘Spruce Goose’. Designed by Howard Hughes, the wooden behemoth (official designation: H-4 ‘Hercules’) can be found at the Evergreen Aviation & Space Museum in McMinnville, Oregon – a Smithsonian affiliate featuring an eclectic array of flying machines and exhibits spanning the Wright Brothers to the Space Age.

The entrance to the Evergreen Aviation & Space Museum in McMinnville, Oregon. A statue of its founder, US Air Force fighter jet pilot Captain Michael King Smith, stands outside.

The museum began as the brainchild of former US Air Force fighter-jet pilot Captain Michael King Smith. He and his father, Delford Smith, an aviation executive, opened the Evergreen Museum with a small collection of vintage aircraft in 1991. The following year, the museum won a bid to acquire the H-4, based on a proposal to expand operations and make the historic plane its centrepiece.

The development took nearly a decade to complete, spawning an extensive complex with two separate 120,000sq ft museums (Aviation and Space), a six-storey IMAX theatre, nature trails, vineyards, and an aviation-themed waterpark.

Key holdings include a Gemini mission space capsule, Titan II rocket, MiG-29, A-4 ‘Skyhawk’, Curtiss JD-N biplane, C-47 ‘Skytrain’, and SR-71 ‘Blackbird’ – the fastest jet ever made. First introduced during the peak of the Cold War, the titanium reconnaissance plane stayed operational from 1966 to 1998, and reportedly exceeded a speed of Mach 3.5 while demonstrating some of the earliest uses of stealth technology. But despite Blackbird’s impressive attributes, it is a more lumbering, bloated bird that crows loudest at the Evergreen.

The Hughes H-4 Hercules dominates the museum. Based on a proposal by industrialist Henry Kaiser, Howard Hughes took up the mammoth task of its construction.

Glückliche Zeit

The Spruce Goose was first conceived during the early stages of World War II, a period hailed by the Kriegsmarine as Glückliche Zeit (‘Happy Time’), when U-boat wolfpacks feasted on Allied ships in the Atlantic. American industrialist Henry Kaiser proposed creating a fleet of flying cargo ships to transport troops and equipment across the pond.

After several leading aviation manufacturers passed on the audacious plan, he turned to Hughes. The maverick record-setting aviator (and budding movie mogul) had built his reputation on taking huge risks – building a 200-ton winged boat would only heighten his enigmatic legacy.

Having secured an $18 million contract with the US government, the joint venture commenced production in the autumn of 1942. The daunting task was made even more challenging due to wartime restrictions, which prevented using critical materials, such as steel and aluminium, or employing any personnel who were already engaged in the war effort. More turbulence soon followed.

A close up of the H-4, dubbed by the press ‘The Spruce Goose’. Its hull was constructed using Duramold, a lightweight composite material similar to plywood.

Originally designated HK-1 (Hughes/Kaiser), Hughes insisted on a design of 400,000 pounds gross weight, capable of moving 750 fully equipped troops or two 30-ton M4 Sherman tanks. Construction of the hull relied on an elaborate process using Duramold, a lightweight composite material similar to plywood in which layers of thin veneers were bonded together with waterproof resins.

The painstaking labour slowed progress, exacerbated by Hughes’ obsessive-compulsive tendencies. The lanky Texan often disappeared for months at a time, engaging in a spate of activities that included two near-fatal air crashes. By 1944, Kaiser had had enough of Hughes’ shenanigans and dissolved the partnership.

As the project neared completion in early 1947, the war had been over for almost two years. The press dubbed it ‘The Spruce Goose’ – a nickname Hughes hated. Its catchy moniker aside, the seaplane consisted primarily of birch wrapped in painted fabric. The wingspan measured a whopping 320 feet (98m), equipped with eight Pratt & Whitney R4360 28-cylinder radial engines. The combined 24,000 horsepower generated an intended range of 4,800km at a cruising speed of 375km/h. But one burning question remained: could it fly?

The museum has a number of other air- and spacecraft on display, including this C-47 ‘Sky Train’. Unlike the H-4, this military transport aircraft was used extensively by the Allies during the war.

The celebrated aviator also faced pressure from the US Congress, which accused him of malfeasance and war profiteering. Hughes ardently defended himself during a highly publicised hearing in Washington, DC. ‘If I made any mistake on this airplane, it was not through neglect,’ Hughes said. ‘It was through supervising each portion of it in too much detail… I am by nature a perfectionist, and I seem to have trouble allowing anything to go through in a half-perfect condition.’

‘So if I made any mistake,’ he added, ‘it was in working too hard and in doing too much of it with my own two hands.’ Shortly afterwards, Hughes and his crew worked in shifts around the clock, hellbent on proving naysayers wrong.


On 2 November 1947, the silver-lacquered giant eased into southern California’s Long Beach Harbor with Hughes at the controls. Following two low-speed taxi runs, he ordered his flight engineer to ‘lower 15 degrees of flap’. Hughes then throttled into a stiff headwind, becoming airborne for 26 seconds before gently touching down.

Although his unannounced flight had silenced the critics, the H-4 would stay permanently grounded. Nonetheless, it claimed the title as the largest plane ever built until 2019, when the twin-fuselage Stratolaunch jet set a new record with a wingspan of 385 feet (117m). The ‘Goose’ remains the largest seaplane, the largest wooden aircraft, and the largest propeller plane ever built.

Over the next three decades, the billionaire insisted that the ‘Hercules’ had been built only for ‘testing and research and to provide knowledge which will advance the art of aviation.’

Inside the hold of the H-4. The eccentric Hughes later expressed regret over ‘working too hard’ on the design of the aircraft, which was completed too late to assist the war effort.

He also kept it housed in a specially constructed climate-controlled facility at the cost of $1 million per year until his death in 1976. The plane was later acquired by the Aero Club of Southern California and displayed in a large geodesic dome next to the Queen Mary luxury liner in Long Beach. However, the rare bird wasn’t done migrating.

After the Evergreen Museum founders won their bid, the aircraft was disassembled and transported by barge along the Pacific coastline, then up the Columbia River to Portland, Oregon. It remained there for several months until water levels permitted the enormous structures to pass safely under a network of bridges.

Next, the pieces were floated down the serpentine Willamette River, and then hauled by truck to the plane’s final resting place in McMinnville. There, Evergreen’s restoration team began meticulously putting the H-4 back together, requiring temporary hangars to house it.

The Spruce Goose around the time of its only flight, November 1947. With Hughes at the helm, it was airborne for just 26 seconds.

Finally, in 2001, the re-assembly was completed, and the newly renamed Evergreen Aviation & Space Museum unveiled its jaw-dropping star attraction. Additionally, the archives department holds all documentation relating to the H-4’s construction and fabrication, containing more than one million pieces of paper, ranging from technical drawings to reports and photographs.

Staying true to its mission of preserving history, the museum continues to advance other restoration projects. Recently, the team put the final touches on an F-86 ‘Sabre’, the first swept-wing aircraft in the United States fighter arsenal, and a workhorse of the Korean War.

The museum offers a slate of events throughout the year, including summer camps for young aviators, an annual air-show ‘watch party’, and a storytelling series presented by special guests. In honour of the 75th anniversary of the first and only flight of the Spruce Goose, a gala event will take place this November, allowing visitors to relive history aboard the infamous flying boat. •

Images: Christopher Warner/Wikimedia Commons.