Protecting The Hughes H4 Hercules With… Beach Balls?

Ryan in the Spruce Goose pilot seat

While visiting the Evergreen Aviation & Space Museum in McMinnville, OR, USA over the weekend, I came across a hack.

In addition to the excellent displays on site and an area where one can watch a video on repeat, the museum offers guided tours for a very reasonable price. And it was during this tour that my life as an aviation geek changed forever. Why? I got to visit the flight deck of the H4 and even sit in the pilots seat where Howard Hughes sat when he flew the plane almost 75 years ago.

It was later in the tour, after I’d had a moment to take in the enormity of sitting in the seat, that I found a wonderful hack to share with you all: and it’s all about beach balls.

The History

The Hughes H4 Hercules is probably better known as the “Spruce Goose” despite it mostly being made out of birch. The Hughes H4 Hercules was the brain child of Howard Hughes, and eccentric but talented engineer, pilot, and business mogul. The H4 constituted a nearly unbelievable undertaking: it was bigger and more powerful than any aircraft ever flown at that time. And instead of being made of aluminum, which was in short supply during the war, it was made from a novel composite called Duramold.

Duramold was invented some years earlier and licensed to Hughes for the Hercules project. Duramold was made with multiple layers of birch or poplar wood impregnated with resin. Duramold was considered to be a technological feat at the time, and given that the wood is still in perfect shape 75 years later, it clearly was. And although several thousands of pounds of nails were used in constructing the Hercules, once the resin cured, they were able to be removed.

Hughes was making the largest airplane to date. A failure of the Hercules, of any nature, would have been disastrous. Not just for the aircraft, but it would have been a death blow to the reputation of Howard Hughes himself, who had already taken a lot of heat for producing a wooden aircraft. Opponents to his project had given him no end of difficulty, and he’d even been hauled in front of the Senate, an audience before whom he swore the following:

“The Hercules was a monumental undertaking. It is the largest aircraft ever built. It is over five stories tall with a wingspan longer than a football field. That’s more than a city block. Now, I put the sweat of my life into this thing. I have my reputation all rolled up in it and I have stated several times that if it’s a failure, I’ll probably leave this country and never come back. And I mean it.” – Howard Hughes

The Beach Balls Hack

With all this weight on the shoulders of the engineers and builders of the aircraft, one does not have to use much imagination to put themselves in an engineers mind in the 1940’s: Somebody wasn’t sure the pontoons would remain water tight, and during a tense meeting, perhaps a young engineer remembered his family outing over the weekend, and called out “Beach Balls!” Likely this meeting was followed up by trips to local stores, where the shelves were emptied of all beach balls, disappointing beach bound kids and adults alike until the next shipment came in. The beach balls were inflated and dropped into the pontoons, making sure that the pontoons could not fill with water, even if they were leaky.

How did it turn out? Hughes loaded the H4 with reporters, and took the flying boat on two taxi runs and then came back to dock. Some reporters left, eager to get the scoop on the Big Story, only to turn back to find the Hercules taxiing back out to take its historic flight.


Beach balls on display in the cargo area

History records the short hop that Hughes flew as a breakthrough flight for such a large aircraft. Did the beach balls save the day? It’s hard to know.

Today, the beach balls still hold air, ostensibly the same that they were inflated with about 75 years ago. They serve as a reminder that the H4 was a prototype and not a final product. And it also helps us remember that engineers of all kinds and from all times, have one thing in common: They all love a good hack!

There are many other details that were gleaned during the tour, including the fact that the tail section nearly detached from the fuselage during the short hop — had Hughes flown much longer, a crash would have been inevitable! Look for the reinforced tail section in the photos below.

And if you ever get the opportunity to make your way to the Evergreen Aviation & Space Museum in McMinnville OR, USA, do it. Get the tour, sit in the seat, and live the history. Feel the rumble of the engines churning through the sea breeze. Smell the salty air, and know that your behemoth of an aircraft has something no other aircraft in history has had backing it up: Beach balls.

45 thoughts on “Protecting The Hughes H4 Hercules With… Beach Balls?

    1. I worked under a chief engineer who got his first airplane ride from Howard Hughes at his farm in Iowa while his dad worked on an award-winning Indianapolis 500 carburetor that hour and wanted. I noticed during the films of the epic flight after they barely skimmed over the waves and lifted there was so much panting on the sides of the plane I don’t think it was good for much more then breaking above the ground effects like he did. Knowing Howard he probably flew it barefoot like he did with all the Jets I’m sure he could feel it.

    1. I did that tour as well, but the story from my tour guide was different. When they were maneuvering the H4 in the bay at Long Beach there was a concern of hitting and damaging the main hull from debris floating in the water during high speed taxi tests. Howard couldn’t risk that and ordered all the beach balls they could find and wedge them under the cabin floor and the hull as a precaution. When the H4 was disassembled they stored all those beach balls in the sponsons.

  1. i do not get it. why those beach balls. the phrase “Somebody wasn’t sure the pontoons would remain water tight” comes out of nowhere. what role do they play in a plane? where they afraid the plane could ditch during test flights?

    1. Ah, a seaplane. They stuffed beach balls in there as backup floatation, seems a bit cheeky for a defense contractor but I guess the phrase “it’ll do” stands here. It’s too bad the name Beechcraft was already taken hah.

    2. It’s a seaplane, it’s meant to land in (and take off from) the water by default. The beachballs go in the pontoons such that if the pontoons leak, they will remain full of air anyway (due to the air being sealed within the beach balls).

      1. I have to admit I want to know what pontoons people are talking about. The H-4 was a flying boat. The hull provided the buoyancy not any pontoons. It does have wingtip floats for balance but no pontoons that I know of. Filling it with floatation before a first flight sounds like a good idea. If you have a rough landing it is much better to get the plane beached so it can be repaired then have your only prototype sink. Beach balls I find a kind of odd choice. I have heard of ping pong balls being used for that purpose but not beach balls. They seem much more fragile.

        1. Tip float is a special use pontoon. In other news, french fries are still a potato dish, earth is also a planet, a pole may be a post, but usually not if it’s a tube or a fishing rod, wings are also aerofoils unless they’re on your maxipad.

          1. So they put the beach balls in the tip floats? The display has them in the hull. You call a tip float a pontoon I guess but I have never heard it called that but I could see it but honestly not in any aircraft museum.

          2. You can call them ‘tip floats’ if you’d like, but the pontoons are larger than many actual boats.

            Beachballs were used because they were cheap and plentifully available to fill the available volume. Ping-pong balls would have been more expensive and required a special order (no store would carry close to enough to fill even one pontoon). they are on display in the fuselage because if they were still in the pontoon they would not be on display, the pontoons being opaque.

          1. Courtesy Merriam-Webster:

            pon·​toon | \ pän-ˈtün \
            Definition of pontoon (Entry 1 of 2)
            1: a flat-bottomed boat (such as a lighter)
            especially : a flat-bottomed boat or portable float used in building a floating temporary bridge
            2: a float especially of a seaplane

            Word use checks out.

    3. The Spruce Goose was a seaplane, so the pontoons functioned as the landing gear would on a regular plane.
      The beach balls were individually sealed air compartments. So if the pontoon would leak water, only a small amount could get inside as most of the empty space in the pontoon was filled with beach balls.

    4. Nobody had ever built what is technically a skyscraper out of plywood, much less this large of an aircraft. The processes were not that well understood or tested so things were improvised for unthought contingencies. Typical engineering response by his teams using commonly available items.

      Hadn’t heard about the tail being that fragile, I thought it was when they cut it up for moving to the museum.

  2. And I was there about 14 years ago September. It was an amazing sight. Further the site of the B17 which was keeping the company of two Piper Cubs was inspiring. One Cub was dressed in her canary work clothes, and the other Cub was dressed in her backup work clothes of Olive Drab.

  3. Different fields have their own jargon. And, different companies have their own dialects of said jargon. Often times the specific choices don’t make sense, but they are at least clear within the context (and culture) they’re used in. As such, they sufficiently fulfill the purpose of clear communication within that group.

    Now, admittedly, some jargon choices are wildly misleading or truly annoying to those of us who are not part of the original context.

    At that time, it was apparently common to refer to all float elements except the main hull (if applicable) “pontoons”. I know for a fact that it wasn’t universal, and caused a certain amount of friction in certain circles. It’s probably aprocryphal, but as the story was told to me, “If it once was a pontoon before we ripped it off and rigged it under a wing, it’s still a pontoon. It’s just on special duty!”

  4. Re: The beach balls.
    Per documents in the museum’s Archives, the beach balls were placed in the wing floats in 1952. They were discovered in the wing floats only by chance during the re-assembly of the aircraft at the museum (2000-2001) — one of the individuals (Paul Paine, now 98 years old) thought that he might have only one chance to satisfy his curiosity as to the interior of the wing floats; so, he opened the hatch on top of the float and climbed in. He found a series of water-tight compartments. In the aft compartment he found the beach balls. The idea was that if the wing float struck an object in the water and was ruptured the beach ball would provide buoyancy to keep the float and wing out of the water.
    It’s the belief that Hughes may have gotten the idea as a result of his Round-the-World 1938 record flight. Some 80 pounds of ping-pong balls were later found in the framework of the Lockheed aircraft. Though not a flying boat, the ping-pong balls intended purpose was to provide a degree of buoyancy if they had gone down in water.

    1. You’ve got a great set of details above. I spent two years restoring the airplane along with Paul Payne and 40 other volunteers. The beach balls were indeed put in the aircraft prior to its one and only flight. During World War II there were many reconnaissance aircraft carrying very valuable cameras iand film that had been filled with ping-pong balls in any void area in the aircraft. This provided flotation of the aircraft in order to recover the camera and film if the aircraft have been shot down. This concept was fairly prevalent during this time. When we pulled the beach balls out of the sponson, the little floats on the wings, we had shared this on the AP wire . It got picked up by a research team in Los Angeles who wanted to test the air. Indeed the balls had been filled in the 1940s and the science team wanted to have a sample of the air. They came up with a little machine and extracted about three balls worth of air. I don’t know what became of it because I am not a scientist and don’t read those articles.

      I think there are 1000 things about the Hercules that are fascinating. But it is also surrounded by untruths because of Howard Hughes and the mystery’s around him. It is untrue that the aircraft was flyable for all of the years between the 1940s and 1970s. After the flight Howard Hughes conducted some upgrades; New engines, a new throttle system, some repairs in the tail, and a fresh air system just for him. In 1952 there was an extraordinarily high tide in the area and water breached through a makeshift dam in the neighboring property at Long Beach. The Aircraft had damage to the top of the wings as if it floated into the rafters. There was water staining as high as the inboard flap hangers. Some of the photographs don’t make sense and don’t tell the entire story of how it could float into the rafters but also be held down allowing the water to rise all the way to the flap mountings. But the photographs don’t lie as to where the water and wing damage were. About two years after that the staffing levels at Long Beach had minimized to about eight people and the airplane was never flyable again. But he Hughes loved it and kept funding its storage.

      1. Other than being a float plane, what was its intended purpose?
        The CO2 tanks and pipelines on the fuselage deck seem to prevent it from being a useful cargo craft. Nor do I see any cargo doors of note. Troop carrier?

  5. You forget to mention the museum’s excellent water park, where slides start at the emergency exits of a 747 parked on the roof. Are your kids not interested in aviation history? Pull a bait-and-switch and bring them anyway!

  6. If you look at the H-4 interior cargo bay (rear) leading up to the tail, you’ll see large containers on the starboard side of styrofoam which replaced the beach balls (seen in late 1947 photos) . They are still there.
    The beach balls were placed in the wing floats and were there years later. The removed eaxtgra beach balls were given to the Hughes employees (I have one) . You are correct about the concern of the ship being holed by a partially submerged log in the harbor water, so the beach balls would help with flotation.

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