Airplanes of The Aviator H-1 Racer
July 2005 Volume 31 Number 7
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As filming began on Martin Scorsese’s Academy Award winning movie, The Aviator, he was faced with a serious dilemma in how to accurately portray the airplanes and flying scenes in the film without having the original airplanes as subjects. Of the original planes needed for the major flying sequences in the film, one was no longer in existence and the other 2 were on permanent display in a museum, unable to fly. Digitally recreating flying airplanes is a notoriously expensive and time-consuming job and even after all the computer finishing work and digital special effects are done, the airplanes look unrealistic. They never really convince the viewer that the airplanes are “real”. Chris Brigham, Executive Producer on The Aviator, frustrated at having to “settle” for the expensive and unconvincing digital effects route for the flying scenes, decided that it was time to try something that had never been done before. Create the largest scale flying models ever built. Howard Hughes’ aircraft would need to be reproduced and flown convincingly enough to sell the movie critics and viewers that the flying sequences in the movie are “real”. This sounds simple, but these airplanes were so big (with wingspans up to 30 feet, that the size classification would put them in the FAA Experimental Aircraft Category.
A Chance to Make History The technical challenge to accomplish the mission fell to Unmanned Air Vehicle pioneer Joseph Bok (also correctly spelled "Bock"). Bok’s company, the Aero Telemetry Corporation specializes in building and flying Unmanned Air Vehicle’s (UAV’s) for the US military. His designs and technical innovations have been used on many of the unmanned airplanes that are currently in service around the world. Joe Bok’s team of 35, a mixture of aerospace engineers, technicians and fabricators put all their know-how and physical might into constructing several large flyable models and motion control miniatures for The Aviator. They did so relying only on old drawings and pictures from museum archives. “To pull off the effect of realism the planes had to be big enough and heavy enough to fly as convincingly as a full size plane,” says Bok. “I think that designing and building 3 totally different unmanned air vehicles of this size, and flying all 3 of them within this time frame (roughly 12 weeks) has never been attempted by anyone, even within military or commercial projects.” Darrel Hofmann, senior engineer and crew chief for Aero Telemetry said “The XF-11 reconnaissance plane, the H-4 Hercules (Spruce Goose), and the H1-B racer were all built by the Hughes Aircraft Company in the 1930’s and 1940’s when aviation was still in its infancy. Hughes was a real aviation pioneer. He hired the best engineers in the world at the time and spoke directly with the leading aviation experts of the time. He personally had a say in the design of the planes and he most certainly took on the tremendous personal responsibility of flying several them for the first time as the test pilot,” continued Hofmann, “This attests to the man’s skill in the cockpit.”
According to Bok, “Howard Hughes himself had an extremely difficult time with the real airplanes and was nearly killed in two of them while flying. Although historians have been unkind to some of his airplane designs (the XF-11 and Spruce Goose are prominently featured in a comprehensive aerospace reference titled The Worlds Worst Airplanes) I have become quite fond of both the XF-11 and H-4, if you study them closely, you can see the subtle genius in each of the planes designs, however, it is these particular design constraints that significantly impact any attempt to successfully build and fly a large-scale replica of them.”
Darrel said, “For safety’s sake, Joe and I chose an airfoil with a significant tolerance for heavy airframe weight and one that would minimize the onset of any tendency to tip stall,” said Hofmann, “The planes had to built so quickly that they would have to forego the benefit of many standard weight-saving manufacturing techniques that would have otherwise been applied and therefore we knew we would have a reasonably high wing-loading going in.” Added Bok, “we concentrated on High Reynolds number airfoils that tend to have lower airspeed envelopes but tremendous Coefficients of Lift.” Bok’s airplane shop would now have to run from 6am until 12 midnight 7 days a week in order to get the job done. Bok’s engineering design team began to close the gap between untested computer drawings of parts and functional working aerospace machinery on both the XF-11 and H-1 Racer. “It was an amazing process to be a part of,” said Bok, “we would come with an idea on the back of a napkin and have it designed, built, and integrated within days of its conception…it was simply amazing”. Bok’s initial plan called for a 16-foot wingspan H-1 airplane, roughly 1/2 scale of the original. It had to take-off under its own power and fly at distances of up to 3 miles while performing many different flight maneuvers.
It would require the use of custom hydraulic retractable main landing gear (these had to be designed from scratch, built, tested and fully operational in 8 weeks!!) Because of the sheer size of the airplane, the weight of the hydraulic and electrical systems, and constraints with both budget and schedule (which impact building options) it was anticipated that the airplane could weigh up to 400 pounds. Since the plane would be heavy, the use of composite technology would help them to build the planes quickly yet still provide a high degree of strength in the structure. After 4 weeks, the H-1 was beginning to look like a formidable machine. Many daunting design issues would need to be addressed for all three airplanes. They would all be radically different from the other and they would all have totally different engines and complex control systems.
H-1 Racer Building, Design and Flights Because of the compressed schedule it was decided to make the Racers’ fuselage out of foam blocks designed in Solid Works™ and finish sanded by Aero Telemetry’s talented shapers led by Jon Neill and Ian Stevenson. Added Bok, “Ian, Jon and their group of artists did an amazing job throughout the project for us, but particularly with the H1 Racer, their work was awesome.”
Darrel Hofmann, crew chief for the H-1 said, “Fundamentally, in order for an airplane to fly, it must be balanced precisely at its Center of Gravity or CG. This was the single most difficult task for the H-1 Racer design and necessarily became the most critical issue.” Added Hofmann, “the ultra long tail moment about the CG and Center of Pressure on the bottom of the wing coupled with the huge chord of the H-1 made the plane severely out of balance (aft CG condition) right on the drawing board. The hard part was that we had to make it look exactly scale.” While the H-1 was finishing up and getting ready for its all important film debut, work on the ultra complex XF-11 was progressing at a blistering pace. Critical engine and propeller testing for both the H-1 and XF-11 commenced at about the same time. “For about three weeks, all throughout the day we were blasted from our daily routine by the powerful engine test runs in the testing area next to the shop” says Kenny Schaefer, Aero Telemetry’s engine instrumentation engineer.”
Finally on November 4th, 2003 the day for the flight of the H1 had come. The team was nervous and Joe was concerned that they had not been able to flight-test the airplane first. In addition to the safety and liability issues for Bok, crashing the plane was not an option at this critical point in the project. Should the plane be destroyed while testing, there would not be enough time or resources to build another one to fit into the filming schedule and the H1 flying scenes would be deleted from the script. In addition, a crash at this early stage would likely result in the cancellation of the entire project which included the other two airplanes, the XF-11 and H-4 “Spruce Goose”, which were already under construction at Joe’s shop. Joe’s initial point of contact indicated that if the H1 failed or crashed, the other planes would be too risky, expensive, and dangerous to try again. So for the team, this single flight would have serious consequences as everything they had worked on up to this point would be at risk.
Welcome to the high stakes world of the UAV business.
To the teams credit the flight test went well, but the H1 would require some modifications before its next flight so the team headed back to the shop to prepare the plane for its next flight.
For it next flight, the Aero Telemetry H1-B Racer would be flown and filmed to simulate the World Speed Record attempt that Howard Hughes had made in 1935 at Santa Ana, California. Between the last flight at El Mirage and the morning of November 17th, amazing things had taken place. At Aero Telemetry, a review of the video and data from the test flight showed that several changes would be needed before the plane would fly again. The changes had to be made quickly and could not disturb the paint or delicate aluminum finish of the plane. With the principal filming finished at the site, Chris Brigham was able to have a perfect runway bulldozed and rolled flat. In addition, there would only be a minimal number of people in the area so as to minimize any safety hazard during the H1 Racers flight. The Aero Telemetry crew arrived in the dark at 4:30am. Within hours, the engine was started and re-tuned for the altitude at this location. After a lengthy safety meeting the cast and crew prepared for another date with destiny. 2 Fire trucks, an ambulance, a helicopter, and a multitude of Los Angeles County emergency personnel stood at the ready. Bok said, “For the film sequences of Howard Hughes’ world speed record attempt in the H1 Racer, we really tried to recreate something very special for Martin Scorsese, Chris Brigham, and Rob Legato. I think we did and it was an utterly amazing sight to behold.” Jason Somes piloted the H1 and executed a perfect 3-point take-off. He retracted the landing gear before the plane had even turned crosswind as it climbed out in a beautiful arc across the sky. The H-1 steadily climbed out, much to the amazement of the film crew and emergency personnel who had never witnessed a spectacle such as this. While the plane began its first pass over the film set in a diving left hand turn, hundreds of spectators were gripped with fascination at what they were seeing. As the big airplane picked up speed it was transforming into the manifestation of the man himself flying the plane as he had over 75 years ago! It was amazing.
“With the throttle pushed full forward and the big three-blade propeller turning at maximum pitch. The H-1 made an incredible sound that literally echoed throughout the canyons surrounding the set,” said Roger Thornton, “when they brought the plane in at full throttle through the pylons only 20 feet from the ground it sounded like a freight train,” he added, “and was indistinguishable from the real thing…it just literally shook the ground around us as it flew past.” The planes rock-steady flight characteristics, high-speed, and detailed finish combined with the vintage airfield setting provided a completely realistic and convincing recreation of Howard Hughes land-plane speed record attempt, even for the spectators on the ground. After several passes through the mock speed course the H1 was ready to land. Before it did though, Jason would perform one more maneuver that was not in the script as a fitting salute to Howard Hughes and those who were there that day as witnesses to the record setting flight of his H1-B Racer. As it flew past the crew at full throttle “the H-1 did the most beautiful slow roll you’ve ever seen,” says Bok, “probably something that Howard would have done too. The record setting performance of our H-1 Racer was absolutely breathtaking to witness and it was done under some the most extreme circumstances imaginable.” Of the day, Bok stated that, “The incredible effort of my team during these last few weeks cannot be understated. The plane flew perfectly and provided the cameras with some of the most amazing aerial footage of the H-1 Racer that could have only been had if Howard Hughes himself was here to do it…in some ways I really think he may have been…” (Editor's note: Next month find out about how Joe Bok and the Aero Telemetry team designed, built and flew the worlds largest and fastest scale model of the Hughes XF-11 for Martin Scorsese and The Aviator.)
Note: Where applicable, excerpts of the article reprinted with permission from Model Aviation and the Academy of Model Aeronautics.