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Most rotorcraft professionals and enthusiasts know the first helicopter to ever receive civil certification was Bell Aircraft Corp.’s Model 47 (see p.124, Vertical, April-May 2010). However, what many may not know is that getting the Bell 47 certificated was not the original plan of company president Lawrence D. (Larry) Bell and his team of aircraft engineers.
Best Laid Plans
As the Second World War came to an end in 1945, most producers of military aircraft in the United States saw the cancellation of their lucrative government contracts. The Bell Aircraft Corp. of Niagara Falls, N.Y., was one of many companies that felt the repercussions of those cancellations. Part of the company’s survival during this period was not only due to its experimental rocket-powered aircraft (the famed Bell X-1) program, but also to its new helicopter development programs.
To make matters difficult, however, the company’s potential helicopter success was not in the hands of its main engineering team, but was based on the efforts of one particular contracted employee: rotary-wing inventor, cosmologist and philosopher Arthur M. Young. Young and his small helicopter team were based in an old Chrysler dealership garage on the outskirts of Gardenville, N.Y., and were tasked with the job of researching, designing and flying two small helicopters — the single-place Model 30 Ship 1 and the two-place Model 30 Ship 2
Still, even with the key research and development work Young’s team was doing between 1942 and 1945, it was Larry Bell’s plan all along to have his own aircraft engineers, at the main Bell Aircraft factory, carry out the production design of the very first commercial civilian helicopter. After all, with the end of wartime military aircraft production looming on the horizon, helicopters were seen as the future of his company.
With that in mind, Larry Bell sent his engineers to Gardenville in 1944 to become familiar with helicopter technology. He then commissioned a marketing survey to look at the potential for a new type of aviation industry centered on helicopters. The survey concluded that a larger helicopter would meet the anticipated demand of transporting passengers to various airports from nearby populated areas.
That survey ended up fostering two separate development programs: the R&D work carried out by the Gardenville team led by Young and close friend and assistant Bartram Kelley (who stayed on at Bell after Young left and eventually became senior vice-president of engineering), and the design and production carried out by helicopter division engineers at the main Bell plant. The helicopter division team was focused on the Model 42, a new civil, five-place helicopter design.
Young’s group, meanwhile, had secretly begun construction of a third Model 30 prototype, which flew on April 20, 1945. Although management wasn’t happy to discover Young’s team had created this aircraft, they finally approved Model 30 Ship 3 when Kelley convinced them that the helicopter would only be a flying test vehicle assisting the main engineers developing the Model 42.
Ironically, without Model 30 Ship 3, Bell’s place in helicopter history may never have been fully realized. Ship 3 was a significant improvement in many areas over the previous two prototypes. Plus, its performance flight-testing indicated that the systems developed were practical, efficient, and adaptable to the commercial helicopter designs Bell Aircraft planned to market in the post-war period.
Meanwhile, even though the engineers designing the proposed five-place Model 42 initially ignored much of the Gardenville team’s work, they did utilize scaled-up versions of various dynamic components taken from the first two Model 30 prototypes, including the main-rotor stabilizing bar and tail rotor systems, the transmission gearboxes, and the powertrain. For the fuselage, however, an industrial design firm from Detroit, Mich., with automotive experience/understanding, developed the final streamlined configuration of the all-metal creation.
Designed around the idea of a flying car, the Model 42 featured a plush interior with seating for five (a pilot and four passengers), an abundance of chrome, and large automotive-type doors for entering the new luxury, flying sedan.
Preliminary (pre-development) engineering data indicated the gross weight of the Model 42 was to be 4,800 pounds, with an empty weight of 3,355 pounds and a useful load of 1,445 pounds (including the 160-pound allowance for the baggage compartment). Power was to be provided by a Pratt & Whitney, 450-horsepower, R-985 Wasp Junior radial engine, allowing for an estimated top speed of 130 miles an hour, a cruise speed of 110 m.p.h., and a planned range of 300 miles. The main rotor diameter was 47.5 feet, the tail rotor diameter was 7.5 feet and the total aircraft length was just over 55 feet.
Bell Aircraft manufactured three examples of the Model 42, and had high expectations for the design’s success. However, the new Bell “helicopter of the future” soon found itself in trouble.
The same, of course, could not be said for Young’s Model 30 Ship 3. Larry Bell was impressed enough with the experimental rotary-wing aircraft that he had the Gardenville team draw up production plans for a commercial two-place helicopter. That helicopter would of course become the Bell 47, and would not only jump ahead of the Model 42 in the certification order, it would go on to reach legendary status.
Rescuing the 42
The Model 42 had a far less auspicious start and end than that of the iconic Bell 47, and could never fully get itself sorted out.
The first flight of the first Model 42 (Registration No. NX33540) took place in September 1945 with Floyd Carlson and Joe Mashman at the controls. The flight highlighted the good and bad of the Model 42 — it was a nice-looking ship, but was badly engineered.
As Bell Helicopter public affairs specialist Richard S. Tipton once wrote, ”The aircraft was like a combination of beauty and the beast. On the outside, its sweeping lines and classic nose seemed to convey — ‘This is the helicopter of the future.’ But strip away the 42’s comely cover and you’d find a monstrous tangle of cables winding around drums and a chamber of mechanical horrors.”
The Model 42 was plagued by vibration; it also had heavy controls, was unstable and was difficult to fly. It became an engineering nightmare. The pilots even refused to fly it for a time. What the Bell engineers hadn’t taken into consideration was the potential of stress on and fatigue of the helicopter airframe, aspects that were not a big concern in fixed-wing aircraft.
In June 1946, Larry Bell finally turned the program over to Young to fix what was wrong and to bring the design to a successful conclusion. Although the solution would be difficult, to Young the problem was clear: “The Model 42’s snag was the engineers had attempted to build a helicopter like an airplane,” he recalled.
The Model 42 program also had its share of accidents, both before and after Young’s involvement. The first involved both Carlson and Mashman. “The Model 42 had manual controls that were so heavy it took two of us to fly it,” remembered Mashman in his book To Fly Like a Bird. “Just as we took off, one of the stabilizing bars fatigued. It flew through the outboard section of one rotor blade and knocked off four or five feet of the outboard. Immediately, both blades disintegrated and the helicopter dropped like a brick to the ground.” Both pilots, luckily, were not seriously hurt, but that particular helicopter never flew again.
Another accident occurred in March 1946: the third Model 42, also registered as NX33540, was tied down for a 100-hour ground running test when the tail boom broke off without warning due to vibration fatigue.
Once Young and his team had sorted out a number of the model’s concerns, the 42 joined an early military two-place R-13 and a Bell 47B prototype on display at the National Aircraft Show in November 1946 in Cleveland, Ohio. Unfortunately, while the bubble canopy R-13 (military Model 47) generated significant attention, there was little-to-no interest in the sleeker, larger Model 42, and no sales were realized.
Undaunted, flight-testing continued with the second Model 42 (NX42063), and progress was made toward the final goal of making the 42 a successful flying helicopter. Some of the changes incorporated included new rotor blades, a stronger rotor hub, a stiffer control system, thicker bulkheads, moving the rubber motor mounts (as they were originally in the wrong place), and moving the stabilizer fin location in order to improve high-speed stability.
Unfortunately, another Model 42 accident occurred on Jan. 17, 1947, when Mashman was taxiing NX42063 near a hangar and a wind gust turned it over on its side — resulting in the rotor blades chopping off the tail boom. Mashman was okay, as was Young, who had been hanging onto the side of the aircraft observing the rotor system.
With all three Model 42s now damaged and no sales forthcoming, Larry Bell had had enough and decided not to turn the design into a commercial product. In the end, no Model 42s survived the test program.
All of the work done by Young and his team, however, was not lost. What they learned from the Model 42 development program ended up in the design and construction of the updated Model 48 (R-/H-12) military helicopter.
The work would also help Bell create larger helicopters in the future, including the company’s most iconic model, as Bart Kelley recalled in Richard Tipton’s book They Filled the Skies: “The Model 42 and its successors gave us a lot of experience in designing larger helicopters. Bell’s experience in the Model 42 and 48 paid off. The Bell Model 204/XH-40 [UH-1] Huey’s later success in 1956 tracks from these early efforts.”
Not bad for a helicopter design that never saw certification and today remains largely unknown.
Bob Petite is an air attack officer with the Alberta Forest Protection Division. He has over 40 years of experience working on wildfires both on the ground and in the air, utilizing air tankers and helicopters.