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• Flight Today

Big Idea

Megalifters prove you’re never too fat to fly.

• By Kara Platoni
• Air & Space Magazine, September 01, 2008

NASA’s Super Guppy Turbine looks like it should be impossible to fly, or at the very least, like it should bumble about the heavens and then clatter to Earth the minute gravity figures out it’s up there. It weighs 50 tons. It is an airplane big enough to swallow other airplanes—a hangar with wings. But when pilots Rick Hull and Terry Pappas bring the Guppy in for a landing at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on a clear December morning, the airplane descends with the stately grace of a steamship cruising into harbor. 

This Guppy is the last in a series of gargantuan cargo aircraft that have been wowing bystanders since 1962, when its grandmother, the Pregnant Guppy—at that time the world’s largest airplane—did the heavy lifting that helped get NASA to the moon on time. Since then, NASA has used the Pregnant Guppy progeny to ferry equipment for Skylab and the International Space Station. Today, this Guppy is picking up a duplicate of the 10-foot-wide, 2,400-pound rotary joint that turns the solar panels on the space station; the original is malfunctioning, and astronauts and engineers in Houston will need the duplicate to devise a fix.

The Guppies also influenced a generation of airplanes designed for more terrestrial matters: Airbus Industrie’s Beluga and Boeing’s Dreamlifter carry aircraft subassemblies between plants in different countries. Pumped-up airplanes are rare—only one of eight Guppies built still flies, there are but five Belugas, and Boeing plans to build only four Dreamlifters.  Their proof of principle, the Pregnant Guppy, is largely responsible for making good on President John F. Kennedy’s 1961 promise to put a man on the moon “before this decade is out.”

The brainchild of Aero Spacelines partners Jack Conroy and Lee Mansdorf, the Pregnant Guppy was conceived to haul 40-foot-long Saturn S-IV-B rocket stages from California to Cape Canaveral, Florida. Previously, NASA had been shipping them through the Panama Canal, but the voyage was far too slow for a race to put a man on the moon by the end of the 1960s, and the long exposure to sea air put the stages at risk for corrosion.

NASA had toyed with a few other concepts, including piggybacking the rocket stages on an Air Force C-133 transport, or slinging them beneath a blimp. But these solutions weren’t aerodynamic and still would have exposed sensitive parts to the elements. Conroy and Mansdorf had another idea: transform Mansdorf’s stockpile of Boeing B-377 Stratocruisers, purchased just as the Jet Age was making the propeller-driven airplanes less desirable, into the U-Haul of the skies. 

First, Aero Spacelines stretched a Stratocruiser fuselage by adding a 16-foot aft section. Then the engineers built a bigger fuselage atop it: More than 19 feet in diameter, it was braced to the original with lumber, to be cut away if the airplane survived test flights. Another key modification would later define the Pregnant Guppy: a tail section that had to be removed for cargo loading. The design necessitated disconnecting the flight control cables each time the tail was opened.

But there was a problem: Aero Spacelines had built the airplane without actually getting a NASA contract. As soon as the Guppy passed its air trials, surprising those who had predicted a fiery crash, the nearly broke Conroy set off in it for Huntsville to demonstrate his concept to Marshall’s famous director, Wernher von Braun. The still-cautious Federal Aviation Agency gave Conroy special clearance, provided he didn’t fly over cities.

Von Braun was so impressed he insisted on taking the Guppy for a spin, much to the alarm of his staffers, who pointed out that it was still held together with two-by-fours. Worse, the airplane, with a full load of fuel to simulate a full payload, was super-flammable. Nevertheless, once von Braun took the pilot’s seat, the irrepressible Conroy secretly told the flight engineer to shut down the two portside engines—a sly demonstration of the airplane’s power. When von Braun finally realized that he was flying comfortably on two engines, Conroy, according to legend, coolly responded, “Oh, we do that all the time to save fuel.” (In fact, says Daren Savage, who runs a Web site called AllAboutGuppys.com, “Conroy was actually standing on the rudder so that von Braun didn’t really know how much effort it was really taking to fly this plane.”)

Aero Spacelines soon had its contract.  The Pregnant Guppy promptly reduced NASA’s cross-country transit time from 18 days to 18 hours. “It enabled them to keep the schedule that they needed so they didn’t have to scrub any launches,” says Savage.

With proof that airplanes could safely be super-sized, NASA ordered an even bigger one. Dubbed the Super Guppy, it had a 141-foot-long body and 25-foot-wide fuselage. A hinged nose that could swing open 110 degrees for loading replaced the removable tail. In the meantime, Airbus, which manufactures aircraft components in France, Germany, Spain, and the United Kingdom, was also warming to the Guppy concept. In the early 1970s, Airbus began using four Super Guppy Turbines—a generation with Allison 501-D22C turboprop engines—to shuttle subassemblies internationally, saving time and eliminating bureaucratic hassles. (However, it also led to the taunt that every Airbus took its first flight on a Boeing.) “By using aircraft, you add flexibility to your industrial process,” says Bruno Gutierres, head of new programs and development for Airbus’ logistics and supply chain. “You are not dependent on weather conditions, for example, like you are with surface transports.”

Despite producing two more airplanes in the 1970s—the shorter, fatter Mini Guppy and Mini Guppy Turbine—Aero Spacelines foundered, particularly after the Mini Guppy Turbine crashed in 1970, killing its crew. NASA retired its original Super Guppy in 1991, and the Pregnant Guppy was cut down for scrap; there were no replacement parts for these unique aircraft, and Aero Spacelines had long gone out of business. Besides, Airbus was manufacturing ever-bigger airplanes, and needed even bigger cargo haulers. 

By 1997, Airbus parked three of its Super Guppies, and traded the youngest of its litter to NASA—the one the agency still uses today— in return for cargo room for the European Space Agency on the space shuttle. Airbus replaced the Guppies with a whale-like airplane of its own invention: the Beluga. A modification of the Airbus A300-600, the Beluga can carry more and fly faster and higher than the Guppy. Cargo is loaded onto the Beluga via a hatch above the nose that swings up; to make this possible, the cockpit was dropped 51 inches, giving the Beluga its distinctive pointy nose.

True workhorses, Airbus’ five Belugas fly daily. “This aircraft is fully integrated into our industrial process and it’s very reliable for us,” says Gutierres. “This is something we are using day to day, something very important.”

Boeing hopes to accomplish something similar with its Dreamlifter, the newest entry into the realm of jumbo airplanes. It will shuttle parts of the company’s new 787 Dreamliner between Italy, Japan, and three U.S. cities, compressing shipping time for components previously routed via rail or sea from 30 days to one. Based on the Boeing 747-400, the Dreamlifter somewhat resembles an overinflated toothpaste tube, with the cockpit where the nozzle would be; when it debuted in 2006 still coated in green primer, bystanders likened it to a flying pickle. (Boeing Commercial Airplanes president Scott Carson reportedly joked to Joe Sutter, chief project engineer for the original 747, “Sorry for what we did to your plane.”) The 787 components are loaded through a swing tail with the world’s largest cargo loader.

Perhaps because of the difficulties Boeing has had with its related Dreamliner program, the company declined to let staff associated with the Dreamlifter give interviews for this article. (The 787’s delivery has been delayed by supply chain problems, according to news reports, and last year the program’s general manager was replaced.) However, the airplane’s specs alone tell an impressive story: The Dreamlifter is the first monster hauler designed to cross oceanic distances—it can fly 7,000 miles without refueling. Although NASA’s Super Guppy Turbine still claims the title of fattest airplane, the Dreamlifter is the most voluminous; according to the company’s magazine, Boeing Frontiers, it’s big enough to engulf a three-level, 10-lane bowling alley.

But, well—how do these enormous airplanes fly?

NASA’s Super Guppy crew members hear this question so often that most of the time, they just shrug good-naturedly and say that they drove in on the highway. When pressed, they’ll admit the big airplane actually feels quite small. “It’s not like flying with a house on your back,” says Frank Marlow, who has piloted Guppies for NASA since 1979. “It is really very clean and very nice.”

In fact, says Beluga pilot François Cantin, pilots of that aircraft get the opposite impression, thanks to the Beluga’s lowered cockpit. “When you are seated in the front of the aircraft, it seems that you are flying almost a small aircraft, because you are quite close to the ground,” he notes. Pilots can barely see the wingtips, much less the plane’s bulk, he says. “It’s really when you leave the cockpit that you notice at once that you are really in an incredible airplane.”

Unless a crosswind hits you. 

“In this aircraft, you can feel it move laterally in turbulence, and no other aircraft behaves like that,” says Cantin. It’s like the sideways push you feel when driving a car over a bridge during a storm, he says. Crosswinds make landing the Super Guppy very difficult, adds pilot Terry Pappas. “Because it’s such a huge surface, a strong crosswind generates a tremendous amount of force on it—it wants to turn the tail downwind and it makes the nose point into the wind,” he explains. “That’s what you call weathervaning. Well, once you get that tendency going, it’s very difficult to counteract. You’ve got this rudder that you can use to help you counteract it, but if you’re a half-second late getting that control surface displaced, now you’ve got this huge 140,000-pound [with payload] machine already starting to rotate into the wind and it’s hard to stop.”

But those are about the only similarities between these two enormous airplanes. The Beluga is a modern jet airplane; the Super Guppy is a dinosaur. It’s a four-engine turboprop and all-manual, with no autopilot and no hydraulics except for the nosewheel steering, the brakes, and the windshield wipers. “It’s old-style flying,” says pilot Rick Hull. “You don’t take off and as soon as the gears are up and the flaps up, the autopilot’s on and you’re talking about what’s going on on Wall Street.” The Guppy prefers to fly out of trim and requires, let’s say, a certain degree of watchfulness. “It’s like going in a china store with a three-year-old,” says Hull. “You can turn your back on it for about two or three minutes, but you’re not going to like what he’s doing, you know?”

It’s also one of the few airplanes that still fly with a nine-person crew. Two flight engineers, two loadmasters, and three mechanics must disconnect the control cables, manually unbolt the nose before it can be swung open, carefully situate the payload, and pack the cargo into the Guppy’s special 16,000-pound shipping fixture. This half-pipe-shaped fixture, which rolls in on rails, mimics the cargo bay of the space shuttle and holds the payload steady. Since the hold is not pressurized or climate controlled, sensitive cargo can be protected by a lid that forms an immense silver cylinder—one, the crew notes, resembling a giant beer can.

While the Beluga flies constantly, the Super Guppy flies maybe a half-dozen missions a year—but they’re each about a week long, and include several stops.  The long hauls, as well as the old-fashioned flying style, make the Guppy crew a very close team. Pilots still call out commands to flight engineers, an unusual exercise in thinking ahead for pilots accustomed to flying two-seaters. As Pappas puts it, it’s like driving a car while having the passenger shift the gears. “We’re kind of like a concert duo,” says flight engineer Larry Glenn, who has been flying NASA Guppies since 1987.

The Beluga, by comparison, flies with a three-person crew—two pilots and a flight engineer. Another key difference: while Cantin says the Beluga’s size affects speed and climb rate only minimally, the Super Guppy flies so low and slow that, as Hull puts it, “you feel like you’re riding in the Goodyear blimp”—an impression aided by the roomy cockpit, the panoramic windows, and the fact that most of the crew ride seated around tables, at which they often share sandwiches and a cooler of drinks. “We’re so slow that birds attack us from the rear,” deadpans Glenn. “I mean, we’ve got semis that pass us on the freeway.” Crew members swear they keep a road atlas on the flight deck so they can follow the interstates.

Traveling in today’s Super Guppy is a cakewalk compared to flying the original, which lacked such niceties as a pressurized cockpit. “Any time we went above 10,000 [feet]—and we did it a lot— everybody was on oxygen. We looked like a bunch of British fighter pilots,” Marlow recalls with a laugh. It had such a long nosegear that on takeoff the wing faced the oncoming air at an angle that generated lift very early. The result was the unnerving tendency for the main landing gear to lift off first, and the nose last, so the aircraft went trundling down the runway like a wheelbarrow. (The current airplane instead has a Boeing 707 nosegear installed backward, and pilots aim for a three-point landing.)

Because Guppies are so novel, the flight crew occasionally faces hair-raising unknowns. Dan Hill, a flight engineer on the original Super Guppy from 1979 to 1991, recalls that the crew sometimes had to guess how much power the Guppy needed to get off short runways: “We never really knew, because of the lack of testing that was done, how safe it was to go to certain power settings. So we had one that was called ‘Fear Setting.’ At 1,000 feet we’d always do a runway remaining check, and that’s when we determined if we needed ‘Fear Power.’ ”

Marlow, who has survived so many misadventures that his colleagues whisper “God loves Frank” in hushed tones, recalls a mission to retrieve a NASA T-38 trainer that, struck by lighting, had had a fuel tank blown open. Although the smaller airplane was supposed to have been defueled, 50 gallons of gas sloshed out after takeoff, creating heavy fumes and a serious risk of explosion for the Guppy. The flight crew got ready for an emergency landing—then realized that if they lowered the electrically powered landing flaps, they risked creating a spark that could immolate their airplane.

They’d have to try a no-flap landing, but as the runway approached, Marlow realized another problem: “We were going fast and we had never made a no-flap landing in the airplane. We never practiced it. None of our training had it!” As the flight engineer desperately looked through charts for the no-flap stall speed for their aircraft’s current weight, Marlow knew he’d have to guess. “We were 165 knots and I said ‘This feels good,’ ” Marlow recalls. Luckily, he’d intuitively picked just the right speed. After making a safe landing, he double-checked: The magic number was 165.  

The original Super Guppy’s most famous lucky break happened in 1965: While it was doing a high-speed dive during its certification test, the force punched a 23-foot hole into the airplane’s domed forehead. The airplane would surely have blown apart, had small access doors at the back of the airplane not popped out, releasing the additional pressure. “For seventeen very long minutes on September 25, 1965, the Super Guppy’s future looked uncertain, indeed,” the pilot, Lieutenant Colonel P.G. Smith, recalled in an article he penned for Air Force magazine. “But who could now say that she is not—quite literally—a great airplane?”

Even though they’re often unflatteringly compared to hippos and elephants and the Oscar Mayer Wienermobile, the Guppy, Beluga, and Dreamlifter all draw crowds wherever they land. Gutierres recalls listening to the radio on the way to an Australian airport to meet up with the Beluga, when suddenly, he says, “they stopped the program and the guy said, ‘I just saw an incredible aircraft!’ ” Even aviation professionals do double-takes. “We always get comments from air traffic control—‘What kind of airplane is that?’ ” says Glenn.

On that clear December day in Huntsville, Glenn stands inside the Super Guppy’s cargo bay, watching the payload slide in. He turns toward the rear of the airplane and unzips the flap that covers the tail section, pointing to a part of the lower fuselage. It came from the Pregnant Guppy, he explains—by the time this Guppy was built, there weren’t any other parts available, so this piece of its forebear was used. It’s sort of the alpha and omega of Guppy history, he says.

This happens to be Glenn’s last mission; he’s retiring after 42 years of flight. But the Super Guppy will fly on, in a program that will bring the history of NASA’s megaplanes full circle. The Super Guppy will soon begin hauling the Ares rocket, the Orion Crew Exploration Vehicle, and other oversize parts for the Constellation program, which will take U.S. astronauts back to the moon.