Recently in Engineering Category

Super Chopper

Gareth Harvey Battle for the Title… In the brief but brilliant “Age of the Helicopter,” there have been many contenders for the title of “Super Copter.” The CH-47 Chinook, the UH-1 “Huey,” which transformed the very nature of warfare in Vietnam, and Eurocopter’s Ecureuil AS350, which has carried out some of the highest altitude rescues in history.
But one of the newest copters that brings it all home is the EH101. Recently chosen to be the next “Marine One”—the Presidential Helicopter, the EH101, will be specially outfitted as the new Oval Office in the sky. It was a tight race with Sikorsky’s S-92, and the competition between the two copters isn’t over yet. Though the EH101 is the president’s vehicle of choice, both of these state-of-the-art flying machines are now vying for a multi-billion dollar contract to supply the U.S. Air Force with their new generation of search and rescue helicopters. Seeing From New Heights Helicopters are a monumental human achievement, a technological feat that’s become so common place we don’t blink an eye at them anymore. But National Geographic’s Explorer takes you for a ride on the EH101 to see why you might want to take a second look. In reality helicopters are among the most complex flying machines ever created. And for three weeks this past summer, we rode with the AgustaWestland EH101, and captured the most spectacular footage I’ve ever seen of helicopters in flight. On location with the British Royal Navy, the Royal Air Force, and the Italian Navy, we quickly discovered that the EH101 – and other cutting-edge helicopters like the Sikorsky S-92 and NH Industries’ NH90 – have taken the science of rotary flight to a whole new level. What Makes Them Fly? What’s keeping them in the air? Their main rotors, for one thing. The EH101, for example, is a fusion of high-tech composite materials – including carbon fibre – built around a core of honeycomb paper and foam. But it’s more durable and more battle-worthy than an all-metal blade – like those used on the famous Hueys in the Vietnam War. Put a bullet through a composite blade and the fibres around the bullet hole remain undamaged – whereas a metal blade fractures around the impact site. Rotors are essentially ‘spinning wings’ that provide a helicopter with lift – but they also have to propel the aircraft through the air. Main rotor blades twist, flap, and move independently of each other to achieve both lift and thrust simultaneously! By using composite materials, designers of the new-generation Super Copters have far more flexibility in the shaping of rotor blades, and thus far more ‘control’ over the air they move through. The EH101 has a special ‘winged tip’ on its main rotor, which according to its pilots gives it the airborne capability of a much smaller aircraft. Life-Saving Features: No More Brown-Outs And the Royal Air Force pilots operating the EH101 in Iraq discovered a life-saving feature of its main rotor blade which even its developers hadn’t counted on. They found a solution to a pilot’s worst nightmare when flying in the desert—“brown out”—which is a dense cloud of swirling sand and dust, virtually blinding pilots as they’re trying to land. To counteract this, the EH101’s ‘winged-tip’ rotor blades create what its pilots call the “donut effect” – a circular window of clear air inside the dust storm that allows them to see the ground as they come in to land. Engines with Ten Times the Power
But perhaps the most remarkable component of the new Super Copter is its state-of-the-art engine. You’d think that ‘jet powered’ helicopters achieved their forward thrust through their jet-engines – but in reality all the power generated by the jets (they’re really ‘gas-turbine engines’) goes into driving the main and tail rotors though an incredibly complex gear-assembly. The latest breed of helicopter engine, while about the same size as the internal-combustion engine of the average family car, develops about ten times the power. The secret is a metal-alloy turbine whose blades exceed their melting point as they spin – forcing air through the chambers of the engine. Each blade is a single crystal of metal, drilled by laser beams, which allows them to be encased in a sheath of air as they whirl around – preventing them from melting. The power generated by this turbine (and transferred through the engine to the rotor blades) is an incredible two thousand horsepower. It’s the sort of power that allows today’s Super Copters to hover rock-steady in high winds – a critical advantage in search and rescue operations. It’s all a long way from the Chinese-rotored flying toys – or from Leonardo da Vinci’s ‘aerial screw’, which many credit as Man’s first inspiration for what would become the ‘helicopter.’ Inventing New Rotors
As with fixed-wing flight, the development of helicopters went hand-in-hand with the invention of the internal-combustion engine – light enough and yet powerful enough to lift a heavier-than-air craft off the ground. But the complexities involved in successfully creating a rotary aircraft, as opposed to one with fixed wings, were immense. The primary problem that early helicopter designers – like Igor Sikorsky, the ‘father of the helicopter’ – had to solve was how to stop the airframe from spinning around the main rotor. One solution was the use of twin rotor blades – each spinning the opposite direction. The most famous twin-rotored helicopter is probably Boeing’s CH-47 Chinook – the massive aerial workhorse of armies and air forces around the world. The invention of the tail rotor not only solved the inherent problem of rotary-winged flight, but gave the helicopter its unique manoeuvrability in the air. What became the accepted model for all modern helicopters also quickly became an indispensable tool of war, rescue, and emergency services. Today’s breed of Super Copters are on their way to marking new benchmarks in the helicopter age. Already their superior engines and rotor systems are setting new records in range and reliability – leading to some remarkable rescues and mind-boggling military strategies. Witnessing the capabilities of this new generation of helicopters, and meeting the pilots and the engineers who are making it all possible, it was like flying higher (and steadier) than Cloud Nine. It was truly the ride of our lives!
0 TrackBacks


Bill Swift - Associate Producer Taking buildings for granted… The idea that a building’s walls will stand up seems as safe a bet as gravity’s pull or the sun’s rising. Most of us don’t worry much about whether our apartments, offices, supermarkets, or schools are going to collapse on us as we go about our daily routines. But should we? National Geographic Channel’s Explorer takes a look at buildings around the world that despite having appeared structurally sound, some for years on end, came crashing down in a moment’s notice. We dig deep into the histories of these buildings to discover why. Collapses around the world… The Sampoong Department store in Seoul, South Korea was one of the swankiest stores in town. It had everything under one roof, from a gourmet grocery to high-end clothing and cosmetic boutiques. Many local Koreans, and in particular the city’s movers and shakers, would drop by for their evening meals and errands.
Image: Remains of the Sampoong Department Store
Remains of the Sampoong Department Store.
That is, until the evening of June 29th, 1995, when in less than 20 seconds, the mall came crashing down with an estimated 1,500 unsuspecting shoppers and employees inside. Not just a single floor or area, but five stories of the North wing pancaking into the four basements, killing more than 500 people and injuring over 900. There was no sign of a natural disaster, terrorist act, or a wrecking ball in sight. Yet one minute the department store was bustling with diners and shoppers and the next, all five floors were a heap of rubble. It is considered the worst structural collapse of a building in modern history. We pulled out our magnifying glass to examine this disaster and two other collapses –the Hyatt Regency in Kansas City Missouri—considered the deadliest structural failure of a building in the United States—and the recent Charles de Gaulle Airport collapse Terminal 2E in Paris, France. Off to Seoul… Despite its shocking death toll, the details of the Sampoong disaster are nearly undocumented in the US media. So to find out what happened – what made this seemingly sound building collapse without a moment’s notice—we decided to pay our own visit to where the disaster occurred. We arrived in Seoul, South Korea in the spring of 2005. The city is home to over 10 million Koreans, about one fifth of the country’s population. A trip from one end of the city to the other can take up to two hours and parts of the journey can be made along a contiguous string of passages and buildings. Seoul’s breathtaking skyline is dotted with magnificent skyscrapers and towers. Dubbed as one of the “Tiger economies” of Asia in the 1980s, South Korea saw foreign investments pouring in as the country surged economically, even hosting the Summer Olympic Games in 1988. This global attraction galvanized a building boom, producing the cosmopolitan Seoul we know today –with its sprawling street mazes, bridges, and skyscrapers. The evening and morning traffic in today’s Seoul could rival that of Los Angeles or New York City. Luckily, to navigate this urban infrastructure, we had the help of our van driver Mr. Lee—friend to many foreign journalists and celebrity to many locals. The cars fly left and right as he forges his way through gridlock, aided by a flashing light and bullhorn, which he uses to declare a “media emergency” when escorting journalists on deadline. Many of the local police officers even seem sympathetic to his mission and let him through. With the help of Mr. Lee, we wove between the towering structures of Seoul relatively unscathed. Downplaying the adversity—the tragedy and trauma… For the most part, the Koreans we spoke with were very kind, letting us into their lives to record their stories. At the same time, however, many of the Sampoong survivors struggled to speak frankly about their experiences—the destruction and their personal loss. Perhaps reflecting on the trauma is too overwhelming. Or they’re reluctant to add their stories to a list of other tragedies in Korea from the last decade – a subway gas explosion and fire (set by a mental patient and killing over 120) in the southern city of Taegu in 2003 and the Songsu cantilever bridge collapse that caused dozens of casualties in 1994, just before the Sampoong disaster. We met with a number of the collapse survivors and heard some amazing stories. Unfortunately, we couldn’t include them all in the Explorer episode. One woman left a particular impression with me – Mrs. Ha. She was a thriving entrepreneur, running two very successful snack shops in the Sampoong building. She recalled the day’s events with incredible repose. She was dropping a package off in the basement garage when a security guard told her the building was going to collapse. He wasn’t going to let her back in, but Ms. Ha insisted on re-entering the building to tell her employees to evacuate. With an ironic twist of fate, her employees narrowly escaped, but Ms. Ha was caught in the basement during the collapse and had to find her way out through one of the emergency stairwells. For our interview, Ms. Ha was confident and composed, but it wasn’t until our cameras were turned off that she began to weep. The collapse had devastated her way of life. The settlement she received following the disaster didn’t come close to being enough to recoup the life, and lifestyle, she had before.
Photo: An actress portrays Ms. Seung-Hyeon Park buried in the collapse
An actress portrays Ms. Seung-Hyeon Park, an employee at the Sampoong Department Store who was buried in the rubble for 17 days without food or water before she was found.
It’s very difficult working on a story like this, particularly in a foreign culture. You struggle to tread the line of being a good journalist and asking the difficult questions, while respecting the cultural sensibilities of privacy and the intimacy of tragedy and trauma. How to tell the story… We wanted our viewers to get a sense of what things were really like on the day of the collapse, to convey the sense of tragedy and trauma the survivors experienced, through a re-creation of the scene. Obviously, there weren’t any cameras filming on the day of the collapse or recording underneath the debris as survivor Seung-Hyeon Park awaited rescue. A Hollywood backlot with an earthquake set would have been helpful to shoot these scenes. Instead, we had to create a realistic set for the re-creation and do it with the limited resources we’ve got here at National Geographic. It took real creativity and a lot of teamwork. Luckily among our staff, we had someone whose father’s a Hollywood set designer and happened to be coming to town. We won't give away his secrets, but with a crew of carpenters, painters, interns, staff members and friends all joined together, we managed to re-create a Korean disaster here in Washington. Seoul post-Sampoong? So what happened in Seoul after the Sampoong disaster? The department store owners and the affiliated government officials were indicted. There was indeed a call for tighter regulations and oversight of the building codes and those who enforce them. It’s not certain, however, if the new policies are working. Recent newspaper articles, memorializing the 10th anniversary of the disaster, decry the lack of enforcement of the legal codes instituted since then. Professor teaching a new generation… But there are individuals in the industry looking to ensure that history doesn’t repeat itself. Central to our exploration was Professor Lan Chung, one of the lead investigators of the Sampoong collapse and currently the Dean of the School of Architecture at Dankook University. We sat in on one of Professor Chung’s very well-attended lectures on the Sampoong disaster. Professor Chung is committed to educating future architects and engineers about past mistakes and future pitfalls to avoid. The packed lecture hall seemed to prove students are eager not to follow in the footsteps of their predecessors. And for the future of architecture? As modern materials and engineering allow architects and designers to build bigger, better and more aesthetically-pleasing structures, are we pushing the limits of technology too far? There’s no clear cut answer. According to Dr. Roger McCarthy, Chairman Emeritus of the California based engineering consultancy firm, Exponent, Inc., modern architects want to create awe-inspiring building designs that are seemingly held up by magic. Dr. McCarthy warns those in this quest: “Anytime you take a design closer and closer to the limit of the material, any time you shrink a factor of safety… with each foot closer to the edge of the cliff, place each foot down very carefully.” Leaving Seoul…Things we take for granted… We left the Sampoong rubble behind, equipped with inspiring survival stories and lessons from engineers and architects alike. Returning to the Incheon International Airport to catch our flight home, I marveled at the airport’s architecture. Just five years old, the new international airport is awe-inspiring – replete with glass ceilings, towering arches, and expansive LCD monitors lining the moving walkways. Coincidentally, I was reminded, as I traveled the passageways through the terminal, that this building was another masterpiece of Architect Paul Andreu – the same architect who designed Terminal 2E of the Charles de Gaulle International Airport in Paris. The same terminal which came crashing down unexpectedly in 2004… Should I have been afraid? Concerned for my safety? Possibly, but oddly enough, I wasn’t. I was hardly bothered at all. While architectural disasters that occur once in a blue moon are traumatic, they are very rare. Even after having completed all the research for this program, I want to trust the engineering feats of the architects embodied in the structures that surround us. Particularly the ones for public use. I’m happy to see engineers and architects take on new challenges, creating more beautiful buildings for us to enjoy. I choose to trust the structural integrity of most architecture, but I temper that with an awareness of my surroundings, and if a building is crying out, making noises, showing signs of sagging, cracking and leaking, I’ll get out quickly.
0 TrackBacks

Recent Blog Comments


Always Know What's On!