Editor's note: As BCA packs for EBACE to report for ShowNews and exhibit at booth X106, we look at the aeronautical history of EBACE host country Switzerland.

From legendary STOL aircraft linking remote communities to a round-the-world quest in a flying machine powered on nothing but the sun’s rays, the innovations of Swiss engineers, pilots and explorers have done much to improve our collective quality of life on this planet.

Switzerland ranked first in the World Economic Forum’s “Global Competitiveness Report 2015-2016,” and first in the Global Innovation Index in 2015. 

If one considers the relatively small country’s considerable aeronautical advances, it’s natural to ponder if there is an entrepreneurial, educational and innovative spirit in Switzerland that places special value on bold exploration of technological possibilities.

Solar Circumnavigation

Born into a dynasty of explorers and scientists, physician/aeronaut Bertrand Piccard dreamt of combining science and adventure to tackle one of the greatest challenges of our times — sustainability. From this dream emerged the idea of a round-the-world aircraft powered solely by the sun.

In 2002, he presented the concept to the Ecole Polytechnique de Lausanne (EPFL), whereupon engineer and professional pilot Andre Borschberg immediately agreed to launch a feasibility study. Undeterred by critics who predicted such an aircraft would be “too big, too light and impossible to control,” a multi-disciplinary team of 80 engineers and technicians spent the next 12 years transforming the dream into the reality of the Solar Impulse 2.

Spanning 72 meters — 40 ft. more than a Boeing 747-400’s — the wing is blanketed with monocrystalline silicon solar cells, as are the fuselage and horizontal tailplane — 17,248 of them. An ultrathin polymer layer protects the photovoltaic cells from water and UV radiation. Energy efficiency had to achieve remarkable levels for the thing to work. The solar cells are 23% efficient, which is to say that 23% of the solar energy hitting the surface is transformed into direct current electricity. By comparison, the average efficiency of solar cells currently being installed on residences ranges from 11 to 15%.

Four motors, each generating 17.4 hp, are fitted with a reduction gear limiting the rotation speed of the 4-meter diameter propeller to 525 rpm. The motors are 97% efficient, versus 70% for standard internal combustion engines.

In order to achieve the lightest weight possible, engineers used a combination of carbon fiber covering a honeycomb core of alveolate foam in the entire frame of the airplane. Insulation made from the foam protects the cockpit and the pods housing the motors and batteries.

Even the aircraft’s flight profile is designed to save energy. During daylight the aircraft climbs to 8,500 meters (27,887 ft.) as the solar cells provide sufficient energy not only for the steady energy consumption by the propellers but also for battery charging. When daylight fades the motors are throttled down and the plane starts to glide down to 1,500 meters (4,921 ft.), consuming almost no electricity in 4 hr. At that point the pilot powers up the motors again, drawing energy from the batteries until daybreak when solar energy again feeds power to the motors and recharges the batteries.

Since pressurization would be too costly in weight, the aircraft carries supplemental oxygen. However, with outside air temperatures ranging from -40C (-40F) to +40C (+104F), the cockpit structure features high-density thermal insulation to help moderate temperature swings from -20C (-4F) to +35C (+95F). Throughout, the pilot is strapped into the confines of a tight space for many days and nights while enduring these uncomfortable (and potentially life-threatening) conditions. Adding further to the difficulty is the need for the pilot to have exceptional stamina to control this plane, which is sensitive to turbulence because of the light loading of its vast wing.

The pilot is in contact by satellite with the Monaco Mission Control Center, where a team of weathermen, mathematicians, air traffic controllers, planning engineers and flight director gather to monitor the aircraft’s performance and condition in real time and to devise flight strategies. Preparation for the flight, during which the solo pilot has to endure days of confinement, included hypnosis, meditation and yoga, along with simulator and free-fall training.

The first leg started on March 9, 2015, at Abu Dhabi, UAE, to Muscat, Oman. The 13-hr., 1-min. flight was flown by Borschberg. Subsequent stops included Ahmedabad and Varanasi, India; Mandalay, Myanmar; Chongqing and Nanjing, China; Nagoya, Japan; and then in its longest leg to date, onward to Kalaeloa, Hawaii, in an astounding 117-hr., 52-min. flight. That Pacific leg smashed a number of long-standing records, including the longest duration solo, nonstop flight ever made and the longest solar-powered flight, both in terms of duration and distance.

The preparation for the record-setting leg started a chain of events that grounded the aircraft in Hawaii and necessitated a redesign, causing a delay that put its next leg outside of the acceptable weather for making the second Pacific leg. While in Nagoya, the Solar Impulse 2 encountered harsh weather on the runway, and the team prudently decided to conduct a test flight before attempting the trans-Pacific leg. In retrospect, more time was needed to cool the lithium polymer batteries between flights. A high climb rate and over-insulation of the motor gondolas caused the battery temperature to rise during the record flight. 

Demanding such performance out of the batteries revealed the necessity for an automatic cooling and manual backup system. The redesigned system has a safety backup so that if the automatic system fails, the pilot can control the air inlet so that it does not stay fully open and freeze the batteries, or stay closed causing an overheat.

Engineers arrived in Hawaii last winter to install the new batteries along with the revised ventilation and cooling system. On Feb. 26, 2016 test pilot Markus Scherdel completed a 1-hr., 33-min. flight from Kalaeloa, climbing to 8,000 feet to check the aircraft stabilization and cooling systems. At the time of writing this report, takeoff was tentatively scheduled for April 2016 with Piccard at the controls for the 100-hr. flight from Hawaii to Phoenix.

Obviously, the Solar Impulse 2 is an utterly impractical, experimental flying machine, but that was never really its purpose. Rather, says Piccard, its intent is “to convey messages.”

“We do not plan to revolutionize the aviation industry,” he explains, “but instead to demonstrate that the actual alternative energy sources and new technologies can achieve what some consider impossible.”

The project’s website further notes, “If an airplane can fly day and night without fuel, everybody could use these same technologies on the ground to halve our world’s energy consumption, save natural resources and improve our quality of life.” 

Visit: http://www.solarimpulse.com

Parabolic Flights Leading to Medical Discoveries

Modern science has done wonders to improve the quality of life, but diseases and the aging process continue to negatively affect human health. One of the tools being employed to further our knowledge base is parabolic flights since these enable researchers to observe phenomena in physiology, biology, material science, fluid science, combustion and atomic physics that are otherwise “masked” by the effects of gravity.

For 10 years faculty members at the University of Zurich, an institution that has produced 12 Nobel laureates, have participated in weightless experiments organized by Novespace, a subsidiary of CNES, the French space agency. Novespace owns and operates a highly modified Airbus A310 “Zero-G” transport used by customers worldwide to conduct research under microgravity. Since 1989, 10,000 scientists have been involved in such flight programs.

During a parabolic flight maneuver, once the aircraft is in steady horizontal flight at 503 mph (437 kt.), the pilots begin a 1.5- to 1.8-g pull-up for 20 sec. When the aircraft reaches 404 mph (351 kt.) at roughly 47 deg. of nose-up pitch, the pilots push over into a “zero g” flight path. When the aircraft reaches the apex of the flight path at approximately 242 mph (211 kt.), the pilots begin a nose-down pitch. Upon again reaching 403 mph (351 kt.) and 47 deg. of nose-down pitch, the pilots begin to pull out of the dive. The aircraft is in a zero-g state for approximately 20 sec.

Previously, all of the parabolic flights had been conducted in France with research organizations working with CNES, ESA (European Space Agency) and DLR (German Aerospace Center). In September 2015, the Zero-G aircraft was re-located to the Dubendorf Air Base near Zurich as the operating base for two flights to conduct experiments for the University of Zurich and other Swiss universities and research institutions. On Sept. 22, 2015, the Zero-G aircraft flew 15 parabolic maneuvers. Not only was this flight campaign the first to be flown outside of France, but it also was the first time it formed a partnership with a foreign university.

What endemic human health problems are the Swiss hoping to solve? Organ and tissue loss is a costly medical problem, and researchers are looking for alternative means for growing complex tissues in a much faster manner. In a microgravity environment tissues such as heart cells, cartilage and nerve regeneration have grown more rapidly. Medical research in microgravity is also advancing knowledge in toxicology, eye irritation, skin corrosion/irritation and vaccine development.

Plasma particles grown in a laboratory under the effect of gravity develop a strictly two-dimensional layer. However, under microgravity, plasma crystals grow in a three-dimensional condition, allowing the use of physical plasmas in novel therapeutic applications. For example, they are capable of killing bacteria without damaging the surrounding tissue and have been shown to stimulate tissue regeneration. The research teams are exploring how this novel field can develop future antimicrobial therapies.

Microgravity allows researchers to study aging, bone and muscle degeneration, cardiovascular deconditioning, balance disorders, disturbed circadian rhythms and reduced immune response. Bone loss during long duration space flights is a serious risk. Microgravity research is necessary for the identification of preventive interventions.

The Swiss project’s main sponsor is H. Moser & Cie., a manufacturer of “haute horlogerie” watches. Additional funding was raised by selling weightless “discovery flights” to the general public. Those monies helped enable the University of Zurich scientific teams to conduct their experiments on board the Zero-G Airbus.

The findings from these parabolic flights will hopefully some day contribute to a better quality of life for us all.

Versatile Aircraft in Austere Environments

The Pilatus Aircraft product line underscores Chairman Oscar J. Schwenk’s belief that “You can only succeed in this market if you are innovative in all sectors.” The Stans, Switzerland, manufacturer has been building rugged, versatile aircraft since 1939 and today tallies nearly 3,500 of them in active service throughout the world. (The company’s headquarters sits at the base of the mountain for which it was named —Mount Pilatus.)

Pilatus’ heritage traces back to the gathering storm that became World War II. Adamantly neutral, the country’s military authorities felt it important to create a native airplane maintenance and manufacturing facility deliberately located in central Switzerland, well away from its borders. Workers at the fledgling enterprise developed the SB-2 Pelican in 1940, designed primarily for use in mountainous regions such as their own.

It wasn’t until 1959 that Pilatus broke onto the international market with its rugged Pilatus Porter PC-6, initially powered by a 360-shp piston engine. Though ungainly in appearance, the Porter provided short takeoff and landing (STOL) capabilities from all types of unprepared, rough and short airstrips, in all weather, at high altitudes and in all climates. In 1961, a turboprop engine replaced the piston mill, thereby creating the Turbo Porter. A vivid in-cockpit flight video of a Pilatus Turbo Porter landing and taking off from remote villages in Indonesia can be seen at https://www.youtube.com/watch?v=ik32TsceQHY.

Pilatus equipped the Porter with low-pressure tires, twin-clipper disc brakes and an undercarriage with high bump absorption to withstand operations on rough terrain, but it could also be modified to accommodate sandy, stony, soft, muddy, snow or water operations as well. Operators of the Pilatus Porter prize its 3-cu.-meter cabin, which is easily accessed through two large, sliding doors on both sides. Those also permit easy removal of passenger seats.

The Turbo Porter holds the world record for highest landing by a fixed-wing aircraft at 18,865 ft. (5,750 meters) on the Dhaulagiri glacier in Nepal. The model remains in active use by many militaries and law enforcement agencies around the world, as well as civil operators, particularly those who specialize in providing humanitarian service to remote locations. Recent upgrades including installation of Garmin G950 avionics provide improved situational awareness while reducing workload.

Training military aviators for highly demanding maneuvers and tactics requires an aircraft with exceptional performance but an affordable price. The Pilatus PC-7 tandem-seat high-performance trainer powered by the Pratt & Whitney Canada PT6A series was first flown in 1978 and has proven to be a popular training aircraft for both civil and military pilots. A total of approximately 450 aircraft have been sold to customers in 21 countries.

In 1986, Pilatus launched the PC-9. Equipped with the 950-shp PT6A-62, the 5,180-lb. aerobatic aircraft has a sea level rate of climb of 3,880 fpm. With structural limitations of +7.0 g to -3.5 g and the latest version equipped with a dual glass cockpit, the aircraft’s excellent performance and agile handling make it a capable platform for training student pilots in basic maneuvers and advanced flight training. Instructor pilots sitting in the rear seat have an elevated seating position to give them better forward vision. Over 260 advanced trainer PC-9/PC-9 M aircraft have been sold to 15 air forces around the world.

In 1995, a modified version of the PC-9 was jointly selected by the U.S. Navy and Air Force to serve as their primary pilot training aircraft. Designated the T6A/B Texan II, it is built and marketed independently by Beechcraft through an agreement with Pilatus. More than 500 T6A/B trainers have been delivered and in addition to the U.S. military, the aircraft is now flying with the militaries of Canada, Greece, Israel, Iraq, Mexico, Morocco, New Zealand and the U.K.

During a June 2015 site visit to Stans, I had the opportunity to watch Swiss Air Force pilots fly the Pilatus PC-21, its latest generation turbine trainer, and readily admit to being envious. It is a vast improvement from the noisy, steam-gauge-equipped T-37 “Tweet” I flew in the brain-baking heat of Columbus, Mississippi. The PC-21 includes the same tandem-seating configuration of its predecessors and features a full glass cockpit with three large, color LCDs, head-up displays, hands-on-throttle-and-stick (HOTAS) controls and zero-zero ejection seats. The PC-21 is such a capable platform that new Swiss pilots transition straight from it to the Boeing F/A-18. It is currently utilized as a highly effective training platform for pilots in the air forces of Switzerland, Singapore, United Arab Emirates, Saudi Arabia and Qatar. These diverse operating environments include desert climates with temperatures climbing to 45C (113F) and wind-blown fine grains of sand, conditions that are unfriendly to high-performance turbine equipment, austere conditions for which Pilatus engineers have developed plenty of expertise.

The highly capable PC-12 is popular in many roles around the globe, including executive transport, cargo, air ambulance, airline and government special missions. The aircraft’s large cabin, single-pilot operations, long range, low operating costs, high speeds and short-field capability have attracted a large group of customers who currently operate over 1,300 PC-12s. The 330-cu.-ft. cabin is an iconic feature of the aircraft, aided by ease of exit and entry through the 52-in.-by-53-in. cargo door. The latest version is the PC-12 NG, which features a Honeywell Primus Apex avionics suite and SmartView, a synthetic vision system that displays a natural 3-D rendering of terrain, providing a view that pilots normally see only on a clear day. The value of SmartView is tremendous when executing the tricky approaches and departures into mountainous airports.

Recent drag reduction efforts by Pilatus engineers have increased the PC-12 NG’s maximum speed to 285 kt. The new five-blade graphite composite propeller designed specifically for the PC-12 NG by Hartzell reduces cabin noise levels, improves takeoff and climb performance, reduces life cycle maintenance costs and is easily repairable in the field. At maximum gross takeoff weight, the aircraft can climb to a cruise altitude of 28,000 ft. 10% quicker, and maximum range has been extended to 1,840 nm with four passengers and VFR fuel reserves.

One of the best examples of the aircraft’s utility is in the service of the Royal Flying Doctor Service of Australia (RFDS). The organization uses its fleet of PC-12s to provide life-saving emergency medical services to remote, unimproved locations in the Australian Outback. The RFDS, which is supported by governments, as well as generous donations from communities and corporations, transports an average of 148 patients at remote isolated locations each day. (See the PC-12 NG Pilot Report)

The volume of the PC-12 cabin allows it to be configured with two patient litters and three passenger seats, along with intensive care medical equipment. A flight nurse is normally on-board for each flight. About 20% of the flights involve carrying a patient in critical condition and therefore also require a physician be on-board.

The engineering expertise learned in designing and supporting aircraft for operation in challenging environments helped shape the PC-24, the first Pilatus jet, which was announced at the 2013 European Business Aviation Convention and Exhibition (EBACE).

In keeping with Chairman Schwenk’s philosophy, the PC-24 is innovative but clearly carries the Pilatus DNA. It is designed to operate from short, unimproved airstrips, features a large cabin and twinjet performance. Notably, it is also fitted with a large cargo door able to accommodate standard pallets — a feature never before seen on a business jet.

The wing is of advanced design to enable the jet to cover the range of performance requirements from short takeoffs and landings to operating efficiently at 45,000 ft. The PC-24’s 2,690-ft. balanced field length enables it to operate from 11,950 paved airports that have this minimum length. By designing this jet to operate from grass, gravel, sand or snow, the number of possible runways expands to over 21,000, according to Pilatus.

The aircraft first flew from Buochs Airport in Stans last May and certification flight-testing is well underway. Certification is expected in 2017, with deliveries to follow shortly thereafter. Among the launch customers is the RFDS, which has ordered four. 

For video of a Pilatus Turbo Porter operating in Indonesian’s remote villages, go here.

This article appears in the May 2016 issue of Business & Commercial Aviation with the title "Switzerland Aloft."